Water-saving irrigation practices for rice yield information and nitrogen use efficiency under sub-tropical monsoon climate

Abstract

Simple and practical water-saving irrigation practices (WIP) with nitrogen-reduction are beneficial to the development of rice cultivation technology with promotion of resource-conservation and environmental friendliness. The effects of WIP with nitrogen-reduction on population quality, annual yield and nitrogen use efficiency were studied by a field experiment. WIP could maintain or increase the annual yield of rice production models. The highest annual yield of more-water-saving irrigation practice (WIP150) was 8.42t hmr2 for the double-season rice production model and 12.71t hmr2 for the ratoon rice production model, respectively. Compared with non-application of nitrogen, the annual yield of nitrogen-reducing practice (NRP) and farms' fertilizer practice (FFP) increased significantly (p < 0.01), while a non-significant difference of annual yield between the FFP and NRP was observed; the annual yield of the NRP and FFP was 9.73 and 10.02t hmr2 of the double-season rice production model, and 12.84 and 14.34t hmr2 of the ratoon rice production model, respectively. AEN, PEN, PFPN and RUEN of the NRP were higher than those of the FFP. Therefore, observing the change of water layer in the soil layer via a simple self-made PVC indicator tube, reducing about 20% nitrogen quantity was a feasible and simple cultivation technique for water-saving and nitrogen-reduction in the rice production models.