旱作对水稻生长及氮、磷利用效率的影响

为了探明旱作对水稻氮、磷利用效率的影响以及产量与氮磷营养的关系,通过温室微区试验研究了传统水作(CT)、覆膜旱作(FM)和裸地旱作(LD)下水稻产量、产量构成因子、氮磷累积、氮磷收获指数、氮磷生理利用效率等的差异。结果表明:旱作在一定程度上阻碍了水稻生长,降低了稻谷产量,产量构成因子中的千粒重受旱作影响较小;FM处理的稻谷产量比CT处理下降6.47%,但未达显著差异,另外,氮、磷累积量均没有受到明显影响;然而LD处理产量的下降幅度则达14.9%,且氮磷累积量均明显下降;与氮磷生理利用效率相比,水稻氮磷收获指数对旱作敏感程度更高,FM和LD处理均显著低于CT处理,其中,LD处理下降程度更大。相关性分析表明,水稻产量与氮素营养的相关性要高于与磷素营养的相关性。总之,FM处理能有效降低旱作对水稻生长及养分利用效率的影响,调控好氮、磷营养,特别是氮素营养有利于旱作条件下水稻生长及产量形成。

Effects of upland cultivation on rice grain yield and N & P use efficiency

To investigate the effects of upland cultivation on N & P use efficiency and the relationship between grain yield and N & P nutrition, a micro-zone experiment in greenhouse was conducted to study rice grain yield, yield components, N & P accumulation, N & P harvest index, N & P physiological use efficiency, and correlation between yield and N & P nutrition under conventional floodwater cultivation (CT), film mulching cultivation (FM), and uncovered cultivation (LD) treatments, respectively. The results showed that upland cultivation inhibited rice growth to some extent and lowered grain yield. However, grain weight was least affected with upland cultivation. Grain yield under FM treatment was reduced by 6.47% compared with that under CT treatment, which was not at a significant level. Also, N & P accumulation under FM treatment were not apparently affected. However, LD treatment reduced grain yield by 14.9% and decreased N & P accumulation. Additionally, N & P harvest indexes were more sensitive to upland cultivation than N & P physiological use efficiency. Though both FM and LD treatments had reduced N & P harvest indexes, LD treatment played a more predominant role. It was further found that rice grain yield showed better correlation with N nutrition than P nutrition. Therefore, it was concluded that FM treatment could efficiently alleviate the effects of upland cultivation on rice growth and nutrients use efficiency. In addition, better N & P nutrition management, especially N nutrition, was favorable for improving rice growth and grain yield.