农田不同耕层构造对玉米生长发育及产量的影响

摘要

在公主岭市吉林省农科院长期定位试验田（1983年）4种耕层构造（上虚下实、全虚耕层、全实耕层和虚实并存）上，通过对玉米出苗率、株高、茎粗、叶片数、叶面积、根系及产量指标测定，探讨不同耕层构造对玉米生长发育及产量的影响。结果表明，虚实并存耕层玉米出苗率为94．90％，明显高于其他耕层，增加苗期玉米株高和茎粗，叶片数较全虚耕层和上虚下实耕层分别增加0．8和1．2片，但与全实耕层相比差异不明显。从玉米生育中后期来看，虚实并存耕层促进玉米生长发育，增加叶面积，改善根系性状，与上虚下实耕层比较，根条数增加16．80条，气生根和地下根干重分别增加4．60g和20．50g，且气生根层数增加0．80层。同时，虚实并存耕层玉米产量显著高于其他耕层，增产幅度为8．17％～15．02％，上虚下实耕层产量最低。可见，虚实并存耕层“既发小苗，又发老苗”，稳产高产，是较为理想的耕层构造。%A long-term positioned experiment had been conducted since 1983 in Gongzhuling empolying plow tillage (PT ) ,no-tillage (NT ) ,spacing tillage (NT ) and conventional tillage (CT ) .The seeding rate ,plant height ,stem diam-eter ,leaf number , root and yield of maize were measured in the study in odrder to investigate the effects of different tillage layer structures on growth and yield of maize .The results showed that the seeding rate was higher in spacing tillage (94 .90% ) ,than that in other treatments .The height and stem diameter of seeding stage were increased in ST .More-over ,compared to those in PT and CT ,leaf numbers in ST were significantly increased by 0 .8 and 1 .2 ,which was not significantly different from that in NT .After flowering stage ,the growth of maize was enhanced ,leaf area of plants was increased and mass of roots was improved .In particular ,compared with CT ,root numbers were increased by 16 .80 ,lay-ers of aerial root were increased by 0 .80 ,gaining 4 .60 and 20 .50 g weight in stalk root and aerial root ,respectively . Meanwhile ,the yield of maize with ST treatment was higher than that with other treatments , ranging from 8 .17% to 15 .02% and the yield of maize was lowest in CT .Therefore ,ST was the optimal layer because it could enhance the growth of seeding and delay the process of decrepitude of maize in black soil zone in Jilin province .