ORGANIC VEGETABLE NUTRIENT MANAGEMENT

Transcription

1 ORGANIC VEGETABLE NUTRIENT MANAGEMENT Headwaters Incubator Program April 6 th, 2016 Nick.andrews@oregonstate.edu (503)

2 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

3 Soil Sampling for ph & nutrients For Home Gardens & Small Acreages (EC 628) 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

4 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

5 ph Scale acid or alkaline? 1, 10, 100, 1000, instead of 1, 2, 3, 4 Courtesy John Hart, OSU Crop & Soil Science

6 Courtesy John Hart, OSU Crop & Soil Science

7 Moderate buffer ph preferred by most plants (6-8) Nutrient availability Microbial growth Aluminum toxicity Heavy metal mobility

8 Yield, t/a 6 Soil ph and Alfalfa Yield Soil ph Courtesy John Hart, OSU Crop & Soil Science

9 Soil ph: SMP Buffer or lime requirement OSU sweet corn nutrient management guide for W. Oregon (EM 9010-E)

10 Macro-nutrient results come back in ppm Dan Sullivan, OSU Extension

11 Veg Nutrient Management Guides (P) OSU sweet corn nutrient management guide for W. Oregon (EM 9010-E)

12 Veg Nutrient Management Guides (K) OSU sweet corn nutrient management guide for W. Oregon (EM 9010-E)

13 Nitrogen & phosphorus CROP UPTAKE (lbs/ac) N P 2 O 5 K 2 O beans cabbage carrot cauliflower cucumber onion radish tomato peas Mean Mean nutrient ratio PAN P 2 O 5 K 2 O Vegetable crop tons chicken manure ORGANIC AMENDMENTS (%) Total N P 2 O 5 K 2 O Dairy manure & bedding Poultry manure & litter Pelleted chicken manure Composted poultry manure Composted dairy manure Mean Mean nutrient ratio Low P options Specialty Products Total N P 2 O 5 K 2 O Feather meal Blood meal Fish meal Soybean meal Sulfate of potash Muriate of potash Bone meal Rock phosphate Legume cover crop

14 Fertilizer Labels N P K Total N NOT available N Available phosphate (P 2 O 5 ) Available potash (K 2 O)

15 Questions?

16 Step-by-step guide to determining an organic nitrogen fertilizer rate: Steps Information source Broccoli 1 General crop nitrogen recommendation University nutrient management guides 200lbs PAN/ac

17 Crop N requirement

18 Steps Information source Broccoli 1 General crop nitrogen recommendation 2 Additional soil organic matter contribution Step-by-step guide to determining an organic nitrogen fertilizer rate: University nutrient management guides Estimate from previous soil building practices 200lbs PAN/ac

19 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

20 Cumulative PAN from an organic source Year 1 = available N Courtesy of Dan Sullivan OSU Crop & Soil Science

21 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

22 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

23 Questions? Field history and your soil building practices?

24 Steps Information source Broccoli 1 General crop nitrogen recommendation 2 Additional soil organic matter contribution 3 Cover crop nitrogen contribution 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

25 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

26 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,

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28 Common vetch Cereal rye Crimson clover Barley Sudex (summer) Buckwheat (summer) Annual ryegrass

29 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:

30 Cover crop sampling

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32 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

33 Submit fresh sample to lab 1. % dry matter 2. total % N analysis Ask lab to dry and grind whole sample

34 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

35 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

36 Cover Crop PAN

37 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

38 Cover crop PAN: PNW 636

39 PAN from tops vs. roots Legume cover crop C:N ratio Total N addition (lb/ac) Top Root Top Root Austrian winter pea (1992) Austrian winter pea (1993) Hairy vetch (1992) Hairy vetch (1993) Adapted from: Kuo et al. (1997) SSSAJ 61: Mineralization / immobilization tipping point C/N

40 Questions?

41 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 =70 OSU Organic Fertilizer & Cover Crop Calculator

42 Fertilizer N Mineralization 120 Calculator 120 Full Season PAN (% of amendment N) Calculator full-season estimate full-season estimate Amendment Total N (%) Amendment Total N (%) Broiler litter Dairy solids Rabbit manure Yard trimmings Specialty products Gale et al. (2006). J Env Qual 35: PAN (% of amendment N) 100 Broiler 80 litter Dairy solids Rabbit 60 manure Yard trimmings Specialty 40 products Specialty Products include Calculator predicted full season Calculator predicted 28 days 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

43 Nutrients Provided

44 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 =70 OSU Organic Fertilizer & Cover Crop Calculator Soil tests and observations of crop performance 1700lbs ch manure + 500lbs feath meal Use a soil probe

45 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

46 End of season nitrate-n (12 ) Around time of harvest, before winter rain NO 3 -N (ppm) Low <10 Medium High Excessive >30

47 Don t forget about other nutrients if they are deficient: Boron is often deficient Mg & Zn are sometimes

48 Questions?

49 ORGANIC VEGETABLE NUTRIENT MANAGEMENT Evergreen State College April 5 th, 2016 Nick.andrews@oregonstate.edu (503)