livestock manure, soil fertaility, livestock production, cattle, livestock feed
The following research question is examined in this article: Can one or more of eight case study integrated crop and cow-calf farms/ranches in South Dakota be simultaneously "balanced" from the standpoints of (1) amounts of manure produced "matching" (plus or minus 10%) the soil fertility needs of producers' cropland and rangeland and (2) amounts of feed-grains and roughages produced "matching" (plus or minus 10%) the nutrient needs of producers' livestock? The livestock manure production-utilization component of the study involves estimation and comparison of amounts of nitrogen (N) and phosphorus (P) (1) available to crops and grass in the manure produced by livestock on the respective case farms and (2) required to meet the fertility needs of the crops and rangeland grasses produced under 64 crop yield and soil test conditions on the respective case farms. The livestock feedstuff production-consumption component of the study involves estimation and comparison of amounts of (1) total digestible nutrients (TDN) produced on the case farms with (2) the TDN required by the livestock on the respective farms. Results from the study show no situation in which a case farm is either balanced (plus or minus 10%) for both livestock manure production-utilization on cropland and rangeland and livestock feedstuff production-consumption with either (1) its current farmland hectarage and livestock population, or (2) simulated contracted or expanded livestock populations and current farmland hectarages in which livestock manure production-utilization is just matched. The primary explanation underlying this conclusion is a very low probability of the N-to-P ratio in the livestock manure produced on a farm being identical with the N-to-P ratios needed in manure for spreading on cropland and manure dropped on rangeland. Thus, while the notion of crop and livestock nutrient requirements being met internally on diversified farms is desirable, it appears that full realization of the concept in particular current real-world farm situations is difficult. If current basic farming systems were altered rather dramatically, however, it is conceivable that livestock manure production-utilization and livestock feedstuff production consumption might be brought into balance with one another.
Department of Economics, South Dakota State University
Number of Pages
Taylor, Donald and Rickerl, Diane, "Ecological Balance on Individual Crop-Livestock Farms: An Idealistic Notion or Also Practically Feasible?" (1996). Economics Staff Paper Series. 130.