Residual Effects of Dairy Cattle Manure on Plant Growth and Soil Properties1

Abstract

AbstractLand spreading of dairy manure is effective both in disposing of waste and in utilizing plant nutrients in the manure. This study was conducted to determine the residual effect of manure after three annual applications at rates of 0, 22.5, 45, 90, 180, and 270 metric tons/ha were each incorporated into two soils. Plots were double‐cropped each of those 3 years with pearl millet [Pennisetum americanum (L.) K. Schum ‘Gahi I’] and rye (Secale cereale L. ‘Wren's Abruzzi’). During the residual phase of the experiment, plots were double‐cropped with rye and corn (Zea mays L. ‘Funks 5757’) for a period of 4 years. Residue from high application rates of dairy cattle manure increased yields of corn on both Dothan loamy sand (Plinthic Paleudults) and Lucedale sandy loam (Rhodic Paleudults) for 4 years after the manure was applied. On the Dothan soil high rates of manure adversely affected rye growth. Most years, the residue increased N uptake in both crops on both soils. The high rates of manure increased pH to a depth of over 100 cm on the Dothan soil. Potassium accumulated in the subsoil to the 100‐cm depth. Phosphorus was increased to the 60 to 75‐cm soil depth. Magnesium also moved into the subsoil, but there was little movement of Ca below the surface 30 cm. The effect on pH, K, P, and Mg movement was much smaller on the Lucedale soil than on the coarser‐textured Dothan soil.The high rates of manure increased soil pH and soil contents of K, Mg, and P and increased the cation exchange capacity of soils. These factors contribute toward higher crop yields on manure‐treated plots. Response to dairy manure may be measured for 4 years or more after high rates of manure applications have been stopped.