Agron 1.2 Theory (1) PDF

GUJARAT AGRICULTURAL UNIVERSITIES Anand / Junagadh / Navsari / Sardarkrushinagar Agron. 1.2 First semester Fundamentals of Agronomy Theory course (Course - 2018) (Course for Polytechnic Students in SAU’s) Compiled by: Dr. V. J. Patel Associate Professor Sheth M. C. Polytechnic in Agriculture Anand Agricultural University, Anand Prof. P. S. Panchal Assistant Professor Sheth M. C. Polytechnic in Agriculture Anand Agricultural University, Anand Course Content Agron. 1.2 Fundamentals of Agronomy Credits 4 (3+1) Theory Topic 1: Agriculture, definition, meaning Topic 2: Agronomy, definition, meaning and its scope Topic 3: Tillage, land configuration and sub soiling Topic 4: Seeds and sowing Topic 5: Crop density and geometry Topic 6: Crop nutrition, manures and fertilizers, nutrient use efficiency Topic 7: Growth and development of crops Topic 8: Agro-climatic zones of India and Gujarat Topic 9: Classification of field crops and factors affecting on crop production Topic 10: Drought, definition and types of drought, effect of drought on crops, management of drought Topic 11: Cropping systems, definition and types of cropping systems Topic 12: Soil fertility and soil productivity Topic 13: Fertility losses and maintenance of soil fertility, soil organic matter Topic 14: Irrigation, Introduction, Importance, definition and objectives Topic 15: Physical and biological classification of water and soil moisture constants Topic 16: Irrigation efficiency and water use efficiency, consumptive use of water Topic 17: Approaches for irrigation scheduling Topic 18: Methods of irrigation including micro irrigation system Topic 19: Quality of water, water logging Topic 20: Weeds, definition, classification and characteristics Practical's 1. Identification of crops, seeds, fertilizers, pesticides and tillage implements 2. Lay out and types of seed bed preparation 3. Practice of different methods of sowing 4. Study of yield contributing characters and yield estimation of major crops 5. Seed germination and viability test 6. Numerical exercises on plant population and seed rate 7. Use of tillage implements-reversible plough, one way plough, harrow and leveler 8. Study of sowing implements/equipment 9. Measurement of field capacity, bulk density and infiltration rate 10. Field layout of various irrigation methods 11. To work out the labour unit and unit of work for various field operations Agron. 1.2 Fundamentals of Agronomy Topic 1: Agriculture: definition, meaning Meaning of Agriculture : The term Agriculture is derived from two Latin words ager or agri and cultura. Ager or agri means Soil or Land or Field and Cultura means cultivation. Agriculture is very broad term covering all aspects of crop production, live stock farming, fisheries, forestry etc. Agriculture may be defined as the art and science of cultivating land, raising crops and feeding, breeding, and raising livestock. Or Agriculture is the cultivation of lands for production of crops for a regular supply of food and other needs for progress of the nation. There are three main spheres of agriculture as under; Geoponic : Meaning cultivation in earth, Hydroponic : Meaning cultivation in water and Aeroponic : Meaning cultivation in air. Agriculture is productive unit where the natural inputs i.e. light; air, water etc. are converted in to usable product by the green plants. The livestock, birds and insect feed on the green plants and provide concentrated products such as milk, meat, eggs, wool, honey, silk and lack. Agriculture provides us with the materials needed for our feeding, housing and clothing. Agriculture consists of growing plants and rearing animals which help to maintain a biological equilibrium in nature. Agriculture is considered as mother of all agro based industries as it supplying the raw material to different industries as listed here under: Polytechnic in Agriculture (Course-2018) Page 1 Agron. 1.2 Fundamentals of Agronomy Sr. Agricultural produce/ Industries maintained No. crop plant 1. Cotton Textile mills, Cottage industry, for spinning, weaving and rope making 2. Sugarcane Sugar mills, Paper industry 3. Oil seeds Oil mills, manufacturing of varnishes, paints, soap, perfumes, vegetable ghee and cakes 4. Maize Starch industry and cattle feed industry 5. Grape Vine and canning industry 6. Fruits and vegetables Canning industry, Juices, Essential oils as by product Animals and their bye products:- 1. Milk Milk industry, processing and bottling of milk, manufacture of butter, cheese, ghee, milk powder, ice cream etc. 2. Beef Mutton industry, processing and packing of mutton. By products Hides Leather industry. Bones Fertilizer industry, manufacture of buttons. Insects :- 1. Silk worm Sericulture: Rearing of silkworm for silk production. 2. Honeybee Apiculture: Rearing of bees for production of honey. Polytechnic in Agriculture (Course-2018) Page 2 Agron. 1.2 Fundamentals of Agronomy Revolution in Agriculture No. Revolution Concerned with Achievements 1. Green revolution Foodgrain production Food grain production increased from 51 million tones at independence to 223 million tones in (2006 - 07), 4.5 times increase. 2. White revolution Milk production Milk production increased from 17 million tones at independence to 69 million tones, four times (1997- 98). 3. Yellow Oilseeds production Oil seed production increased from revolution 5 million tones to 25 million tones since independence, 5 times increase 4. Blue revolution Fish production Fish production increased from 0.75 million tones to nearly 5.0 million tones during the last five decades. 5. Brown Food Total fertilizer production = revolution processing/Fertilizer 178.10 Lakh tone (2015-16) 6. Golden Horticulture All India total horticulture (Fruits, revolution vegetables, flowers, plantation crops and spices) production = 300642.95 (000 MT)(2016-17) 7. Round Potato All India total potato production = revolution 48.60 Million tone (2016-17) 8. Rainbow Overall development ---- revolution of agriculture sector 9. Black revolution Petroleum products India produced 231.92 MTs of petroleum products in 2015-16, recording a growth of 4.88% over the previous year 10. Silver revolution Egg Production All India total egg production = 82.9 Billion Nos. (2016-17) 11. Grey revolution Fertilizer Total fertilizer production = 178.10 Lakh tone (2015-16) 12. Pink revolution Onion All India total onion production = production/Prawn 22.42 Million tone (2016-17) production 13. Red revolution Meat/Poultry/Piggery All India total meat production = 70.20 Million tone (2015-16) Polytechnic in Agriculture (Course-2018) Page 3 Agron. 1.2 Fundamentals of Agronomy Topic 2: Agronomy: definition, meaning and its scope Agronomy is a Greek word derived from agros meaning field and nomos meaning management. It is a field management. Agronomy is a specialized branch in agriculture dealing with crop production and soil management. It is defined as an agricultural science deals with principles and practices of crop production and field management. Agronomist is a scientist who is dealing with the study of problems of crop production and adopting/recommending practices of better field crop production and soil management to get high yield and income. In recent times, agronomy has assumed newer dimensions and can be defined as a branch of agricultural science that deals with methods which provides favourable environment to the crop for higher productivity. Norman (1980) has defined agronomy as the science of manipulating the crop environment complex with dual aims of improving agricultural productivity and gaining a degree of understanding of the process involved. Scope of Agronomy Agronomy is a dynamic discipline. With the advancement of knowledge and better understanding of plant and environment, agricultural practices are modified or new practices developed for higher productivity. For example;-  Availability of chemical fertilizers and herbicides for control of weeds has led to development of a vast knowledge about time, method and quantity of fertilizer and herbicide application.  Big irrigation projects are constructed to provide irrigation facilities. However, these projects created side effects like water logging and salinity. To overcome these problems, appropriate water management practices are developed.  Population pressure is increasing but the area under cultivation is static. Therefore, to feed the increasing population, more number of crops has to be grown on the same piece of land in a year. As a result, intensive cropping has come into vogue.  Similarly, no tillage practices have come in place of clean cultivation as a result of increase in cost of energy. (Fuel prices of oil).  Likewise, new technology has to be developed to overcome the effect of moisture stress under dry land conditions.  As new varieties of crops with high yield potential become available, package of practices has to be developed to exploit their full yielding potential. Polytechnic in Agriculture (Course-2018) Page 4 Agron. 1.2 Fundamentals of Agronomy Topic 3: Tillage, land configuration and sub soiling  Tillage: Tillage is as old as agriculture. Primitive man used to disturb the soil for placing seeds. The word tillage is derived from the Anglo- Saxon words tilian and teolian, meaning to plough and prepare soil for seed to sow, to cultivate and to raise crops. Jethro Tull, who is considered as father of tillage suggested that thorough ploughing is necessary so as to make the soil into fine particles. After harvest of the crop, soil becomes hard and compact may be due to : (a) Beating action of rain drops, (b) irrigation and subsequent drying and (c) movement of intercultivation implements and labour cause soil compaction. Definition of tillage "Tillage is the mechanical manipulation of soil with tools and implements for obtaining ideal conditions for seed germination, seedling establishment and growth of crops is called tillage" or Any operation carried out on the soil surface by agricultural implements for the purpose of softening the soil surface for better advantage to germination and plant growth. Tilth: It is the physical condition of soil obtained out by tillage. (or) It is the resultant effect of tillage in which soil air, soil water and soil aggregates are in perfect harmony or in balance condition. Objectives of tillage: There are several objectives of tillage of which the most important are suitable seedbed preparation, weed control and soil and water conservation. 