Fertility aspects of green pea production Lyndon Porter, Research Plant Pathologist, USDA-ARS Rich Koenig, Extension Soil Fertility Scientist, WSU Clive Kaiser, Extension Educator, Oregon State University
Some context Little published green pea fertility research Short season crop so nutrient access and timing is important Relatively low nutrient demand Some important nutrients
Topics Benefits of peas in a rotation Fertilizing peas Survey of recommendations Soil testing Tissue testing Data from recent green pea studies in the Milton-Freewater area
Nitrogen fertility benefits Small nitrogen credit attributed to grain legume residues Previous crop and dry yield Peas >2500 lb/acre Peas 1500 to 2500 lb/acre Peas <1500 lb/acre Lentils >1000 lb/acre Alfalfa Credit (lb N/acre) 20 15 10 10 50
Rotational benefits (dry peas) Recent studies at the Cook Agronomy Farm (data from Dave Huggins, USDA-ARS Pullman) Altering the standard 3-year rotation Winter wheat spring wheat spring pea Winter wheat spring pea spring wheat Hard red winter and spring wheat emphasize protein No-till system where erosion is minimal over winter in pea residue
Rotational benefits (dry peas) Beyond nitrogen Hard Red Spring Wheat Previous crop* Canola Barley Peas Yield (bu/ac) 68 73 75 % Protein 13.5 13.0 14.0 *Nitrogen management adjusted for previous crop
Rotational benefits Disease cycles Improved rooting and nutrient (nitrogen) uptake Residue issues less when a spring crop follows peas Impacts on soil temperature Other (unexplained) Seriously underestimated
Further rotational benefits Green vs. dry peas Dryland: estimated 20% higher yield of winter wheat after green pea compared to winter wheat after dry pea Moisture effect Additional nitrogen credit from green peas More N left in the field with green peas about 2x that of dry peas
Fertilizing green peas Caveat: little fertility research on green peas
Dry pea fertility Oregon State University, Commercial Vegetable Production Guide for Processing Peas in Eastern Orgeon. http://hort-devel-nwrec.hort.oregonstate.edu/pea-e.html Emphasize 15 to 20 lb N/A banded with P and possibly K at planting. 40 to 75 lb P205/A can be drilled with the seed. Soil test is 0-10 P = 40 to 120, 10-20 = 0-60 P, over 20 = none. Potassium Soil test 0-75 = 90-120 lb/a 75-150 = 60-90 lb/a 150-200 = 40-60 Over 200 = None Sulfur 20-30 lb/a, in the form of sulfate at planting. Responses of peas to other nutrients not observed.
Dry pea fertility University of Idaho fertility guides authored by R. Mahler http://www.uidaho.edu/wq/wqfert/wqfertls.html Emphasize Inoculation for fields without a history of same legume in last 3 years, or ph below 5.7 Soil test for phosphorus, sulfur, zinc and boron Molybdenum when ph < 5.7 (seed treatment)
Phosphorus recommendations Soil test P (ppm) 0 to 12-inch depth Acetate method Bicarbonate method Application rate lb P 2 O 5 /acre 0 to 2 2 to 3 3 to 4 4 to 6 Above 6 0 to 8 8 to 10 10 to 12 12 to 18 Above 18 60 40 20 10-20 0* *Starter applications may still be beneficial for spring-seeded legumes (cold soils)
Sulfur recommendation Below 10 ppm SO 4 -S, 15 to 20 lb S/acre
Boron and molybdenum High rainfall environments (>20 inches) Low ph (5.7 or below) soils Boron soil test below 0.5 ppm ½ to 1 lb boron/acre broadcast, not banded Molybdenum 1 oz/acre as seed treatment
Element Nitrogen Tissue testing 50 most recently developed leaflets at first bloom Phosphorus Potassium Sulfur Zinc Boron Iron Manganese Molybdenum Copper Source: Plant Analysis Handbook II (1996) Micro-Macro Publishing Sufficiency range 4 to 5% 0.3 to 0.8% 2.0 to 3.5% 0.2 to 0.3% 25 to 400 ppm 5 to 60 ppm 50 to 300 ppm 25 to 400 ppm >0.6 ppm 7 to 100 ppm
Fertilizer placement for legumes No nitrogen, potassium or sulfur with the seed (soluble fertilizers reduce germination) Small amounts of phosphorus (<10 lb P 2 O 5 /ac) with the seed are okay Ideal placement is below or below and beside the seed
Rooting patterns and starter and deep band fertilizer placements Wheat Peas Secondary root system Primary root systems
Recent fertility studies Dryland green peas in Milton-Freewater area 2005, 2007 study years (2006 crop failed) Pre-plant soil tests collected Representative of dryland green pea fields N, P, S, B, Zn treatments
