ANNUAL REPORT Relative Effectiveness of Various Amendments in Preventing Nutrient Deficiencies under Organic Crop Production

Transcription

1 ANNUAL REPORT 2010 Relative Effectiveness of Various Amendments in Preventing Nutrient Deficiencies under Organic Crop Production Sukhdev S. Malhi Agriculture and Agri-Food Canada, Research Farm, P.O. Box 1240, Melfort, Saskatchewan S0E 1A0 Phone: Ext. 230; Fax: ; Reynald L. Lemke Agriculture and Agri-Food Canada, Research Centre, Saskatoon, Saskatchewan Prepared for Western Alfalfa Milling Co. Ltd. 1

2 Relative Effectiveness of Various Amendments/Practices in Preventing Nutrient Deficiencies under Organic Crop Production Abstract: In organic farming, inorganic fertilizers/chemicals are not applied to increase crop yields, but adequate amounts of nutrients are essential for sustainable production from agricultural crops. Field experiments were established in 2008 at Naicam (Experiment 1; Thin Black Chernozem, potentially P deficient) and Star City (Experiment 2; Gray Luvisol, potentially S deficient) in northeastern Saskatchewan to determine the feasibility of organic amendments (compost, alfalfa pellets, wood ash, rock phosphate, Penicillium bilaiae, MykePro, gypsum) and/or management practices (intercropping barley or canola with pea) in improving yield and nutrient uptake in organic crops. In 2010, there was a substantial seed yield benefit of barley from the use of compost and alfalfa pellets, and moderate increase in seed yield of barley from wood ash compared to unamended control in both experiments. Compared to the unamended control, seed yield of barley tended to be higher with rock phosphate and/or Penicillium bilaiae in Experiment 1, but no beneficial effect of MykePro on seed yield in both experiments. There was no increase in seed yield of barley from gypsum, used only in Experiment 2 on a potentially S-deficient soil. In the barley-pea intercrop field treatments, seed yield improved with barley-pea intercropping compared to both barley or pea sole crops in Experiment 1, but not in Experiment 2. Rationale: The interest and demand for organically-grown food and fibre products are increasing in Canada and internationally, because of the price premiums on organically-grown products. In organic farming, inorganic fertilizers/chemicals are not applied to increase crop production. Adequate amounts of nutrients are essential for sustainable production from agricultural crops. Any nutrient (s) limiting in soil can cause substantial reduction in crop yield. In the Prairie Provinces, most soils are deficient in available N for optimum yield. There are many soils low in available P, and some soils contain insufficient amounts of S and K for high crop yields. The N deficiency in soil on organic farms can be corrected by growing N-fixing legume crops in the rotations. However, if soils are deficient in available P, K or S, the only alternative is to use external sources to prevent these nutrient deficiencies. Manure/compost can provide these nutrients, but usually there is not enough manure to apply on all farm fields, particularly in remote areas because of the cost of transporting manure long distances. On such soils, rock phosphate fertilizer, gypsum, elemental S fertilizer, alfalfa pellets or wood ash (wood ash, waste product of industry, contains about 0.4% P, 4% K, 1% S, and lots of Ca and Mg) as a source of P, S or K can be used to correct deficiencies of these nutrients. The information on the feasibility of these products in preventing nutrient deficiencies under organic farming is lacking under prairie soil-climatic conditions and in other parts of Canada. Objectives: To determine the feasibility of: Penicillium bilaiae on the release of available P from rock phosphate fertilizer in preventing P deficiency on P-deficient soils; gypsum fertilizer in preventing S deficiency on S-deficient soils; wood ash in preventing P, K or S deficiency in P, K or S-deficient soils; and compost and alfalfa pellets in preventing N, P, K or S deficiency in N, P, K or S-deficient soils on organic crops. 2

