井水灌溉条件下沿黄盐碱地水稻种植不同生育期土壤盐度动态变化

The dynamic changes of soil salinity in different growth periods of rice growing along the Yellow river in Shaanxi province under well water irrigation

为研究井水灌溉条件下陕西沿黄盐碱地水稻种植不同生育期土壤盐度的动态变化,以灌溉频率、灌水深度为因素开展大规模水稻田间试验,测定不同生育期不同深度土壤的电导率和pH。结果表明:0～40cm土壤电导率有所下降,土壤盐度呈脱盐趋势;而40～60cm土壤电导率升高,土壤盐度呈积盐趋势;土壤层越浅,水稻种植的脱盐作用越明显。水稻种植后的土壤pH较种植前有所增高,且20cm以下土层pH增加比浅层明显。不同灌水深度和灌水频率对土壤盐分的影响表现出了一定的差异,且灌水过勤、灌水量过大对土壤脱盐有一定的负面影响。水稻生育期中,土壤电导率和pH二者存在一定的负相关性,在土壤浅层表现得尤为显著。

In order to study the dynamic changes of soil salinity in different growth periods of rice planting in alkali land along the Yellow River,in Shaanxi province under well water irrigation,large-scale rice field experiments were carried out with irrigation frequency and irrigation depth as the factors,and the electrical conductivity and pH of soil at different depths in different growth periods were measured.The results show that:The electric conductivity of 0~40 cm soil decreased,and the soil showed a trend of desalination.However,the electric conductivity of 40~60 cm soil increased,and the soil tended to accumulate salt.The shallower the soil layer is,the more obvious desalination of rice planting shows.The soil pH after rice planting was higher than that before,and the pH in soil layer below 20 cm was higher than that in the shallow soil layer.The effects of irrigation depth and irrigation frequency on soil salinity were different,and overirrigation for exessvie times and amount of water had negative effects on soil desalination.During the growth period of rice,there was a negative correlation between soil conductivity and pH,especially in the shallow soil.