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Winter cover crops to minimize nitrate losses in intensive lettuce production

  • L. E. Jackson (a1), L. J. Wyland (a1) and L. J. Stivers (a1)


A 2-year study conducted in Salinas, California in 1989–91 showed that soil nitrate (NO3–N) concentrations were reduced by cover crops during a short winter fallow period and that this practice can be compatible with year-round vegetable crop production schedules by planting and incorporating cover crops directly on the beds into which the lettuce crop will be direct seeded in the early spring. Cover crops grown the first year were oilseed radish (Raphanus sativus cv. Renova), white senf mustard (Brassica hirta cv. Martigena), white mustard (Brassica alba), Phacelia (Phacelia tanacetifolia cv. Phaci), rye (Secale cereale cv. Merced) and annual ryegrass (Lolium multiflorum). Only phacelia and Merced rye were included in the second year. In both years, all of the cover crops depleted soil NO3-N and soil moisture relative to the fallow control. Estimates of cover crop root length, based on core sampling to 60 cm soil depth, averaged 18800 m/m2 after 17 weeks of growth the first year and 12500 m/m2 after 13 weeks of growth the second year. Above-ground dry matter production averaged 449 g/m2 (12·8 g N/m2) the first year and 161 g/m2 (61 g N/m2) during a shorter growing period and under the more adverse growing conditions of the second year. Following cover crop incorporation with a rotary tiller, soil ammonium (NH4-N), N03-N and net mineralizable N (anaerobic incubation) peaked after c. 1 week, then gradually declined for 1 month. Cover-cropped plots sustained higher net mineralizable N levels than the fallow control after incorporation. Nitrate concentrations after spring rains were lower in soils left fallow during winter. The subsequent lettuce crop was not affected by cover crop treatment.



