Wednesday, November 15, 2006

Effects of Manure Application on Wheat Yield and Soil Properties in Degraded Prime Farmland.

Philip Schroeder, Mathew Johnson, and Leon Fischer. Cameron University, 13925 Highway 62, Elgin, OK 73538-3114

Winter wheat and cotton are the principal agronomic crops in the southwestern region of Oklahoma with approximately 1.3 million acres of wheat and 140 thousand acres of cotton planted annually. Continuous crop production has had negative effects on soil chemical and physical properties and lead to a reduction in soil quality and, pH. A green house study was undertaken to determine the ability of manure application to improve soil properties and increase wheat yield. Five treatments, 3 rates of feedlot manure (11, 22, and 44 Mg/ha) , fertilizer, fertilizer+lime, and unfertilized controls) were applied in a randomized complete block design with three replications. Hard red winter wheat (var. Jagalene) was planted at a seeding rate of 84 kg ha-l in plastic pots (20 cm dia). After 9 weeks, above ground biomass was harvested and soil samples were collected to a depth of 15 cm from all pots. Plant matter was analyzed for moisture, protein, P, Ca, Mg, K, S, Cu, Fe and Zn. Soil samples were analyzed for OM, nitrate, pH, P, Ca, Mg, K, S, Cu, Fe and Zn. The fertilizer plus lime treatment produced the highest dry matter yield, however there was no significant (α= 0.05) differences between the treatments except that the unfertilized control produced the lowest yield. In general, the 20 ton manure treatment had the highest levels of OM, pH, and soil nutrients. Soil pH levels were not different among the limed, 10 ton, and 20 ton treatments. Plant nutrient uptake levels were also highest from manure and limed treatments. The results of this study suggest that application of feedlot manure can affect pH and nutrient availability in degraded farmland and may increase wheat yield as much as liming.