有机物料还田对夏玉米穗位叶光合性能及氮代谢的影响

Effects of organic material returned on photosynthetic performance and nitrogen metabolism of ear leaf in summer maize

明晰不同物料还田对夏玉米穗位叶光合性能及氮代谢的影响,为有效利用农业废弃物提供理论依据。2018—2019年在川中丘陵区石灰性紫色土上进行大田试验,设置无物料还田(CK)、蚕豆秸秆还田(faba bean straw,FS)、油菜秸秆还田(rape straw,RS)、猪粪还田(pig manure,PM)4个处理,研究不同物料还田下夏玉米产量、叶片光合性能及氮代谢的特征。结果表明:(1)不同有机物料还田第2年FS处理的玉米籽粒增产效果最佳,比CK显著增加24.85%。(2)各物料还田处理的夏玉米叶面积指数、叶面积积累速率、群体光合势和光合色素含量,随生育期推进均呈先增后降的趋势。与CK比,FS、PM处理提高叶面积指数、叶面积积累速率和群体光合势,但RS处理有降低效果;夏玉米六叶期光合色素含量在处理间差异不显著,吐丝期叶绿素b、总叶绿素和类胡萝卜素含量均是RS处理比CK显著增加,但吐丝后20d时FS处理的叶绿素a、b、总叶绿素含量分别比RS处理显著增加34.67%、42.08%、36.24%。(3)有机物料还田显著增加夏玉米穗位叶硝酸还原酶活性,各还田处理的营养器官氮素积累与转运表现为FS、PM>RS。主成分分析结果表明,不同物料还田下夏玉米光合性能、氮代谢能力表现为FS>PM>CK>RS。综上,不同有机物料还田对玉米光合性能和氮代谢影响不同,对比无物料还田和油菜秸秆还田,蚕豆秸秆和猪粪还田更有利于提高叶片光合氮代谢能力,促进营养器官中的光合代谢产物向籽粒运输,从而为夏玉米籽粒产量的增加奠定基础。

The objective of this study is to clarify the effects of returning different materials on photosynthetic performance and nitrogen metabolism of summer maize,and to provide a theoretical basis for the effective use of agricultural wastes.Field experiments were conducted on calcareous purple soil in hilly areas of central Sichuan in 2018 and 2019.Four treatments were set up,including no material returning(CK),faba bean straw(faba bean straw,FS),rape straw(rape straw,RS),and pig manure(pig manure,PM)returned.The yield,photosynthetic performance,and nitrogen metabolism of summer maize by different materials returned were studied.The experimental results show that:(1)By different organic materials returned,the effect of FS in the second year on maize grain yield was the best,which was significantly increased by 24.85%compared with the CK.(2)The leaf area index,leaf area accumulation rate,leaf area duration,and photosynthetic pigment content of summer maize each material returned all increased first and then decreased with the growth period.Compared with CK,FS,and PM could improve leaf area index,leaf area accumulation rate,and leaf area duration of summer maize,but the effect of RS was decreasing.The photosynthetic pigment content of summer maize at 6-leaf stage was not significantly different among treatments.The chlorophyll b,total chlorophyll,and carotenoid content of RS at silking stage were the higher than CK.At 20 days after silking,the contents of chlorophyll a,b,and total chlorophyll of FS were significantly increased by 34.67%,42.08%,and 36.24%compared with RS,respectively.(3)Organic material returned significantly increased the nitrate reductase activity of summer maize,and the nitrogen accumulation and transport in vegetative organs of each returning treatment were FS,PM>RS.The results of principal component analysis revealed that the photosynthetic performance and nitrogen metabolism capacity of summer maize by different materials returned to the field were FS>PM>CK>RS.In summary,the effects of different organic materials returned on photosynthetic performance and nitrogen metabolism of maize were different.Compared with no material and rape straw returned,faba bean straw and pig manure returned can improve the photosynthetic nitrogen metabolism ability of leaves,promote the transport of photosynthetic metabolites in vegetative organs to grains,and lay the foundation for the increase of grain yield of summer maize.