稻草与钾肥配合施用对冬作马铃薯土壤钾素的影响

Effects of combined application of rice straw and potassium fertilizer on soil K of winter potato

为研究施钾肥和稻草还田对南方冬作马铃薯土壤钾素状况的影响,在施氮磷肥基础上设计了稻草与钾肥不同组合的盆栽试验。结果表明:相对于仅施氮磷肥,增施钾肥和稻草可显著增加土壤速效钾、有效钾、缓效钾含量,且以氮磷钾肥配施稻草处理对土壤钾素提高的效果明显好于氮磷肥基础上施用钾肥或稻草;至马铃薯成熟期,氮磷钾肥配施稻草处理的土壤速效钾、有效钾和缓效钾含量平均高180.13%、125.16%和10.62%,而且较种植前也有较大提升,土壤速效钾含量平均提高33.33%。钾肥与稻草不同配比中以T5(K3S2)、T8(K2S3)对土壤钾素影响比较明显,速效钾和缓效钾含量比种植前分别增加69.69%、14.09%和81.98%、10.76%。从节约资源和改善土壤钾素状况综合考虑,在南方早稻-晚稻-马铃薯种植模式下,钾肥和稻草施用量以199.7 kg/hm2和9 000 kg/hm2较佳。

In order to research the effects of potassium（K） fertilizer application and rice straw（S） application on soil potassium in southern winter potato, a pot experiment was conducted with different combinations of S and K fertilizer on the basis of nitrogen（N） and phosphate（P） fertilizer application. The main results showed that added K fertilization and S could increase the contents of soil available K, effective K and slowly available K compared to only appling N and P fertilizer, and increment effects of combination NPKS were better than those of combination NP with K or S. In potato maturation stage, compared to NP, soil available K, effective K and slowly available K of NPKS treatment, average increased by 180.13%, 125.16% and 10.62% respectively, and soil available K increased by 33.33% compared to before cultivating potato. T5（K3S2） and T8（K2S3） treatments had significant influence on soil K status, soil available K and slowly available K respectively increased by 69.69%, 14.09% and 81.98%, 10.76%compared to before cultivating potato. To conserve resource and improve soil K status, it was better to appling K with199.7 kg/hm2 and S fertilizer 9 000 kg/hm2 under early rice-late rice-winter potato cropping pattern.