Soil Chemistry after Eleven Annual Applications of Cattle Feedlot Manure

In a long‐term experiment at Lethbridge, AB, the effects of cattle ( Bos sp.) manure on soil characteristics were determined after 11 annual applications. Manure, incorporated by cultivating, rototilling, or plowing, was applied annually from 1973 to 1983 at 30, 60, and 90 Mg ha −1 (wet wt.) and 60, 120, and 180 Mg ha −1 , respectively, to nonirrigated and irrigated dark brown Chernozemic (Typic Haploborolls) clay loam soil. On both the nonirrigated and irrigated soil, the effects from manure, applied annually at greater than recommended rates for 11 yr, were minimal on Cu and NH 4 content and substantial on other parameters determined. There were no significant effects due to tillage methods on these soil parameters. The effects on these soil parameters extended to greater depths under irrigation than under nonirrigation. Most of the applied NH 4 was nitrified, volatilized, or fixed. The accumulation of organic matter, total N, NO 3 , total P, available P, soluble Na, Ca + Mg, Cl, SO 4 , HCO 3 , and Zn in the soil increased with increasing rates of manure applied. The electrical conductivity and sodium adsorption ratio of the soil increased and the soil pH in the surface 60 cm of nonirrigated and 90 cm of irrigated decreased with increased manure rates. The total NO 3 accumulation in the 150‐cm soil depth was near 1 Mg ha −1 , even at recommended rates, and was high enough to potentially cause soil and water pollution. The available P accumulated mostly in the surface soil and might be sufficient to interfere with the nutrient balance of some crops. Long‐term annual application of cattle manure to southern Alberta soils at maximum recommended rates [30 mg ha −1 and 60 Mg ha −1 (wet wt.) for nonirrigated and irrigated land, respectively] is not advisable.