Are reduced acidification rates a feasible, achievable option for future agricultural systems?

Abstract

Soil acidity is a major soil constraint impacting on the productivity and sustainability of Australianagriculture. While soil acidification is a natural process it is accelerated by agricultural production. Application of lime is an effective means of neutralising soil acidity. However, the cost and availability of sources of lime in some areas, increased cost of accessing and spreading lime, variable yield responses to liming and a drive to improve the environmental sustainability of current agricultural systems have lead to interest in farming systems that are less acidifying. To date there has been little work to examine the feasibility or practicality of reducing acidification rates. We used a simple, mechanistic model to estimate the likely impact on acidification rates of a range of crop management options. Data from a factorial of runs of a simulation model were used to provide probabilistic estimates of nitrate leaching under different crop management. From these analyses we concluded that rates of acidification could only be reduced by from 5–30%. These values represent the upper limit of estimates from this analysis.