Lecture 2: Agronomy - Classification of Crops PDF

LECTURE 2 Agronomy – definition – Agronomic classification of crops and their importance - Major crops in India and Kerala Agronomy is derived from a Greek word ‘agros’ meaning ‘field’ and ‘nomos’ meaning ‘management’. Prin...

LECTURE 2 Agronomy – definition – Agronomic classification of crops and their importance - Major crops in India and Kerala Agronomy is derived from a Greek word ‘agros’ meaning ‘field’ and ‘nomos’ meaning ‘management’. Principles of agronomy deal with scientific facts in relations to environment in which crop are produced. Definition of Agronomy It is defined as an agricultural science deals with principles and practices of crop production and field management. Agronomy is branch of agricultural science, which deals with principles, & practices of soil, water & crop management. It is branch of agricultural science that deals with methods which provide favorable environment to the crop for higher productivity, Boundaries and scale Crop management, and its scientific study agronomy, are part of a system that comprises the physical elements of the climate, soil and land, the biological constituents of the vegetation and soil, the economic opportunities and constraints of markets, sales and profit, and the social circumstances and preferences of those who work the land. Scope of Agronomy Agronomy is a dynamic discipline with the advancement of knowledge and better understanding of planet, environment and agriculture. Agronomy science becomes imperative in Agriculture in the following areas.  Identification of proper season for cultivation of wide range of crops is needed which could be made possible only by Agronomy science. Proper methods of cultivation are needed to reduce the cost of cultivation and maximize the yield and economic returns. Availability and application of chemical fertilizers has necessitated the generation of knowledge to reduce the ill-effects due to excess application and yield losses due to the unscientific manner of application. Availability of herbicides for control of weeds has led to development for a vast knowledge about selectivity, time & method of its application. Water management practices play greater role in present day crisis of water demand and Agronomy science answer to the questions ‘how much to apply?’ and ‘when to apply?’. Intensive cropping is the need of the day and proper time and space intensification not only increase the production but also reduces the environmental hazards. New technology to overcome the effect of moisture stress under dry land condition is explored by Agronomy and future agriculture is depends on dry land agriculture. Packages of practices to explore full potential of new varieties of crops are the most important aspects in crop production which could be made possible only by Agronomy science. Keeping farm implements in good shape and utilizing efficient manner to nullify the present day labour crisis is further broadening the scope of agronomy. Maintaining the ecological balance through efficient management of crops, livestock and their feedings in a rational manner is possible only by knowing agronomic principles. Care and disposal of farm and animal products like milk and eggs and proper maintenance of accounts of all transactions concerning farm business is governing principles of agronomy. Relation of agronomy to other sciences Agronomy is a main branch of Agriculture. It is synthesis of several disciplines like soil science, Agricultural chemistry, crop physiology, plant ecology, biochemistry and economics. The Soil Science helps the agronomist to thoroughly understand the soil physical, chemical and biological properties to effect modification of the soil environment. The Agricultural Chemistry help the agronomist to understand the chemical composition and changes involved in the production, protection, and use of crops and livestock. The crop physiology helps to understand the basic life process of crops to understand functioning of each parts of plant to determine their input requirement like nutrients etc. The plant ecology helps us to understand the associated environment in which the crops grown like the influence of weather (Temperature, Rainfall etc). The biochemistry shows the way in which biochemical process takes place in crops which helps to understand critical requirements to favourably activate this process. The economics paves the way for profit and loss analysis in farming. Role of Agronomist 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. Agronomist aims at obtaining maximum production at minimum cost by exploiting the knowledge of the basic and applied sciences for higher crop production.  