水氮减量对地膜玉米免耕轮作小麦主要光合生理参数的影响

Abstract

<p id="C3">The effect of no-tillage combined with water and nitrogen reduction of mulching maize on the stability and increase of wheat yield has been verified, but the research of the photosynthetic physiological mechanism of its formation is still relatively weak. From 2018 to 2020, the split zone design was adopted, and two farming methods of film-mulched corn no-tillage (NT) and traditional tillage (CT) was arranged with two irrigation levels of traditional irrigation (I₂, 2400 m ³ hm ^‒2) and traditional irrigation reduce 20% (I₁, 1920 m ³ hm ^‒2) and three nitrogen application levels of 225 kg hm ^‒2 (N₃), 180 kg hm ^‒2 (N₂) and 135 kg hm ^‒2 (N₁). The results showed that farming measures and nitrogen application level had significant effects on wheat leaf area index, photosynthetic potential, SPAD value, and photosynthetic rate; irrigation level had significant effects on photosynthetic rate. During the whole growth periods, compared with CT, NT increased wheat leaf area index, photosynthetic potential, SPAD value, and photosynthetic rate by 14.5%-44.1%, 13.2%-16.3%, 7.4%-9.0%, and 14.5%-24.2%, respectively; Compared with I₂, the photosynthetic rate of wheat I₁ decreased by 6.5%-13.6%. Compared with N₃, the leaf area index, photosynthetic potential, SPAD value, and photosynthetic rate of N₁ decreased by 6.4%-13.6%, 7.5%-12.7%, 6.0%-10.2%, and 7.5%-17.5%, respectively. There was no significant difference between N₂ and N₃. Cultivation measures, nitrogen application level, and irrigation level all had significant effects on dry matter accumulation and grain yield in wheat. Compared with CT, NT increased by 13.4%-16.5% and 9.0%-13.4%; Compared with I₂, I₁ decreased by 6.5%-6.7% and 4.3%-7.4%; Compared with N₃, the dry matter accumulation and grain yield of N₁ decreased by 10.0%-11.9% and 12.6%-19.4%, respectively, and there was no significant difference between N₂ and N₃. Correlation matrix analysis showed that the combined water and nitrogen reduction of no-tillage maize mulching could delay the decrease of wheat SPAD value, prolonged the photosynthetic time, and increased the photosynthetic potential and photosynthetic rate of wheat to increase yield.