盐渍化棉田施用含氯肥料对土壤及棉花产量的影响

Effect of Chlorine Fertilizer Application in Saline Soil on Soil Cl^- and Cotton Yield

采用模拟土柱方法,研究了含氯肥料施入盐渍化土壤后Cl-的淋溶及残留特点,并通过田间试验研究了不同程度盐渍化土壤施用硫酸钾和氯化钾后对棉花产量及对土壤盐分、Cl-残留的影响。模拟试验结果表明,施入土壤中的Cl-很容易被淋洗掉,在不考虑返盐的情况下,每年正常降雨量能够将40 cm土层中氯离子淋洗掉的数量可高达施肥带入量的24~74.7倍。田间试验结果表明,在速效钾含量332 mg/kg的土壤上,棉花施用2种钾肥均未表现出明显的增产效果,而在速效钾含量189.5 mg/kg的土壤上,棉花施用2种钾肥增产效果都显著。在轻度盐渍化土壤上,施用硫酸钾和氯化钾的产量差异不显著,但在中度以上盐渍化土壤上,硫酸钾的增产效果显著高于氯化钾。在氯化钾施用量较大的情况下,20~40 cm土层中的盐分和氯离子含量明显增加。

The leaching and residual characteristics of Cl-in saline soil were studied after the chlorine fertilizer application,adopting simulated soil column method.Also the application effects of potassium sulfate and potassium chloride on cotton yield,soil salinity and Cl-residue were studied through plot trials with different soil salinities.Simulated experiment results showed that the added Cl-was very easy to be leached out.The possibility of Clleached amount out of 0-40 cm soil layer under normal annually rainfall could reach as high as 24-74.7 times of the added amount,without considering its upward movement.Plot trials results showed that cotton yield did not increase statistically with the application of two kinds of potassium fertilizer,under the soil available K content of 332 mg / kg,while it increased statistically under the soil available K content of 189.5 mg / kg.Cotton yield did not differed remarkably between two kinds of potassium fertilizer application under light salinity soil,while potassium sulfate application showed remarkably higher yield-increasing effect compared with potassium chloride,under mid salinity soil.The salinity and Cl-content in 20-40 cm soil layer increased obviously under higher amount application of potassium chloride.