免耕覆盖对旱地玉米生长发育的影响  

Study on Corn Growth and Development under No-tillage with Stalk Mulching in Semi-arid Regions

作　　者：籍增顺[1] 刘虎林[1] 洛希图[1] 武金芳 张象俊 

机构地区：[1]山西省农业科学院农业资源综合考察研究所,汾阳县区划办

出　　处：《山西农业科学》1994年第3期22-27,共6页Journal of Shanxi Agricultural Sciences

摘　　要：玉米拔节以前其生长点一直处在地表以下，免耕覆盖后玉米生长早期５ｃｍ土壤温度比常规耕作低４℃左右，抑制了前期玉米的生长速度和叶分化速度，使各生育时期相应推迟；免耕覆盖玉米生长发育可分为两个阶段，即土壤温度决定期和土壤水分决定期；春季多雨、夏旱年份，免耕覆盖玉米最大生长速度明显大于常规耕作；在春夏连旱年份，免耕覆盖玉米旺盛生长期比常规耕作显著延长；随覆盖量增加，玉米最大生长速度增大；免耕覆盖造成的前期土壤温度回升慢，形成玉米弱苗，这样一个低温一弱苗组合有利于增强作物一土壤系统的抗旱性。与常规耕作相比，免耕覆盖后玉米根系拔节以前长度短、于重低，拔节后逐渐超过对照，但根系分布以浅层为主。中后期充足的土壤水分配合浅层庞大的根系，使免耕覆盖玉米根系伤流明显多于常规耕作；免耕覆盖土壤水分充足，使玉米中后期绿叶片多，植株体内含水量高，穗粒数提高１７．７％，千粒重高１０．１％。Growing point of the corn is under the soil surface before stem elongation, lower soil temperature under mulch would retard early season corn growth. Each growth and development stage was delayed compared to convenntional tillage. Corn growth and development was divided into two stages, i. e. Stage controlled by soil temperature, and stage controlled by soil water. Before stem elongation, mulched corn at emergence were spindly with narrow-leaves. Lower soil temperature-spindly seedling under no-tillage with mulch could mitigate a contradiction between water utilization and shortage in water in semi-arid region. With heavy mulches, roots tended to accumulate at the surface of the soil and beneath the mulch. The concentration of roots in this later was attributed to moisture conditions. Compared to conventional tillage mean number of seeds per ear and weight per 1000 seeds incerased 17. 7 % and 10. 1 %, respectively, under natillage with mulching.

关 键 词：旱地 免耕 覆盖 玉米 根系 

分 类 号：S513.051[农业科学—作物学]