1. To produce a satisfactory seed bed for good germination and good crop growth. 2. To make the soil loose and porous. 3. To provide aeration to the soil. 4. To control weeds. 5. To remove the stubbles (that may harbour pests). 6. To expose the soil inhabiting pathogens and insect pests to sun and kill them. 7. To break hard pans in the soil. Polytechnic in Agriculture (Course-2018) Page 5 Agron. 1.2 Fundamentals of Agronomy 8. For deep tillage and inversion of soil. 9. For incorporating bulky organic manures. 10. To increase infiltration rate. Classification of Tillage Tillage Preparatory tillage After tillage Harrowing Primary tillage Secondary tillage Hoeing Interculturing Deep Sub- Year round Harrowing Planking Tillage soiling tillage Earthing- up Weeding Types of tillage:- Tillage operations are grouped in to two types based on the time (with reference to crop) at which they are carried out. They are (1) Preparatory tillage:- Which is carried out before sowing the crop and (2) After tillage:- That is practiced after sowing of crop. (1) Preparatory tillage Tillage operation that are carried out to prepare the field for raising crops- from the time of harvest of a crop to the sowing of the next crop are known as preparatory tillage. It is divided in to primary and secondary tillage operations. (A) Primary tillage or ploughing:- "The Tillage operation that is done after the harvest of crop to bring the land under cultivation is known as primary tillage". Polytechnic in Agriculture (Course-2018) Page 6 Agron. 1.2 Fundamentals of Agronomy Ploughing is the opening of the compact soil with the help of different ploughs. Primary tillage is done mainly to open the hard soil and to separate the top soil from lower layers and to uprooting the weeds and stubbles of previous crop. e.g. Country plough, Disc plough, Mould board plough, etc. are used for primary tillage. Type of Primary tillage:- 1. Deep tillage 2. Sub soiling 3. Year round tillage (1) Deep Tillage: - Central Research Institute for Dry land Agriculture (CRIDA) Hyderabad, classified poughing of - 5-6 cm depth as shallow - 15- 20 cm depth as medium deep and - 25- 30 cm depth as deep ploughing The rhizomes and tubers of perennial weeds and pupae of insects are die due to exposure to hot sun. Deep tillage also improves soil moisture. (2) Sub soiling: - Hard pans may present in the soil which restrict root growth of crops. These may be silt pans, iron or aluminum, clay or manmade pans. Sub soiling is breaking the hard pan without inversion and with less disturbance of top soil. A narrow cut is made in the top soil while share of the sub soiler shatters hard pans. Chisel ploughs are also used to break hard pans present even of 60 - 70 cm. (3) Year round tillage: - Tillage operations carried out throughout the year are known as year round tillage. (B) Secondary tillage: - Lighter or finer operations performed on the soil after primary tillage are known as secondary tillage. Disc harrows, cultivators, blade harrows, planking are used for this purpose. Generally sowing operation is also included in secondary tillage. Harrowing: An agricultural implement with spike like teeth or upright disks, drawn chiefly over plowed land to level it, break up clods, up root the weeds, etc. Planking : It is secondary tillage equipment for clod crushing, levelling and smoothing of land surface before seeding Polytechnic in Agriculture (Course-2018) Page 7 Agron. 1.2 Fundamentals of Agronomy (2) After tillage The tillage operations that are carried out in the standing crop are called after tillage. It includes harrowing, hoeing, intercultivation, earthing up and weeding. Harrowing: An agricultural implement with spikelike teeth or upright disks, drawn chiefly over plowed land to level it, break up clods, up root the weeds, etc. Hoeing: Any of several kinds of long-handled hand implement equipped with a light blade and used to till the soil, eradicate weeds, etc. Inter-cultivation: Inter-cultivation also known as interculturing, is the cultivation of soil between crop rows. In other words, the soil between the two row of crops are ploughed using dedicated agricultural equipment (such as blade harrow, tined harrow, and even by hand) for weeding, improving soil aeration, and loosening the soil compaction. Earthing up: To raise the soil at base of the plant for the purpose of proving support against lodging, root penetration etc. Weeding: The process of eliminating the weeds from cropped area is called "weeding". Weeding can be done by hand or with a gardening tool. Modern concepts in tillage Conventional tillage involves primary tillage to break open and turn the soil followed by secondary tillage to obtain seed bed for sowing or planting. With the introduction of herbicides in intensive farming systems, the concept of tillage has been changed. Continuous use of heavy ploughs create hard pan in the subsoil. This results in poor infiltration. It is more susceptible to run off and erosion. It is capital intensive and increase soil degradation. The concept of minimum tillage was started in U.S.A. The immediate cause for introducing minimum tillage was high cost of tillage due to steep rise in oil prices in 1974. Dr. G.B. Triplett is considered as father of modern tillage. Polytechnic in Agriculture (Course-2018) Page 8 Agron. 1.2 Fundamentals of Agronomy  Minimum Tillage: Minimum tillage is aimed at reducing tillage to the minimum necessary for ensuring a good seedbed, rapid germination, a satisfactory stand and favorable growing conditions. Tillage can be reduced in two ways: (1) By omitting operations which do not give much benefit when compared to the cost. (2) By combining agricultural operations like seeding and fertilizer application. Advantages of minimum tillage: (1) Improved soil conditions due to decomposition of plant residues in Situ (2) Higher infiltration caused by the vegetation present on the soil and channels formed by the decomposition of dead roots (3) Less resistance to root growth due to improved structure (4) Less soil compaction by the reduced movement of heavy tillage vehicles and less soil erosion compared to conventional tillage Disadvantages of minimum tillage: (1) Seed germination is lower (2) More nitrogen has to be added as rate of decomposition of organic matter is slow (3) Sowing operations are difficult with ordinary equipment (4) Continuous use of herbicides causes pollution problems and dominance of perennial problematic weeds.  Zero Tillage Zero tillage is an extreme form of minimum tillage. Primary tillage is completely avoided and secondary tillage is restricted to seedbed preparation in the row zone only. It is known as no-till and is resorted to where soils are subjected to wind and water erosion. In zero tillage: (1) The organic matter content increases due to less mineralization. (2) Surface runoff is reduced due to presence of mulch. (3) Clean a narrow strip over the crop row. (4) Open the soil for seed insertion, place the seed and cover the seed properly. Polytechnic in Agriculture (Course-2018) Page 9 Agron. 1.2 Fundamentals of Agronomy (5) Before sowing, the vegetation present has to be destroyed for which broad spectrum, nonselective herbicides with relatively short residual effect (Paraquat, Glyphosate etc.) are used (6) During subsequent stages, selective and persistent herbicides are needed. (7) The seeding establishment is 20 per cent less than conventional methods. (8) Higher dose of nitrogen to be applied as mineralization of organic matter is slow. Land configuration techniques The productivity of any crop is the complex phenomenon governed by number of factors viz., use of improved varieties, appropriate sowing method, time of sowing, spacing, judicious use of water as well as nutrients and weeds, pests and disease management. Among all these, appropriate sowing method or proper land configuration is the most critical factor for realizing desired yield potential. The genotypes can express their full potential only when grown under optimum conditions and at optimum plant base. Land management system plays a major important role in minimizing soil erosion and improving water use efficiency of field crops. Easy and uniform germination as well as growth and development of plant are provided by manipulation of sowing method. Land configuration increases water use efficiency and also increases availability of nutrients to crops. It is particularly useful in areas having saline irrigation water because it helps to avoid direct contact of young plants with saline irrigation water. Various land configuration techniques helps in increasing growth and development of plants and thereby yield. 1. Flat beds Flat beds are prepared easily in sandy loam type of soil because sandy soil is better workable. The length of the beds should be kept according to the slop of nursery. For easy working the beds should be prepared about 3.60 meter in length and 1.20 meter in width for easy and convenient operations. 2. Raised beds Raised beds are mostly preferred in heavy black soil having maximum water holding capacity and poor drainage capacity. The basal measurement of raised beds should be 10.0 meter x 1.0 meter. Dig the soil near to the boundary of the beds and raised the soil on top. Polytechnic in Agriculture (Course-2018) Page 10 Agron. 