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

Effect of water and nitrogen reduction on main photosynthetic physiological parameters of film-mulched maize no-tillage rotation wheat

地膜玉米免耕结合水氮减量对小麦稳产增产的作用已经验证,但其形成的光合生理机制研究仍比较薄弱。2018—2020年,采用裂区设计,设置地膜玉米免耕(NT)和传统耕作(CT)两种耕作方式,传统灌水(I_(2),2400 m^(3) hm^(-2))和传统灌水减量20%(I_(1),1920 m^(3) hm^(-2)) 2个灌水水平和施纯N 225 kg hm^(-2) (N_(3))、180 kg hm^(-2) (N_(2))和135 kg hm^(-2) (N1) 3个施氮水平。结果表明,耕作措施、施氮水平对小麦叶面积指数、光合势、SPAD值、光合速率均有显著影响;灌水水平对光合速率影响显著。全生育期平均来看,NT较CT显著提高了小麦叶面积指数、光合势、SPAD值、光合速率,分别提高14.5%~44.1%、 13.2%~16.3%、 7.4%~9.0%、14.5%~24.2%;与I_(2)相比,I_(1)小麦光合速率显著降低了6.5%~13.6%。N1较N_(3)叶面积指数、光合势、SPAD值、光合速率分别显著降低了6.4%~13.6%、7.5%~12.7%、6.0%~10.2%、7.5%~17.5%,N_(2)与N_(3)无显著差异。耕作措施、施氮水平、灌水水平三者均对小麦干物质积累量和籽粒产量影响显著。NT较CT分别显著提高13.4%~16.5%和9.0%~13.4%;I_(1)较I_(2)分别显著降低6.5%~6.7%、4.3%~7.4%;与N_(3)相比,N1处理分别显著降低10.0%~11.9%、12.6%~19.4%,N_(2)与N_(3)无显著差异。关联矩阵分析表明,地膜玉米免耕结合水氮减量通过延缓小麦SPAD值的降低,延长光合时间,提高小麦的光合势和光合速率从而实现增产。

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(I_(2),2400 m^(3) hm^(-2)) and traditional irrigation reduce 20%(I_(1),1920 m^(3) hm^(-2)) and three nitrogen application levels of 225 kg hm^(-2)(N_(3)),180 kg hm^(-2)(N_(2)) 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 I_(2),the photosynthetic rate of wheat I_(1) decreased by 6.5%–13.6%.Compared with N_(3),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 N_(2) and N_(3).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 I_(2),I_(1) decreased by 6.5%–6.7% and 4.3%–7.4%;Compared with N_(3),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 N_(2) and N_(3).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.