Abdul-Baki, A., Bryan H. H., Zinati, G, Klassen, W., Codallo, M. and Heckert, N.2001. Biomass yield and flower production in sunn hemp: Effect of cutting the main stem. Journal of Vegetable Crop Production 7:83-104.
Abdul-Baki, A.A., Klassen, W.,Bryan, H.H., Codallo, M., Hima, B.L., Wang, Q.R., Li, Y.C., Lu, Y.C., Handoo, Z.A. 2005.A biologically-based system for winter production of fresh market tomatoes in south Florida Proc.Fla.State Hort. Soc. 118:153-159.
Roberts, D.P., Abdul-Baki, A.A. Zasada, I.A. Meyer, S.L.F. and Klassen, W.2005. Biologically-based technologies for suppression of soilborne pathogens of vegetables. In Pandalai, S.G. (Ed.) Recent Research Developments in Applied Microbiology and Biochemistry.
Summer tropical cover crops for desert orchards.
Date production in the U.S. is localized in the Coachella Valley in southeastern California. Tree growth, yield, and fruit quality had been declining in spite of standard management practices including high fertilizer and irrigation inputs. This decline was caused by a number of stresses which included high soil compaction, trees with shallow roots, high salinity due to poor drainage, low fertility, lack of organic matter in sandy soils, and improper management of irrigation water. The ARS Sustainable Agricultural Systems Lab in collaboration with NRCS developed a two-step solution consisting of, first, a one-time slip plowing between the tree rows to a depth of 5 feet to break the hard pan and allow the movement of water and nutrients deeper into the soil profile and, second, a management system using a native legume cover crop, Lana vetch, to cover the soil surface between October and May of each year.The cover crop suppressed weeds, improved soil fertility, recycled macro- and micro-nutrients, improved water percolation, shaded the soil surface, reduced evaporation, and lowered soil temperature that was a source of severe stress to root function in this excessively hot region. Within three years of implementing the cover cropping system, tree growth per year tripled, yields significantly increased by an average of 12 to 20%, and fruit quality also improved. At the same time, production cost was reduced by $100/acre due to savings on cultivation, fertilizer, and water. Approximately 45% of the date orchards in Coachella Valley are presently applying the cover cropping system.In addition, this technology has been extended to other crops resulting in an increase of cover cropping acreage from 500 to 25,000 acres in the Coachella Valley, including use in approximately 40% of the grape acreage.
Characteristics of Hairy Vetch-Tomato System
A highly successful system for no-tillage production of vegetable crops in a hairy vetch cover crop was developed at the Beltsville Agricultural Research Center during the previous decade.Tomatoes grown in a hairy vetch cover crop were shown to:
· Produce higher leaf area duration, marketable yield, and net returns than those grown with a standard black polyethylene mulch,
· Reduce inputs of fertilizers, herbicides, and fungicides for producing fresh-market tomatoes.
· Reduce water runoff, as well as sediment, nutrient, and pesticide losses in runoff by 75 to 95%,
· Activate a suite of genes that are interlinked with delayed senescence and enhanced disease resistance in vetch grown tomatoes.
For more details click here.
Weed Suppression by Cover Crops
For information on the following topics link to
Understanding the Complexities of Cover Crop Residue Influences on Weed Emergence.
PDF document available here.
Principles and Practices for using Cover Crops in Weed Management Systems.
See: Teasdale, J.R. 2003. Principles and practices for using cover crops in weed management systems. Pages 169-178 in R. Labrada (ed.) Weed Management for Developing Countries. FAO Plant Production and Protection Paper 120, Add.1, Rome, Italy. This chapter can be accessed online here.
On-Going Research
• Breeding improved cultivars of hairy vetch with early flowering and improved winterhardiness. [Tom Devine]
• Determining molecular mechanisms for crop responses to cover crops.[Autar Mattoo]
• Understanding rhizosphere and soil microbial populations associated with cover cropping. [Jeff Buyer]
• Enhancing weed [John Teasdale] and pest [Don Weber] suppression with cover crops.
• Determining the behavior of allelopathic compounds in soil. [Cliff Rice]
Links to Useful Cover Crop Websites
Sustainable Agriculture Network. 1998. Managing Cover Crops Profitably, Second Edition. Handbook Series Book 3. 212 p. Download PDF
University of California Cover Crop Resource Page with links to extensive databases.
Overview of Cover Crops and Green Manures by Preston Sullivan. Published 2003 ATTRA Publication #IP024