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Download Soil Sampling and Nutrient Recommendations
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Nutrient Uptake by Crops Soil Education Short Course Outline Essential Nutrients Mobile/immobile nutrients in soil Ways nutrients reach the plant Nutrient accumulation Mobile/immobile nutrients in plants Deficiency symptoms Nutrient removal (grain and biomass) Essential Plant Elements Nitrogen Phosphorus Potassium Sulfur Calcium Magnesium Silicon Zinc Chlorine Iron Boron Manganese Sodium Copper Molybdenum Nickel Mobility of Nutrients in Soil Mobile Nitrogen, Sulfur, Chloride, Boron Not held tightly by soil Plants can use nearly all of the nutrient if supply is limited Immobile Phosphorus, Potassium, Calcium, Magnesium, Iron, Zinc, Manganese, Copper, and Molybdenum Tightly held by soil Nutrients absorbed from soil solution next to roots Ways Nutrients Reach Plants Mass Flow Movement of ions in soil solution (water) Long distance transport Diffusion Movement of ions from high concentration to low concentration Short distances Root Interception Root moves to the nutrient Mobility and Uptake Mechanisms Mass Flow - Mobile nutrients Diffusion - Immobile and mobile nutrients Root Interception - Immobile nutrients Supply Mechanism, % Nutrient Interception Mass Flow Diffusion Nitrogen 1 99 0 Phosphorus 2 5 93 Potassium 2 20 78 Nutrient Accumulation in Plants Nutrient Mobility in Plants Mobile Nitrogen, Sulfur, Chloride, Boron Immobile Phosphorus, Potassium, Calcium, Magnesium, Iron, Zinc, Manganese, Copper, and Molybdenum Notice how plant mobility influences deficiency symptoms Macronutrients Nitrogen Phosphorus Potassium Nitrogen Part of important plant components Proteins Chlorophyll Enzymes Required for respiration and growth Necessary for optimum grain and forage yield N Deficiency N Deficiency Phosphorus Component of ATP (energy storage) Part of DNA Function in respiration and photosynthesis Cell division Root development Growth Flowering Drought and cold tolerance P Deficiency P Deficiency Potassium Function in photosynthesis Important for metabolism Converts N to protein Activates enzymes Suppresses plant diseases Potassium Deficiency Lower leaf tips and margins brown Premature leaf senescence Lodging may occur Stalk rot or leaf diseases Grain may be shriveled Potassium Deficiency Potassium Deficiency Secondary Nutrients Sulfur Calcium Magnesium Sulfur Constituent of some amino acids Part of coenzymes and vitamins Essential for metabolism Sulfur Deficiency Similar to N deficiency Immobile in plants – symptoms start with young leaves Yellowing Stunted growth Long thin leaves Sulfur Deficiency Commonly found on: Low Organic Matter Soils Sands High demand crops such as alfalfa remove more sulfur and respond to sulfur fertilization Responsive crops/situations such as wheat and corn Low sulfate irrigation water Soil tests are more reliable on sandy soils Plant tissue tests more useful in diagnosing a deficiency Sulfur Deficiency Correction Manure Irrigation water Sulfur gasses in rain and snow 5-20 lb/ac per year Fertilizers Ammonium Sulfate (24%) Calcium Sulfate (15-18%) Ammonium thiosulfate solution (26%) Potassium-magnesium sulfate (22-23%) Elemental sulfur (88-95%) Calcium Immobile in plants Cell wall strength Cell division Membrane production Rarely deficient On acid soils only Calcium Deficiency Symptoms Necrosis of leaf tips and roots (growing points) Roots may be brown, short, and excessively branched Correction Apply lime Magnesium Part of chlorophyll Phosphorus metabolism Part of enzymes Synthesis of DNA Magnesium Deficiency Mobile in plants Old leaves affected Yellowing between leaf veins Common on: Acid soil Sandy soil Micronutrients Zinc Iron Boron Copper Manganese Molybdenum Chlorine Nickel Zinc Involved in enzymatic processes Production of proteins Important for chlorophyll Most common micronutrient deficiency in Kansas