RESOURCE USE EFFICIENCY IN AGRICULTURE

Trajectories over time of nitrogen use and yield show that the fertilizer is used as efficiently at the high end of the yield range, as at the low end. Apparently, any decrease in marginal returns as predicted by the law of diminishing returns is more or less compensated by the benefits of other technological changes. Main processes that govern such opposing trends are analyzed in this paper to contribute towards more efficient use of resources in agriculture. The analyses elaborate on the optimum law of Liebscher, formulated at the end of the ]9th century. This law states that a production factor which is in minimum supply contributes more to production, the closer other production factors are to their optimum. With some reservations regarding the control of pests, diseases and weeds, this law is fully confirmed. Accordingly, no production resource is used less efficiently and most production resources are used more efficiently with increasing yield level due to further optimizing of growing conditions. Whether external means of production are used at all depends of course on their price, but as soon as the farmer can afford them, they should be used in such a way that the production possibilities of all other available resources are fully exploited It thus appears that with further optimizing of the growing conditions an increasing number of inputs gradually lose their variable character and the number of fixed operations on the farm increase. This makes more and more inputs not a variable cost element, but a complementary cost element of the decision to farm a piece of land. Therefore strategic research that is to serve both agriculture and its environment should not be so much directed towards the search for marginal returns of variable resources, as towards the search for the minimum of each production resource that is needed to allow maximum utilization of all other resources.