宁夏引黄灌区春小麦不同生育期土壤有效氮磷钾养分含量的动态变化特点

Variation of Soil Available Nutrient Contents in Farmlands at Different Growth Stages of Spring Wheat in Irrigating Region of Ningxia

采用肥料田间试验和测试分析方法,研究了宁夏引黄灌区春小麦不同生育期耕层土壤有效养分含量的变化特点。结果表明,在小麦生育期间,不施肥处理土壤铵态氮、硝态氮、速效氮、有效磷和速效钾含量的变异系数分别为36.6%、106.6%、24.3%、18.2%、32.2%,而施肥处理其分别为22.7%、82.7%、41.4%、23.8%、19.5%,施肥可使铵态氮、硝态氮和速效钾的变异性降低。平均来看,土壤硝态氮的变异性最大,而有效磷和速效钾的变异性较小。在不施肥条件下,铵态氮和速效钾均出现2个高峰期和2个低峰期,硝态氮仅在分蘖期较高,速效氮和有效磷没有明显的高峰和低峰期。在施肥条件下,铵态氮出现3个高峰期和2个低峰期,硝态氮出现2个高峰期和2个低峰期,速效氮和有效磷在分蘖期较高,速效钾在整个生育期变化幅度较小。但施肥能明显提高土壤有效养分含量。

Field experiment and testing analysis were conducted to study the variation of soil available nutrient contents in the plowing layers（0-20 cm） of farmlands at different growth stages of spring wheat in irrigating region by Yellow River water of Ningxia. The results showed that the variation coefficients of soil ammonium, nitrate, readily available nitrogen ,available phosphorus and quick available potassium contents during wheat growth period were 36.6%,106.6%,24.3%,18.2%,32.2% without fertilization and 22.7% ,82.7% ,41.4%,23.8% ,19.5% with fertilization,respectively. The fertilization to soil can decrease the variation coefficients of soil ammonium,nitrate nitrogen and quick available potassium. On average,the variation coefficient of soil nitrate nitrogen was the most,and that soil available phosphorus and quick available potassium was less under fertilization condition. There were 2 high peaks and 2 low peaks for soil ammonium nitrogen and quick available potassium, only a higher value for soil nitrate nitrogen at tillering stage,no significant high peak and low peak for soil readily available nitrogen and available phosphorus during wheat growth period without fertilization. There were 3 high peaks and 2 low peaks for soil ammonium nitrogen,2 high peaks and 2 low peaks for soil nitrate nitrogen,higher values for soil readily available nitrogen and available phosphorus at tillering stage,hardly variation for soil quick available potassium at wheat growth stages with fertilization. Fertilization can increase the contents of soil available nutrients.