ORGANIC VEGETABLE NUTRIENT MANAGEMENT Headwaters Incubator Program April 6 th, 2016 Nick.andrews@oregonstate.edu (503) 913-9410
Organic nutrient management topics Soil sampling Soil ph and lime P & K sufficiency levels Crop N requirements PAN from soil organic matter PAN from cover crops PAN from fertilizers
Soil Sampling for ph & nutrients For Home Gardens & Small Acreages (EC 628) 15-20 soil cores per area Sample 6-8 deep, 12 for nitrate Mix samples in clean bucket, remove organic layer & submit ~1 cup to a lab
SOIL PH IS IMPORTANT TO PLANT GROWTH no lime lime As shown by alfalfa growth from David Swanson s field in Lane County during 1926 Courtesy John Hart, OSU Crop & Soil Science
ph Scale acid or alkaline? 1, 10, 100, 1000, instead of 1, 2, 3, 4 Courtesy John Hart, OSU Crop & Soil Science
Courtesy John Hart, OSU Crop & Soil Science
Moderate buffer ph preferred by most plants (6-8) Nutrient availability Microbial growth Aluminum toxicity Heavy metal mobility
Yield, t/a 6 Soil ph and Alfalfa Yield 3 0 5.5 6 6.5 Soil ph Courtesy John Hart, OSU Crop & Soil Science
Soil ph: SMP Buffer or lime requirement OSU sweet corn nutrient management guide for W. Oregon (EM 9010-E)
Macro-nutrient results come back in ppm Dan Sullivan, OSU Extension
Veg Nutrient Management Guides (P) OSU sweet corn nutrient management guide for W. Oregon (EM 9010-E)
Veg Nutrient Management Guides (K) OSU sweet corn nutrient management guide for W. Oregon (EM 9010-E)
Nitrogen & phosphorus CROP UPTAKE (lbs/ac) N P 2 O 5 K 2 O beans 100 40 150 cabbage 220 75 300 carrot 140 50 170 cauliflower 220 90 300 cucumber 110 45 110 onion 160 45 140 radish 100 50 100 tomato 160 60 170 peas 100 40 70 Mean 146 55 168 Mean nutrient ratio 2.6 1.0 3.1 PAN P 2 O 5 K 2 O Vegetable crop 150 60 170 3.5 tons chicken manure 145 210 210 ORGANIC AMENDMENTS (%) Total N P 2 O 5 K 2 O Dairy manure & bedding 0.5 0.2 0.5 Poultry manure & litter 2.8 2.3 1.7 Pelleted chicken manure 4.0 3.0 3.0 Composted poultry manure 0.9 2.0 1.2 Composted dairy manure 0.6 0.6 1.3 Mean 1.7 1.6 1.5 Mean nutrient ratio 1.1 1.0 1.0 Low P options Specialty Products Total N P 2 O 5 K 2 O Feather meal 12.0 0.0 0.0 Blood meal 12.0 0.0 0.0 Fish meal 10.0 6.0 2.0 Soybean meal 7.0 2.0 1.0 Sulfate of potash 0.0 0.0 22.0 Muriate of potash 0.0 0.0 60.0 Bone meal 2.0 15.0 0.0 Rock phosphate 0.0 2.0 0.0 Legume cover crop 3.0 - -
Fertilizer Labels N P K 3 2 2 Total N NOT available N Available phosphate (P 2 O 5 ) Available potash (K 2 O)
Questions?
Step-by-step guide to determining an organic nitrogen fertilizer rate: Steps Information source Broccoli 1 General crop nitrogen recommendation 2 3 4 5 6 University nutrient management guides 200lbs PAN/ac
Crop N requirement
Steps Information source Broccoli 1 General crop nitrogen recommendation 2 Additional soil organic matter contribution 3 4 5 6 Step-by-step guide to determining an organic nitrogen fertilizer rate: University nutrient management guides Estimate from previous soil building practices 200lbs PAN/ac
Types of Soil Organic Matter Pool Biologically Active Protected Stable Size/Age (years) Small 1-5 Intermediate 5-30 Large 50-10,000 Functions Meat: nutrient mineralization, macroaggregation, disease suppression Bones: soil structure, porosity, water relations Micro-aggregation, CEC, fate of compounds, color
Cumulative PAN from an organic source Year 1 = available N 2 + 3 + + 4 + + + 5 + + + + Courtesy of Dan Sullivan OSU Crop & Soil Science
Organic equilibrium When shifting from conventional to Organic (greater organic inputs) Soil fertility (N, P, K etc.) increases over time when nutrient inputs > outputs (harvest removal) MAINTENANCE PHASE SOIL BUILDING PHASE 2-4 years or more
PAN from soil organic matter Make pre-plant estimate based on field/farm history, rotation, etc. Ballpark estimate: after 3 years of organic management with increased organic inputs, PAN from soil organic matter will increase by at least 50 lb N/acre Established organic growers can often credit much more than 50lb N/ac from soil N mineralization Monitor soil nitrate in growing season (PSNT timing) and crop performance (>25-30ppm NO 3 -N) Monitor postharvest soil nitrate (<20 ppm NO 3 -N?) Adjust N mineralization credit for future years
Questions? Field history and your soil building practices?
