磷钾肥施用对日光温室土壤溶液离子组成的影响

Effects of application of phosphorus and potassium fertilizers on ion compositions of soil solution in solar greenhouse

采用土培模拟试验研究了施用磷、钾肥对大田和温室土壤溶液电导率(EC)、离子含量及其比例的影响。结果表明,温室栽培土壤溶液EC、K+、Na+、Ca2+、Mg2+、NO3-含量以及K+/Ca2+、K+/Mg2+摩尔比分别为大田土壤的2.5、95.0、16.6、1.9、3.2、4.0、31.0和39.0倍,说明日光温室土壤离子累积及养分比例失调问题突出。施用磷、钾肥对土壤溶液中不同离子含量的影响不同,增加磷肥施用量,显著降低了大田和温室土壤溶液EC和Ca2+、Mg2+离子含量,而对土壤溶液K+、NO3--N和NH4+-N离子浓度均无显著影响;随施钾量增加,大田及温室土壤溶液EC、K+、Na+、Ca2+、Mg2+和K+/Ca2+、K+/Mg2+摩尔比均呈显著增加趋势。温室栽培实践中因过量施用磷、钾肥而造成的阳离子养分比例失调而带来的营养及生态环境问题值得关注。

An incubation method was used to study the effects of application of phosphorus（P） and potassium（K） fertilizers on the electric conductivity（EC） and ion compositions in soil solution under sunlight greenhouse.The EC and concentrations of K＋,Na＋,Ca2＋,Mg2＋,NO3-ions and mole ratios of K＋ / Ca2＋,K＋ / Mg2＋ in soil solution of greenhouse without addition of fertilizer were 2.5,95.0,16.6,1.9,3.2,4.0,31.0 and 39.0 times of that in arable soil,respectively,indicating the serious accumulation and imbalances of ions in greenhouse soil.The application of P and K fertilizers had different effects on ion composition of soil solution.Addition of P fertilizer significantly decreased the EC and concentrations of Ca2＋,Mg2＋ ions both in arable and greenhouse soils,its effect on concentrations of K＋,NO3——N and NH4＋-N ions in the soils was not significant.As the increasing addition of K fertilizer,the EC and concentrations of K＋,Na＋,Ca2＋,Mg2＋ ions and mole ratios of K＋/Ca2＋,K＋/Mg2＋ in solutions of arable and greenhouse soils increased.The study indicated that the effects of inadequate application of P and K fertilizer on the over accumulation of salts and cation imbalances deserve further study.