2005 green pea fertility trial soil test results (1 foot depth) Parameter Soil ph Phosphorus Potassium Sulfur Zinc Boron Iron Manganese Copper Average of 4 samples 5.5 22 ppm 360 ppm 3 ppm 1.7 ppm 0.18 ppm 49 ppm 27 ppm 1.5 ppm Interpretation Borderline for peas (>5.5) Adequate for peas (>18) Adequate for peas (>100) Very low for peas (>10) Adequate for peas (>1.0) Very low for peas (>0.5) Adequate for peas (>5) Adequate for peas (>1) Adequate for peas (>0.2)
2007 green pea fertility trial soil test results (1 foot depth) no-till site Parameter Soil ph Phosphorus Potassium Sulfur Zinc Boron Iron Manganese Copper Average of 4 samples 5.6 16 ppm 492 ppm 4 ppm 1.15 ppm 0.29 ppm 43 ppm 36 ppm 1.3 ppm Interpretation Borderline for peas (>5.5) Adequate for peas (>18) Adequate for peas (>100) Very low for peas (>10) Adequate for peas (>1.0) Very low for peas (>0.5) Adequate for peas (>5) Adequate for peas (>1) Adequate for peas (>0.2)
2007 green pea fertility trial soil test results (1 foot depth) conventional site Parameter Soil ph Phosphorus Potassium Sulfur Zinc Boron Iron Manganese Copper Average of 4 samples 5.5 18 ppm 422 ppm 5 ppm 0.38 ppm 0.27 ppm 43 ppm 38 ppm 1.5 ppm Interpretation Borderline for peas (>5.5) Adequate for peas (>18) Adequate for peas (>100) Very low for peas (>10) Very low for peas (>1.0) Very low for peas (>0.5) Adequate for peas (>5) Adequate for peas (>1) Adequate for peas (>0.2)
Yield (lb/ac) 3000 2500 2000 1500 1000 500 0 Unfertilized 2005 green pea yields 2230 2317 Fertilizer banded 2 inches below the seed row Phostrol 2561 2561 2579 11-52-0 OSU 11-37-0+2 lb Zinc 11-37-0 Treatment (20 lb P 2 O 5 /ac) Pre-season soil test showed below adequate levels 11-37-0+0.25 lb boron * * 2718 2788 16-20-0-13S *different from unfertilized
2007 green pea yields (no-till) 5000 4000 3746 3659 3000 2000 1000 * * * * 3920 3920 4007 4147 4321 4356 4513 Yield (lb/ac) 0 Unfertilized K-silicate 11-52-0 Boron/urea 11-37-0 11-37-0 + 0.25 lb B 16-20-0-13S 11-37-0 + Phostrol 11-37-0 + 2 lb Zinc Fertilizer banded 2 inches below the seed row Treatment (20 lb P 2 O 5 /ac) *different from unfertilized
2007 green pea tenderometer (no-till) 95 91.2 90.8 90.8 90.7 90 90.3 90.2 89.9 89.8 85 * 86.9 Tenderometer 80 Unfertilized Phostrol 11-37-0 +K silicate 11-37-0+2 lb Zinc 11-37-0+0.25 lb boron 11-52-0 11-37-0 + Boron/Urea 11-37-0 16-20-0-13S Fertilizer banded 2 inches below the seed row Treatment (20 lb P 2 O 5 /ac) *different from unfertilized
2007 green pea yields (conventional till) 6000 5000 4000 3000 2000 1000 4339 4339 4391 4461 4547 4826 3711 3851 3938 Yield (lb/ac) 0 Unfertilized 11-37-0+0.25 lb boron K-silicate 11-52-0 16-20-0-13S 11-37-0+2 lb Zinc 11-37-0 Phostrol Boron/Urea Fertilizer banded 2 inches below the seed row Treatment (20 lb P 2 O 5 /ac) *different from unfertilized
2007 green pea tenderometer (Conventional) 90 85.6 86 85.4 85.3 85 84.9 85 * 84.1 * * 83.8 83.8 Tenderometer 80 Unfertilized Phostrol 11-37-0 +K silicate 11-37-0 + Boron/urea 11-37-0+ 2.0 lb zinc 11-37-0 16-20-0-13S 11-52-0 11-37-0 + 0.25 Boron Fertilizer banded 2 inches below the seed row Treatment (20 lb P 2 O 5 /ac) *different from unfertilized
2005 Green Pea Root Disease (Conventional) 5 4 3.35 3 2 1 * * 3.68 3.66 3.52 3.51 * 3.27 3.13 Root disease 0 Unfertilized 16-20-0-13S 11-52-0 11-37-0 + 0.25 lb B 11-37-0 + 2.0 lb zinc 11-37-0 11-37-0 + Phostrol Fertilizer banded 2 inches below the seed row Treatment (20 lb P 2 O 5 /ac) *different from unfertilized
2007 Green Pea Root Disease (Conventional) 5 4 3 2.41 2 1 * 2.66 * * 2.45 2.38 2.37 2.3 2.23 2.23 * 1.65 Root disease 0 Unfertilized 11-52-0 K-silicate 11-37-0 + 2 lb Zinc 11-37-0 Boron/urea 11-37-0 + 0.25 lb B 16-20-0-13S 11-37-0 + Phostrol Fertilizer banded 2 inches below the seed row Treatment (20 lb P 2 O 5 /ac) *different from unfertilized
2007 Green Pea Root Disease (no-till) 5 4 3 2 1 * * * * * 2.13 2.17 2.03 1.98 1.97 1.96 1.89 1.84 1.7 Root disease 0 Unfertilized 11-52-0 11-37-0 + 0.25 lb B Boron/urea 16-20-0-13S 11-37-0 + 2 lb Zinc 11-37-0 K-silicate 11-37-0 + Phostrol Fertilizer banded 2 inches below the seed row Treatment (20 lb P 2 O 5 /ac) *different from unfertilized
Summary from fertility studies Evidence of responses to sulfur and perhaps boron; occasionally zinc and phosphorus Broadcast applications of boron, not banded The preplant soil test predicted a fertilizer response in most situations Phostrol and 16-20-0-13S limited root disease