|Cole, Noel - Andy|
Submitted to: ASABE Annual International Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 4/1/2002
Publication Date: 7/28/2002
Citation: Rhoades, M.B., Parker, D.B., Sweeten, J.M., Cole, N.A., Brown, M.S. 2002. Beef feedyard effluent application effects on nutrient mass balances for three cropping rotations of sorghum and wheat. In: Proceedings of the ASABE Annual International Meeting, July 28-31, 2002, Chicago, Illinois. Paper No. 024147. Interpretive Summary:
Technical Abstract: Feedlot runoff was applied to 27 plots of winter wheat and forage sorghum over 24 months at the Agriculture Research Station located at Bushland, TX, 12 miles west of Amarillo. Each plot measured 16 m x 4.5 m to allow for access of farming implements. All plots were plowed with an offset disc, chiseled, and leveled with a laser plane before planting. Wheat was sown at the rate of 67 kilograms of seed per hectare. Sorghum was planted in 6 rows, 75 cm apart, at the rate of 11.25 kg/ha. Runoff was applied by flood irrigation on the level borders. Rates applied were as follows: 0 cm/cropping season (Treatment 1, control), 25 cm (Treatment 2), and 50 cm (Treatment 3). Cropping rotations of sorghum-fallow, wheat-fallow, and sorghum-wheat (two crops per year) were used for each TRT. Plots were irrigated every two weeks after plant emergence until the appropriate amount of effluent was obtained. The crop was then allowed to mature until the majority of the plants had reached an early boot stage. At this time, vegetative samples were collected and allowed to dry for three weeks, after which they were ground, mixed and analyzed in the laboratory. Soil samples were collected before planting and after harvest and also analyzed in the laboratory. Effluent samples were collected three times during each irrigation, composited, and analyzed. Nutrient mass balances were calculated for total N, plant¿available P, K, Mg, Na, and Cl. Total N tended to have positive balances in year one and negative balances in year two. P had positive balances both years, but balances were smaller in year two. Both K and Na had large increases for both years.