铁茬不同处理方式对夏玉米籽粒灌浆积累、生理特性和土壤含水量的影响

Effects of different stubble treatments on grain filling and accumulation,physiological characteristics of summer maize and soil water content

研究了铁茬不同处理方式对夏玉米籽粒灌浆积累、生理特性和土壤含水量的影响.结果表明:铁茬不同处理方式夏玉米授粉15 d之前千粒质量增长缓慢,授粉25 d之后籽粒灌浆积累逐渐加快,授粉30 d籽粒灌浆积累速度最快,随后逐渐降低.拔节前单株干物质的累积比较缓慢,低于对照T4(传统耕翻),拔节后进入生殖生长始单株干物质累积明显加快并且高于对照,质量增加比与单株干物质的累积变化趋势基本一致.苗期株高与对照相比均有不同程度降低,拔节始株高渐渐追上并超过对照.产量性状中穗粒数、千粒质量的提高是产量比对照增产的主要原因,T1(立茬免耕)、T2(立茬秸秆覆盖免耕)、T3(灭茬秸秆覆盖免耕)产量比对照T4分别增产10.55%、12.24%、7.48%.苗期铁茬不同处理方式可以减少表层土壤水分的蒸发,有效增加土壤水分含量,但随着生长发育进程的发展对土壤的抑蒸作用渐渐减弱.

Study was conducted to the effect of different stubble treatments on grain filling and accumulation,physiological characteristics of summer maize and soil water content.The results showed that summer maize 1000-grain weight of different stubble treatments increased slowly 15 days before pollination,grain filling accumulation increased gradually 25 days after pollination,which was the fastest after 30 days pollination,and then decreased gradually.Dry matter per plant accumulation was slower than conventional tillage before jointing stage,after jointing stage,which was significantly accelerated at the beginning of reproductive growth and higher than the control.The basic change trend of mass gain ratio was the same as dry matter accumulation per plant.At seedling stage,plant height decreased in different degree comparison with the control,which gradually overtook and exceeded the control at the beginning of jointing stage.The increase of ear grain numbers and 1000-grain weight in yield characters was the main reason for yield increase comparison with the control,the yield of T1(standing stubble no-tillage),T2(standing stubble no-tillage with straw mulching)and T3(pulverized straw mulching no-tillage)increased by 10.55%,12.24%and 7.48%respectively comparison with control T4(conventional tillage).Different stubble treatments can reduce evaporation of surface soil water at seedling stage,effectively increase soil water content,however,with the development of growth process,inhibition evaporation gradually weakened on soil.