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 NH4 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 NH4 was nitrified, volatilized, or fixed. The accumulation of organic matter, total N, NO3, total P, available P, soluble Na, Ca + Mg, Cl, SO4, HCO3, 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 NO3 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.

The effects of long‐term annual applications of cattle (Bos taurus) feedlot manure on the accumulation, decomposition (amounts and rates), and movement of organic matter (OM) and Kjeldahl‐determined N (total N) in soil were determined. Manure was applied annually since 1973 at three different levels to nonirrigated and irrigated Dark Brown Chernozemic (Typic Haploborolls) clay loam soil. Significant increases in soil OM and total N content in the first 8 and 6 yr, respectively, as affected by the level of manure application, were limited to the surface 30 cm of soil of the nonirrigated and irrigated land. Tillage did not affect the amount of OM and total N accumulated in the soil, but it did affect their distribution within the 0 to 30‐cm depth, which is attributed to placement during incorporation. The accumulation of OM and total N were similar under nonirrigated and irrigated conditions. Manure (C/N ratio of ca. 10.2) lowered the C/N ratio of the soil (ca. 8.2) by small amounts. The accumulation of OM and total N was described by a Michaelis‐Menten type of function. A response surface was generated for the accumulation of OM and total N with increasing levels and years of manure application, from which the rates of accumulation and decomposition were derived. The rates of accumulation decrease with years of application such that after two or three decades increases will be small. The model can be used to develop general guidelines for use and disposal of feedlot manure under similar conditions.

A long‐term manure study was set up in which cattle feedlot manure was applied annually at four rates to nonirrigated and irrigated land and was incorporated into the soil by plow, rototiller, or cultivator. The soil is a Dark Brown Chernozem (Typic Haploborolls) at the Lethbridge Research Station. The effects of the manure, incorporated by different methods, on the physical properties and organic matter content of the soil were determined. On both nonirrigated and irrigated land, the soil organic matter content of the surface 0 to 15 cm increased with increasing rates of manure application. Spring‐time soil temperatures, at 8‐cm depth, were coldest where the highest rate of manure had been incorporated. Drawbar draft decreased with increasing rates of manure application. Similarly, bulk density of the surface 0 to 15 cm of soil decreased with increasing rates of manure application, the greatest effect being where the manure had been incorporated by cultivator on irrigated land. But, at 15 to 30‐cm depth, the smallest bulk density was where the manure had been incorporated by plow. Increasing rates of manure on irrigated land tended to decrease the amount of aggregates < 1 mm and increase the amount > 1 mm in size, at the 15 to 30‐cm depth. These results indicate that manure, applied at the relatively low rates that are currently recommended, can maintain and increase the organic matter content of the soil and ameliorate the physical condition of southern Alberta soils.

No abstract

Approximately 4800 cattle feedlots currently operate in Alberta, Canada. The large amount of manure produced annually creates disposal problems for feedlot operators. The objective of the present study was to evaluate the effects of long‐term annual manure application on barley (Hordeum vulgare L.) performance grown on clay loam soil (Dark Brown Chernozemic, Typic Haploboroll) near Lethbridge, AB. Feedlot cattle manure was applied annually from 1973 to 1989 to irrigated plots at 0, 60, 120, and 180 Mg ha−1 (wet wt. basis) and to nonirrigated plots at 0, 30, 60, and 90 Mg ha−1. Manure was incorporated with a cultivator plus disk, rototiller, or plow. Method of incorporation did not affect barley yields, but timeliness and amount of precipitation in the current and previous year were important in determining barley response to manure treatments. When moisture conditions were below normal, manure at any rate of application had a negative effect on yield of nonirrigated barley. Under nonirrigated conditions, average barley yield was depressed by 10 and 16% for the 60 and 90 Mg ha−1 manure rates, respectively. Barley yield increased when manure was applied under irrigation, with the 60 Mg ha−1 rate producing a 20% higher average yield than the control. Although manure was disposed of annually on the soil at up to three times the recommended rate without reducing barley yields below those of the unmanured plots under irrigated conditions, such practice is not recommended because of potential soil and water pollution.