Nitrate accumulation under pea cropping and the effects of crop establishment methods: a sustainability issue.
Evans, J.; Fettell, N. A.; O'Connor, G. E.;
Australian Journal of Experimental Agriculture Year: 1996 Vol: 36 Issue: 5 Pages: 581-586 Ref: 24 ref.
1996
บทคัดย่อ
Two field experiments were conducted on red, clay-loams in the cropping zone of central western New South Wales (Australia) to determine whether soil mineral N concentrations during crop growth are higher under pea than barley, and whether the nitrate concentration under pea crops can be decreased by amending soil with cereal straw before sowing. There was higher mineral N, particularly nitrate, under pea than under barley, as early as 6 weeks following autumn sowing, and also in spring. The pea effect represented an increase of less than or equal to 23 kg N/ha of mineral N (0-30 cm). It is proposed that the source of higher nitrate concentration under pea may be residual soil nitrate not utilized by pea, or nitrate derived from the mineralization of pea roots or exudate. The increase in soil nitrate during pea growth contributes to greater postharvest soil mineral N and higher wheat yields after pea, but also increases the risk of soil acidification. Soil amendment with cereal straw was partial
ly effective in reducing nitrate concentration under pea, but a more effective treatment is required.