plant nutrients

Download Plant Nutrients

Post on 05-Feb-2016




0 download

Embed Size (px)


Plant Nutrients. Assessment of Nutrient Needs. Visual inspection of crops for deficiency symptoms Damage could have occurred already Symptoms may not be reliable. Soil tests to measure nutrient levels Growers depend on this method to determine lime and fertilizer needs. - PowerPoint PPT Presentation


  • Plant Nutrients

  • Assessment of Nutrient NeedsVisual inspection of crops for deficiency symptomsDamage could have occurred alreadySymptoms may not be reliableTissue testing for nutrients in plantsMay uncover problems that soil test missesSoil tests to measure nutrient levelsGrowers depend on this method to determine lime and fertilizer needs

  • Soil TestingSoil samplingSoil testingSoil InterpretationRecommendation

  • Take a Good Soil Sampleto Help Make Good Decisions

  • Taking a Soil SampleSampling Depth

    Conventional tillage: 6-9 inches

    No till: Use special pH sample in top 2Sod or pasture: 2-3 inches

    Tree Crops: 18-24 inches

    Sampling Area

    Should not exceed 10 acresFor row crops

  • Soil Test ResultspH: Acid, Neutral, Alkaline(How much of a nutrient is available)Soil Test Index: (How high or how low a nutrient is in the soil)Soil Test Rating: VL, L, M, H, VH, EH

  • Soil Test Rating Soil Test Explanation IndexVery Low (H)0-50 Severe deficiencyLow (L) 60-70Moderate deficiency

    Medium (M) 80-100Near optimum: some fertilizer recommendedHigh (H) 110-200Adequate for most crops Very High (VH) 210-400 Two to four times the amount considered adequate; none should be applied

    Extremely High (EH)410+ Excessive; none should be applied

    Phosphorus, Potassium, Magnesium, calcium

  • Resources

    (1) Nitrogen Fertilizer Recommendation for Corn in Iowa

    (2) Iowa State University Soil Testing

    (3) Extension Publications.

  • Plant Food Elements

    Used in Large AmountsMacronutrientsUsed in Small AmountsPrimary NutrientsSecondary NutrientsMicronutrientsNitrogen (N)Calcium (Ca)Iron (Fe)Phosphorus (P)Magnesium (Mg)Manganese (Mn)Potassium (K)Sulfur (S)Zinc (Zn)Copper (Cu)Boron (Bo)Chlorine (Cl)Cobalt (Co)

  • NitrogenNitrogen is a primary component of proteins and is part of every living cell.Functions of Nitrogen Speeds growth Vigorous growth, large leaves, and long stem internodes. Required for the formation of dark green pigment: chlorophyll. Promotes better production of chlorophyll hence it is required for better source of forage, feed and human nutrition. Plants use water best when they have ample nitrogen.

  • Excess NitrogenSoft, weak easily injured growthStems are weaker and more easily to lodge Soft growth is more prone to diseases and insects Overly rapid growth slows maturity and ripening of many crops N promotes vegetative rather than reproductive growth of flowers and leaves.

    Over-fertilized tomato plants promote lush growth but few fruits

  • Nitrogen deficiencySlow growth and stuntingPlants lack dark green color of well fed plants: Chlorosis

  • PhosphorusFunctions Phosphorus is part of chromosomes and genes and so it is involved in plant reproduction and cell division. P spurs early and rapid growth and helps a young plant develop its roots P helps plants resist cold and diseasesP speeds up crop maturity

    P aids blooming and fruiting

    P improves the quality of grains and fruits

  • Phosphorus DeficiencyThere is stunted growth but plants could remain green.Plants have a purple tint to leaves and stems, starting on lowerOlder leaves

  • Potassium (Potash) Activates enzymes needed in the formation of protein, starch cellulose and lignin.FunctionsIt is important in the formation of thick cell walls and strong, rigid plant stems. Regulates the opening and closing of pores in the leaf through which water, oxygen and carbon dioxide pass. Important in the development and ripening of fruits like apples or tomatoes Needed for proper growth of root and tuber crops

  • Potassium DeficienciesSeen less often than the other primary nutrients.Shortages occur primarily in sandy heavily leached soils.Marginal scorch or burnt edges of lower, older leaves

  • Secondary NutrientsCalciumFunctions of Calcium Required by plants mainly to build cell wall Crispness of apples come from calcium pectate in the fruit cells Ca largely controls soil pH and helps in the formation of soil structure Calcium plays a role in protein formation and carbohydrate movement in plants

  • Calcium Deficiencies Commonly appear in fruits and vegetables. Apple growers prevent water core (collapse of cell walls) in apples by spraying trees with Ca.This is similar to blossom end rot in tomatoes. Soil dries out and slows movement of Ca to roots during rapid root development. Ca deficiency cause misshapen roots on root vegetables.

