不同直播方式对水稻出苗状况的影响

摘要

To make clear the effects of rice direct seeding models on seedling emergence,taking Shengdao 2572 as material,the emergence rate and growth of seedlings were investigated under the conditions of dry direct seeding with the soil depth of 0,1,2,3 cm and water direct seeding with the water depth of 5,10 cm.The results indicated that the emergence rate decreased with the increase of soil and water depth.The emergence rate of H0,H1 and H2 treatments were all over 70％.Compared with H0 treatment,the emergence rate of H1,H2 and H3 treatments decreased by 10.9％ ～ 36.9％,and those of W5 and W10 treatments decreased by 30.8％ and 64.8％.For 18 days after sowing,the plant height,aboveground fresh weight and dry weight decreased with the increase of soil and water depth.H0 treatment had the highest plant height and the biggest aboveground fresh and dry weight.For 22 and 26 days after sowing,the plant height,aboveground fresh weight and dry weight increased with the increase of soil depth and decreased with the increase of water depth.The comprehensive analysis showed that the water depth under the water direct seeding had bigger influence on the rice emergence rate,plant height,aboveground fresh weight and dry weight.Under the condition of dry direct seeding,the suitable sowing depth was 2 ～ 3 cm.Under the condition of water direct seeding,the water depth after sowing was not more than 5 cm.%为明确不同直播方式对水稻出苗的影响,以圣稻2572为材料,测定其在旱直播条件下不同土层深度(0、1、2、3 cm)和水直播条件下不同水层深度(5、10 cm)的出苗率与幼苗生长情况.结果表明:随着土层和水层深度的增加,出苗率呈现下降趋势,H0、H1和H2处理出苗率均在70％以上,H1、H2、H3处理比H0处理的出苗率降低10.9％ ～36.9％;W5和W10处理比H0处理的出苗率降低30.8％、64.8％.播种后18天,株高、地上部鲜重和干重随土层和水层深度的增加而降低,具体表现为H0处理的株高最高,地上部鲜重和干重最大.播种后22、26天,随着旱直播播种深度的增加,水稻株高、地上部鲜重和干重开始表现出增加的趋势;随着水直播水层深度的增加,水稻株高、地上部鲜重和干重表现出降低趋势.综合分析,水直播下的水层深度对水稻出苗率、株高、地上部鲜重和干重的影响较大.旱直播条件下,适宜的播种深度为2 ～3 cm,水直播条件下播后水层深度不要超过5 cm.