3 Potential Benefits: The studies on Penicillium bilaiae, rock phosphate, gypsum, compost, alfalfa pellets and wood ash will determine if these amendments can be used to prevent deficiency of P, K or S in crops grown on soils deficient in these nutrients under organic farming systems. The findings will increase the sustainability of crop production by improving nutrient use and water use efficiency through better plant and root growth. This will result in higher net returns to producers as well as improving soil quality by returning more residues to soil. This will also minimize environmental damage of nitrate-n (leaching to ground water and nitrous oxide emissions) by leaving less residual nitrate-n in soil. Materials and Methods: Two 3-year ( wheat, 2009 pea, and barley) field experiments were established in spring During the summer of 2007, the land was managed as tilled fallow in Experiment 1 at Naicam, and as green manure fallow in Experiment 2 at Star city. Some characteristics of soils used in these experiments are presented in Table 1. Precipitation in the growing season (May, June, July and August) at the two sites and at the nearest Environment Canada Meteorological Station (AAFC Melfort Research Farm) is given in Table 2. The precipitation in the 2010 growing season was above average at both sites, and the season can be described as wet and cool. A randomized complete block design was used to lay out the treatments in four replications. Each plot was 7.5 m long and 1.8 m wide. Amendments were broadcast on surface and all plots were rotovated to about 10 cm soil depth few days prior to seeding. Plots were seeded with a double-disc press drill at 17.8 cm row spacing. Seed yield was determined by combine harvesting a 7 m long and 1.2 m wide strip in each plot. Seed and straw samples were analyzed for total N, P, K and S to calculate nutrient uptake, in order assess the availability of nutrients from various amendments. Greenhouse gas samples in selected treatments were collected and are being analysed for nitrous oxide (N 2 O) to determine greenhouse gas (GHG) emission from soil receiving various amendments. The data were subjected to analyses of variance using GLM procedure in SAS (SAS Institute Inc. 1999) and LSD 0.05 was used for mean separation. Experiment 1. Feasibility of amendments in preventing P deficiency in organic crops Location: Naicam (P-deficient soil) Researchers: S. S. Malhi, R. Lemke, J. J. Schoenau and B. Frick Treatments: 1. Control (no amendment) Mg ha Mg ha Mg ha Wood 1 Mg ha Wood 2 Mg ha Wood 3 Mg ha Rock phosphate 10 kg P ha Rock phosphate 20 kg P ha Rock phosphate 30 kg P ha Rock phosphate 10 kg P ha Rock phosphate 20 kg P ha Rock phosphate 30 kg P ha Alfalfa 1 Mg ha -1 3

4 15. Alfalfa 2 Mg ha Alfalfa 4 Mg ha Alfalfa 6 Mg ha Control + Inoculate seed with Penicillium bilaiae 19. Rock phosphate 20 kg P ha -1 + Inoculate seed with Penicillium bilaiae 20. Rock phosphate 20 kg P ha -1 + Inoculate seed with Penicillium bilaiae 21. Cereal (no amendment) 22. Cereal + Pulse intercrop (no amendment) 23. Additional Treatment. MykePro Data Collection: 1. Soil test N, P, K and S. 2. Seed and straw yield. 3. Total N, P, K and S in seed and straw. 4. GHG emissions in selected treatments in second and third year. 5. Soil properties (if needed) at termination. Experiment 2. Feasibility of amendments in preventing S deficiency in organic crops Location (Researchers): Star City (S-deficient soil) Researchers: S. S. Malhi, R. Lemke, J. J. Schoenau and B. Frick Treatments: 1. Control (no amendment) Mg ha Mg ha Mg ha Wood 1 Mg ha Wood 2 Mg ha Wood 3 Mg ha Alfalfa 1 Mg ha Alfalfa 2 Mg ha Alfalfa 4 Mg ha Alfalfa 6 Mg ha kg S ha kg S ha Pulse (no amendment) 15. Cereal + Pulse intercrop (no amendment) 16. Control + Inoculate seed with Penicillium bilaiae 17. Rock phosphate 20 kg P ha Rock phosphate 20 kg P ha -1 + Inoculate seed with Penicillium bilaiae 19. Rock phosphate 20 kg P ha Rock phosphate 20 kg P ha -1 + Inoculate seed with Penicillium bilaiae 21. Additional Treatment. MykePro Data Collection: 1. Soil test N, P, K and S. 2. Seed and straw yield. 3. Total N, P, K and S in seed and straw. 4. GHG emissions in selected treatments in second and third year. 5. Soil properties (if needed) at termination. 4

5 Results: Experiment 1. Yield 2010 At Naicam, there was a substantial seed yield benefit of barley from the use of compost and alfalfa pellets, and moderate increase in seed yield of barley from wood ash compared to unamended control (Table 3). Compared to the unamended control, seed yield of barley tended to be higher with rock phosphate and/or Penicillium bilaiae, but no beneficial effect of MykePro on seed yield. In the barley-pea intercrop field treatments, seed yield improved with barley-pea intercropping compared to both barley or pea sole crops. Experiment 2. At Star City, the experimental site was infested only mildly with wild oat in 2010, and seed yields of barley were fairly high. Seed yield of barley increased considerably with application of alfalfa pellets, followed closely by compost and also some increase with wood ash over the unamendment control (Table 4). There was no beneficial effect of MykePro on seed yield. There was also no increase in seed yield of barley from gypsum application on this potentially S- deficient soil. In the barley-pea intercrop treatments, there was no beneficial effect of barley-pea intercropping on seed yield. Additional Treatment with Pea-Barley Intercrop: In Experiment 1, barley alone and barley intercropped with pea produced higher seed yield than the pea alone (Table 3). The order of seed yield was barley alone > barley + pea intercrop > pea alone. Total biomass yields showed trends similar to seed yield. In experiment 2, barley intercropped with pea tended to produce higher seed yield than barley or pea alone (Table 4). The order of seed yield was barley + pea intercrop > pea alone = barley alone. One should remember that pea fix N 2 in the soil which can be used for future crop production, resulting in reduction of N requirement from external nutrient sources, and also may have different economic returns depending on the value of the crop. Conclusions: Overall, there was a substantial increase in seed yield of barley from compost and alfalfa pellets, and a moderate increase from wood ash. In any case, it is hope that some amendments may provide economic yield benefit in the long term, and the experiments will be continued in 2011 growing season for residual effects of amendments on seed yield. Acknowledgements: The author gratefully thanks the Canadian Wheat Board for its generous financial contribution, Western Alfalfa for financial assistance and supplying alfalfa pellets amendment for this study, International Compost Ltd., Calgary, Alberta, for supplying Rock Phosphate fertilizers for this study, and D. Leach, M. Allgrove, K. Strukoff, for technical help. Disclaimer: Any and all data, analyses of data, project results, and conclusions or other information contained within are those reached by Agriculture & Agri-Food Canada and not of the Canadian Wheat Board. 5

