Combined effect of nitrogen and phosphorous fertiliser on nitrogen absorption and utilisation in rice

Abstract

The objectives of this study were to investigate the nitrogen (N) and phosphorus (P) balance fertilization strategy in paddy fields, and to evaluate the effects on N uptake and utilization in rice. In 2017-2018, the experiment was conducted using Deyou4727 hybrid rice with four different P fertilizer levels (0, 30, 60, and 90 kg/ha), marked as P0, P1, P2, P3 in turn, and four different N levels (0, 90, 150, and 270 kg/ha), similarly marked as N0, N1, N2, N3 in turn. The results showed that in the N-insufficient (N0, N1) environments, the P1 treatment increased N uptake and promoted transfer to the grain. However, high-P (P3) application increased the dry matter accumulation than other P levels, but limited the production and translocation of dry matter to some extent. In N-sufficient (N2, N3) environments, P2 level increased crop yield and N use efficiency by 11.35% and 37.01%. Unlike P2, none-P (P0) and high-P levels decreased rice dry matter translocation and transport capacity, which further affected N uptake and utilization in N-sufficient environments. Overall, the combination of the N application rate of 90 kg/ha and P application rate of 30 kg/ha, N application rate of 150, 270 kg/ha, and P application rate of 60 kg/ha had a high yield; strong nutrient accumulation and transfer ability. It was more inclined to balance N and P, which was beneficial to plant N absorption and utilization.