Effect of nitrogen on photosynthetic pigments of relay strip intercropping soybean under drought stress

A pot experiment was designed under drought stress condition to study the effect of different nitrogen levels on photosynthetic pigments in the leaves of relay strip intercropping soybean. The Chla, Chlb, were measured, Chl content, Chla/b was calculated. The result showed that effects of nitrogen and drought stress on Chla were not as big as that of Chlb. When severe drought happened, Chla content reduced significantly, mild and moderate drought stress did not decrease Chla content significantly. With N supply, mild and moderate drought enhanced Chlb content and Chl content, but Chlb content and Chl content decreased significantly when drought happened without N supply. Appropriate N supply is recommended to improve photosynthetic pigments efficiency under drought stress.