喷灌条件下河西走廊春小麦土壤硝态氮动态分布及产量关系

Dynamic Distribution of NO_3-N in Spring Wheat and Its Relationship with Yield in Hexi Corridor under Sprinkler Irrigation

以当地灌溉施肥模式为对照并以探索河西走廊春小麦适宜喷灌灌溉施肥制度为目的,在甘肃省永昌县试验基地开展了田间基础性试验研究,试验分别设置高、中、低三个灌水(3 300、2 550、1 800 m^3/hm^2)、施肥(337.5、225、187.5 kg/hm^2)水平。研究了喷灌条件下不同处理间土壤硝态氮分布运移规律,分析了产量及水分利用效率与灌水量、施肥量之间相关性。结果表明:土壤硝态氮含量主要受施肥量影响;喷灌条件下中等灌水水平土壤硝态氮主要分布在0~40 cm土层,有利于春小麦根系对氮素的吸收利用,灌水水平过高或过低都不利于根系对氮素的吸收;产量及水分利用效率与灌水量呈线性正相关关系,与施肥量相关性不显著;中等灌水水平比大水漫灌增产5%、节水32%,节水、增效效果显著;根据产量回归结果,适合河西走廊喷灌灌溉施肥制度为中等灌水施肥水平。

Based on the local irrigation and fertilization model, in order to explore the suitable irrigation and fertilization system for spring wheat in Hexi Corridor, the field experiment was carried out in Yongchang County, Gansu Province. The experiment was conducted with three irrigation levels （3 300, 2 550, 1 800 m3/hm2） and fertilization levels （337.5, 225, 187.5 kg/hm2）. The distribution law of NO3--N in soil among different treatments under sprinkler irrigation was studied, and the correlation between yield, water use efficiency and quantity of irrigation, fertilization was analyzed. The results show that the content of NO3--N in the soil is mainly affected by the amount of fertilizer applied; the NO3--N is mainly distributed in 0 ~ 40 cm soil layer under the condition of sprinkler irrigation, which is beneficial to the uptake and utilization of nitrogen in spring wheat roots. The yield and water use efficiency are linearly related to the amount of irrigation. However, the correlation between the yield and water use efficiency is not significant. The medium irrigation level is 5% higher than that of the flood irrigation, the water is saved by 32%, and the water and synergistic effect is remarkable. According to the yield regression results, the irrigation and fertilization system for irrigation and fertilization in Hexi Corridor is the middle irrigation and fertilization level.