1.2 Fundamentals of Agronomy 3. Ridges and furrows The field must be formed into ridges and furrows. Furrows of 30-45 cm width and 15-20 cm height are formed across the slope. The furrows guide runoff water safely when rainfall intensity is high and avoid water stagnation. They collect and store water when rainfall intensity is less. It is suitable for medium deep to deep black soils and deep red soils. It can be practiced in wide row spaced crops like cotton, maize, chillies, tomato etc. It is not suitable for broadcast sown crops and for crops sown at closer row spacing less than 30 cm. Tied ridging It is a modification of the above system of ridges and furrows wherein the ridges are connected or tied by a small bund at 2-3 m interval along the furrows to allow the rain water collection in the furrows which slowly percolated in to the soil profile. Polytechnic in Agriculture (Course-2018) Page 11 Agron. 1.2 Fundamentals of Agronomy 4. Broad bed furrows (BBF) This practice has been recommended by ICRISAT for vertisols or black soils in high rainfall areas (> 750 mm). Here beds of 90-120cm width, 15 cm height and convenient length are formed, separated by furrows of 60 cm width and 15 cm depth. When runoff occurs, its velocity will be reduced by beds and infiltration opportunity time is increased. The furrows have a gradient of 0.6%. Crops are sown on the broad beds and excess water is drained through number of small furrows which may be connected to farm ponds. It can be formed by bullock drawn or tractor drawn implements. Bed former cum seed drill enables BBF formation and sowing simultaneously, thus reduces the delay between receipt rainfall and sowing. Broad bed furrow has many advantages over other methods.  It helps in moisture storage  Safely dispose of surplus surface runoff without causing erosion  Provide better drainage facilities  Facilitate dry seeding  It can accommodate a wide range of crop geometry i.e. close as well as wide row spacing.  It is suitable for both sole cropping and intercropping systems.  Sowing can be done with seed drills. Polytechnic in Agriculture (Course-2018) Page 12 Agron. 1.2 Fundamentals of Agronomy 5. Dead furrows At the time of sowing or immediately after sowing, deep furrows of 20 cm depth are formed at intervals of 6 to 8 rows of crops. No crop is raised in the furrow. The dead furrows can also be formed between two rows of the crop, before the start of heavy rains (Sep – Oct). It can be done with wooden plough mostly in red soils. The dead furrows increase the infiltration opportunity time. 6. Scooping Scooping the soil surface to form small depressions or basins help in retaining rain water on the surface for longer periods. They also reduce erosion by trapping eroding sediment. Studies have shown that runoff under this practice can be reduced by 50 % and soil loss by 3 to 8 t /ha. Scoops for insitu moisture conservation Sub Soiling Sub soil meaning: The layer or bed of earth beneath the top soil. Also called under soil the layer of soil beneath the surface soil and overlying the bed rock. To gain maximum benefit from sub soiling, this operation needs to be done when the lower levels of the soil are relatively dry. What is a Sub soiler? A sub soiler is a type of tillage implement that’s used to break up compacted soil in an effort to improve the setting for growing crops. The subsoiler is so named because it cuts and loosens soil below the normal tillage depth of 100–200 mm. Its shape is similar to the chisel plow except that it is made with a stronger shank or leg in order to resist the higher force required to till soil at Polytechnic in Agriculture (Course-2018) Page 13 Agron. 1.2 Fundamentals of Agronomy greater depth. Chisel ploughs are also used to break hard pans presents even at 60- 70 cm.  Chisel Plough: It is mainly used for breaking hard pans and for deep ploughing (60-70 cm) with less disturbance to the top layers. Its body is thin with replaceable cutting edge so as to have minimum disturbance to the top layers. It contains a replaceable share to shatter the lower layers.  Subsoil Plough: The subsoil plough is designed to break up hard layers or pans without bringing them to the surface. The body of the subsoil plough is wedge shaped and narrow while the share is wide so as to shatter the hard pan and making only a slot on the top layers. Chiesel plough Sub soiler Polytechnic in Agriculture (Course-2018) Page 14 Agron. 1.2 Fundamentals of Agronomy Topic 4: Seeds and sowing Seeds are the vital part of agriculture. Selection of good quality seeds is a challenge for farmers. Only good quality seeds which are sown properly can give an expected result or yield. Seeds of a variety of types and strains are available; cultivators have to choose from these and these have to be sown in the field. Definition: Seed is a fertilized ovule consisting of intact embryo, store food and seed coat which is viable and has got the capacity to germinate under favourable condition. or A seed is the small, hard part of a plant from which a new plant grows. Characters of good seeds (1) Seed should be of recommended crop and their varieties. (2) It must be true to its type. (3) The seed must be healthy, pure and free from all the inert materials and weed seeds. (4) The seed must be viable. The germination capacity is up to the standard and it has been tested recently. (5) The seed must be uniform in its texture, structure and outlook. (6) The seed should be free from insects, insect eggs, disease spores etc. (7) The seed should be collected from fully matured crop, well developed, bold and plump in size. Quality of seed Viability and vigour are the two important characters of seed quality. Viability can be expressed by the germination percentage, which indicates the number of seedlings produced by a given number of seeds. Vigour of seed and seedlings is difficult to measure. Low germination percentage, low germination rate and low vigour are often associated. Seeds with low vigour may not be able to withstand unfavourable conditions in the seedbed. The seedlings may lake the strength to emerge if the seeds are planted too deep or if the soil surface is crusted. Polytechnic in Agriculture (Course-2018) Page 15 Agron. 1.2 Fundamentals of Agronomy Germination percentage It is the number of seeds germinated to number of seeds planted and it is expressed as percentage. Germination rate is expressed in two ways as under  The number of days required to produced a given germination percentage.  The average number of days required for radical or plumule to emerge. Vigour is indicated by the higher germination percentage, high germination rate and quicker seedling growth. Classes of seed With respect to genetic purity and stages of development, seeds are classified into different categories as under. Nuclear seed This is the hundred percent genetically pure seed with physical purity and produced by the original breeder/Institute /State Agriculture University (SAU) from basic nucleus seed stock. A pedigree certificate is issued by the producing breeder. Breeder seed It is also known as Nucleus seed. It is very important class of seed. It is produced at breeder’s institute with the responsibilities of the concern breeder who developed a particular variety. Breeder seed is the main source for the increase of foundation seed. It is 100 % genetically pure. A golden yellow colour tag is issued by seed certification agency for this category of seed. Foundation seed This seed is directly produced from the breeder seed. Production of foundation seed is done carefully under the strict supervision of the highly qualified seed experts because genetic purity and identity of the variety should be maintained, as this seed is the source of all certified seed classes, either directly or through the registered seed. Foundation seed is produced at State Government farms and Agricultural university farms. A white colour tag is issued by seed certification agency for this category of seed. Polytechnic in Agriculture (Course-2018) Page 16 Agron. 1.2 Fundamentals of Agronomy Certified seed Certified seed means the production of commercial seed sold to the farmers for raising the crop. This type of seed is produced from foundation seed or registered seed. The National Seed Corporation, Agricultural Universities, State Government, Private seed companies, Private seed producers and some Co-operative society produce this type of seed. The seed produced by various agencies is certified by State Seed Certification Agency. A blue colour tag is issued by seed certification agency for this category of seed. Truthful Seed It is the category of seed produced by cultivators, private seed companies and is sold under truthful labels. But field standard and seed standard should maintain as per seed act and certified seed stage. Under the seed act, the seed producer and seed seller are responsible for the seed. A green colour tag is issued by seed certification agency for this category of seed.  Sowing Sowing is an operation for putting the seeds in the soil at particular distance and depth for raising the crop after proper preparation of a land. Seeds are sown either directly on the field (seed bed) or in nursery where seedlings are raised and transplanted later in to the main field. Time of Sowing Sowing very early in the season may not be advantageous. For example, sowing rainfed groundnut in June may result in failure of the crop if there is prolonged dry spell from the second week of June to second week of July. But sometimes, sowing early in certain situations increases the yield of crop. Advancing sowing of rabi sorghum from November to September- October, increases the yields considerably as more moisture would be available for early sown crop. Delayed Sowing Delayed sowing invariably reduces the yields. Rainfed sorghum yields are reduced due to delay in sowing beyond June. Similarly, the yields of pigeonpea and soybean are reduced due to delay in sowing. The reduction in yields is attributed to early induction of flowering, unfavourable temperature and rainfall. Most of the tropical crops are short- day plants. Day length starts falling from July onwards, but the reduction in day length is steep from October onwards. Flowering is induced in Polytechnic in Agriculture (Course-2018) Page 17 Agron. 