In a broader sense, agronomist is concerned with production of food and fibre to meet the needs of growing population. He develops efficient and economic field preparation method for sowing crops in different season. (Flat bed, Ridges and furrows) He is also involved to selection of suitable crop and varieties to suit or to match varied seasons and soils. Eg. Red soil - groundnut, Black soil - cotton, Sandy soil – tuberous crops, Saline soil – Finger millet (Ragi). In Kharif if water is sufficient go for rice and water is not sufficient go for maize, sorghum. Evolves efficient method of cultivation (whether broadcasting, nursery and transplantation or dibbling, etc.) provides better crop establishment and maintain required population He has to identify various types of nutrients required by crops including time and method of application (e.g. for long duration rice (150-60-60 kg NPK), short duration: 120:50:50 kg NPK/ha Application P&K basal and N in three splits) Agronomist must select a better weed management practice. Either through mechanical or physical (by human work) or chemical (herbicides or weedicides, e.g. 2-4-D) or cultural (by having wide space it may increase weed growth by using inter space crops). Weeds are controlled by integrated weed management method also Selection of proper irrigation method, irrigation scheduling i.e. irrigation timing and quantity based on the crops to be irrigated, whether to irrigate continuously or stop in between and how much water to be sup plied are computed by agronomy science so as to achieve maximum water use efficiency. Crop planning (i.e.) suitable crop sequence are developed by agronomist (i.e.) what type of crop, cropping pattern, cropping sequence, etc. (Rice - Rice - Pulse) Agronomists are also develops the method of harvesting, time for harvesting, etc. (Appropriate time of harvest essential to prevent yield loss) Agronomist is responsible for every decision made in the farm management. (What type of crop to be produced? How much area to be allotted for each crop? How and when to market? How and When to take other management activities?) All the decisions should be taken at appropriate time to efficiently use resources available) CROPS In general, crop is an organism grown and / or harvested for obtaining yield. Agronomically, crop is a plant cultivated for economic purpose. Classification of crops Classification is done to generalize similar crop plants as a class for better understanding of them. Classification types used in crops Based on ontogeny (Life cycle) Based on economic use (Agronomic) Based on Botany (Scientific) Based on seasons Based on climate 1) Based on Ontogeny (Life cycle) a) Annual crops: Crop plants that complete life cycle within a season or year. They produce seed and die within the season. Ex. Wheat, rice, maize, mustard etc. b) Biennial crops: Plants that have life span of two consecutive seasons or years. First years/ season, these plants have purely vegetative growth usually confined to rosette of leaves. The tap root is often fleshy and serves as a food storage organ. During the second year / season, they produce flower stocks from the crown and after producing seeds the plants die. Ex. Sugar beet, beet root, etc. c) Perennial crops: They live for three or more years. They may be seed bearing or non-seed bearing. Ex. Napier fodder grass, coconut, etc. 2. Based economic use (Agronomic) a) Cereals: Cereal derived from word ‘Ceres’ which denotes as ‘Goddess’ who was believed as the giver of grains by Romans. Cereals are the cultivated grasses grown for their edible starchy grains. Larger grains used as staple food – Rice, wheat, maize, barley, oats etc. Cereal grain contains 60 to 70% of starch and is excellent energy rich foods for humans. In almost every country and region, cereals provide the staple food. In the world as a whole, only 5% of starchy staple food comes from root crops (mainly