节水减氮对温室番茄生长及水氮利用率的影响

为研究番茄生长对不同生育期节水和不同施氮水平的敏感程度,通过温室小区试验,设4个灌水水平和3个施氮水平;分析番茄地上、地下生长指标对不同灌水和施氮水平的响应,并探究节水减氮对番茄水氮利用率的影响.结果表明:番茄株高、茎粗及产量均随着灌水量和施氮量的减少而减小,均在处理W1N1(常规水氮)下达到最大值;而整根特征参数随灌水量和施氮量的减少先增大后减小,在处理W2N2(苗期节水50%,施氮300 kg/hm²)下番茄总根长、细根总根长、总表面积及总体积最大,分别较W1N1 高33%,34%,46%和67%,常规灌水施氮会促进表层(0~30 cm)根系的发育,而节水减氮会使根系深扎.处理W2N2根系最发达,灌溉水利用效率最高,且有较高的氮肥偏生产力,在略有减产(8%)的同时节省了水(20%)肥(25%)资源,是本试验条件下最佳的节水减氮组合.

Effects of water saving and nitrogen reduction on tomato growth and utilization rate of water and nitrogen in greenhouse

To study the sensitivity of tomato growth to water saving at different growth stages and diffe-rent nitrogen application levels, through the greenhouse plot experiment, four irrigation levels and three nitrogen application levels were set.The response of the above-ground and underground growth indexes to different irrigation and nitrogen application levels was analyzed, and the effect of water saving and nitrogen reduction on water and nitrogen utilization rate of tomatoes was studied. The results show that the plant height, stem diameter and yield of tomatoes decreased with the decrease of irrigation and nitrogen application, all reached the maximum value under the treatment of W1N1(conventional water and nitrogen application). However, the characteristic parameters of the whole root first increased and then decreased with the decrease of irrigation and nitrogen application, the total root length, fine root length, total surface area and total volume of tomatoes were the highest under W2N2 treatment(50% water saving at the seedling stage and 300 kg/hm² nitrogen application), which were 33%, 34%, 46% and 67% higher than those of W1N1, respectively. Conventional irrigation and nitrogen application will promote the development of root system at the surface layer(0-30 cm), while water saving and nitrogen reduction will make root system deeper. The treatment of W2N2 has the most developed root system, the highest utilization efficiency of irrigation water, and the higher nitrogen fertilizer partial productivity. It is the best combination of water saving and nitrogen reduction in this experiment that water(20%)and fertilizer(25%)resources were saved while slightly reducing production(8%).