EFFECT OF WATER-NITROGEN COUPLING ON YIELD ANDWATER USE EFFICIENCY OF KIDNEY BEAN

摘要

In order to reveal the efficient utilization mech- anism of water and fertilizer in Kidney bean with dif- ferent water and nitrogen management modes, this article explores the effects of different water and ni- trogen management modes on kidney bean physiol- ogy, growth and water use efficiency. Through pot experiment, this paper set 2 kinds of irrigation amount (W1: conventional irrigation, W2: controlled irrigation) and 5 different kinds of nitrogen applica- tion rate (NO: 0 kg/hm2, NI: 25 kg/hm2, N2: 30 kg/hm2, N3:35 kg/hm2. N4:40 kg/hm2). This article observes the physiological growth and water use ef- ficiency of Kidney bean. The results showed that the dry matter mass increased with the growth of nitro- gen application and was positively correlated with the vield. Under conventional irrigation conditions. chlorophyll A, chlorophyll B, chlorophyll total, ni- trate reductase activity, and yield of kidney bean leaves showed a trend of first increasing and then de- creasing with the growth of nitrogen application. Un- der WIN3 treatment, they reached the maximum value and the water use efficiency was the highest. Under the controlled irrigation condition, the W2N4 treatment reached the maximum value. However, the W2N3 treatment reached the maximum value, which is only 4% higher than W2N4 treatment, with no sig- nificant difference. The yield and water use effi- ciency of WIN3 treatment were 33.31% and 24% higher than those of W2N4 treatment were. There- fore, in summary, WIN3 treatment (80% field water capacity, nitrogen application 35kg/hm2) is the opti- mal combination of water and nitrogen.