Impacts of drip fertilizer irrigation on nitrogen use efficiency and total nitrogen loss load

Fertilizer use efficiency, crop yield and total nitrogen loss load were compared between the agricultural systems with drip fertilizer irrigation strategy and conventional fertilization strategy, through the field trials and nitrogen loss monitoring conducted in 2006 and 2007. It indicated that with the drip fertilizer irrigation system, the fertilizer could be centralized in the root zoom of the crops, which increased the fertilizer use efficiency, reduced the N fertilizer consumption and TN loss load while without losing the crop yield. Compared with the conventional fertilization strategy, in 2006, the N fertilizer consumptions per unit yield of pear, soybean and corn under drip fertilizer irrigation were reduced by 10.8, 11.8 and 8.9 g/kg, respectively. And the reduction rate reached 22.8％, 22.6％ and 30.8%. On the other hand, the TN loss loads per unit yield of pear, soybean and corn were reduced by 45.2％, 14.5% and 26.3%, respectively. In 2007, the N fertilizer consumptions per unit yield of pear, watermelon and corn were reduced by 11.1, 8.1 and 5 g/kg, respectively, and the reduction rate reached 29.7％, 65.8％ and 21.5％. Meanwhile, the TN loss loads per unit yield of pear, soybean and corn were decreased by 56.4％, 49.7％ and 51.8％.