干播湿出灌水量和灌水频率对棉田土壤板结、水盐分布及出苗的影响

Effects of irrigation quantity and irrigation frequency of dry sowing and wet seedling on soil compaction,water-salt distribution and seedling emergence in cotton fields

为探究干播湿出对棉花覆土板结程度、土壤水盐分布以及出苗情况的影响,设置不同出苗水量与灌水频率2个因素,共计6个处理和1个对照处理,分别为WP1(675 m^(3)·hm^(-2))、WP2(900 m^(3)·hm^(-2))、WP3(1125 m^(3)·hm^(-2))、WP4[(675+225)m^(3)·hm^(-2)]、WP5[(675+450)m^(3)·hm^(-2)]、WP6[(675+300+225)m^(3)·hm^(-2)]与冬灌处理,对各处理的表层覆土板结度、灌前与灌后含水率及含盐量、出苗率、株高、茎粗等指标进行分析。结果表明:表层土壤板结度受灌溉水总量与灌水频次影响,WP4处理表层土壤板结程度最低(99.87 kPa),少量高频灌溉可以降低表层土壤板结度;各处理膜间电导率最大,高于窄行土壤9%以上;WP4处理出苗率最高(84.74%);窄行电导率、窄行含水率和表层覆土板结度与出苗率均具有显著负相关关系,土壤含水率与窄行电导率与株高、茎粗均呈现显著负相关关系。通过评判各处理出苗率与生长指标,WP4处理为最优处理。

To investigate the effects of dry sowing and wet seedling on cotton soil compaction,soil water and salt distribution and seedling emergence,six treatments and a control treatment were set up with different emergence water and irrigation frequency,namely WP1(675 m^(3)·hm^(-2)),WP2(900 m^(3)·hm^(-2)),WP3(1125 m^(3)·hm^(-2)),WP4[(675+225)m^(3)·hm^(-2)],WP5[(675+450)m^(3)·hm^(-2)],WP6[(675+300+225)m^(3)·hm^(-2)]and winter irrigation treatments.The indexes of topsoil cover slab,water content and salinity before and after irrigation,seedling emergence,plant height,and stem thickness for each treatment were measured.The results showed that the surface soil slump was affected by the total amount of irrigation water and the frequency of irrigation,and the WP4 treatment had the lowest surface soil slump(99.87 kPa),and a small amount of high-frequency irrigation reduced the surface soil slump.The conductivity between the membranes was the highest for each treatment,being more than 9%higher than that of the narrow-row soil.The highest seedling emergence(84.74%)was observed for the WP4 treatment.The narrow-row conductivity,narrow-row water content and top-soil bulking all had significant negative correlations with seedling emergence,and soil water content and narrow-row conductivity showed significant negative correlations with plant height and stem thickness.By evaluating the seedling emergence rate and growth index of each treatment,WP4 treatment was the best treatment.