Experimental Study of Irrigation on Total Nitrogen Leaching in Loess Layer

Soil infiltration experiment and nitrogen balance analysis was carried out to study the transfer regular pattern and leaching intensity of nitrogen under the certain nitrogen level and different irrigation level in loess soil.The results indicated that soil moisture is the transfer medium and controlling factor of nitrogen leaching.When the nitrogen level is 6 mg/cm2,there is a negative correlation between soil nitrogen content and irrigation quota,and between soil water content,nitrogen leaching rate and nitrogen concentration,and a positive correlation between soil water content,nitrogen leaching rate and irrigation quota.When the irrigation quota is higher than 229.3 mm,the nitrogen leaching rate is higher than 37.18% in 51 cm soil layer.So in order to prevent nitrogen loss and groundwater pollution,the irrigation quota should be controlled strictly in loess areas.