水氮耦合对盐碱地柳枝稷光合生理及生物质产量的影响

通过设置750 m3/hm2(W1)、1 500 m3/hm2(W2)、3 000 m3/hm2(W3)3个灌水及施氮0 kg/hm2(F0)、60 kg/hm2(F1)、120 kg/hm2(F2)、240 kg/hm2(F3)4个水平,研究水氮对盐碱地柳枝稷光合生理特性及生物质产量的影响.结果表明:施氮和灌水对盐碱...

Effects of Water-nitrogen Coupling on Photosynthetic Physiology and Biomass Yield of Switchgrass in Saline-alkali Soil

The effects of water and nitrogen on photosynthetic physiological characteristics and biomass yield of switchgrass in saline-alkali land were studied by three irrigation levels of 750 m/hm(W1), 1 500 m/hm(W2), 3 000 m/hm(W3) and four nitrogen levels of 0 kg/hm(F0), 60 kg/hm(F1), 120 kg/hm(F2), and 240 kg/hm(F3).The results showed that nitrogen application and irrigation had significant effect on the soil moisture content at 0-20 cm soil layers in saline-alkali land, and the soil moisture content at 20-40 cm soil layers was mainly affected by nitrogen fertilizer; The irrigation and nitrogen management simultaneously affected the leaf chlorophyll content,net photosynthesis rate, transpiration rate, stomatal conductance and biomass yield, and its order was water effect > water-nitrogen coupling effect > nitrogen fertilizer effect. The synergistic effect of nitrogen fertilizer will stop increasing after it reached a certain level; The correlation analysis showed that there was a significant positive correlation between switchgrass biomass yield and photosynthetic indicators during flowering stage. In the saline-alkali area of northern Yinchuan plain, appropriate irrigation and nitrogen management was beneficial to increase the chlorophyll content of switchgrass at flowering stage, and promoted leaf photosynthesis, and higher biomass yield was obtained under the condition of irrigation amount of 3 000 m/hm and nitrogen application level of 120 kg/hm.