6 Table 1. Some characteristics of soils at initiation of field experiments at Naicam (Larry Hoffman) and Star City (Shaun Dancey) in northeastern Saskatchewan Site Soil Great Group Z Depth (cm) Texture Organic matter (%) ph (1:2 water) Nitrate-N (mg kg -1 ) Extractable P (mg kg -1 ) SO 4 -S (mg kg -1 ) Extractable K (mg kg -1 ) Naicam 2008 Thin Black? 0-15 SL Star City 2008 Gray Luvisol 0-15 L Z Based on Canadian Soil Classification System. Table 2. Growing season monthly and total precipitation for the four site-years, and average 30-yr average precipitation and temperature in northeastern Saskatchewan Precipitation in the growing season (mm) z Naicam Star City 30-yr average (Melfort Research Farm) Month Precipitation (mm) Temperature ( o C) May June July August Total z At the nearest Environment Canada Meteorological Station (Hoffman used weather from Muenster. Dancey used Melfort weather). 6

7 Table 3. Seed, dockage and total biomass (crop + weeds) yield of barley with various amendments applied in spring 2010 at Naicam, Saskatchewan (P-deficient soil Experiment 1) Treatment Seed yield (kg ha -1 Total biomass ) yield (kg ha -1 ) No. Amendments Barley Dockage Crop + weeds 1 Control (no amendment) Mg ha Mg ha Mg ha Wood 1 Mg ha Wood 2 Mg ha Wood 3 Mg ha Rock phosphate 10 kg P ha Rock phosphate 20 kg P ha Rock phosphate 30 kg P ha Rock phosphate 10 kg P ha Rock phosphate 20 kg P ha Rock phosphate 30 kg P ha Alfalfa 1 Mg ha Alfalfa 2 Mg ha Alfalfa 4 Mg ha Alfalfa 6 Mg ha Control + Inoculate seed with Penicillium bilaiae Rock phosphate 20 kg P ha -1 + Inoculate seed with Penicillium bilaiae 20 Rock phosphate 20 kg P ha -1 + Inoculate seed with Penicillium bilaiae 23 MykePro LSD SEM 117.0*** 49.1 Sole crops versus intercrop 1 Barley (no amendment) Pea (no amendment) Barley (1/2 rate) + Pea (1/2 rate) intercrop (no amendment) 990 ( ) LSD SEM 123.8* 56.6*, * and *** refer to significant treatment effects in ANOVA at P 0.10, P 0.05 and P 0.001, respectively

8 Table 4. Seed, dockage and total biomass (crop + weeds) yield of barley with various amendments applied in spring 2010 at Star City, Saskatchewan (S-deficient soil Experiment 2) Treatment Seed yield (kg ha -1 Total biomass ) yield (kg ha -1 ) No. Amendments Barley Wild oat Crop + weeds 1 Control (no amendment) Mg ha Mg ha Mg ha Wood 1 Mg ha Wood 2 Mg ha Wood 3 Mg ha Alfalfa 1 Mg ha Alfalfa 2 Mg ha Alfalfa 4 Mg ha Alfalfa 6 Mg ha kg S ha kg S ha Control + Inoculate seed with Penicillium bilaiae Rock phosphate 20 kg P ha Rock phosphate 20 kg P ha -1 + Inoculate seed with Penicillium bilaiae 19 Rock phosphate 20 kg P ha Rock phosphate 20 kg P ha -1 + Inoculate seed with Penicillium bilaiae MykePro LSD SEM 129.3*** 32.0*** Sole crops versus intercrop 1 Barley (no amendment) Pea (no amendment) Barley (1/2 rate) + Pea (1/2 rate) intercrop (no amendment) 2569 ( ) LSD SEM ns 86.3* *, *** and ns refer to significant treatment effects in ANOVA at P 0.05, P and not significant, respectively