1.2 Fundamentals of Agronomy short-day crops earlier due to absolute short days or relative reduction in day length. If sowings are delayed, there is very little time for vegetative growth and thus, there is reduction in yield. In addition, late sown crops are exposed to increased population of pests and diseases. Sorghum sown late is subjected to severe attack of shootfly. Optimum Time of Sowing Sowing the crop at optimum time increases yields due to suitable environment at all the growth stages of the crop. Flowering is induced after sufficient vegetative growth. Moisture stress or dry spells may be avoided during critical stages. The optimum time of sowing for most of tropical crops is immediately after the onset of monsoon i.e. June or July. The optimum time of sowing for temperate crops like wheat and barley are from last week of October to first week of November. Types of Sowing  Dry sowing Dry sowing is adopted in black soils where sowing operations are difficult to carry out once rains commence. Field is prepared with summer and seeds are sown in dry soil around seven to ten days before the anticipated receipts of sowing rains. The seeds germinate after the receipts of rains. By this method, rainfall is effectively utilized.  Wet Sowing Wet sowing is the most common method of sowing crops. The minimum amount of rainfall necessary for taking up sowing is 20 mm. Certain amount of moisture is wasted during the period between receipt of rainfall and sowing. Methods of sowing 1. Broadcasting: This is an oldest method. This method is suitable for close planted crop which do not require a specific geographic area. Crop plants which do not require special type of cultural practices e.g. earthingup or interculturing etc. may be sown by broadcasting. This method is followed in the crop having short life period. Seeds are spread or scatter by hands over the field and covered with the help of wooden rake or light plank. Advantages:  This method is cheap.  It is easy and quick. Polytechnic in Agriculture (Course-2018) Page 18 Agron. 1.2 Fundamentals of Agronomy Disadvantages:  Require more seed rate.  Uneven distribution of seed is possible.  Uneven depth of sowing.  Interculturing is not possible.  Weeding becomes difficult.  Selections of seeds are not possible.  Covering seeds with the help of rake is necessary.  e.g. Cumin, Isabgul, Lucerne, Coriander, Rajgira, Berseem etc. and in mix cropping situation. 2. Drilling: Drilling is a practice of dropping the seeds in furrows by a mechanical device at a distance between rows. Seed are drilled in parallel line. Distribution of seeds is regulated by releasing seeds in to the bowl by the hand. For covering the seeds light planking is done by plank. Advantages:  Uniform distance between two rows can be maintained.  Less seed rate as compared to broadcasting.  Interculturing is possible between two rows.  Seeds are placed at uniform depth and covered and compacted uniform Disadvantages:  Distance between two plants within the row is not maintained.  Thinning and gap filling operations are necessary  Selection of seed is not possible.  e.g. Upland rice, Wheat, Bajra, Barley, Mustard, Greengram, Cowpea, etc. and in intercropping situation. 3. Dibbling: Putting the seed or few seeds in a hole or pit or pocket, made at predetermine spacing and depth with a dibbler or very often by hand. This method is suitable for wide space crops requiring a specific geometric area for their canopy development or cultural practices. First all lines are marked vertically and horizontally with the help of marker at a particular distance. At each cross seeds are dibbled with the help of dibbler by manual labour. Then seeds are covered with soil. Polytechnic in Agriculture (Course-2018) Page 19 Agron. 1.2 Fundamentals of Agronomy Advantages:  Spacing is maintained between two rows and between two plants in the row.  Requirement of seed rate is less as compared to broadcasting and drilling.  Depth of sowing is maintained.  Selection of good seed is possible.  Give rapid and uniform germination with good seedling vigour. Disadvantages:  More laborious and time consuming method.  It is costly.  e.g. Cotton, Castor, Indian bean, Pigeon pea etc. 4. Planting: Placing of plant part (vegetative propagules) in soil called planting. The vegetative propagules are planted directly on the field should be good in health, vigour, age, stage of growth and desirable number of readily sprouting buds. Advantages:  Proper distance can be maintained between two rows and between two plants within the row.  Providing opportunity for selection of planting material.  Depth of sowing can be maintained. Disadvantages:  It requires more labour.  It is costly and time consuming method. e.g. Tuber : Potato, Rhizomes : Ginger and Turmeric, Bulb : Onion, Cloves : Garlic, Vine set : Sweet potato, Setts : Sugarcane, Root cutting : Pointed gourd, Rooted slips : Napier grass, Blue panic grass. 5. Transplanting: Transplanting is the removal of an actively growing plant from one place and planting it in another for further growth and production. In this method seeds are not directly sown in the field but seeds are sown first in nursery with proper care. Polytechnic in Agriculture (Course-2018) Page 20 Agron. 1.2 Fundamentals of Agronomy After proper growth (generally four weeks), seedlings are uprooted and transplanted in well prepared main field. This method is useful for raising the crops which have small size seeds and require more care in the initial stage. Advantages:  Economy of costly seeds.  Maintaining of desire plant density with healthy and pure seedlings.  Available sufficient time for preparing seedbed.  Provide better chances for better care in small area during seedling stage. Disadvantages:  Total duration of crop may be more.  It increases the labour and power requirement in a peak period.  It increases the cost of land preparation, uprooting and transplanting of seedling.  e.g. Seedlings- Rice, Tobacco, Tomato, Brinjal, Chilli, Onion, Cabbage, Cauliflower etc. Saplings - Subabool, Sag, Eucalyptus. Polytechnic in Agriculture (Course-2018) Page 21 Agron. 1.2 Fundamentals of Agronomy Topic 5: Crop density and geometry Plant Population or Plant Density Number of plants per unit area in the cropped field is the plant population or plant density. Optimum plant population 1. Optimum plant population – It is the number of plants required to produce maximum output or biomass per unit area. 2. Any increase beyond this stage results in either no increase or reduction in biomass. Importance of plant population / crop geometry 1. Yield of any crop depends on final plant population 2. The plant population depends on germination percentage and survival rate in the field 3. Under rainfed conditions, high plant population will deplete the soil moisture before maturity, where as low plant population will leave the soil moisture unutilized 4. Under low plant population individual plant yield will be more due to wide spacing. 5. Under high plant population individual plant yield will be low due to narrow spacing leading to competition between plants. 6. Yield per plant decreases gradually as plant population per unit area is increased, but yield per unit area increases upto certain level of population, that level of plant population is called as optimum population So to get maximum yield per unit area, optimum plant population is necessary. Plant geometry Plant geometry refers the shape of the plant / plant canopy. Like Vertical growth in sorghum, maize, paddy etc. Horizontal growth in cotton, tobacco, pulses etc. Crop geometry Crop geometry refers the shape of the land available to individual plant to grow. e.g. random, square, rectangular etc. Polytechnic in Agriculture (Course-2018) Page 22 Agron. 1.2 Fundamentals of Agronomy The arrangement of the plants in different rows and columns in an area to efficiently utilize the natural resources is called crop geometry. It is otherwise area occupied by a single plant e.g. rice – 20 cm x 15 cm. This is very essential to utilize the resources like light, water, nutrient and space. Different geometries are available for crop production. Different crop geometries are available for crop production 1. Random geometry This type of geometry is observed under broadcasting method of sowing, where no equal space is maintained, resources are either under exploited or over exploited. 2. Square method or square geometry The plants are sown at equal distances on either side. Mostly perennial crops, tree crops follow square method of cultivation. Advantages 1. Light is uniformly available, 2. Movement of wind is not blocked and 3. Mechanization can be possible. 3. Rectangular method of sowing There are rows and columns, the row spacing are wider than the spacing between plants. The different types exist in rectangular method a. Solid row Each row will have no proper spacing between the plants. This is followed only for annual crops which have tillering pattern. There is definite row arrangement but no column arrangement, e.g., wheat. b. Paired row arrangement It is also a rectangular arrangement. If a crop requires 90 cm spacing and if paired row is to be adopted the spacing is altered to 75 -120 - 75 instead of 90 cm, i.e. distance between two pair is 120 cm, whereas the distance between two rows within pair is 75 cm. The intercrop can be grown in-between two pair. The base population is kept constant. Polytechnic in Agriculture (Course-2018) Page 23 Agron. 1.2 Fundamentals of Agronomy c. Skip row A row of planting is skipped and hence there is a reduction in population. This reduction is compensated by planting an intercrop; practiced in rain fed or dry land agriculture. d. Triangular method of planting It is recommended for wide spaced crops like coconut, mango, etc. The number of plants per unit area is more in this system. Factors affecting Plant population / Plant density 1. Size of the plant 2. Foraging area or soil cover 3. Dry matter partitioning 4. Crop and variety Crop Duration Distance Plant population Rice Short duration 15 cm x 10 cm 6,66,666 plants/ha Medium duration 20 cm x 10 cm 5,00,000 plants/ha Long duration 20 cm x 15 cm 3,33,333 plants/ha Cotton Medium duration 60 cm x 30 cm 55,555 plants/ha Long duration 75 cm x 30 cm 44,444 plants/ha Hybrids 120 cm x 45 cm 18,518 plants/ha Maize Varieties 60 cm x 20 cm 83,333 plants/ha Hybrids 60 cm x 35 cm 47,619 plants/ha Groundnut Erect 30-45 cm x 10 cm 2,22,222 plants/ha Semi-spreading 45-60 cm x 10 cm 1,66,666 plants/ha Spreading 60-90 cm x 10 cm 1,11,111 plants/ha 5. Time of sowing 6. Rainfall / irrigation 7. Seed rate 8. Depth of sowing Depth of sowing is governed by size of seed and soil moisture content. Uneven depth of sowing results in uneven crop stand. Plants will be of different sizes and ages and finally harvesting is a problem as there is no uniformity in maturity. Shallow or deep sowing results in low plant population because all seeds do not germinate. Therefore, it is essential to sow the crop at optimum depth for obtaining good stand of the crop. Polytechnic in Agriculture (Course-2018) Page 24 Agron. 