免耕播种机在干湿土壤条件下的性能对比试验

Performance of a no-till seeder under dry and wet soil conditions

免耕播种到干燥的土壤中(在灌溉前)的作物与免耕播种在潮湿土壤中相比,节省了大量的时间。播种到干燥的土壤中会缩短作物的收获期。在干土壤条件下,免耕播种的关键是种子播种精度,对免耕播种机的种子播种精度的研究很少。针对玉米、棉花在干湿土壤件下研究双圆盘式开沟器的免耕播种机的性能。并对大豆、小麦在两种不同残茬量的土壤进行了试验。测定平均出苗时间、出苗率、重播指数、漏播指数、播种均匀度和播深均匀度。湿土中的免耕播种推迟所有作物的出苗时间,增加玉米和大豆的出苗百分比。大豆植株出现在干土壤条件下的百分比相对较低,因此本研究中使用免耕播种机将大豆播种到干粉质粘土壤土的效果较差。湿土和残茬量较少的播深均匀性优于干土壤和全残茬量地。研究结果同时表明,将玉米和棉花播种到干湿土壤中,大豆播种到湿土中,有一个可接受的变异性范围。

No-till sowing of second crops into dry soil(i.e.before irrigation)results in significant savings in time compared to no-till sowing into wet soil.Sowing into dry soil can also result in the earlier harvest of second crops.Seed plac ementaccuracy is critical with no-till sowing into dry soil and there is little research on the seed placement accuracy of no-till seeders under dry soil conditions.The performance of a no-till seeder,equipped with a double disc-type furrow opener,was investigated under dry and wet soil conditions using maize(Zea mays L.),cotton(Gossypium hirsutum L.),and soybean(Glycine max L.)seeds sown following wheat(Triticum aestivum).The experiments were carried out on soils covered with two different crop residue levels.Mean emergence time,percentage of emergence,multiple index,miss index,quality of feed index,precision index of horizontal distribution pattern,and sowing depth uniformity were determined.No-till sowing into wet soil delayed emergencefor all plants and increased percentage of emergence for maize and soybean.The percentage of emergence of soybean plants for dry soil condition was relatively low;therefore the no-till sowing of soybean into dry soil using a no-till seeder experienced in this study was not satisfactory for silty clay loam soils.The horizontal distribution pattern and sowing depth uniformity in the wet soil and reduced crop residue plots were better than those in the dry soil and whole crop residue plots.The range of precision indices used in this study indicated that there was an acceptable range of variability for sowing maize and cotton into dry and wet soils and for soybean into wet soil.