【摘要】 为探索节水灌溉条件下蔬菜的水肥高效利用模式,采用番茄盆栽试验,以常规充分灌水为对照,研究了时空亏缺调控灌溉和氮肥处理对番茄营养器官干物质累积、灌溉水分利用效率、氮素累积及土壤水氮分布的影响。在交替灌溉条件下,设置控水时期、灌水水平和施氮水平3因素,控水时期分别为开花座果期和结果期,2个灌水水平分别为高水和低水,3个施氮水平分别为高氮、低氮和无氮,并以常规灌溉作为对照。结果表明:与常规充分灌水处理相比,交替灌溉持续高水处理、交替灌溉开花座果期低水处理、交替灌溉结果期低水处理及交替灌溉持续低水处理分别降低干物质累积总量4.52%、11.93%、17.76%和23.94%,分别降低氮素累积总量1.74%、12.86%、15.50%和22.47%,分别降低氮素干物质生产效率2.24%、3.93%、2.55%和0.89%,而分别增加灌溉水分利用效率12.39%、8.99%、15.02%和12.96%。在交替灌溉条件下,中氮处理的干物质累积、灌溉水分利用效率和氮素累积总量最大。与低氮处理相比,中氮和高氮处理的氮素干物质生产效率分别降低6.87%~12.70%和17.81%~24.38%,土壤硝态氮分别提高31.64%~159.58%和57.37%~297.37%。综合考虑干物质累积、水分利用及氮素累积等因素,番茄适宜的水氮供给模式为交替灌溉持续高水中氮处理:灌水定额为80%W0(W0为常规充分灌溉的灌水定额,保持土壤含水量为田间持水量的70%~85%),施氮量为0.30g(N)·kg-1(干土)。更多还原

【Abstract】 For sustainable water use in protected agriculture,crop-specific and water-saving irrigation techniques that do not negatively affect crop productivity must be developed.Globally,successful attempts have been documented regarding the use of deficit irrigation methods.Regulated deficit irrigation(RDI) and controlled alternate partial root-zone irrigation(CRAI) have been used to improve irrigation water use efficiency(IWUE) of various crops.Because nitrogen(N) has been the most widely used fertilizer,N demand was likely to grow in the future.Thus the optimization of water and fertilizer use in vegetable production was a critical water/fertilizer-saving strategy.Four irrigation treatments under CRAI and three N levels were explored for optimum modes of water and fertilizer supply in vegetable production under water-saving irrigation in a pot tomato experiment.The irrigation treatments were WH WH(high water level through out growth period),WH WL(high water level at flowering and fruit-setting stages with low water level at full-fruit stage),WL WH(low water level at flowering and fruit-setting stages with high water level at full-fruit stage) and WL WL(low water level through out growth period).Then the N levels included NH [high N,0.45 g(N)·kg-1],NM [medium N,0.30 g(N)·kg-1] and NL [low N,0.15 g(N)·kg-1].Using conventional irrigation(CI) as control experiment,the effect of spatio-temporal of deficit controlled deficit irrigation(STCDI),which combined RDI and CRAI,and N rates on the vegetative parts of tomato dry matter accumulation(DMA),irrigation water use efficiency(IWUE),N accumulation(NA) and soil water and mineral N distribution were studied.Compared with CI,the results showed that WH WH,WL WH,WH WL and WL WL under CRAI decreased tomato DMA by 4.52%,11.93%,17.76% and 23.94%,respectively.They respectively decreased NA by 1.74%,12.86%,15.50% and 22.47%.The four irrigation treatments decreased N dry matter production efficiency(NDMPE) by 2.24%,3.93%,2.55% and 0.89% and increased IWUE by 12.39%,8.99%,15.02% and 12.96%,respectively.DMA,IWUE and NA of NM were highest under CRAI.Compared with NL,NM and NH decreased tomato NDMPE by 6.87% 12.70% and 17.81% 24.38% while increasing soil NO3-N content by 31.64% 159.58% and 57.37% 297.37%,respectively.High DMA,IWUE and NA were obtained under WH WH,CRAI and NM.The optimum mode for water and N supply under CRAI was 80% of CI irrigation(which was 70% 85% of soil field capacity) and nitrogen rate of 0.30 g(N)·kg-1(dry soil).更多还原