1.2 Fundamentals of Agronomy Crops with bigger sized seeds like groundnut, castor, sunflower, etc. can be sown even up to the depth of 6 cm. Whereas, small sized seeds like tobacco, sesamum, bajra, mustard have to be sown as shallow as possible. If the seeds are sown too shallow, the surface soil dries up quickly and germination may not occur due to lack of moisture. Therefore, small sized seeds which are sown shallow should be watered frequently to ensure good emergence of the crop. If the small seeds are sown deep in the soil, the seed reserve food may be inadequate to put forth long coleoptiles for emergence. Even if the seedling emerges, it is too weak to survive as an autotrophic. For better germination, the soil should have sufficient moisture in the surface layer. Crop grown in rabi are sown deeper than kharif crop, because in rabi surface soil have insufficient moisture for germination. The thumb rule is to sow seeds to a depth approximately 3 to 4 times their diameter. The optimum depth of sowing for most of the field crops ranges between 3 cm to 5 cm. Shallow depth of planting of 2 cm to 3 cm is follow for small seeds like bajra, sesamum, mustard. Very small seeds like tobacco are placed at a depth of 1 cm. This is generally done by broadcasting on the soil surface and mixing them by racking. Polytechnic in Agriculture (Course-2018) Page 25 Agron. 1.2 Fundamentals of Agronomy Topic 6: Crop nutrition, Manures and fertilizers, Nutrient use efficiency The normal green plant is autotrophic that means it can synthesize all its organic substances; provided it is supplied with all the inorganic elements and growth under normal condition. The nutrition of green plant is therefore, solely inorganic. It is, in fact, commonly called mineral nutrition. Elements absorbed from the soil by the roots are generally known as plant nutrients or mineral nutrients. Yield and the quality of products from crops are strongly linked to the supply of nutrients. In the absence of fertilizer application, most nutrients are supplied from the soil. Over 95 percent of the dry weight of a flowering plant is made up of three elements—carbon, hydrogen, and oxygen—taken from the air and water. The remaining 5 percent of the dry weight comes from chemicals absorbed from the soil. Roots absorb the chemicals present in their surroundings, but only 14 of the elements absorbed are essential for plant growth. These 14 elements, along with carbon, hydrogen, and oxygen, are called the 17 essential inorganic nutrients or elements. Plant nutrients Nutrients available in the soil Nutrients available in air and water Carbon (C) Hydrogen (H) Oxygen (O) Macronutrients Micronutrients (needed in larger amounts) (needed in lesser amounts) Iron (Fe) Zinc (Zn) Manganese (Mn) Primary Nutrients Secondary Nutrients Copper (Cu) Nitrogen (N) Calcium (Ca) Molybdenum (Mo) Phosphorus (P) Magnesium (Mg) Boron (B) Potassium (K) Sulphar (S) Chlorine (Cl) Nickel (Ni) Polytechnic in Agriculture (Course-2018) Page 26 Agron. 1.2 Fundamentals of Agronomy Criteria for essentiality of nutrient Arnon and Stout (1939) proposed criteria of essentiality which was refined by Arnon (1954) as: 1. The plant must be unable to grow normally or complete its life cycle in the absence of the element. 2. The element is specific and cannot be replaced by another. 3. The element plays a direct role in plant metabolism. Nutrient use efficiency Nutrient use efficiency may be defined as yield (biomass) per unit input (fertilizer, nutrient content). Agronomic efficiency Agronomic efficiency may be defined as the economic production obtained per unit of nutrient applied. Manures and fertilizers Manure: Manures are the substances which are organic in nature, capable of supplying plant nutrients in available form, bulky in nature having low analytical value and having no definite composition and most of them are obtained from animal and plant waste products. The word “Manure” is originated from the French word “MANOEUVRER” which refers to “work with soil”. Bulky Organic Manures Bulky organic manures contain small percentage of nutrients and they are applied in large quantities. 1. FYM Farmyard manure refers to the decomposed mixture of dung and urine of farm animals along with litter and left over material from roughages or fodder fed to the cattle. It contains 0.5 per cent N, 0.2 per cent P2O5 and 0.5 per cent K2O. 2. Compost A mass of rotted organic matter made from waste is called compost. It contains 0.5 per cent N, 0.15 per cent P2O5 and 0.5 per cent K2O. Polytechnic in Agriculture (Course-2018) Page 27 Agron. 1.2 Fundamentals of Agronomy 3. Night soil Night soil is human excreta, both solid and liquid. It contains 5.5 per cent N, 4.0 per cent P2O5 and 2.0 per cent K2O. 4. Sewage and Sludge The solid portion in the sewage is called sludge and liquid portion is sewage water. 5. Vermicompost Compost that is prepared with the help of earthworms is called vermicompost. It contains 3.0 per cent N, 1.0 per cent P2O5 and 1.5 per cent K2O. 6. Green Manure Definition: Crops grown for the purpose of restoring or increasing the organic matter content in the soil are called green manure crops while there green undecomposed plant material used as manure is called green manure. Their use in cropping system is generally referred as green manuring. It is obtained in two ways-either by grown in situ or brought from out site. 1. In situ green manuring: Growing of green manure crops in the field and incorporating it in its green stage in the same field (i.e. in situ) is termed as green manuring. e.g Sunnhemp, Dhaincha, Sesbania, Pulses etc. 2. Green leaf manuring: is the application of green leaves and twigs of trees, shrubs and herbs collected from nearby location and adding in to the soil. Forest tree leaves are the main source of green leaf manuring. e.g Gliricidia, Pongania, Gulmohur etc. Advantage of green manuring : - 1. It has positive influence on the physical and chemical properties of soil. 2. Helps to maintain the organic matter status of arable soil. 3. All green manures supply extra organic matter to feed and breed beneficial soil organisms for soil fertility and soil health. 4. Increases the water holding capacity of light soils. 5. It facilities the penetration of rain water, thus decreasing run off and soil erosion. 6. The green manure crops hold plant nutrients that would otherwise be lost by leaching (e.g. Nitrogen) 7. When leguminous plants like sannhemp and dhaincha are used as green manure crops, they add nitrogen to the soil for the succeeding crops. 8. Green manuring crops helps in reclamation of saline and alkaline soils by the release of organic acids. Polytechnic in Agriculture (Course-2018) Page 28 Agron. 1.2 Fundamentals of Agronomy Limitations of green manuring : - (1) Under rainfed condition it is feared that proper decomposition of the green manure crop may not take place if sufficient rainfall is not received after burying the green manure crop. (2) Since green manuring for wheat loss of Kharif crops, the practice of green manuring may not be always economical. (3) Sometimes the cost of green manure crops may more than the cost of commercial fertilizers. (4) Sometimes it increases termite problem. (5) The green manure crop may be failed if sufficient rainfall is not available. Characteristics of green manure crops : - An ideal green manure crop should have the following characteristics. (1) It should be preferably from leguminous family so that atmospheric nitrogen can be fixed. (2) It should have quick initial growth so as to suppress the weed growth. (3) It should have more leafy growth than woody so that its decomposition will be rapid. (4) It should yield a large quantity of green material in short period. (5) It should have a deep rooted system so that it would penetrate deep layers of the soil and thus aid in creating good will structure. 7. Sheep and Goat Manure, Penning It contains 3.0 per cent N, 1.0 per cent P2O5 and 2.0 per cent K2O. 8. Poultry Manure It contains 3.03 per cent N, 2.63 per cent P2O5 and 1.4 per cent K2O. Concentrated Organic Manures Concentrated organic manures have higher nutrient content than bulky organic manure. e.g oil cakes, Blood meal, meat meal etc. The oil-cakes are of two types: 1. Edible oil-cakes which can be safely fed to livestock; e.g. Groundnut cake, coconut cake, cotton cake etc. 2. Non-edible oil-cakes which are not fit for feeding livestock; e.g. Castor cake, neem cake, mahua cake etc. Polytechnic in Agriculture (Course-2018) Page 29 Agron. 1.2 Fundamentals of Agronomy Fertilizer: A fertilizer can be defined as a mined or manufactured material containing one or more essential plant nutrients in potentially available forms in commercially valuable amounts. It is most essential to apply fertilizer at proper time and at proper place for its efficient use. Thus, the time and method of fertilizer application will vary in relation to (i) Nature of fertilizer (ii) Soil types (iii) Differential nutrient requirement and (iv) Nature of field crops.  