苗带少耕对黄淮海夏玉米产量形成与根冠特征的影响

Effects of Minimal Belt Tillage on Yield Formation and Root Cap Characteristics of Summer Maize in the Huanghe-Huaihe-Haihe River Area

为探讨苗带少耕方式对夏玉米根冠特征和产量的影响,于2019年玉米季分别在泰安市马庄镇岳洋农业专业合作社和德州市农业科学院试验田进行玉米贴茬直播(CK)和苗带少耕(MT)两种耕作方式对比试验。结果表明,耕作方式影响吐丝期和灌浆中期的单株玉米根系总干重,泰安点和德州点均表现为MT> CK,吐丝期MT较CK分别增加8.92%、7.38%,灌浆中期分别增加5.40%、5.44%,且苗带少耕较CK能够显著增加21~60 cm土层根系干重。两试点,21~40 cm土层MT根长比CK分别增加7.16%、9.95%,根表面积分别增加9.66%、10.94%;41~60 cm土层MT根长比CK分别增加17.79%、6.76%,根表面积分别增加26.54%、33.07%。两试点叶面积指数灌浆中期分别提升5.15%、10.23%。两试点大喇叭口期单株干物质积累量分别增加44.0%、32.8%,吐丝期分别增加5.78%、8.21%,灌浆中期分别增加24.96%、16.15%,成熟期分别增加11.64%、15.02%。上述农学指标的改善在保障玉米群体密度的同时,两试点穗粒数分别增加14.92%、14.44%,千粒重分别增加19.96%、10.46%,产量分别增加8.57%、11.48%。本研究表明,玉米苗带少耕能够改善土壤理化性状、促进根系下扎和伸长、提升干物质积累量,从而增加穗粒数和千粒重,进而提高产量。

In order to explore the effects of minimal belt tillage on the root cap characteristics and yield of summer maize,a comparative experiment of two tillage methods including minimal belt tillage(MT)and direct seeding of corn stubble(CK)was conducted in the experimental field of Yueyang Agricultural Professional Cooperative in Mazhuang Town,Taian City and Dezhou Academy of Agricultural Sciences in 2019.The results showed that the total dry weight of roots of per plant was affected by tillage methods at silking stage and middle grain filling stage,and that of MT was higher than that of CK at Taian and Dezhou points,which increased by 8.92%and 7.38%at silking stage,and 5.40%and 5.44%at middle grain filling stage respectively,and the root dry weight of 21~60-cm soil layer was significantly increased by MT.The root length of MT in 21~40-cm soil layer increased by 7.16%and 9.95%,and root surface area increased by 9.66%and 10.94%.The root length of MT in 41~60-cm soil layer increased by 17.79%and 6.76%compared with CK in the two test points,and the root surface area increased by 26.54%and 33.07%.Leaf area index(LAI)increased by 5.15%and 10.23%respectively at the middle grain filling stage.The dry matter accumulation per plant increased by 44.0%and 32.8%,5.78%and 8.21%,24.96%and 16.15%,11.64%and 15.02%at bell mouth stage,silking stage,middle filling stage and mature stage,respectively,in the two test points.With the improvement of agronomic indexes,the number of grains per ear increased by 14.92%and 14.44%,thousand-grain weight increased by 19.96%and 10.46%,and yield increased by 8.57%and 11.48%,respectively.In this study,it was found that minimal belt tillage of maize could improve soil physical and chemical properties,promote root binding and elongation,increase dry matter accumulation,and increase grain number per ear and thousand-grain weight,thus increasing the yield of maize.