关键词: 灌水器流量, 涌泉根灌, 肥液入渗, 湿润体, 氮素分布

Abstract: In order to improve the efficiency of water and fertilizer utilization under the bubbled-root irrigation, the infiltration experiment of the wetting body was carried out on the undisturbed soil of the Mizhi Experimental Station of the Northwest A & F University, and the variation characteristics and the influence of water and nitrogen migration laws on the characteristic values of the different emitters were studied. The results showed that the water flow rate of the emitters had different effects on the moisture content and nitrogen distribution of the infiltration of the bubbled-root irrigation, and the infiltration capacity and the wetting front migration distance increased with the increase of the emitter flow, and obtained the mathematical model of the emitter flow and the cumulative infiltration of the bubbled-root irrigation and the wetting front migration distance. The shape of the wetting body formed under the infiltration condition of fertilizer solution was approximately ellipsoid, and the soil moisture content in the wet body was characterized by low surface layer (18.55%), intermediate height (20.39%) and low bottom layer (14.46%). In the actual production process, the characteristic value of the wetting body should be used as the basis for irrigation technology when the distribution was 1 d. The contents of NO-3-N and NH+4-N in the same soil depth increased with the increase of the emitter flow. The longer the redistribution time was the higher the NO-3-N content in the soil increased, and the NO-3-N content in the surface soil was the largest. The deeper the depth was, the lower the NO-3-N content; the NH+4-N content in the soil decreased. The trend  was more obvious while the reduction of NH+4-N content in deep soil. The distribution and migration of NO-3-N content in water movement were significant, and the distribution and migration of NH+4-N content in water movement were not significant. Above results provided a technical reference for the efficient use of Yongquan root irrigation and fertilizer.

Key words: emitter flow, bubbled-root irrigation, fertilizer infiltration, wetted body, nitrogen distribution