Classification of Fertilizers 1. Nitrogenous fertilizers :  Ammonium fertilizer : e.g. Ammonium sulphate, ammonium chloride  Nitrate fertilizer : e.g. Potassium nitrate, sodium nitrate, calcium nitrate  Ammonium – nitrate fertilizers : e.g. Ammonium nitrate, calcium ammonium nitrate  Amide fertilizers : e.g. Urea, calcium cyanamide 2. Phosphatic fertilizers :  Water soluble P fertilizers : e.g. Superphosphate  Citrate soluble P fertilizers : e.g. Basic slag  Insoluble P fertilizers : e.g. Rock phosphate 3. Potassic fertilizers : e.g. Muriate of potash (KCL), Potassium sulphate Differences between Manures and Fertilizers Sr. MANURES FERTILIZERS No 1 Organic in nature Inorganic in nature 2 Slow acting Quick acting 3 Having low nutrient value Having high nutrient value 4 Having no definite chemical Having definite chemical composition composition 5 Obtained from plant, animal and Obtained from Mined or manufactured human resources 6 Improves physical properties of Don’t improve the physical properties soils of soils 7 Supply almost all major, minor and Supply one or very few plant nutrients. micronutrients 8 Bulky in nature Non-bulky in nature Polytechnic in Agriculture (Course-2018) Page 30 Agron. 1.2 Fundamentals of Agronomy  Different methods of fertilizer application: Different methods of fertilizer application Application in solid from Application in liquid form 1. Direct application to soil 2. Fertigation 3. Starter solution 4. Foliar spray Broadcasting Placement Localized placement 1. Basal application 1. Plough sole 1. Drill 2. Top dressing 2. Deep 2. Band placement 3. Sub-soil 3. Side dressing 4. Contact placement 5. Side placement Brown manuring Brown manuring is a technique to grow sesbania in standing rice crop and kill them with the help of herbicide for manuring. After killing the colour of the sesbania residue become brown so it called brown manuring. Biofertilizers Bio-fertilizer is microorganism's culture capable of fixing atmospheric nitrogen when suitable crops are inoculated with them. Bio-fertilizer offers an economically attractive and ecologically sound means of reducing external inputs and improving the quality and quantity of products. Microorganisms are capable of mobilizing nutritive elements from non-usable form to usable form through biological process. These are less expensive, eco-friendly and sustainable. Advantages: 1. They help in establishment and growth of crop plants and trees. 2. They enhance biomass production and grain yields by 10-20%. 3. They are useful in sustainable agriculture. 4. They are suitable organic farming. 5. They play an important role in Agroforestry / silvipastoral systems. Polytechnic in Agriculture (Course-2018) Page 31 Agron. 1.2 Fundamentals of Agronomy Types of Biofertilizers: There are two types of bio-fertilizers. 1. Symbiotic N-fixation: These are Rhizobium culture of various strains which multiply in roots of suitable legumes and fix nitrogen symbiotically. Rhizobium: It is the most widely used bio-fertilizers, which colonizes the roots of specific legumes to form tumours like growth called root nodules and these nodules act as factories of ammonia production. 2. Asymbiotic N-fixation: This includes Azotobacter, Azospirillium, BGA, Azolla and Mycorrhizae, which also fixes atmospheric N in suitable soil medium. Mycorrhizae: Mycorrhizae are the symbiotic association of fungi with roots of Vascular plants. The main advantage of Mycorrhizae to the host plants is facilitating an increased phosphorous uptake. Integrated Nutrient Management Plant nutrients can be supplied from different sources viz. organic manure, crop residues, biofertilizers and chemical fertilizers. For better utilization of resources and to produce crops with less expenditure, integrated nutrient management is the best approach. Polytechnic in Agriculture (Course-2018) Page 32 Agron. 1.2 Fundamentals of Agronomy Topic 7: Growth and development of crops Definition Growth can be defined as an irreversible permanent increase in size of an organ or its parts or even of an individual cell. Types of growth / Stages of growth Vegetative growth: The earlier growth of plant producing leaves, stem and branches without flowers is called ‘vegetative growth’/ Phase. Reproductive growth: After the vegetative growth, plants produce flowers which are the reproductive part of the plant. This is called reproductive growth/phase. Growth curve: It is an ‘S’ shaped curve obtained when we plot growth against time (Fig.). It is also called ‘sigmoid ‘curve. This curve mainly shows four phases of growth- 1. Initial slow growth (Lag phase), 2. The rapid period of growth (log phase/grand period of growth/exponential phase) where maximum growth is seen in a short period, 3. The diminishing phase where growth will be slow and 4. Stationary / steady phase where finally growth stops. The three phases of cell growth are cell division, cell enlargement and cell differentiation. The first two stages increase the size of the plant cell while the 3 rd stage brings maturity to the cells. Polytechnic in Agriculture (Course-2018) Page 33 Agron. 1.2 Fundamentals of Agronomy Measurement of Growth Growth can be measured by a variety of parameters as follows A. Fresh Weight Determination of Fresh weight is an easy and convenient method of measuring growth. For measuring fresh weight, the entire plant is harvested, cleaned for dirt particles if any and then weighed. B. Dry Weight The dry weight of the plant organs is usually obtained by drying the materials for 21 to 48 h at 70 to 80oC and then weighing it. The measurements of dry weight may give a more valid and meaningful estimation of growth than fresh weight. However, in measuring the growth of dark grown seedling it is desirable to take fresh weight. C. Length Measurement of length is a suitable indication of growth for those organs which grow in one direction with almost uniform diameter such as roots and shoots. The length can be measured by a scale. The advantage of measuring length is that it can be done on the same organ over a period of time without destroying it. D. Area It is used for measuring growth of plant organs like leaf. The area can be measured by a graph paper or by a suitable mechanical device. Nowadays modern laboratories use a photoelectric device (digital leaf area meter) which reads leaf area directly as the individual leaves is fed into it. Growth Analysis Growth analysis is a mathematical expression of environmental effects on growth and development of crop plants. This is a useful tool in studying the complex interactions between the plant growth and the environment. Growth analysis in crop plants was first studied by British Scientists (Blackman 1919, Briggs, Kidd and west 1920, William 1964, Watson 1952 and Blackman, (1968). This analysis depends mainly on primary values (Dry weights) and they can be easily obtained without great demand on modern laboratory equipment. The basic principle that underlie in growth analysis depends on two values (1) total dry weight of whole plant material per unit area of ground (w) and (2) the total leaf area of the plant per unit area of ground (A). Polytechnic in Agriculture (Course-2018) Page 34 Agron. 1.2 Fundamentals of Agronomy The total dry weight (w) is usually measured as the dry weight of various plant parts viz., leaves, stems and reproductive structures. The measure of leaf area (A) includes the area of other organs viz., stem petioles, awns and pods that contain chlorophyll and contribute substantially to the overall photosynthesis of the plants. Advantages of growth analysis a) We can study the growth of the population or plant community in a precise way with the availability of raw data on different growth parameters. b) These studies involve an assessment of the primary production of vegetation in the field i.e. at the ecosystem level (at crop level) of organization. c) The primary production plays an important role in the energetic of the whole ecosystem. d) The studies also provide precise information on the nature of the plant and environment interaction in a particular habitat. e) It provides accurate measurements of whole plant growth performance in an integrated manner at different intervals of time. Growth indices in summary Few key indices are commonly derived as an aid to understanding growth responses. Mathematical and functional definitions of those terms are summarized below. Growth index Functional definition Relative growth rate Rate of mass increase per unit mass present (efficiency of (RGR) growth with respect to biomass) Net assimilation rate Rate of mass increase per unit leaf area (efficiency of leaves (NAR) in generating biomass) Leaf area ratio Ratio of leaf area to total plant mass (a measure of ‘leafiness’ (LAR) or photosynthetic area relative to respiratory mass) Specific leaf area Ratio of leaf area to leaf mass (a measure of thickness of (SLA) leaves relative to area) Leaf weight ratio Ratio of leaf mass to total plant mass (a measure of biomass (LWR) allocation to leaves) Development It is an overall term which refers to the various changes that occur in a plant during its life cycle. Plants produce new tissues and structures throughout their life from meristems located at the tips of organs, or between mature tissues. Polytechnic in Agriculture (Course-2018) Page 35 Agron. 1.2 Fundamentals of Agronomy Initiation and Development of Vegetative Structures 1. Root growth: Radicle is the embryonic root. During the seed germination and seedling formation, it grows to form primary root of the seedlings. 2. Stem growth: The life of stem starts as a plumule. It grows to form the shoot of the seedling. The longitudinal growth of stem and formation of various organs like branches, leaves, flowers is the function of stem meristem. 3. Leaf initiation and Growth: Elevations appear on the periphery of the meristem in a regular pattern. Leaf primordia appear as dome shaped on the periphery of the stem. Initation and Development of Reproductive Structures 1. Initiation and Development of Flower: Once the biochemical requirements for evocation of flowering are completed and the meristem has reached the point of no return, it develops either into an inflorescence (a cluster of flowers) or solitary flowers. In most plants, the pattern of flower initiation and development is almost similar. 