小麦填闲减施磷肥对连作黄瓜生长及土壤酶活性的影响

Effects of Wheat Cover Crop and Phosphorus Fertilizer Reduction on Growth and Soil Enzyme Activity in Continuously Cropped Cucumber(Cucumis sativus L.)

以黄瓜为试材,采用盆栽的方式,设置5个梯度的磷肥施用量,即P_(100)(常规施用量)、P_(75)(常规施用量的75%)、P_(50)(常规施用量的50%)、P_(25)(常规施用量的25%)及P_(0)(不施磷肥),研究采用小麦填闲处理后不同施磷水平下黄瓜生长、产量、果实品质及土壤酶活性的变化情况。结果表明,与不填闲相比,填闲有助于提高黄瓜植株茎粗、全株鲜质量、全株干质量,增加产量,增加黄瓜果实糖酸比、可溶性蛋白及VC含量,降低果实硝酸盐含量,提高土壤酶活性。在填闲处理中,与其他施磷水平相比,P_(50)处理黄瓜产量最高,为1.78 kg·株^(-1),显著高于其他处理,黄瓜茎粗、全株鲜质量、全株干质量在定植后的第20、35天时均最高。P_(25)处理的黄瓜果实可溶性蛋白含量最高,P_(50)处理的VC含量、糖酸比均较高,果实硝酸盐含量较低。在第20、35天时,P_(50)处理的土壤脲酶、酸性磷酸酶、碱性磷酸酶活性均较高,均与P100处理差异显著。第50天时,P_(25)、P_(50)处理的土壤蔗糖酶活性较高,P_(0)、P_(50)处理的过氧化氢酶活性较高,均与P100处理差异显著。综上,在小麦填闲条件下,将磷肥施用量减少至8.71 g·株^(-1)时(P_(50)处理)可有效促进连作黄瓜的生长,增加产量,提高品质,增加土壤酶活性,是设施连作黄瓜栽培较为理想的磷肥施用量。

This study evaluates the impact of varying phosphorus fertilizer levels on the growth,yield,fruit quality of cucumbers,and soil enzyme activity following a wheat cover crop.A pot trial was conducted using cucumber(Cucumis sativus L.)withfive phosphorus application levels:P_(100)(conventional application),P_(75)(75% of conventional application),P_(50)(50%of conventional application),P_(25)(25% of conventional application),and P_(0)(no application).Results demonstrated that compared with no cover crop treatments,the wheat cover crop positively influenced stem diameter,total fresh biomass,total dry biomass,yield,sugar-acid ratio,soluble protein,and VC content while reducing nitrate levels and enhancing soil enzyme activity.Notably,in the wheat cover crop treatments,the P_(50) treatment yielded the highest production of 1.78 kg per plant,with peak values in stem diameter,total fresh biomass,and total dry biomass observed at 20、35 days post-transplanting.Soluble protein content was the highest in P_(25) treatment,while P_(50) treatment exhibited a higher VC content and sugar-acid ratio along with a lower nitrate level.Additionally,at 20、35 days after transplanting,urease,acid phosphatase,and alkaline phosphatase activities were significantly higher in P_(50) than P_(100).By 50 days after transplanting,sucrase activity in P_(25) and P_(50),and catalase activity in P_(0) and P_(50) were relatively high and significantly exceeded those in P_(100).Thus,under wheat cover crop conditions,reducing phosphorus fertilizer to 8.71 g per plant can effectively enhance cucumber growth,yield,fruit quality,and soil enzyme activity,making it the optimal phosphorus application level for continuous cucumber cropping.