  • MagnesiumFunctions of MagnesiumIt is an essential ingredient in chlorophyll formationEach chlorophyll molecule has one magnesium atom at the centerMagnesium activates a number of important enzyme systemsMg is involved in protein, carbohydrates and fat synthesis

  • SulfurFunctions of SulfurNeeded in the formation of proteins and chlorophyllAids in the formation of nodules in legumes and seed productionS improves stress tolerance.Alfalfa, members of the mustard family and members of the onion family need much sulfur.

    The pungent flavors derive from sulfur compounds

  • Sulfur DeficienciesStunted growthOlder leaves are pale green similar to N-deficient plants

  • MicronutrientsThese form special organic-metal molecules called Enzymes. Enzymes activate biological reactions in living systems.The difference between enough and too much can be quite narrow, sometimes only a few pounds per acrePlease apply elements with caution

  • Effect of pH on nutrient availability

  • IronIron is part of many enzymes necessary for the formation ofchlorophyllIt is an abundant element in rocks and soils but it is also one of the most commonly deficient micronutrient Functions of Iron

  • Symptoms of Iron Hunger Chlorosis: Yellowing of interveinal leaves. Mainly new leaves

  • ManganeseFunctions of ManganeseSpeeds up germination and crop maturityHelps uptake of several other nutrientsFunctions in chlorophyll development

  • Symptoms of Manganese Deficiency DwarfingChlorosis on new leaves

  • ZincFunctions of ZincNeeded in the metabolism of protein

    Involved somehow in the production of chlorophyll

  • Symptoms of Zinc Deficiency Fruit crops including peaches and citrus are sensitive to zincdeficiencyField crops also include corn, soybeans, cotton, and potatoesSymptoms include spots on leaves

    Chlorosis between veins is also common

  • Added to the soil to provide essential nutrients to plants

  • Fertilizer Grade: 13 - 13 - 13

  • Some Popular Fertilizer Grades Available in Alabama Fertilizer Grade % of all Grades sold in Alabama13 - 13 - 1349%8 - 24 - 24 7%8 - 8 - 8 7%5 - 10 - 15 7%7 - 21 - 21 7%5 - 15 - 30 6%18 - 46 - 0 (diammonium phosphate) 5%0 - 20 - 20 4%3 - 9 - 18 4%10 - 10 -10 2%15 - 0 - 15
  • Examples of Fertilizer CalculationsRecommendation:120 Ib N, 60Ib Phosphate, 60 Ibs potash per acre

    Fertilizer Grade: 13 - 13 - 13

    Before Planting60/13% percent = 461 pounds / acre of 13 - 13 - 13 Amount neededAnalysis of source

    Size of Garden : 50 x 20 = 1,000 square feet1 acre = 43, 000 square feet1,000 square feet = 1,000 / 43,000 = 0.023 acres

    Fertilizer needed = 0.023 x 461 pounds per acre = 0.6 Ib

  • Examples of Fertilizer CalculationsRecommendation:120 Ib N, 60Ib Phosphate, 60 Ibs potash per acre

    Fertilizer Grade: 13 - 13 - 13

    SidedressingUse ammonium nitrate (34 - 0 - 0)Amount needed per acre = 60 / 34% = 176 pounds

    Size of Garden = 0.023 acresAmount required for side dressing = 0.023 x 176 = 4 pounds

  • Recommendation:Per 50 ft x 20 ft garden apply 6 pounds of 8 - 8 - 8 at planting and sidedress with 4 pounds of 8 - 8 - 8

    Fertilizer Grade Available: 13 - 13 - 13

    At Planting 6 Ib (expected) x 8 (required) / 13 (available ) = 3.7 Sidedressing

    4 x 8 / 13 = 2.5 Ib, 13 - 13 - 13



View more >