cassava, potato, and yams, depending on climate), whereas the rest is from cereal. Cereals are an excellent source of fat soluble vitamin E, which is an essential antioxidant. Whole cereal grains contain 20 to 30% of the daily requirements of the minerals such as selenium, calcium, zinc and copper. b) Millets: Millets are small grained cereals, staple food in drier regions of the developing countries are called ‘millets’. They are also annual grasses of the group cereals. But’ they are grown in lesser area or less important area whose productivity and economics are also less important. These are also staple food for people of poor countries. In India, pearl millet is a staple food in Rajasthan. Millets are broadly classified in to two, 1) Major millets and 2) Minor millets. Major millets 1. Sorghum /Jowar/Cholam - Sorghum bicolor 2. Pearl millet /Bajra/Cumbu - Pennisetum glaucum 3. Finger millet or Ragi - Eleusine coracona Minor millets 1. Foxtail millet / Thenai - Setaria italica 2. Little millet / Samai - Panicum miliare 3. Common millet / Panivaraugu - Panicum miliaceum 4. Barnyard millet / Kudiraivali - Echinchloa colona var. frumentaceae 5. Kodo millet / Varagu - Paspalum scrobiculatum c) Pulses: Seeds of leguminous plants used as food (Dhal) rich in protein. Pod containing grain is the economic portion. Pulses are preferred for protein rich value & also economic important in cropping system. The wastes or stalk is called the ‘haulm’ or ‘stover’. Haulm is used as green manure and has high value cattle feed. Green pods used as vegetables, e.g. cowpea, lablab. Seed coat of pulses are nutritious cattle feed. 1. Red gram - Cajanus cajan 2. Black gram - Vigna mungo 3. Green gram - V. radiata 4. Cowpea - V. unguiculata 5. Bengalgram - Cicer arietinum 6. Horsegram - Macrotyloma uniflorum 7. Lentil - Lens esculentus 8. Soybean - Glycine max 9. Peas or gardenpea - Pisum sativum 10. Garden bean - Lablab purpureus 11. Lathyrus/Kesari - Lathyrus sativus  d) Oil seeds: Those crops which are rich in fatty acid are cultivated for the production of vegetable oil. They are used either for edible or industrial or medicinal purposes. Groundnut or 1. peanut - Arachis hypogeae 2. Sesame or gingelly - Sesamum indicum 3. Sunflower - Helianthus annuus 4. Castor - Ricinus communis 5. Linseed or flax - Linum usitatissimum 6. Niger - Guizotia abyssinia 7. Safflower - Carthamus tinctorius Rapeseed & Mustard Brown or Indian Mustard - Brassica juncea 9. Sarson - Brassica sp. Groundnut: Pod is economic portion in groundnut and contains 50% of oil content. Oil is edible or cooking oil and haulm is a used as cattle feed and also has manure value. The shell has fuel value; it is used for soil amendment. It is a bed material in the poultry forms. Oil cake is used as cattle feed and has manural value. Oil is used for production of Vanaspathi and soap making. Sesame: Sesame Sesame oil(poormans ghee) is cooking oil and economic parts are generally seeds (in the pod). Gingelly cake is used as a cattle feed, whereas capsule and stalk are used for composting / burning purpose. Castor: Seed (kernel) of castor contains oil and used as medicinal and industrial oil. Mainly aviation industries use this for lubrication purpose. Castor cake is concentrated organic manure. The shell and stalk is used for fuel purpose. Mustard: Mustard oil is edible oil and seeds are the economic portion. Oil cake is a good cattle feed. Safflower and sunflower: Oil is used for cooking purpose. Both of these oils contain more of unsaturated fatty acids and used for heart patients. Cake is used as cattle feed and also organic material and decorticated manure. Niger: Seed is the economic portion and used in soap making, paint, varnish & light lubricant. Crop is generally an industrial crop. Linseed: Oil extracted from seeds is used in preparation of paints and varnishes. e) Sugar crops: Crops cultivated for sugar. Juice is extracted from stem of sugarcane used for jaggery or sugar. Number of by products like molasses, bagasse, pressmud etc. is obtained from sugar industry. Molasses used for alcohol and yeast formation and bagasse for paper making and fuel. Pressmud used for soil amendment; whereas, trash (green leaf + dry foliage) is used for cattle feed. Sugar beet is another sugar crop where tubers are mainly used for extraction of