Plant Nutrients And Fertilizers PDF

Plant Nutrients and Fertilizers M. Scott Tilley 10-25-2022 Essential elements There are 18 essential elements that are required by most plants. These elements are deemed essential because of the following: 1. Plants cannot grow and develop properly without them 2....

Plant Nutrients and Fertilizers M. Scott Tilley 10-25-2022 Essential elements There are 18 essential elements that are required by most plants. These elements are deemed essential because of the following: 1. Plants cannot grow and develop properly without them 2. They play critical roles in plant metabolism 3. Their roles cannot be replaced by another element 4. Deficiency symptoms can be corrected only by supplying that deficient element 18 essential elements are classified as…… Macronutreints – chemical elements needed in large amounts for plant growth 1. Nitrogen – building block for creation of proteins / major component of cholorophyll 2. Phosphorus – production of DNA / makes up cell membrane 3. Potassium – ATP synthase / gas exchange in the stoma by regulating guard cells 18 essential elements are classified as…… Micronutreints – chemical elements needed in small amounts for plant growth The following three elements are also known as secondary nutrients 4. Calcuim – activates plant enzymes which send signals to plant cells 5. Magnesium – needed to make chlorophyll 6. Sulfur – needed to construct amino acids – a precursor to what element already mentioned? Nitrogen 18 essential elements are classified as…… Micronutreints – chemical elements needed in small amounts for plant growth 7. Boron 8. Iron 9. Molybenum 10.Manganese 11.Zinc 12.Copper 13.Chlorine 14.Cobalt 15.Nickel 18 essential elements are classified as…… Mineral vs. Non-mineral The following are non-mineral elements 16. Carbon – carbohydrates / sugar 17. Hydrogen – used to produce ATP within electron transport chain 18. Oxygen – root development / respiration Essential elements Luxury consumption – the intake by a plant of an essential nutrient in amounts in excess of what it needs. Nutrient deficiency symptom – visible change in plant morphology or appearance associated with the deficiency of a specific plant nutrient. Guide to Nutrient Deficiency Symptoms - link Nitrogen Chlorosis –condition in which a plant or a plant part is light green or greenish yellow because of poor chlorophyll development or destruction of chlorophyll resulting from a pathogen or a mineral deficiency. Nitrogen Necrosis –tissue death associated with discoloration and dehydration of all or some parts of plant organs. Nitrogen – NO3 and NH4 is the only form taken up by plants Nitrogen – NO3 and NH4 is the only form taken up by plants Mineralization – the conversion of an element from an organic form to an inorganic form as a result of microbial decomposition https://www.youtube.com/watch?v=C0zZT9-EZRE Phosphorus Plants utilize about 1/10 as much phosphorus as nitrogen Very low solubility and therefore not readily available to plants, except in organic soils or soils with a high CEC – cation exchange capacity Plants absorb phosphorus in the soluble ions of H2PO4 and HPO4 Soluble – able to be dissolved, especially in water Deficiency is purpling of the leaf Phosphorus concerns Eutrophication – excessive enrichment of surface water leading to excessive plant growth and oxygen deficiency (true for nitrogen) Potassium Very soluble cation. A luxury consumption element with no consequences However, excess potassium can hinder the adsorption of magnesium Deficiency Calcuim, Magnesium, Sulfur Ca – cell growth, cell division, and N accumulation Mg – central atom in the structure of a chlorophyll molecule S – amino acids. Essential for protein production. Potassium Very soluble cation. A luxury consumption element with no consequences However, excess potassium can hinder the adsorption of magnesium Deficiency Mulder’s Nutrient Chart High levels of a particular nutrient in the soil can interfere with the availability and uptake by the plant of other nutrients. Those nutrients which interfere with one another are said to be antagonistic. Stimulation occurs when the high level of a particular nutrient increases the demand by the plant for another nutrient. Fundamentals of a soil test 1. Humic matter – measurement of organic matter. This is used to provide guidance for lime recommendations, phosphorus index, and micronutrient recommendations as well as safe use of pesticides. 2. Weight per volume – measured in g/cm3 1.5 g/cm3 is high in sand 1.0 g/cm3 is silt and clay loam 0.4 g/cm3 is high in organic matter 3. Cation exchange capacity – soils rich in colloids have a high CEC (hold more cations). Soils with low CEC are susceptible to leaching. 4. Base saturation percent – Calcium and Magnesium 5. pH – used to determine lime recommendations Fundamentals of a soil test Nutrients are reported as Index values A range is provided to indicate the likelihood of the crop’s response to supplemental application of an element. 0 - 25 = low 26 - 50 = medium 51 – 1000 = high 1000 = very high Liming High soil acidity decreases (pH increases) by liming. The goal of liming is to neutralize toxic elements. The effect of liming is to add hydroxide ions (OH-1) to decrease the solubility of Al3+, Mn2+, Fe3+, Zn2+, and Cu2+ ions. Benefits of Liming Helps increase supply of basic elements such as Ca, Mg to the soil. Increases availability of P, Mo, and B Promotes microbial growth Liming Reaction 1. CaCO3 + H2O  Ca2+ + HCO3- + OH- 2. H+ + OH-  H20 Types of Liming Material Calcite = CaCO3 Dolomite = CaMg(CO3)2 Hydrated = Ca(OH)2 Burnt = CaO Basic slag = CaSiO3 Soil nutrients are depleted in a variety of ways Soil erosion Volatilization Leaching (N, K, S) Use by the crop Highly bonded Fertilizer Terminology A fertilizer label indicates the amount of N-P-K in that order. In order to calculate the amount of each element in the bag, you need to know the weight of the bag. For Example: Bag weighs 50 lbs. N = 50lbs * 0.16 = 8 lbs of N P = 50lbs * 0.04 = 2 lbs of P K = 50lbs * 0.8 = 4 lbs of K Fertilizer Terminology A fertilizer label indicates the amount of N-P-K in that order. In order to calculate the amount of each element in the bag, you need to know the weight of the bag. For Example: A homeowner needs to apply 100 lbs of N to his garden based on the soil report. How much of the following product would he/she apply? 1 Bag = 100 lbs How much P and K would also be applied? N Fertilizer sources Methods of Fertilizer Application Starter Application Methods of Fertilizer Application Broadcast Application Band Application Farm Basics #955 Banding vs Broadcasting (Air Date 7-2 4-16) - YouTube Methods of Fertilizer Application Split Application Side Application Side Dressing Corn-CEC #947 (Air Date 5-29-16) - YouTu be Methods of Fertilizer Application Top Dressing Fertigation Foliar Application Side Dressing Corn-CEC #947 (Air Date 5-29-16) - YouTu be Not all Applied Fertilizer is Used by the Plants Fertilizer efficiency – percentage of added fertilizer that is actually used by the plants N = 30 to 70% P = 5 to 30% K = 50 to 80% Efficiency is influenced by: 1. Technique of application 2. Weather conditions 3. Soil type 4. Type of crop