Soil and fertilizer management in vegetable production Dan M. Sullivan Dept. Crop & Soil Science Oregon State University, Corvallis N. Willamette Hort Society Vegetable Day Jan 9, 2018 3:30 pm
Free download. OSU EM 9165.
Practices that maintain soil health Maintain soil organic matter and soil biology Maintain soil ph Maintain nutrient balance
Fate of fresh organic inputs to soil 60-80% of C to air as CO 2 Fresh organic inputs Digestion by soil microbes 10-30% of C fresh soil organic matter Plant-available nutrients (N, P, S...) Figure 2. Sullivan et al. OSU EM 9165.
Adding organic matter to soil is the fuel that drives soil biology Add Organic Matter to soil Soil biology responds Increased or reduced soil borne pests and plant diseases Release of plant-available nutrients Increased soil aggregation, tilth, & water storage Figure 1. Sullivan et al. OSU EM 9165.
Practices to maintain soil organic matter Practice Increase crop biomass Practice Increase crop biomass Increase duration of plant growth Increase duration of plant growth Reduce tillage intensity, frequency, or depth Retain crop residues Reduce tillage intensity, frequency, or depth Retain crop residues Examples of management actions Improve crop management (via soil fertility, planting density, irrigation, etc.) Examples of management actions Improve crop management (via soil fertility, planting density, irrigation, etc.) Plant winter cover crop; rotate to perennial grass, relay, or interseeded Plant winter cover crop; rotate to perennial grass, relay, or interseeded crops Z Consider crops order of tillage intensity: no-till < strip till < disc < rototill Chop residue and leave in place instead of burning or baling Consider order of tillage intensity: notill < strip till < disc < rototill Chop residue and leave in place instead of burning or baling Sullivan et al. OSU EM 9165.
Interseeded cover crop or relay cover crop Nov 6, 2015 Conv. seeding Sept 19 Interseeded V6 July 15 Source: Ed Peachey, OSU
Interseeded cover crop, Aug 30, 2017. OSU Veg. Research Farm, Corvallis
Measuring soil movement Ed Peachey, OSU, Fall 2017 Source: Ed Peachey, OSU
Interseeded in summer Direct seeded in fall Source: Ed Peachey, OSU
Cover Crop Effects on Soil Sediment Loss 600 Oct 24 to Nov 17, 2017 Monroe, OR 500 400 300 200 100 17-Nov-01 13-Nov 24-Oct 0 Fallow Interseeded wheat Conv till fall + cover crop Direct Seed Cover crop Source: Ed Peachey, OSU
Practices that maintain soil health Maintain soil organic matter and soil biology Maintain soil ph Maintain nutrient balance
When is liming needed? Liming is like insurance, you get insurance before you need it Soil ph declines about 0.1 unit per year in medium-textured Willamette Valley soils (e.g. Woodburn silt loam) when fertilized with approximately 100 lb N/acre/yr from N fertilizer So if your ph is 6 today, in ten years with no lime application, ph will be near 5
Lettuce EM 9165
Practices that maintain soil health Maintain soil organic matter and soil biology Maintain soil ph Maintain nutrient balance
P and K removed by harvest Crop Yield P 2 O 5 K 2 O ton/a lb/a Cucumber, slicing 10 10 40 Snap beans, bush 6 15 40 Tomato 12 10 80 Carrots 15 25 100 Broccoli 8 20 110 Peppers, bell 20 30 110 Squash, winter 18 20 120 Onion, bulb 34 50 160 Cabbage 30 55 230 Potatoes 20 60 250 Average (across 16 veg crops) 27 113 From Table 3. Sullivan et al. OSU EM 9165.
Phosphorus recommended based on soil test Table 5. Sullivan et al. OSU EM 9165.
Phosphorus mass balance for beans average for grower fields with Bray soil test P 55 ppm (10 fields) 97 lb P2O5/acre Residues 16 lb/acre 84 lb P2O5/acre 13 lb P2O5/acre Predicted increase of soil test P by ~4-6 ppm A. Heinrich, 2014 report to OVPC
Corn ear yield not increased by starter P in 6 field trials (2012 & 2013) 18 16 0 15 30 60 120 Gross ear yield (ton/a) 14 12 10 8 6 4 93 ppm 108 ppm 81 ppm 77 ppm 42 ppm 135 ppm 2 0 Corvallis I (May 11,2012) Gervais (May 16, 2012) Independence (May 29, 2012) Corvallis II (June 27, 2012) Corvallis I (May 14,2013) Corvallis II (June 3, 2013) Bray soil test P (ppm)
Soil testing
OSU soil test methods https://catalog.extension.oregonstate.edu/sites/catalog/files/project/pdf/ec1478.pdf
Soil test interpretation is based on crop yield response data Plant Response (Relative Yield) marginal medium optimum adequate sufficient high/very high above optimum excessive Relative Yield Yield / Max yield deficient low/very low below optimum Soil test value
Table 4. Sullivan et al. OSU EM 9165.
Key Soil Fertility Testing Concepts 1. Pick a NAPT or ALP certified lab 2. Pick a lab with a good reputation and clean soil test report. 3. Use a lab familiar with soil test methods for Western Region 4. Request correct analysis methods (consult region/extension publication) 5. Don t rely solely on soil test interpretations from lab or from fertilizer dealers. 6. Sample on a routine schedule and keep records.
