干旱区施不同浓度硝酸钾对后备耕地土壤水盐的影响

Effects of Different Concentrations of Potassium Nitrate on Water and Salt of Reserved Land in Arid Area

采用野外试验和室内分析相结合的方法,研究施用不同量硝酸钾对新疆盐碱土水盐及离子分布的影响。结果表明:(1)随着外源硝酸钾施入土壤,土壤上层含水率增加,下层减少。(2)土壤上层的全盐含量增大,并且施钾浓度越高含盐量也越高。(3)施钾样地整个土层的Ca2+、Mg2+、SO42-浓度相对于对照地(非施钾样地)有所增加,而Na+和Cl-浓度降低。当施钾浓度为400mg/L时上层Na+浓度显著增加,可能对作物造成危害;施钾浓度达到1 000mg/L时Na+浓度变化不大,即施钾浓度越高Na+浓度越低。(4)施钾浓度为1 000mg/L时,土壤上层钠吸附比(SAR)、Cl-/SO42-大大降低。施用硝酸钾可增加后备耕地土壤上层的含水量,减少钠吸附比(SAR)、Cl-/SO42-,有利于农作物的生长,但也增加了土壤上层的含盐量。

Using a combined method of field trial and analysis indoor to investigate the improvement of reserved land of Xinjiang in the arid area, the article studied the effects of different concentrations of potassium nitrate on water, salt and ions distribution. Results showed that the water content of soil increased in the upper horizons, decreased in the lower horizons through using fertigation of potassium nitrate-using fertilizers. Meanwhile, the total salt content of the upper layer increased, and it was higher with the high potassium nitrate-using concentration. Compared to CK（unpotassium nitrate-using fertilizers land）, Ca2＋, Mg2＋ and SO~ concentrations increased, but Na＋ and CI- concentrations reduced. Na＋ concentration in the upper horizons relatively increased with 400 mg/L potassium nitrate-using fertilizer, but it could be harm to the crop. However it changed little with 1 000 mg/L potassium nitrate-using fertilizer. Na＋ concentration decreased with increasing potassium nitrate-using concentration. The sodium absorption ratio （SAR） and C1-/SO42-- significantly reduced when it was 1 000 mg/L potassium nitrate-using fertilizer. The increasing of water in the upper horizons in reserved land and the decreasing of sodium absorption ratio（SAR） and C1-/SO^- through using fertigation of potassium nitrate-using fertilizers would benefit for crop growth, but also make soil salt content increase in the upper horizons.