Wheat zinc deficiency is rare Zinc Deficiency Deficiency on young tissue immobile in plant Yellowing at the whorl Interveinal chlorosis Stunting, short internodes Zinc Deficiency Common in High pH Low OM Sandy Soil Wet cold conditions Eroded land Leveled fields Zinc Deficiency Correction Broadcast applications of high percentage water soluble zinc source (zinc sulfate, zinc chelate) Band application with starter fertilizers. Foliar application of zinc Application of animal manure Generally contains large amounts of zinc Iron Production of chlorophyll Part of enzymes Oxidation-reduction reactions in photosynthesis and respiration Iron Deficiency Immobile in plant Deficiency symptoms on youngest leaves Interveinal Chlorosis Leaves may turn white Found on high pH Low lying areas Eroded or leveled areas Iron Deficiency Correction Hard to correct with soil applied fertilizers Quickly converted to unavailable forms Band applications up to 10 lbs Iron Sources are expensive Foliar applications of ferrus sulfate work, but need multiple applications Manure application Best option – Variety selection Boron Cell division Growth will be severely hampered Flowering Growth of pollen tubes and grains Boron Deficiency Immobile in plants Symptoms on new leaves Poor seed set Yellowing of young leaves Soil Conditions Leached sands Dry soil conditions Low organic matter Boron Deficiency Correction Broadcast application: 1-2 lbs Borate Foliar application: 0-0.5 lbs soluble Borate NEVER apply as starter or near the row Highly toxic to germinating seeds Uniform distribution is important Soil test for Boron is poorly correlated Try plant analysis Be careful to not apply too much and create toxicity Copper Functional part of enzymes Chlorophyll formation Copper Deficiency Mobile in plants Deficiency symptoms on young tissue Necrosis and twisting of leaf tips Deficiency not found in Kansas Conditions for deficiency: High organic matter soils Highly weathered soils Copper Deficiency Correction Broadcast 5 lbs copper as copper sulfate per acre Foliar application 1-2 lbs copper sulfate per acre Has good residual activity Watch for over application Can be toxic Has been used as a fungicide in some crops Warning: Soil test not correlated in Kansas Manganese Involved in photosynthesis Evolution of O2 from water Oxidation reduction reactions Enzyme reactions Manganese Deficiency Very Immobile Interveinal chlorosis on young leaves Not yellow or brown like iron Maintain green tint Soil Conditions High pH High organic matter Manganese Deficiency Roundup Ready Soybeans Yellowing occurs after glyphosate application Believed that roundup gene affected root exudates RR plants solubilize less Mn than conventional Generally found on sites low in Mn Correcting Manganese Deficiency Poor Soil Test for Mn Band application Foliar application Manganese Deficiency Correction Poor Soil Test for Mn Band application Foliar application Creating a Molybdenum Converts nitrate to ammonium in plants Very important to legumes for N fixation Very low levels needed by plants Often enough stored in seed to meet demands Molybdenum Deficiency Symptoms Stunted Light green N deficiency?? Mobile in Plants Soil Conditions Availability increases with pH Legumes on acid sandy soil Highly weathered soil aggie-horticulture.tamu.edu/.../leaf/36.2.html Molybdenum Deficiency Correction Poor soil test Plant analysis is an option Seed treatment with 1-2 ounces of ammonium molybdate 2-4 ounces of ammonium molybdate foliar Caution: Apply carefully as Molybdenum is toxic to ruminants Chloride Disease suppression Wheat leaf rust Sorghum and corn stalk rot Required for water splitting in photosynthesis Cell division in leaves and roots Chloride Deficiency Symptoms Mobile in plants Deficiencies found in central and eastern Kansas Historical applications of KCL increased yields Nickel Recently added to essential nutrient list No deficiencies in Kansas Questions?
