The economic potential of feedlot wastes utilization in agricultural production

Feedlot wastes contain the essential elements for plant growth. Effective utilization of feedlot wastes as a source of fertilizer for crops is a function of the nutrient content in the manure, the mineralization rates of the organically combined molecules in the manure, and the cost associated with the management, hauling, and spreading of manure. This study, using simulation approach, evaluates the simultaneous effect of these variables in determining the economic potential of feedlot waste utilization in agricultural production. Least cost manure application is determined for various crops in four rotation systems and for three different nutrient content and mineralization rates.

The results show that the cost associated with the management, hauling, and spreading of manure to satisfy the nutrient requirements for the crops considered in the four rotation systems is significantly less than the cost of commercial fertilizer. Depending on the mineralization rate and the rotation system considered, the cost of applying manure ranges between 20 and 35 per cent of the cost of commercial fertilizer. The results also show that the maximum distance of transferring manure from the feedlot to the field that will equate the cost of applying manure with cost of commercial fertilizer ranges between 10·0 to 78·4 km.