宁南山区不同种植体系土壤水分变化规律

Soil moisture distribution in different cultivating systems in mountainous area of south Ningxia Hui Aotonomous Region

了解旱地土壤水分变化状况,可为半干旱地区旱作农业水资源合理利用提供科学依据。该文通过田间试验,研究了宁南山区胡麻、冬小麦、马铃薯、草地和苜蓿等5类旱地在主要生长季节的土壤水分变化规律。结果表明,不同旱作农田土壤水分随时间的变化趋势基本一致,均出现失墒期和增墒期,其分界点多在7月中下旬;冬小麦、胡麻和马铃薯等1a生作物整个生长期内的土壤含水率要高于草地和苜蓿等多年生作物(植物);胡麻地、冬小麦地和马铃薯地的土壤水分垂直分布为上层低、下层高,而草地和苜蓿地相反。研究结果显示,各类旱地表层土壤水分变化剧烈,中下层变化相对较小,且生长期内的降水量均不能满足作物生长需求,秋季继续蓄墒是保障来年旱地获得良好收成的关键。

The study of soil moisture distribution of dry land crops can supply scientific evidences for water resource use. The article studied dynamic changes of soil water of five kinds dry land- winter wheat, flax, potato, alfalfa and natural grass in different stages. The results showed that temporal variations of soil moisture on different dry land crops were similar. All five kind crops include 'soil moisture content raising period' and 'soil moisture content declining period', that dividing line were at the middle of July. Soil moisture of annual crops (as winter wheat, flax and potato) were more higher perennial crop (as alfalfa and natural grass) in whole growing time. The soil moisture vertical distribution of winter wheat, flax and potato were ‘topsoil highness, subsoil lowness’, alfalfa and natural grass in reverse. Topsoil moisture movement was obvious, subsoil moisture movementwas inconspicuous all dry crops. In growing time, rainfall didn’t satisfy the all crops needs. The raising soil moisture in autumn is pivotal for harvest of dry crops.