sugar. Tubers and tops are used as a fodder for cattle feed. Sugarcane - Saccharum officinarum Sugar beet - Beta vulgaris  f) Fibre crops: Plants are grown for obtaining fibre. Different kinds of fibre are, i) seed fibre – cotton; ii) Stem/ bast fibre – Jute, mesta; iii) leaf fibre – Agave, pineapple. Cotton: Important fibre crop of the world, used for garment purpose. Seed for cattle feed and oil is edible purpose. Epidermal hairs of seed coats is the economic portion. Lint (Kapas-seed) has industrial value (fibre) and stalk is of fuel nature. Jute, Sunhemp, mesta: The fibre obtained from stems is used for gunny bags, ropes. Stem itself is used as fuel. Sunhemp is used for both stem fibre and green manure crop. g) Tuber crops: The crop plants grown in which the economic part consumed or traded is the fleshy or hard thick tubers. They are richest source of carbohydrates in the form starch. They are of two types. Stem tubers: here the tuber is formed from primary or adventitious stem. Eg. potato Root tubers: the tuber is formed by the enlargement of root by the accumulation of starch. h) Commercial crops/cash crops: These crops provide a higher significant benefit for the farmer. Atleast 75-80% of produce/product is exclusively for trade only. Not for self consumption. Eg: cashew, rubber, sugarcane, tobacco. i) Fodder / Forage: It refers to vegetative matter, fresh or preserved, utilized as feed for animals. It includes hay, silage, pasturage and fodder. Ex. 1. Grasses - Bajra napier grass, guinea grass, fodder sorghum, fodder maize. 2. Legumes - Lucerne, Desmanthus, etc. j) Spices and condiments: Crop plants or their products used for flavour, taste and add colour to the fresh or preserved food. Ex.– Ginger, garlic, fenugreek, cumin, turmeric, chillies, onion, coriander, anise and asofetida. k) Medicinal plants: Crops used for preparation of medicines. Ex. Tobacco, mint., Plumbago, Isabgol etc. l) Beverages: Products of crops used for preparation of mild, agreeable and simulating drinking. Ex. Tea, coffee, cocoa (Plantation crops). m) Narcotic crops: Crops, the parts or products of which are utilized for a sensational/simulating/excitation purpose. eg: Tobacco, betelvine, arecanut n) Green manuring crops: Green manure crops are those crops which are used for incorporating their plant tissues into the soil for improving the soil productivity. They are of two types. i) In situ green manuring crops: grown in same field where they are incorporated. Eg:Sunhemp and dhaincha ii) Ex - situ green manuring or green leaf manuring crops: leaves of which are collected from different places for incorporation in field. Eg: Glyciridia, Pongamia 3. Scientific or botanical classification Botanical or scientific names of plants which consist of genus and species and are universally accepted. Carolus Linnaeus, a Swedish botanist, was responsible for the binomial system of classification.  Group Grass (Wheat) Legume (Alfalfa) Rice Kingdom Plant Plant Division Spermatophyta Spermatophyta Sub-division Angiospermae Angiospermae Class Monocotyledonae Dicotyledonae Order Graminales Rosales Family Gramineae Leguminosae Genus Triticum Medicago Species Aestivum Sativa 4. Based on seasons Crops are grouped under the seasons in which their major field duration falls. Kharif crops: Crops grown during June-July to September–October which require a warm wet weather during their major period of growth and shorter day length for flowering. Ex. Rice, maize, castor, groundnut. Rabi crops: Crops grown during October–November to January-February, which require cold dry weather for their major growth period and longer day length for flowering. Ex. Wheat, mustard, barley, oats, potato, bengal gram, berseem, cabbage and cauliflower. Summer crops: Crops grown during February–March to May–June which require warm dry weather for growth and longer day length for flowering. Ex.Black gram, greengram, seasome, cowpea etc. This classification is not a universal one. It only indicates the period when a particular crop is raised. Ex. Kharif rice, kharif maize, rabi maize, summer pulse etc. 5. Based on climatic condition 1) Tropical crop : Coconut, sugarcane 2) Sub-tropical crop : Rice, cotton 3) Temperate crop : Wheat, barley 4) Polar crop : All pines, pasture grasses You should write important crops of KERALA and INDIA.