干湿交替灌溉与硝化抑制剂对水稻产量及土壤性状的影响

探明干湿交替灌溉与硝化抑制剂对水稻产量以及土壤性状的影响,以期为水稻高效栽培提供理论依据和技术参考。采取干湿交替灌溉方式,以“金香玉1号”和“扬稻6号”为试验材料,设置4个处理,分别为尿素（CK）、尿素+双氰胺（DCD）、尿素+3,4-二甲基吡唑磷酸盐（DMPP）、尿素+DCD+DMPP。DCD和DMPP为硝化抑制剂。结果表明,在相同灌溉方式下,与CK处理相比,硝化抑制剂的添加有利于获得较高的产量,提高了穗粒数和结实率。与CK处理相比,添加DCD、DMPP以及DCD与DMPP配施,均提高了水稻生育时期的土壤脲酶和蔗糖酶活性,降低了水稻生育时期土壤硝酸还原酶活性。另外,各硝化抑制剂处理均显著提高了水稻生育时期土壤铵态氮含量,降低了硝态氮含量,在此基础上增加了土壤有效态氮含量。其中DMPP抑制效果优于DCD,且2种抑制剂同时配施作用效果优于其单独施用。在干湿交替灌溉方式下,硝化抑制剂处理在水稻关键生育期有利于产生较高土壤养分,能进一步增加水稻产量。

Effects of Dry-Wet Alternate Irrigation and Nitrification Inhibitor on Rice Yield and Soil Properties

The impacts of dry-wet alternate irrigation and nitrification inhibitors on rice yield and soil properties were investigated for providing theoretical foundation and technical reference for efficient rice cultivation. The dry-wet alternate irrigation method was adopted, with “Jinxiangyu 1” and “Yangdao 6” as the test materials, and four treatments were set up, urea (CK), urea+DCD, urea+DMPP, and urea+DCD+DMPP, the nitrification inhibitors were DCD and DMPP. The results indicate that under the same irrigation method, compared with CK treatment, the inclusion of nitrification inhibitor had a higher yield owing to its higher number of grains per panicle and seed setting rate. Compared with CK treatment, the inclusion of DCD, DMPP and the combined use of DCD and DMPP increased the activity of soil urease and invertase, while decreased the activity of soil nitrate reductase during the growth period of rice. In addition, various nitrification inhibitors the treatments significantly increased soil ammonium nitrogen (NH₄⁺-N) during the growing season of rice and reduced nitrate nitrogen (NO₃^--N) levels and on this basis increased soil available nitrogen levels. Among them, the inhibitory effect of DMPP was better than that of DCD, and the combined effect of the two inhibitors at the same time was better than that of their single use. In general, the nitrification inhibitor treatment had higher soil nutrients during the key growth period of rice under the condition of dry-wet alternate irrigation, which could further increase rice yield.