深松蓄水和施磷对旱地小麦产量和水分利用效率的影响

【目的】针对黄土高原旱地小麦干旱缺水、肥料不合理施用的问题,探索旱地小麦休闲期深松蓄水和播前配施磷肥的最佳技术途径。【方法】于2012—2016年连续4年在山西农业大学闻喜旱地小麦试验基地开展试验,主区为休闲期深松与对照2个耕作方式,副区为施磷(P_2O_5)0、75、150、225、300、375 kg·hm~(-2) 6个施磷量处理,以明确年际间休闲期深松和播前配施磷肥对旱地小麦产量和水分利用效率的影响。【结果】夏季休闲利于旱地麦田土壤水分恢复,可提高土壤蓄水效率20%—86%;休闲期深松较对照显著提高播种期3 m内土壤蓄水量24—90 mm;提高穗数1%—18%,提高产量3%—25%,提高2012—2013年水分利用效率4%—20%。施磷肥对土壤水分有一定影响,施磷量在0—225 kg·hm~(-2)范围内,旱地小麦生育期内0—300 cm土壤蓄水量以施磷量150 kg·hm~(-2)最低;施磷(4年定位试验)降低了生育期内0—300 cm土壤蓄水量,各处理间差异以第4年最显著。本试验中施磷肥的第3年和第4年的土壤水分未达平衡,施磷量150 kg·hm~(-2)与未施磷肥间的周年耗水量差异显著,说明长期施磷肥增加了作物对水分的消耗和利用,0—300 cm土壤蓄水量会降低。随施磷量(0—225 kg·hm~(-2))增加,旱地小麦4年平均产量和水分利用效率表现为先增加后降低的变化趋势,并且均以施磷量150 kg·hm~(-2)最高,产量各处理间差异显著,水分利用效率施磷量150 kg·hm~(-2)与未施磷肥处理间差异显著。此外,F测验显示年份对产量和水分利用效率影响最大,增产效果显示休闲期深松的增产效果高于磷肥的增产效果,最终4年定位试验形成的播前0—300 cm底墒414—546 mm配施磷量150 kg·hm~(-2)、底墒556—607 mm配施磷量75 kg·hm~(-2),穗数、产量、水分利用效率均较高。【结论】旱地麦田休闲期深松有利于蓄积休闲期降水,改善底墒;施磷增加了旱地小麦对土壤水分的消耗和利用,降低了生育期土壤水分,增加了周年耗水;休闲期深松每多蓄1 mm水分可增产2—31 kg·hm~(-2),在施磷量0—150 kg·hm~(-2)范围内每多施1 kg·hm~(-2)磷肥可增产2—13 kg·hm~(-2);播前0—300 cm底墒550 mm以下配施磷量150 kg·hm~(-2)、底墒550 mm以上配施磷量75 kg·hm~(-2)均可实现较高的产量和水分利用效率。

Effects of Sub-Soiling in Fallow Period and Phosphorus Fertilizer on Yield and Water Use Efficiency in Dry-Land Wheat

【Objective】 To cope with the drought, lower water storage and unreasonable fertilization of dry-land wheat in the Loess Plateau, the best technology way of water conservation of sub-soiling at fallow period and phosphorus fertilization at sowing stage of dry-land wheat was explored. 【Method】 Field experiments were carried out from 2012 to 2016 in Qiujialing village, Wenxi, Shanxi, the main plots were dealt with two tillage methods of sub-soiling and no tillage during fallow period, the subplots were dealt with six pure phosphorus fertilization amount of 0, 75,150, 225, 300, 375 kg·hm^-2,in order to make clear the effect of sub-soiling during fallow period and phosphorus fertilization on yield, water use efficiency of dry-land wheat in different years. 【Result】 The results showed that soil storage efficiency was improved by 20%-86% during fallow period. Under sub-soiling during fallow period, soil water storage of 3 m soil layer was improved by 24-90 mm significantly, spike number was improved by 1%-18%, yield was improved by 3%-25%, water use efficiency was improved by 4%-20% in 2012-2013. The results also showed that phosphorus levels affected dry-land wheat soil water storage of 0-300 cm soil layer, which was the lowest at 150 kg P·hm^-2 under the range of 0-225 kg·hm^-2 phosphorus amount, and was decreased under the long-term phosphorus application (4 year positioning test), and the difference was significant the fourth year. The difference of soil water because of different water consumption of phosphorus was restored through precipitation during fallow period, in the third and fourth year, soil moisture is not balanced, annual soil water consumption was different between phosphorus of 150 kg·hm^-2and0. In the end, with the phosphorus fertilizer amount (0-225 kg·hm^-2) increasing, average yield and WUE of four years were largest under phosphorus of 150 kg·hm^-2, and the differences of yield were significant among different treatments, differences of WUE were significant between 150 kg·hm^-2and0. In addition, the F value test showed that years had the greatest influence on yield and water use efficiency, the yield increase effect of sub-soiling was higher than that of phosphorus fertilizer. The sowing water storage of 0-300 cm layer with more than 550 mm combined with the phosphorus amount of 75 kg·hm^-2, or below 550 mm combined with the phosphorus amount of 150 kg·hm^-2, made the spike number, yield and WUE higher. 【Conclusion】 Sub-soiling during fallow period is conducive to the accumulation of the precipitation and the improvement of the sowing water storage. Phosphorus fertilizer increased soil water consumption of dry-land wheat, decreased soil water storage of 0-300 cm during growth stages, increased annual water consumption. Yield was increased by 2-31 kg·hm^-2 with increase of 1 mm water storage of sub-soiling during fallow period, yield increased by 2-13 kg·hm^-2 with increase of 1 kg·hm^-2 phosphorus amount. The sowing water storage below 550 mm of 0-300 cm combined with the phosphorus amount of 150 kg·hm^-2, or the sowing water storage more than 550 mm combined with the phosphorus amount of 75 kg·hm^-2 could achieve higher yield, water and fertilizer efficiency.