交替根区滴灌下不同施氮量对葡萄干物质积累、分配和产量的影响

Effects of different nitrogen application rates on dry matter accumulation, distribution and yield of grape under alternate partial root-zone drip irrigation

本试验采用盆栽的方法,在避雨栽培条件下,研究不同的灌溉方式和供氮水平对葡萄干物质积累与分配、产量和水氮生产效率的影响,以探讨北方鲜食葡萄生产最佳的水氮耦合管理模式。灌溉方式包括常规灌溉100%灌溉量(CDI)、单侧固定根区灌溉50%灌溉量(FDI)和双侧根区交替灌溉50%灌溉量(ADI);土壤施氮浓度设置0.4(N_(1))、0.8(N_(2))、1.2 g·kg^(-1)(N3) 3个水平。结果表明:与CDI模式相比,ADI和FDI总修剪量降低了34.8%和11.2%;随着施氮量的增加,生长冗余增加;CDIN3处理葡萄树体冗余生长最高。ADI干物质积累量最高,分别比CDI、FDI提高5.1%和12.8%;N_(2)和N3处理的树体总干物质量显著高于N_(1)处理。与其他灌溉模式相比,ADI模式下叶果比显著降低,收获指数显著提高;施氮量对各项指标影响不显著。所有组合中,ADIN_(2)处理冗余生长量与当年生物量比值最低。葡萄产量表现为ADI分别比CDI和FDI平均提高6.0%和10.4%,同一灌溉模式下,产量随着施氮量的增加而增加,以ADIN_(2)、ADIN3耦合处理葡萄产量最高。与其他灌溉模式相比,ADI模式显著提高了葡萄水分利用效率,以ADI与N_(2)、N3水平的耦合处理水分利用效率较高;不同施氮水平下,氮素利用效率表现为ADI>CDI>FDI,并随施氮水平的增加而降低。综合分析认为,ADIN_(2)处理能够减少葡萄冗余生长,有利于干物质向果实积累,产量较高,水氮生产效率较高,是较适宜北方葡萄生产的水氮组合模式。

To get an optimal mode of irrigation and nitrogen supply for table grape production in North China, a pot experiment was conducted to investigate the effects of different irrigation modes and N application rates on dry matter accumulation and distribution, yield, water use efficiency, and nitrogen use efficiency of table grape. The irrigation modes included conventional drip irrigation(CDI, with sufficient irrigation), alternate partial root-zone drip irrigation(ADI, with 50% amount of the irrigation water of CDI) and fixed partial root-zone drip irrigation(FDI, with 50% amount of the irrigation water of CDI). The nitrogen application rates were set at 0.4(N_(1)), 0.8(N_(2)) and 1.2(N3) g·kg^(-1) dry soil. The results showed that compared with CDI, ADI and FDI reduced new shoot pruning amount by 34.8% and 11.2%, respectively. New shoot pruning amount increased with increasing N application rates, being highest under CDIN3. Dry matter accumulation of ADI was the highest, being 5.1% and 12.8% higher than CDI and FDI. Dry matter accumulation was higher under N_(2) and N3 than N_(1). Compared with CDI and FDI, leaf to fruit ratio reduced but harvest index significantly increased in ADI, while those variables showed no significant difference among diffe-rent N application rates. The ratio of pruning amount to the biomass accumulated in the current year in ADIN_(2) was the lowest among the treatments. Compared with CDI and FDI, ADI increased grape fruit yield by 6.0% and 10.4%, respectively. Fruit yield was enhanced with increasing nitrogen application rates under the same irrigation condition, with the highest yield under the ADIN_(2) and ADIN3. Water use efficiency(WUE) increased significantly in ADI compared with CDI and FDI, with the highest value being observed in ADI coupled with N_(2) or N3. Nitrogen use efficiency(NUE) showed a trend of ADI>CDI>FDI. In addition, NUE decreased with increasing nitrogen supply level across the irrigation modes. In conclusion, ADIN_(2)could reduce the redundant growth of grape tree, promote the transfer of dry matter to fruit, which increased yield and use efficiency of both water and nitrogen, which is a suitable coupling water and nitrogen supply mode for grape production in northern China.