Shallow injection of hog manure into grassland

Non-Peer ReviewedWith the expected increase in hog production in Saskatchewan, concern has risen regarding the availability of sufficient land to utilize the manure resource to its full potential as a source of plant nutrients. Increases in inorganic fertilizer costs and concerns about the environmental effects of alternative manure disposal methods have stimulated interest in the use of livestock manure as a plant nutrient source (Hoff , Nelson and Sutton, 1981). Liquid hog manure is a valuable plant nutrient source, which is best perceived as a dilute multi-nutrient solution fertilizer blend. Therefore, application rates in the order of several thousand liters per hectare are required to meet the nutrient requirements of the crop versus 90 to 200 liters per hectare for concentrated commercial solution fertilizer blends (Schoenau, 1997). Ammonia-N losses from livestock manure have been reported to range from 10 to 90% when surface-applied to the soil (Vanderholm, 1975). Hoff, Nelson and Sutton, (1981) showed that 14 to 65% of the ammonia-N was lost over a 3.5 day period, when the hog manure was broadcast on the soil surface. However, if the hog manure was injected, the ammonia-N losses were reduced to 2.5% or less. Hoff, Nelson and Sutton, (1981) suggested that injecting hog manure into the soil would maximize the nutrient value of the hog manure as a fertilizer and would minimize surface water and atmospheric N contamination. There currently is little information on the plant and soil response to injection of hog manure into grasslands on the Canadian prairies. The objectives of the study are (1) to evaluate the practicality of shallow injection of hog manure into typical grassland stands in Saskatchewan (2) to determine the effect hog manure has on forage yield, forage quality and forage nitrate levels at various application rates (3) and to determine the effect on soil nutrients under various hog manure application rates