The influence different farming systems have on soil nitrogen, phosphorus and potassium – NSW northern region

Abstract

Key findings • Most farming systems extract more nutrients than are supplied by common fertilisation strategies. • Increasing the frequency of legumes in the system does not necessarily reduce the nitrogen (N) inputs required, but it does increase the potassium (K) export across the crop sequence. • Higher soil mineral N levels have been maintained by increasing fertiliser applications, but grain yields or total system N use have rarely been increased.