Measuring the relative economic costs of legume and fertiliser nitrogen

Abstract

In assessing the economics of nitrogen in a farming system, there is a need to assess the full economic costs and benefits of each potential source of nitrogen. In this paper, the basis for measuring and comparing the full economic costs of fertiliser and legume nitrogen is explored. The relative costs of different forms of nitrogen for the South-West Slopes of New South Wales are examined, to identify the least-cost forms of nitrogen. The results indicate that legume nitrogen can be cheaper or more costly than fertiliser nitrogen, depending on the legume used and that different outcomes can be obtained when different time horizons are used in assessing the cost of the nitrogen. Therefore, farmers need to make those comparisons for their particular situation before they can make informed decisions on the farm. Farmers need to be aware of these issues if they are to make fully informed decisions about their nitrogen use.