1. Soil Fertility Montana Small Grain Guide pages 35-42

2. Essential Elements Nutrients from Air and Water:Nutrients from Air and Water: Carbon, Hydrogen, Oxygen CHO Carbon, Hydrogen, Oxygen CHO Primary Nutrients:Primary Nutrients: Nitrogen, Phosphorus, Potassium NPK Nitrogen, Phosphorus, Potassium NPK Secondary Nutrients:Secondary Nutrients: Sulpher, Calcium, Magnesium SCaMg Sulpher, Calcium, Magnesium SCaMg Micronutrients:Micronutrients: zinc, iron, magnanese, copper, boron, molybdenum, chlorine

3. Essential Nutrients C HOPKNS CaFe Mg B Mn CuZn ClMoC HOPKNS CaFe Mg B Mn CuZn ClMo See Hopkins Café Managed By Mine Cousin ClomoSee Hopkins Café Managed By Mine Cousin Clomo

4. Soil Fertility Harvesting crops removes nutrients from the soilHarvesting crops removes nutrients from the soil Chemical fertilizer, animal waste, sewage sludgeChemical fertilizer, animal waste, sewage sludge

5. Nutrient Deficiencies Visual symptoms can give a clue to deficienciesVisual symptoms can give a clue to deficiencies Tissue analysis: identify shortagesTissue analysis: identify shortages At this time it is usually too late to correctAt this time it is usually too late to correct

6. Soil Testing Availability of nutrients in soilAvailability of nutrients in soil Soil sample collectionSoil sample collection Lab analysisLab analysis Interpretation of test resultsInterpretation of test results RecommendationRecommendation

7. Soil Sampling Collect at least 20 subsamples to 6” depth for standard soil testsCollect at least 20 subsamples to 6” depth for standard soil tests Nitrogen: test 6-12”, 12-24”, 24-48”Nitrogen: test 6-12”, 12-24”, 24-48” Avoid areas not representative of fieldAvoid areas not representative of field Place subsamples in clean plastic bucketPlace subsamples in clean plastic bucket Mix samples, select approx. one cup in plastic bagMix samples, select approx. one cup in plastic bag

8. Soil Sampling Mail with name, field ID, depth of test, information sheetMail with name, field ID, depth of test, information sheet Nitrate test: samples must be dried or frozen immediately after collectionNitrate test: samples must be dried or frozen immediately after collection –prevent soil organisms from converting organic N to nitrate

9. Interpretation Must consider:Must consider: -crop nutrient requirements -crop nutrient requirements -expected yield -expected yield -cropping history -cropping history -tillage & residue mgmt techniques -tillage & residue mgmt techniques

10. Nitrogen Wheat & Barley take up Nitrogen in the ammonium (NH 4 ) and nitrate (NO 3 )Wheat & Barley take up Nitrogen in the ammonium (NH 4 ) and nitrate (NO 3 ) Most nitrogen in soil is tied up in the organic matterMost nitrogen in soil is tied up in the organic matter 1-3% becomes available to the crop each year by microorganisms1-3% becomes available to the crop each year by microorganisms Mineralization: Organic matter breaks down to ammonium (NH 4 )Mineralization: Organic matter breaks down to ammonium (NH 4 )

11. Nitrogen Nitrification: ammonium is converted to (NO 3 )Nitrification: ammonium is converted to (NO 3 ) Soil temps below 40 deg., nitrification is very slowSoil temps below 40 deg., nitrification is very slow Nitrate is very mobile, moves readily with water (Leaching)Nitrate is very mobile, moves readily with water (Leaching) Ammonium is attracted to the clay minerals and organic matterAmmonium is attracted to the clay minerals and organic matter

12. Nitrogen Budget ¶ Determine realistic yield goal · Determine crop Nitrogen requirement -yield goal x constant -wheat = 2.5 -barley = 1.8 ¸ Subtract soil test N from total N requirement

13. Nitrogen Budget ¹ Add 20# for each ton of residue incorporated just before planting -1 bu. Yield = 100# of straw º Subtract 30# if alfalfa was previous crop » Subtract 8# for each ton of manure ¼ Remainder is N fertilizer requirement

14. Nitrogen Budget Example: Goal is 30 bu/ac of Spring WheatGoal is 30 bu/ac of Spring Wheat Tests show soil has 30#/acreTests show soil has 30#/acre Previous crop yield was 20 bu/acPrevious crop yield was 20 bu/ac Add 10 tons of manure/acAdd 10 tons of manure/ac How much N should be added?How much N should be added? ((30 x 2.5)-30)+20-80=-15((30 x 2.5)-30)+20-80=-15 Do not need to add NDo not need to add N

15. Timing of Fertilizer Application Small grains take up most of their Nitrogen early in the growing seasonSmall grains take up most of their Nitrogen early in the growing season Nitrogen applied after tillering usually won’t affect yieldNitrogen applied after tillering usually won’t affect yield