IMPROVING SOILS AND THEIR MANAGEMENT FOR MORE EFFICIENT WATER USE IN ENVIRONMENTALLY SUSTAINABLE AGRICULTURE
Location: Coastal Plain Soil, Water and Plant Conservation Research
Title: Physical effects of organic matter amendment of a southeastern USA coastal loamy sand
Submitted to: Soil Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 31, 2011
Publication Date: December 1, 2011
Citation: Busscher, W.J., Novak, J.M., Ahmedna, M., Niandou, M. 2011. Physical effects of organic matter amendment of a southeastern USA coastal loamy sand. Soil Science. 176(12):661-667.
Interpretive Summary: Twelve organic soil amendments were tested in subsurface layers of a sandy coastal soil to improve their characteristics for plant growth. Amendments included (in alphabetic order) biochar, cellulose insulation, corn stalk, corn starch, cotton hull, cotton meal, manure residual, peanut hull, poultry litter, soybean plant, wheat straw, and wood shavings. Amendments were added to the soil in amounts that increased its carbon content by about 1%. The amended soil was allowed to incubate for 60 days. Cellulose, corn stalk, and corn starch improved soil structure the most; this would increase root growth. Peanut hull, poultry litter, wood shavings, and biochar improved aggregation the least. Corn starch, cotton meal, and poultry litter lost the most carbon; biochar lost the least implying it would be best for carbon sequestration. Biochar, wood shavings, and corn starch amended soils were the hardest; cellulose and cotton meal were the softest. All amendments held more water for plant growth than the control. Adding clay along with amendments improved their effects on increased carbon, reduced soil hardness, or improved structure. All amendments improved the soil in one way or another. Though biochar was not the best amendment for hardness or aggregation, it may be the best amendment because it will not deteriorate as quickly at the others.
We tested 12 different organic sources as amendments for E horizon or a mixture of E and Bt horizons of a southeastern coastal loamy sand. Amendments included biochar, cellulose, corn stalk, corn starch, cotton hull, cotton meal, manure residual, peanut hull, poultry litter, soybean plant, wheat straw, and wood shavings. We hypothesized that amendments would increase carbon and improve soil physical/chemical properties. Amendments of ~1% organic carbon content were allowed to incubate for 60 days. Over the course of the experiment, cellulose, corn stalk, and corn starch gave the greatest improvement in aggregation; the control, peanut hull, poultry litter, wood shavings, and biochar gave the lowest. Cotton meal and poultry litter had the highest carbon dioxide evolution; biochar had the lowest. Corn starch and poultry litter had the highest amount of dissolved organic carbon leached; the control and biochar had the lowest. Biochar, wood shavings, and corn starch had the highest soil penetration resistance; cellulose and cotton meal had the lowest. Poultry litter and manure residual had the greatest improvement in water holding capacities; cellulose, biochar, and soybean plant had the lowest, though all were better than the control. The Bt horizon mixed into the E essentially added clay, which improved parameters for most treatments. All treatments improved the soil in one way or another – more carbon, softer soil, or more aggregation. Biochar retained the most carbon throughout the incubation period.