Organic mulches and high residue no-till for collard production in Alabama
A 4×2 factorial randomized complete block design with four replicates was initiated at the Plant Breeding Unit at the E.V. Smith Research Station in Shorter, AL. The experimental site was selected, prepared, fertilized according to soil test recommendations and sown with winter rye (Secale cerale) in October, 2005. Experimental units were flagged and composite soil samples were collected from each replicate for soil chemical and physical analysis. The successful establishment of the experiment in 2005 will allow us to begin collecting data on treatments in 2006.
The objectives of our experiment are:
1.To evaluate mimosa prunings, Chinese bush clover cuttings and hay straw as organic mulches in a high residue no-till system; and
2. To compare sorghum-sudangrass and a high biomass legume as high-residue cover crops for no-till production of collards and the interaction of cover crop and mulch type on assessment parameters.
Mulches and cover crops will be evaluated in terms of weed control, percent ground cover, decomposition and nutrient release rates of mulches and summer cover crops, changes in soil chemical and physical properties, soil moisture status and crop yields.
To date, the experiment has been established with a healthy stand of rye and soil samples have been collected in order to determine “time zero” conditions for each replicate. We will begin application of treatments in May 2006 and collect data for the next three years. Cover crop treatments will be established around May 7, after collecting soil moisture data. The summer cover crops will be terminated around July 21, after which weed population counts, percent ground cover data, soil moisture data and nutrient release experiments from the summer cover crops will begin. Measurements on these parameters will continue for the duration of 2006 and beyond. Collard seedlings will be no-till transplanted around August 7 and mulch treatments will be applied around August 21. Organic mulch decomposition and nutrient release studies will begin at this time. Collards will be harvested around October 21, immediately followed by a winter cover crop of rye.
Impacts and Contributions/Outcomes
A combination of high residue cover crops with in situ organic mulches should provide vegetable growers with multiple benefits, including weed control, improved soil quality and reduced input costs. The selection of collards, as well as summer cover crops, makes this research particularly relevant to growers concerned with reduced-input agricultural systems in the Southern region.
Auburn University National Soil Dynamics Lab
411 S. Donahue Drive
Auburn, AL 36849
Office Phone: 3348444666
Auburn University Dept. of Horticulture
101 Funchess Hall
Auburn, AL 36849-5412
Office Phone: 3348443050
Auburn University Dept. of Agronomy and Soils
202 Funchess Hall
Auburn, AL 36849-5412
Office Phone: 3348443963