Labs listed in OSU list of soil testing labs that are enrolled in ALP program in 2017 A&L Western Agricultural Laboratories AgSource Laboratories ALS Environmental Best-Test Analytical Services, LLC Brookside Laboratories, Inc. Edge Analytical Kuo Testing Laboratories, Inc. Magic Valley Labs Soiltest Farm Consultants, Inc. Stukenholtz Laboratory, Inc. Waterlab Corp. Waypoint Analytical California, Inc. Western Laboratories, Inc.
NAPT-labs passing evaluation http://www.naptprogram.org/pap/labs
Nitrogen This presentation: How much, and when does crop take up nitrogen from soil? How much of crop N uptake comes from mineralization of pre-existing soil organic matter? Using a midseason nitrate test (PSNT) to adjust N fertilizer rate
Denitrification N 2 or N 2 O N Cycle Ammonia NH 3 Nitrate NO3 - Plant Uptake Ammonium NH 4 + Leaching Organic Nitrogen
Crop nitrogen uptake patterns 250 Crop N uptake (lb/acre) 200 150 100 50 0 Broccoli Sweet corn Bean Specialty Potato 0 20 40 60 80 100 120 Days from seeding Sullivan et al. OSU EM 9165
Crop N uptake during rapid vegetative growth Crop Growth Stages Days elapsed Crop N uptake (lb/ac) 4 to 6 leaf to Sweet corn silking 30 170 Specialty potato Tuber bulking 60 120 2nd trifoliate leaf Snap bean to harvest 30 105 Broccoli 4 to 6 leaf to harvest 45 160 Sullivan et al. OSU EM 9165
Whole plant biomass on unfertilized sweet corn, conventional fields. N in crop biomass = background soil N mineralization (no N added during the current growing season)
Crop N uptake, sweet corn fields Will. Valley, OR Crop N uptake (kg/ha) 200 Zero N fert 180 Grower N fert 160 140 120 100 80 60 40 20 0 2011 2012 2013 All (n=27)
Pre-sidedress Soil Nitrate Test (PSNT) Sample when corn has 4-6 true leaves Take 12 in. deep soil samples Send soil sample in for analysis immediately Test for nitrate-n If test is > 25 to 30 ppm N, apply minimal or no sidedress N fertilizer
Side-dress N rates based on PSNT soil test When 25+ ppm nitrate-n, apply minimal N to meet crop need.
Conventional N fertilizer management Recent OSU research (Peachey, Heinrich, Sullivan, 2010-13) finding: Pre-sidedress nitrate-n test, taken at V-4 to V-6 accurately predicts sidedress N fertilizer requirement
PSNT trial, ear harvest (2011)
PSNT vs. Ear Yield (2011) Coho Basin OSU recommended PSNT rates
When more sidedress N was applied than recommended by pre-sidedress N test (PSNT) nitrate-n remaining in soil at harvest increased 1 = sidedress N rate based on PSNT test Field 1 Field 2 2011
Conventional N fertilizer management Recent OSU research (Peachey, Heinrich, Sullivan, 2012-15) findings: 1. No improvement in crop N uptake efficiency/crop yield with Enhanced Efficiency N fertilizers vs. urea in sweet corn production 2. Little or no loss of N as ammonia gas following broadcast application of urea to soil surface (so incorporation of N fertilizer is not a big issue) 3. Preplant soil test for mineralizable N was not well correlated with actual N mineralization in field trials.
Free download. OSU EM 9165.
Dan.Sullivan@oregonstate.edu Extension publications, free download (pdf): https://catalog.extension.oregonstate.edu/
Bonus slides: N mineralization from soil organic matter
Baseline N already included in N fertilizer response trials that were used to determine OSU recommendations Crop N uptake (lb/acre) Crop N uptake with no N fertilizer applied is "background" N mineralized Nitrogen fertilizer rate (lb per acre)
Baseline N mineralization N mineralization from Relatively stable soil organic matter Doesn t include current season inputs (cover crop or other organic amendment) Baseline N mineralization is already included (indirectly) in OSU fertilizer/nutrient mgmt. guide recommendations
Soil N mineralization verification zero N fertilizer field plots in conventional sweet corn (with E. Peachey, A. Heinrich) 27 fields, 2011-13 Overhead irrigation applied throughout growing season So, soil moisture not limiting mineralization process
Whole plant biomass on unfertilized sweet corn, conventional fields. N in crop biomass = background soil N mineralization (no N added during the current growing season)
Crop N uptake, sweet corn fields Will. Valley, OR Crop N uptake (kg/ha) 200 Zero N fert 180 Grower N fert 160 140 120 100 80 60 40 20 0 2011 2012 2013 All (n=27)
Crop N uptake from soil N mineralization conventional sweet corn Willamette Valley, OR 2011-13. sandy loam, silt loam, silty clay loam soils Crop N uptake Zero N fertilizer kg/ha 99* Grower N fertilizer kg/ha 156* Soil Total N % 0.15 Organic matter % 2.9 Total N (0-30 cm) kg/ha 5850 Soil N mineralized/crop Soil Nmin estimate % of soil N 1.7 N supplied by N mineralization zero N/grower N* 0.66
Corn N uptake (lb N/acre) 180 160 140 120 100 80 60 40 20 N uptake by conventional sweet corn (no N fertilizer applied) N min = 70 to 120 lb N/acre 1 3 5 7 9 11 13 15 17 19 21 23 25 Field ID Sullivan et al. OSU EM 9165