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Armstrong, M. (1990). Sugar beet – towards a greener crop. British Sugar Beet Review 58 (3), 2024.
Bolton, H. Jr, Elliot, L. F., Papendick, R. I. & Bezdicek, D. F. (1985). Soil microbial biomass and selected soil enzyme activities: effect of fertilization and cropping practices. Soil Biology and Biochemistry 17, 297302.
Bruehl, G. W. (1973). Systems and mechanisms of residue possession by pioneer fungal colonists. In Biology and Control of Soil-borne Plant Pathogens (Ed. Bruehl, G. W.), pp. 7783. St. Paul, MN: American Phytopathological Society.
Carlson, R. M. (1978). Automated separation and conductimetric determination of ammonia and dissolved carbon dioxide. Analytical Chemistry 50, 15281532.
Carlson, R. M. (1986). Continuous flow reduction of nitrate to ammonium with granular zinc. Analytical Chemistry 58, 15901591.
Cassman, K. G. & Munns, D. N. (1980). Nitrogen mineralization as affected by soil moisture, temperature, and depth. Soil Science Society of America Journal 44, 12331237.
Estler, M. (1991). Conservation of soil and water by using a new tillage system for row crops. In Cover Crops for Clean Water (Ed. Hargrove, W. L.), pp. 3436. Ankeny, IA: Soil Water Conservation Society.
Flocker, W. J., Agamlian, H. & Lugg, J. (1959). Effect of winter cover cropping and subsoiling on some physical properties of Chualar sandy loam. Department of Vegetable Crops Series 100, University of California, Davis, USA.
Goss, M. J., Colbourn, P., Harris, G. L. & Howse, K. R. (1988). Leaching of nitrogen under autumn-sown crops and the effects of tillage. In Nitrogen Efficiency in Agricultural Soils (Eds Jenkinson, D. S. & Smith, K. A.) Vol. 1, pp. 269282. New York: Elsevier Applied Science.
Holton, B., Barbour, M. G. & Martens, S. N. (1991). Some aspects of the nitrogen cycle in a Californian strand ecosystem. Madroño 38, 170184.
Huntington, T. G., Grove, J. H. & Frye, W. W. (1985). Release and recovery of nitrogen from winter annual cover crops in no-till corn production. Communications in Soil Science and Plant Analysis 16, 193211.
Jackson, L. E., Schimel, J. P. & Firestone, M. K. (1989). Short-term partitioning of ammonium and nitrate between plants and microbes in an annual grassland. Soil Biology and Biochemistry 21, 409415.
Krober, H. & Beckman, E. O. (1975). Pilzparasitare Schaden an Phacelia tanacetifolia Benth. Nachrichtenblatt des Deutschen Pflanzenschützdienstes 27, 177180.
Ladd, J. N. & Amato, M. (1986). The fate of nitrogen from legume and fertilizer sources in soils successively cropped with wheat under field conditions. Soil Biology and Biochemistry 18, 417425.
Ladd, J. N., Oades, J. M. & Amato, M. (1981). Distribution and recovery of nitrogen from legume residues decomposing in soils sown to wheat in the field. Soil Biology and Biochemistry 13, 251256.
Lamb, J. A., Peterson, G. A. & Fenster, C. R. (1985). Fallow nitrate accumulation in a wheat-fallow rotation as affected by tillage system. Soil Science Society of America Journal 49, 14411446.
Martinez, J. & Guiraud, G. (1990). A lysimeter study of the effects of a ryegrass catch crop, during a winter wheat/maize rotation, on nitrate leaching and on the following crop. Journal of Soil Science 41, 516.
Meisinger, J. J., Hargrove, W. L., Mikkelsen, R. L., Williams, J. R. & Benson, V. W. (1991). Effects of cover crops on groundwater quality. In Cover Crops for Clean Water (Ed. Hargrove, W. L.), pp. 5768. Ankeny, IA: Soil Water Conservation Society.
Monterey County Flood Control and Water Conservation District (1988). Nitrates in groundwater, Salinas Valley, California.
Muller, J. C., Denys, D., Morlet, G. & Mariotta, A. (1988). Influence of catch crops on mineral nitrogen leaching and its subsequent plant use. In Nitrogen Efficiency in Agricultural Soils (Eds Jenkinson, D. S. & Smith, K. A.) Vol. 2, pp. 8598. New York: Elsevier Applied Science.
Ocio, J. A., Brookes, P. C. & Jenkinson, D. S. (1991). Field incorporation of straw and its effects on soil microbial biomass and soil inorganic N. Soil Biology and Biochemistry 23, 171176.
Paul, E. A. (1984). Dynamics of organic matter in soils. Plant and Soil 76, 275285.
Powlson, D. S. (1988). Measuring and minimising losses of fertilizer nitrogen in arable agriculture. In Nitrogen Efficiency in Agricultural Soils (Eds Jenkinson, D. S. & Smith, K. A.) Vol. 1, pp. 231245. New York: Elsevier Applied Science.
Powlson, D. S., Jenkinson, D. S., Pruden, G. & Johnston, A. E. (1985). The effect of straw incorporation on the uptake of nitrogen by winter wheat. Journal of the Science of Food and Agriculture 36, 2630.
Radke, J. K., Andrews, R. W., Janke, R. R. & Peters, S. E. (1988). Low-input cropping systems and efficiency of water and nitrogen use. In Cropping Strategies for Efficient Use of Water and Nitrogen (Ed. Hargrove, W. L.), pp. 193218. Madison, WI: ASA, CSSA and SSSA.
Roberson, E. B., Sarig, S. & Firestone, M. K. (1991). Cover crop management of polysaccharide-mediated aggregation in an orchard soil. Soil Science Society of America Journal 55, 734739.
Roberts, B. W. & Cartwright, B. (1991). Alternative soil and pest management practices for sustainable production of fresh-market cabbage. Journal of Sustainable Agriculture 1, 2135.
Rolston, D. E. (1981). Nitrous oxide and nitrogen gas production in fertilizer loss. In Denitrification, Nitrification, and Atmospheric Nitrous Oxide (Ed. Delwiche, C. C.), pp. 127149. New York: J. Wiley and Sons.
Ryden, J. C. & Lund, L. J. (1980). Nature and extent of directly measured denitrification losses from some irrigated vegetable crop production units. Soil Science Society of America Journal 44, 505511.
Sas Institute. (1985). SAS User's Guide: Statistics. 5th edn.Cary, NC: SAS Institute Inc.
Schimel, J. P., Jackson, L. E. & Firestone, M. K. (1989). Spatial and temporal effects on plant-microbial competition for inorganic nitrogen in a California annual grassland. Soil Biology and Biochemistry 21, 10591066.
Schlang, J. (1985). Ziir Populationsentwicklung von Heterodera schachtii unter dem Einfluss von Phacelia tanacetifolia. Mededelingen van de Faculteit Landbouwetenschappen Rijksuniversiteit 50, 774784.
Schnürer, J., Clarholm, M. & Rosswall, T. (1985). Microbial biomass and activity in an agricultural soil with different organic matter contents. Soil Biology and Biochemistry 17, 611618.
Smith, M. S., Frye, W. W. & Varco, J. J. (1987). Legume winter cover crops. Advances in Soil Science1 7, 95139.
Tisdall, J. M. & Oades, J. M. (1982). Organic matter and water-stable aggregates in soils. Journal of Soil Science 33, 141163.
Waring, S. A. & Bremner, J. M. (1964). Ammonium production in soil under waterlogged conditions as an index of nitrogen availability. Nature (London) 201, 951952.
Williams, W. A. (1966). Management of nonleguminous green manures and crop residues to improve the infiltration rate of an irrigated soil. Soil Science Society of America Proceedings 30, 631634.


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