腐植酸缓释钾肥对土壤钾素含量和甘薯吸收利用的影响

利用腐植酸和硫酸钾制备一种腐植酸钾肥(HA-K),沙柱淋溶试验结果表明其对钾素具有一定的缓释作用。为阐明施用腐植酸缓释钾肥对土壤不同形态钾素含量的影响,在田间小区试验条件下,研究了腐植酸缓释钾肥对土壤不同形态钾素含量以及甘薯产量和对钾素吸收利用的影响。结果表明:与不施钾（空白对照）相比,施用腐植酸促进了甘薯对钾素的吸收,降低了甘薯全生育期土壤中的速效钾和缓效钾含量以及生长前期土壤有效钾含量,但是提高了甘薯生长中、后期土壤有效钾含量。与施等量氧化钾对照相比,施用腐植酸缓释钾肥促进了甘薯对钾素的吸收,降低了甘薯全生育期土壤缓效钾含量和甘薯生长前、中期土壤速效钾和有效钾的含量,提高了甘薯生长后期土壤速效钾和有效钾的含量。与施等量氧化钾对照相比,施用腐植酸缓释钾肥显著提高了钾肥吸收利用率(REK)、农学利用率(AEK)、偏生产力(PFPK)和甘薯块根产量,增幅分别为20.09 %,42.69 %,5.89%和22.83%。

Effects of Ha-K fertilizer on potassium content of soil and absorption and utilization of potassium in sweet potato

Humic acid was compounded with K2SO4 to produce a kind of Ha-K fertilizer in this study.The evaluation results of using the potassium sand leaching method indicate that the Ha-K fertilizer has slow-releasing effect on potassium.In order to clarify the effects of the Ha-K fertilizer on the contents of different forms of potassium of soil,the field study was conducted to investigate the effects of Ha-K on the contents of different forms of potassium of soil,the yield of storage root,and the absorption and utilization of potassium in sweet potato.The results show that compared with the control,the application of the HA promotes the absorption of potassium in sweet potato,reduces the rapidly available potassium and slowly available potassium contents in soil during the whole growth period,reduces available potassium content in soil during the early growth period of sweet potato,and increases the available potassium content in soil from intermediate to later periods of sweet potato.Compared with the equivalent K2O contrast,the application of Ha-K promotes the absorption of potassium in sweet potato,reduces the slowly available potassium content in soil during the whole growth period of sweet potato,reduces the rapidly available potassium and available potassium contents in soil during the early growth period while increases the rapidly available potassium and available potassium contents in soil during the later period.Compared with the equivalent K2O contrast,the recovery efficiency of potassium fertilizers(REK),agronomy efficiency of potassium fertilizers(AEK),partial factor productivity from applied K(PFPK) and the yield of storage root are increased by 20.09%,42.69%,5.89% and 22.83% in the Ha-K treatment.