Study On Absorption And Utilization Of Nitrogen, Potassium & Water Productivity Under Insufficient Irrigation Of Hybrid And Aerobic Rice

The experiment was carried out on the middle rice (hybrid rice) and aerobic rice in 2002 at experimental filed of Zhanghe Irrigation Experimental Station, Hubei, following split-plot designs. The objective of this study was to quantify the effects of water saving irrigation and timing N-fertilizer, K-fertilizer application on rice growth. The main plots were water treatments: alternately wetting and drying, WAWD; flushing irrigation without standing water, FI (W30), flushing irrigation without standing water, FI (W50). The sub-plots were rice treatments, hybrid rice and aerobic rice. Sub-subplots were fertilizer treatments, consisted of two N-application treatments as: NO, control; N180, fore times input N-fertilizer, basal and three times applied after transplanted. And the total N input was 180 kg N/hm2 in the all growth-date. K-fertilizer and P-fertilizer were applied with 70kg/ hm2, all as basal application. The main results based on the experiments were as follows:1 , The WAWD treatment could improve the ANUE (Agronomic Nitrogen Use Efficiency) of the rice significantly. At the early growth-date of hybrid rice, WAWD could improve the AR (Apparent Recovery of Applied Nitrogen) and made the hybrid rice body stronger. Later of the hybrid growth-date, applied N-fertilizer could also improved the AR and lead into high yield. W50 was propitious to the absorption and utilization of N of the aerobic rice at the early growth-date and improved the AR. Later of the growth-date, WAWD was better than W50. N-application could improve the AR significantly2, Applied N-fertilizer could improve the contents of N and K in the panicles and grains significantly. The AWD could make rice absorb and utilize N and K, and make the hybrid yield and its related factors better. As to the aerobic rice, W50 was propitious to the absorption and utilization of N and K. W50 could improve the contents of N and K in the panicles and grains of aerobic rice, and increase the yield of aerobic. 3, The difference of the hybrid rice WP (water productivity) was evidence under different treatments. WP under FI was higher than the one under AWD. There was no significant difference between WP of two FI (W30 and W50) treatments, and WP under Wso treatment was a little higher than W30.As to aerobic rice, the effect of fertilizer on WP was less than on hybrid rice, and the difference was very distinct between different treatments. The WP of W30 , W50 was significantly higher than WAWD, and the WP of was W50 highest.;4, Appropriately water menacing was good to root growth and to absorbing and using N, K. Adding N-fertilizer was good for haulms and leaves of rice to grow and to absorb N, K, under the condition of AWD. W50 was much fit for aerobic rice.5 , Using N-fertilizer could improve rice height, tiller and parameter of, and increase rice growth. If the treatment was AWD, the shape of rice would be developed into rationalization. FI treatment was good for aerobic rice, and made the shape of rice rational.