2. Fruit and Seed Development: The first stage in fruit and seed development is rapid cell division without much enlargement due to cytokinin production by the endosperm which is growing at this stage. Various tissues of the parent plant viz, the ovary, receptacle and sometimes parts of the floral tube may be involved in the formation of fruits. Developmental Stages 1. Germination and Emergence 2. Seedling Growth 3. Maximum Vegetative Growth Stage 4. Primordial Differentiation 5. Flowering Stage 6. Fruit Growth 7. Fruit Maturity 8. Physiological Maturity 9. Harvest Maturity Difference between growth and development Sr.No. Growth Development 1. Growth is quantitative. Development is quantitative as well as qualitative. 2. Growth is for limited period. Development takes place till death. Polytechnic in Agriculture (Course-2018) Page 36 Agron. 1.2 Fundamentals of Agronomy Topic 8: Agro-climatic zones of India and Gujarat  Agro-climatic zones of India The Planning Commission has categorized 15 agro-climatic zones in India, taking into account the physical attributes and socio-economic conditions prevailing in the regions. I. Western Himalayan Region: The Western Himalayan Region covers Jammu and Kashmir, Himachal Pradesh and the hill region of Uttarakhand. Polytechnic in Agriculture (Course-2018) Page 37 Agron. 1.2 Fundamentals of Agronomy Average temperature in July ranges between 5°C and 30 °C, while in January it ranges between 5 °C and -5 °C. Mean annual rainfall varies between 75 cm to 150 cm. The valley floors grow rice, while the hilly tracts grow maize in the kharif season. Winter crops are barley, oats, and wheat. The region supports horticulture, especially apple orchards and other temperate fruits such as peaches, apricot, pears, cherry, almond, litchis, walnut, etc. Saffron is grown in this region. II. Eastern Himalayan Region: The Eastern Himalayan Region includes Arunachal Pradesh, the hills of Assam, Sikkim, Meghalaya, Nagaland, Manipur, Mizoram, Tripura, and the Darjeeling district of West Bengal. Temperature variation is between 25 °C and 30 °C in July and between 10 °C and 20 °C in January. Average rainfall is between 200-400 cm. The red-brown soil is not highly productive. Jhuming (shifting cultivation) prevails in the hilly areas. The main crops are rice, maize, potato, tea. There are orchards of pineapple, litchi, oranges and lime. III. Lower Gangetic Plain Region: West Bengal (except the hilly areas), eastern Bihar and the Brahmaputra valley lie in this region. Average annual rainfall lies between 100 cm-200 cm. Temperature in July varies from 26 °C to 41 °C and for January from 9 °C to 24 °C. The region has adequate storage of ground water with high water table. Rice is the main crop which at times yields three successive crops (Aman, Aus and Boro) in a year. Jute, maize, potato, and pulses are other important crops. IV. Middle Gangetic Plain Region: The Middle Gangetic Plain region includes large parts of Uttar Pradesh and Bihar. The average temperature in July varies from 26 °C to 41 °C and that of January 9 °C to 24 °C average annual rainfall is between 100 cm and 200 cm. It is a fertile alluvial plain drained by the Ganga and its tributaries. Rice, maize, millets in kharif, wheat, gram, barley, peas, mustard and potato in rabi are important crops. V. Upper Gangetic Plains Region: In the Upper Gangetic Plains region come the central and western parts of Uttar Pradesh and the Hardwar and Udham Nagar districts of Uttarakhand. Polytechnic in Agriculture (Course-2018) Page 38 Agron. 1.2 Fundamentals of Agronomy The climate is sub-humid continental with temperature in July between 26 °C to 41 °C and temperature in January between 7 °C to 23 °C. Average annual rainfall is between 75 cm-150 cm. The soil is sandy loam. Canal, tube-well and wells are the main source of irrigation. This is an intensive agricultural region wherein wheat, rice, sugarcane, millets, maize, gram, barley, oilseeds, pulses and cotton are the main crops. VI. Trans-Ganga Plains Region: This region (also called the Satluj-Yamuna Plains) extends over Punjab, Haryana, Chandigarh, Delhi and the Ganganagar district of Rajasthan. Semi- arid characteristics prevail over the region, with July’s mean monthly temperature between 25 °C and 40 °C and that of January between 10 °C and 20 °C. The average annual rainfall varies between 65 cm and 125 cm. The soil is alluvial which is highly productive. Canals and tube-wells and pumping sets have been installed by the cultivators and the governments. The intensity of agriculture is the highest in the country. Important crops include wheat, sugarcane, cotton, rice, gram, maize, millets, pulses and oilseeds etc. The region is also facing the menace of water logging, salinity, alkalinity, soil erosion and falling water table. VII. Eastern Plateau and Hills: This region includes the Chhotanagpur Plateau, extending over Jharkhand, Orissa, Chhattisgarh and Dandakaranya. The region enjoys 26 °C to 34 °C of temperature in July, 10 °C to 27 °C in January and 80 cm-150 cm of annual rainfall. Soils are red and yellow with occasional patches of laterites and alluviums. The region is deficient in water resources due to plateau structure and non-perennial streams. Rainfed agriculture is practiced growing crops like rice, millets, maize, oilseeds, ragi, gram and potato. VIII. Central Plateau and Hills: The region is spread over Bundelkhand, Baghelkhand, Bhander Plateau, Malwa Plateau, and Vindhyachal Hills. Semi-arid climatic conditions prevail over the region with temperature in July 26 °C to 40 °C, in January 7 °C to 24 °C and average annual rainfall from 50 cm-100 cm. Soils are mixed red, yellow and black. There is scarcity of water. Crops grown are millets, wheat, gram, oilseeds, cotton and sunflower. Polytechnic in Agriculture (Course-2018) Page 39 Agron. 1.2 Fundamentals of Agronomy IX. Western Plateau and Hills: Comprising southern part of Malwa plateau and Deccan plateau (Maharashtra), this is a region of the regur (black) soil with July temperature between 24 °C and 41 °C, January temperature between 6 °C and 23 °C and average annual rainfall of 25 cm-75 cm. Wheat, gram, millets, cotton, pulses, groundnut, and oilseeds are the main crops in the rain-fed areas, while in the irrigated areas, sugarcane, rice, and wheat, are cultivated. Also grown are oranges, grapes and bananas. X. Southern Plateau and Hills: This region falls in interior Deccan and includes parts of southern Maharashtra, the greater parts of Karnataka, Andhra Pradesh, and Tamil Nadu uplands from Adilabad District in the north to Madurai District in the south. The mean monthly temperature of July varies between 25 °C and 40 °C, and the mean January temperature is between 10 °C and 20 °C. Annual rainfall is between 50 cm and 100 cm. It is an area of dry-zone agriculture where millets, oilseeds, and pulses are grown. Coffee, tea, cardamom and spices are grown along the hilly slopes of Karnataka plateau. XI. Eastern Coastal Plains and Hills: In this region are the Coromandal and northern Circar coasts of Andhra Pradesh and Orissa. The mean July temperature ranges between 25 °C and 35 °C and the mean January temperature varies between 20 °C and 30 °C. The mean annual rainfall varies between 75 cm and 150 cm. The soils are alluvial, loam and clay and are troubled by the problem of alkalinity. Main crops include rice, jute, tobacco, sugarcane, maize, millets, groundnut and oilseeds. XII. Western Coastal Plains and Ghats: Extending over the Malabar and Konkan coastal plains and the Sahyadris, the region is humid with the mean July temperature varying between 25 °C and 30 °C and mean January temperatures between 18 °C and 30 °C. The mean annual rainfall is more than 200 cm. The soils are laterite and coastal alluvial. Rice, coconut, oilseeds, sugarcane, millets, pulses and cotton are the main crops. The region is also famous for Polytechnic in Agriculture (Course-2018) Page 40 Agron. 1.2 Fundamentals of Agronomy plantation crops and spices which are raised along the hill slopes of the Western Ghats. XIII. Gujarat Plains and Hills: This region includes the hills and plains of Kathiawar and the fertile valleys of Mahi and Sabarmati rivers. It is an arid and semi-arid region with the mean July temperature reading 30 °C and that of January about 25 °C. The mean annual rainfall varies between 50 cm and 100 cm. Soils are regur (black) in the plateau region, alluvium in the coastal plains and red and yellow soils in Jamnagar area. Groundnut, cotton, rice, millets, oilseeds, wheat and tobacco are the main crops. It is an important oilseed producing region. XIV. Western Dry Region: Extending over Rajasthan, West of the Aravallis, this region has an erratic rainfall of an annual average of less than 25 cm. The desert climate further causes high evaporation and contrasting temperatures 28 °C to 45 °C in June and 5 °C to 22 °C in January. Bajra, jowar and moth are main crops of kharif and wheat and gram in rabi. Livestock contributes greatly in desert ecology. XV. Island Region: The island region includes Andaman-Nicobar and Lakshadweep which have typically equatorial climate (annual rainfall less than 300 cm; the mean July and January temperature of Port Blair being 30 °C and 25 °C respectively). The soils vary from sandy along the coast to clayey loam in valleys and lower slopes. The main crops are rice, maize, millets, pulses, arecanut, turmeric and cassava. Nearly half of the cropped area is under coconut. Polytechnic in Agriculture (Course-2018) Page 41 Agron. 1.2 Fundamentals of Agronomy  Agro-climatic zones of Gujarat Taking into consideration the rainfall pattern, topography, soil characteristics, the climate in general and the cropping patterns, eight (8) agro-climatic zones have been identified in Gujarat. Polytechnic in Agriculture (Course-2018) Page 42 Agron. 