Steps Information source Broccoli 1 General crop nitrogen recommendation 2 Additional soil organic matter contribution 3 Cover crop nitrogen contribution 4 5 6 Step-by-step guide to determining an organic nitrogen fertilizer rate: University nutrient management guides Estimate from previous soil building practices OSU Organic Fertilizer & Cover Crop Calculator 200lbs PAN/ac 50lbs PAN/ac
Cover Crop Species Legumes: clovers, vetches, peas, beans Fix atmospheric N with Rhizobia Put on most biomass in the spring Provide flowers Grasses: oats, rye, wheat, triticale Scavenge soil N in the fall Provide C and build O.M. Non-legume broadleaf crops Scavenge soil N Provide C and build O.M. Provide flowers
Four ways to time cover crops Cover crop Main crop After perennial cover Main crop Cover crop Main crop Winter cover Main crop Cover crop Main crop Relay seeded Main crop Cover crop Main crop Cover crop Summer cover January July January July January Adapted from Building Soils for Better Crops, F. Magdoff & H van Ess,
Common vetch Cereal rye Crimson clover Barley Sudex (summer) Buckwheat (summer) Annual ryegrass
http://www.mokkka.hu/drupal/en/node/2901 Rhizobium in nodules Fix atmospheric N at room temperature & normal atmospheric pressure Häber Bosch process fixes N at about 400 C and 200 atm. Fertilizer use represents about 29% of energy use in US ag. (Miranowski, 2004: http://www.farmfoundation.org/rojects/03-35energyconferencepresentations.htm)
Cover crop sampling
1. Mix sample to break up large plants and remove soil 2. Record fresh weight of field sample (x.xlb) 3. Package to avoid wilting or molding
Submit fresh sample to lab 1. % dry matter 2. total % N analysis Ask lab to dry and grind whole sample
Denitrification N 2 or N 2 O N Cycle Ammonia NH 3 Nitrate NO3 - Plant Uptake Ammonium NH 4 + Leaching Organic Nitrogen Courtesy of Dan Sullivan OSU Crop & Soil Science
Nitrogen Availability Low N = Immobilization ~2% total N High N = Mineralization Mineral N is converted to Organic N Organic N is converted to Mineral N Microbes have ~10:1 C:N ratio
Cover Crop PAN
Cover crop PAN (PNW 636) Cover Crops tested at mid vegetative and flowering GS Oats Cereal Rye Phacelia Common Vetch Crimson Clover Soils tested: Amity silt loam (Mollic), Aloha silt loam, Canderly sandy loam
Cover crop PAN: PNW 636
PAN from tops vs. roots Legume cover crop C:N ratio Total N addition (lb/ac) Top Root Top Root Austrian winter pea (1992) 14 28 76 13 Austrian winter pea (1993) 10 24 35 13 Hairy vetch (1992) 23 30 99 8 Hairy vetch (1993) 10 29 120 8 Adapted from: Kuo et al. (1997) SSSAJ 61:1392-1399. Mineralization / immobilization tipping point 20-24 C/N
Questions?
Steps Information source Broccoli 1 General crop nitrogen recommendation 2 Additional soil organic matter contribution 3 Cover crop nitrogen contribution 4 Site specific nitrogen recommendation 5 Fertilizer PAN estimate & fertilizer application rate 6 University nutrient management guides Estimate from previous soil building practices OSU Organic Fertilizer & Cover Crop Calculator 200lbs PAN/ac 50lbs PAN/ac 80lbs PAN/ac Line 1 line 2 line 3 200-50-80=70 OSU Organic Fertilizer & Cover Crop Calculator
Fertilizer N Mineralization 120 Calculator 120 Full Season PAN (% of amendment N) 100 80 120 Calculator 60 100 full-season estimate 40 80 60 40 20 0 20 0 full-season estimate 0 2 4 6 8 10 12 14 16 Amendment Total N (%) Amendment Total N (%) 0 2 4 6 8 10 12 14 16 Broiler litter Dairy solids Rabbit manure Yard trimmings Specialty products Gale et al. (2006). J Env Qual 35:2321-2332 PAN (% of amendment N) 100 Broiler 80 litter Dairy solids Rabbit 60 manure Yard trimmings Specialty 40 products 20 0-20 Specialty Products include Calculator predicted full season Calculator predicted 28 days 0 2 4 6 8 10 12 14 16 Amendment Total N (%) Fish meals Alfalfa meal Fish bone meal Soybean meal Blood meal Meat & bone meal Corn gluten meal Kelp meal Bone meal Feather meal Sol. Seaweed Extract Seabird guano
Nutrients Provided
Steps Information source Broccoli 1 General crop nitrogen recommendation 2 Additional soil organic matter contribution 3 Cover crop nitrogen contribution 4 Site specific nitrogen recommendation 5 Fertilizer PAN estimate & fertilizer application rate 6 Adjust nitrogen rates based on monitoring University nutrient management guides Estimate from previous soil building practices OSU Organic Fertilizer & Cover Crop Calculator 200lbs PAN/ac 50lbs PAN/ac 80lbs PAN/ac Line 1 line 2 line 3 200-50-80=70 OSU Organic Fertilizer & Cover Crop Calculator Soil tests and observations of crop performance 1700lbs ch manure + 500lbs feath meal Use a soil probe
Monitor soil nitrate-n (12 depth) Early season plantings (May June): Pre side-dress nitrate test for spring and early summer planted crops Just before period of rapid N-uptake Mid to late season plantings (July Sept): Pre plant nitrate test 25-30ppm NO 3 -N is sufficient during early crop growth sidedress or top dress if needed
End of season nitrate-n (12 ) Around time of harvest, before winter rain NO 3 -N (ppm) Low <10 Medium 10-20 High 20-30 Excessive >30
Don t forget about other nutrients if they are deficient: Boron is often deficient Mg & Zn are sometimes
Questions?
ORGANIC VEGETABLE NUTRIENT MANAGEMENT Evergreen State College April 5 th, 2016 Nick.andrews@oregonstate.edu (503) 913-9410