适雨灌溉下不同施肥模式对机插稻稻田水环境及产量的影响

【目的】探讨江汉平原地区适雨灌溉条件下不同施肥模式对机插稻稻田水环境及水稻生长的影响,为当地机插稻水肥管理措施的改善提供理论和数据支撑。【方法】采用田间小区试验,研究了适雨灌溉条件下,农民习惯施肥(FFP)、70%控释掺混肥+30%尿素(70%CRF+30%N)和有机无机复混肥(OIF)对稻田降雨利用率、田面水氮磷质量浓度的动态变化与径流流失量、干物质积累及水稻产量的影响。【结果】适雨灌溉下,返青期、分蘖期、拔节孕穗期和灌浆成熟期的降雨利用率分别为17.5%、100%、100%和84.2%;基肥和分蘖肥施用过后,FFP、70%CRF+30%N和OIF处理田面水TN、NH4+-N和TP质量浓度迅速提高,在第1天达到峰值,水稻移栽后30 d内70%CRF+30%N处理田面水TN、NH4+-N和TP的平均质量浓度较FFP处理分别降低40.4%、47.4%和0.5%;稻田氮磷径流流失量的90%左右在返青期,10%左右在灌浆成熟期,70%CRF+30%N处理TN、NH4+-N和TP径流损失量较FFP处理分别降低31.4%、30.9%、1.9%;70%CRF+30%N处理在返青期干物质积累量显著低于FFP和OIF处理,移栽-返青期阶段干物质积累量占总积累量比例表现为FFP处理>OIF处理>70%CRF+30%N处理,成熟期OIF处理干物质积累量显著高于70%CRF+30%N和FFP处理,实际产量表现为OIF处理>70%CRF+30%N处理>FFP处理。【结论】适雨灌溉条件下,70%CRF+30%N处理有助于减少稻田氮素流失,OIF处理有助于机插稻干物质积累与产量的增加。

Effects of Different Fertilization Models on Paddy Water Environment and Yield in Machine-transplanted Rice under Irrigation Adjusted by Rainfall

【Objective】Machine-transplanted rice has the characteristics of young seedling age, long seedling stage and heavy plant injury, etc.. Exploring the effects of different fertilization modes on paddy water environment of machine-transplanted rice and rice growth under rainfall adaption irrigation in Jianghan Plain can provide theoretical and data support for the improvement of water and fertilizer management measures of local machine-transplanted rice.【Method】The field plot experiments were carried out to study the effects of farmers’ fertilization practice(FFP), 70% controlled release compound fertilizer+30% urea(70%CRF+30%N), Organic-inorganic mixed fertilizer(OIF) on rainfall utilization rate, dynamic changes of nitrogen and phosphorus concentration in surface water, runoff loss, dry matter accumulation and rice yield under rainfall adaption irrigation.【Result】Rainfall utilization efficiency at the re-greening stage, tillering stage, jointing booting stage and filling maturity stage were 17.5%, 100%, 100% and84.2%, respectively, under rainfall adaption irrigation. After application of base fertilizer and tillering fertilizer, the concentrations of TN, NH4+-N and TP increased rapidly in surface water of FFP, 70% CRF+30% N and OIF treatments, reaching the peak value on the first day. The average concentrations of TN, NH4+-N and TP in surface water with 70% CRF+30% N decreased by 40.4%, 47.4% and 0.5%, respectively, in 30 days after rice transplantation compared with FFP treatment. About 90% of nitrogen and phosphorus runoff loss in paddy field was in the re-greening stage, and about 10% was between grouting to ripe period, and the runoff loss of TN, NH4+-N and TP were 31.4%, 30.9% and 1.9% lower in 70% CRF+30% N than that in FFP;The dry matter accumulation of 70% CRF+30% N treatment was significantly lower than that in FFP and OIF treatmentat the re-greening stage. The proportion of dry matter accumulation in total accumulation was shown as FFP>OIF>70% CRF+30% N in thetransplant to re-greening stage. The dry matter accumulation of OIF treatment at the mature stage was significantly higher than that in 70% CRF+30% N and FFP treatment, and the actual yield was as bellow: OIF>70% CRF+30% N>FFP.【Conclusion】Under the condition of rainfall adaption irrigation, 70% CRF+30% N was helpful to decrease nitrogen runoff loss in paddy, and OIF was contributive to increase dry matter accumulation and yield of machine-transplanted rice.