1.2 Fundamentals of Agronomy Salient –geographical and agro-climatic features of agro climatic zones of Gujarat Zon Name of Geographical area included in Mean Broad soil Major crops e the zone the zone annual group of the zone No. rainfall (mm) I South Whole of Dangs district, Part of 1500 – Typical Nagli, Vari, Gujarat Valsad district (excluding 2200 lateritic, Sugarcane, (Heavy Navsari and Gandevi), Part of Deep black Paddy, rain fall) Surat district (Including Valod, with few Sorghum, Songadh and Mahuva). coastal Vegetables & alluvial, Fruit crops. Medium black. II South Area between river Ambica & 1000- Heavy Cotton, Gujarat Narmada, Part of Valsad district 1500 black Sorghum, (Navsari & Gandevi), Part of Clayey Paddy, Surat district (Kamrej, soils Wheat, Chhoriashi, Nizer, Palsana, Sugarcane, Bardoli, Mangrol and Mandvi) Vegetables & Fruit crops. III Middle Area between Narmada and 800 - Medium Cotton, Gujarat Vishwamitri river including 1000 black to Pearlmillet, Whole of Panchmahals district, Goradu Tobacco, Part of Vadodra district (Karjan, soils Pulses, Sinor, Dabhoi, Sankheda, Wheat, Naswadi and Jabugam) Part of Paddy, Maize Bharuch district (Bharuch, & Sorghum Amod, and Jambusar) Part of Kheda district (Khambhat and Matar) IV North Whole of Kheda district (except 625 – Sandy Pearlmillet, Gujarat Khambhat and Matar), Whole of 875 loam to Cotton, (Dry zone) Sabarkantha district, Part of Sandy Wheat, Ahmedabad district (Dehgam, soils Pulses, Daskroi and Sanand), Sorghum, Gandhinagar district, Part of Mustard, Banaskantha district (Deesa, Groundnut, Dhanera, Palanpur, Danta and Potato, Vadgam), Whole of Mehsana Spices & district except (Sami and Harij), Condiments Part of Vadodra district (Baroda, crops. Savli, Waghodia and Padra) Polytechnic in Agriculture (Course-2018) Page 43 Agron. 1.2 Fundamentals of Agronomy V North-West Whole of Kutch district, Maliya 250 - Sandy Cotton, Gujarat of Rajkot, Halvad, Dhangadhra 500 and Sorghum, (Arid zone) & Dasada of Surendranagar, Saline Pearlmillet, Sami, Harij & Chansama of soils Wheat, Mehsana, Santalpur, Groundnut & Radhanpur, Kankrej, Diodar, Pulses crops Vav & Tharad of Banaskantha and Viramgam of Ahmedabad districts. VI North Whole of Jamnagar district, 400 - shallow Groundnut, Saurashtra Part of Rajkot (Paddhari, 700 and Cotton, Lodhika, Jasdan, Rajkot, Medium Wheat, Vankaner & Morvi), Part of black to Pearlmillet, Surendranagar (Vadhwan, Sandy Pulses crops. Muli & Sayla), Part of soils Bhavnagar (Gadhda, Umrala & Botad) VII South Whole of Junagadh, Part of 625 – 750 Medium Groundnut, Saurashtra Bhavnagar (Shihor, Ghogha, few black, Cotton, Gariadhar, Palitana, Talaja, pockets Shallow Wheat, Mahuva & Savarkundla), Part with soils with Pearlmillet, of Amreli (Dhari, Kodinar, 1000 mm few Sorghum, Rajula, Jafrabad, Khambada, around pockets Pulses, Amreli, Babra, Liliya Lathi Junagadh of Sugarcane & &Kunkawav), Part of Rajkot Calcareou fruit crops. (Jetpur, Gondal, Dhoraji & s soils. Upleta) VIII The Bhal Area around Gulf of Cambay 625 - Medium Paddy, region and Bhal tract & coastal area 700 black, Pearlmillet, of Bharuch and Surat districts. Poorly Pulses, Cotton, Olpad of Surat, Hansot and drain & Wheat, Wagra of Bharuch, Cambay of Saline Groundnut, Kheda, Dholka & Dhandhuka soils. Tobacco, of Ahmedabad, Vallbhipur & Sorghum, Bhavnagar of Bhavnagar Vegetables & district and Limbdi of Oil seed crops. Surendranagar district. Polytechnic in Agriculture (Course-2018) Page 44 Agron. 1.2 Fundamentals of Agronomy Topic 9: Classification of field crops and factors affecting on crop production and Classification of field crops Detailed classification of crops 1. Classification according to Agronomical or economic: This type of classification is done on the base of use of agriculture products there are another three class in this group. (A) Edible Crop (B) Non-Edible crops (C) Special purpose crops Those crops which do not utilized (1) Cereal crop : Wheat, Bajara directly as human foods but utilized in (2) Pulses crops (Dicot): Gram agro based industries. These non edible (3) Fruits crops : Mango, Banana crops are further divided in eight (8) (4) Vegetable crops: Brinjal, Potato different groups as under (5) Legumes : Groundnut (6) Oil seeds: Sesamum, Groundnut 1. Forage crops: Lucerne, Fodder sorghum 2. Fiber crops : Cotton, Sanhemp (1) Leafy Vegetables 3. Non-edible oil seeds crops: Castor (2) Fruit Vegetable : Tomato, Brinjal 4. Colour crops: Safflower, Turmeric (3) Roots Vegetable :Radish 5. Narcotic crops: Tobacco (4) Flowers Vegetable 6. Cash crops: Sugarcane (5) Pods Vegetable :Pegion pea 7. Medicinal crops: Isabgol (6) Bulb : Onion 8. Spices & condiments: Cumin, Garlic (7) Stem / Tuber : Potato (C) Special purpose crops: Some time edible or non-edible crops which are not grown for the common uses, but they are grown for the certain /special purposes 1. Row crops: Crops which are sown in rows keeping uniform distance throughout the field. e.g. Cotton, Pigeon pea, Pearl millet 2. Cover crops: Crops grown primarily to cover the soil surface and to reduce the loss of moisture and erosion by wind and water. e.g. Ground nut, Lucerne, Kidney bean 3. Mixed crops: Pigeon pea – Maize, Pigeon pea – Castor 4. Nurse crops: Those crops used to protect or nurse the other crops in young stage grown with them. e.g. Sanhemp, Pulse crop 5. Pasture crops: This type of groups grown where former crops are not Polytechnic in Agriculture (Course-2018) Page 45 Agron. 1.2 Fundamentals of Agronomy taken as to prevent soil erosion Guinea grass. 6. Silage crops: Silage crops are those preserved in a succulent condition by partial fermentation in a tight receptacle (vessel) or soil pit. e.g. Maize, Sorghum. 7. Green manure crops: Any crop grown and buried into the soil improving the soil physical condition by addition of organic matter. Mostly legume crops are grown for this purpose. e.g Sanhemp, Cowpea, Cluster bean. 8. Support crops: Certain fast growing crops grown to provide support to vine crops. e.g. Castor, Shevri 9. Truck crops: Crops which yield in tones (huge quantity) and required heavy transport cost. e.g. Potato, Sugarcane, Onion. 10. Wind breaking crops: Crops grown to protect against high wind velocity to avoid the logging to the crop. e.g. Sugarcane, Banana, Castor. 11. Companion crops: Two crops are taken together with the aim that they are benefited to each other e.g. Cereal and legumes. 12. Trap crops: Crops which are grown on boundary of field for protection against pest, insects, nematodes etc. e.g. Castor around groundnut crop to reduce the nematode problem. 13. Cash crops: Crops grown for sale and bring money immediately are termed as cash crop. e.g. Cotton, Tobacco, Sugarcane. 14. Catch crops: Crops, which are grown as substitute of main crop that have failed due to unfavorable climatic conditions. e.g. Semi rabi Sesamum, Sorghum, Castor 2. Classification according to season A) Monsoon/Kharif crops B) Winter/Rabi crops C) Summer crops - The crop which requires - The crop which requires - The crop which requires hot and humid weather for cold and dry weather for hot weather for their their better growth and their better growth and better growth and production are raised in production are raised in production are raised in monsoon season. winter season. summer season. Sowing time: Sowing time: Sowing time: June to September October to January February to May e.g. Pear millet, Sesamum, e.g. Wheat, Barley, Gram, e.g. Summer bajra,Summer Sorghum, Groundnut, Safflower, Cumin, etc. groundnut, Watermelon, Maize, Cotton, Paddy etc. Fodder sorghum etc. Polytechnic in Agriculture (Course-2018) Page 46 Agron. 1.2 Fundamentals of Agronomy 3. Classification according to duration of crops (Ontogeny) Annual crops Biannual crops Perennial crops Those crops, which Those crops which Those crops which complete their life complete their life complete their life in within the year. within 2 Years but more more than two year than 1 year e.g. Sorghum, Rice, e.g. Banana Papaya, e.g. Mango, Sapota, Maize, Brinjal Sugarcane Guava 4. Classification according to Water requirement Irrigated crops Unirrigated crops Those Crops which are dependent on rain as well as well as other irrigation Those crops which are only sources (e.g. Cannel, Tube well, etc.) for dependent on rain for completing completing their life span are known as their life span are known as un- irrigated crops. irrigated crops. These crops can be grown in kharif, Rabi and summer seasons where irrigation e.g. Pigeon pea, Cotton, Groundnut, facility is available. Pearl millet, Clusterbean, Castor e.g. Summer : Lady’s finger (Okra), Groundnut, Pear millet, Paddy etc. Rabi : Potato, Cumin, Mustard, Wheat etc. Kharif : Pearmillet, Paddy, Vegetable etc. Polytechnic in Agriculture (Course-2018) Page 47 Agron. 1.2 Fundamentals of Agronomy 5. Classification according to No. of cotyledons Monocotyledon Di-cotyledons 1. Embryos have a single seed leaf, Embryos have two seed leaves, referred to as referred to as a cotyledon - hence cotyledons- hence the name di (two) the name mono (one) Cotyledon. cotyledon. 2. Leaves have parallel veins and are Leaves have network of veins and are broad. long and narrow 3. Flowers have petals and floral parts Flowers have petals and floral parts in in multiples of three multiples of four or five 4. In the stem, vascular bundles are In the stem, the vascular tissue is arranged scattered circularly 5. A pollen grain with one opening A pollen grain with three openings 6. Root system is generally fibrous Root system is generally branched and , shallow taproot. 7. It contains carbohydrates. It contains proteins. 8. When seed is broken, it does not When seed is broken, it breaks in certain break in certain shape. shape (being split). 8. Two important monocotyledon Di-cotyledon plants include six important families are: families : 1. Gramineae : e.g millet, 1. Fabaceae : e.g. beans, peas, peanuts, corn, wheat, barley, rye, vetches, alfalfa, clovers, soybeans. rice, oats, and other 2. Solanaceae : e.g. white potatoes, cereal grains. tobacco, peppers, eggplants, and ground cherries. 2. Liliaceae : e.g. lilies, onions, 3. Brassicaceae : e.g. turnips, tulips, and garlic. cabbage, cauliflower, brussels , radishes, watercress, and mustard. 4. Convolvulaceae : e.g. morning glories, sweet potatoes, and dodder. 5. Malvaceae: e.g. cotton and okra. 6. Rosaceae: e.g. ornamental roses, peaches, almonds, apricots, pears, Polytechnic in Agri

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