宁南半干旱偏旱区旱作糜子田水分动态与平衡研究

Water Dynamic and Balance of Broomcorn Millet Field on Semiarid Prone to Draught Area of South Ningxia

1997～ 1999年在宁南半干旱偏旱区宁南 (海原 )旱农试区设置了旱作糜子田水分动态与平衡观测试验。结果表明 ,从播种至成熟 2m土层土壤含水率呈缓慢下降趋势 ,不同干旱年型水分变化动态略有不同 ,不同肥力处理水分变化动态差异不显著 ;0～ 2 0cm和 2 0～ 80cm土层含水率变化显著 ,不同肥力处理之间差异明显 ,80cm以下土层含水率相对稳定 ;糜子生长期降水量 189.8mm ,需水量 345mm ,实际耗水量仅 2 6 1.9mm ,水分亏缺 83.1mm ,水分满足率仅为 76 %。

The field experiment of water dynamic and balance of broomcorn millet on semiarid prone to draught area of south Ningxia was carried out in 1997 to 1999. The results of experiment show that soil water content of 2m soil layer decreased slowly from sowing to harvesting, there is a small difference in soil water content change in different rainfall years and little difference in soil water content change under different fertilizer treatments. There is a remarkable change in soil water content in 0～20cm and 20～80cm soil layers under different fertilizer treatments and relative small changes in soil water content below 80cm soil layer. The average rainfall and water requirement in broomcorn millet growth period is 189.8mm and 345mm respectively. The actual water consumption is only 261.9mm, with water shortage of 83.1mm, the proportion of soil water content is 76% only.