半干旱区减氮增钾、有机肥替代对全膜覆盖垄沟种植马铃薯水肥利用和生物量积累的调控

Regulations of Reduced Chemical Nitrogen, Potassium Fertilizer Application and Organic Manure Substitution on Potato WaterFertilizer Utilization and Biomass Assimilation Under Whole Field Plastics Mulching and Ridge-Furrow Planting System on Semi-Arid Area

【目的】减氮增钾和有机肥替代是提高中国作物生产中资源利用效率、改善农田生态环境、提升农产品质量和降低作物生产病害风险的有效途径。研究明确半干旱区全膜覆盖垄沟种植马铃薯减氮追施、有机肥替代和增施钾肥对马铃薯干物质积累和水分利用的影响,为该区域实施水肥高效管理提供依据。【方法】在4年大田定位试验基础上,通过测定全膜覆盖垄沟种植条件下传统施肥(PM)、减氮25%并花期追施和增施钾肥(PMN)和减氮50%与有机肥替代并花期追施(PMO)的土壤贮水量、马铃薯的生物量和产量等指标,计算不同施肥模式的耗水量、生长速率、水分利用效率和肥料偏生产力,以明确不同养分管理模式对马铃薯耗水过程的调控及其对干物质积累和水肥利用效率的影响。【结果】2011—2014年PMN花前耗水量较PM分别降低了17.4、28.7、26.8和34.2 mm,花后耗水量增加了31.1、34.7、36.7和49.2 mm;PMO没有显著降低马铃薯花前耗水,而花后耗水量分别增加了17.8、24.3、11.2和10.3 mm。与PM相比,PMN在盛花期后显著提高马铃薯地上地下生物量和生长速率,使马铃薯产量在2012—2014年平均增加2 595.1 kg·hm-2,并使水分利用效率(WUE)在2013—2014年分别增加了14.4%和6.3%,达到显著差异;PMO显著提高马铃薯各生育期的地上地下生物量和生长速率,4年平均马铃薯块茎产量增加了2 945 kg·hm-2,而且WUE在2012—2014年显著高于PM。PMN和PMO较PM均能显著提高马铃薯肥料偏生产力、化肥偏生产力、氮素偏生产力和化肥氮素偏生产力,表明PMN和PMO能协同提高作物的养分和水分利用效率,实现以肥调水和以水促肥的目标。2011年为严重干旱年份,虽然PMN和PMO能调节马铃薯花前花后耗水,提高地上地下生物量和生长速率,显著提高养分偏生产力,但产量和水分利用效率无显著提高。【结论】PMN和PMO均能显著调节马铃薯花前花后耗水量,增加生物量和提高生长速率,使得马铃薯块茎产量、水分利用效率和养分利用效率增加。与PMN相比,PMO对马铃薯产量、WUE和养分偏生产力的增加幅度更大,是资源更加高效和作物增产的养分管理模式。

【Objective】Chemical nitrogen fertilizer reduction, potassium fertilizer application and organic manure substitution are useful methods to increase crop resource use efficiency, enhance agro-environment, improve quality of agricultural products and decrease the disease risk in China. The understanding on the effects of reduced chemical nitrogen fertilizer dressing, organic manure substitution and potassium fertilizer application on potato dry matter assimilation and water utilization, are helpful to apply the efficient managing strategy of water and nutrient resource.【Method】A 4-year field experiment was carried out from 2011 to 2014 with three treatments：（1） traditional chemical fertilizer application（PM）,（2） chemical nitrogen fertilizer reduced by 25% and dressing at flowering stage, and potassium fertilizer application（PMN）, and（3） chemical nitrogen fertilizer reduced by 50% and organic manure substitution, and potassium fertilizer application（PMO）. The soil moisture, potato biomass and yield had been investigated, crop water consumption, potato growth rate, water use efficiency（WUE） and partial factor productivity from applied fertilizer（PFP） were calculated to understand the effects of different nutrient management methods on potato dry matter assimilation and water-nutrient use efficiency, as well as its regulations on potato water use process on semiarid rain-fed area.【Result】The potato water consumption decreased by 17.4, 28.7, 26.8, 34.2 mm in pre-flowering stage, but increased by 31.1, 34.7, 36.7, 49.2 mm in post-flowering stage in PMN treatment, compared with PM. PMO increased the potato water consumption by 17.8, 24.3, 11.2, 10.3 mm than PM in post-flowering stage, but had no significant effect in the pre-flowering stage. Compared with PM, PMN increased potato above- and under- ground biomass, as well as the growth rate after early blooming, caused 2 595.1 kg·hm-2 tuber yield increment from 2012 to 2013 averagely; the water use efficiency（WUE） increased by 14.4% and 6.3% in 2013 and 2014, the significant difference observed in these years. PMO significantly increased potato above- and under- ground biomass, and the growth rate, resulted in 2 945 kg·hm-2 tuber yield increment in 4 experimental years on average. Its WUE was significantly higher than PM from 2012 to 2014. PMN and PMO increased potato fertilizer partial factor productivity from applied fertilizer（PFPT）, chemical fertilizer partial factor productivity from applied fertilizer（PFPC）, nitrogen partial factor productivity from applied fertilizer（PFPTN） and chemical nitrogen partial factor productivity from applied fertilizer（PFPCN） as compared with PM. It was indicated that PMN and PMO increased nutrient and water use efficiency synergistically, both realized the objective to regulate water utilization by fertilizer application, and improve nutrient utilization by water management. In 2011（dry year）, PMN and PMO regulated the water consumption between pre- and post- flowering stage, increased above- and under- ground biomass, growth rate and PFP, but the potato tuber yield and WUE didn＇t increase significantly.【Conclusion】Both PMN and PMO regulated potato water consumption between pre- and post- flowering stage significantly, and increased potato biomass and growth rate, resulted in increased tuber yield, WUE and PFP. However, PMO showed more significant effects than PMN on the increment of tuber yield, PFP and WUE, so it was the more efficient nutrition management model for higher resource use efficiency and yield under whole field plastics mulching and ridge-furrow planting system on semi-arid areas.