Effects of Mechanical Precise Hill-drop Drilling and Located Depth-fertilization on Rice Nitrogen-Saving

The effects of combining mechanical precise hill-drop drilling with controlled release fertilizers located depth-locating fertilization on growth and development,grain yield of rice and nitrogen utilization efficiency were studied in the paper.The results showed that one-off fertilizing the controlled release fertilizers by special machine can ensure nutrient stable supply to rice growth at late growth stage.Compared with the conventional fertilization all layer,the grain yield of super early rice were increased from 630 kg/hm2 to 624.7 kg/hm2,and the percentage was from 10.3%to 16.5%.Nitrogen agronomy efficiency were increased from 4.2 kg/kg N to 7.9 kg /kg N by depth-located fertilizing the controlled release fertilizers,and the percentage was from 29.0% to 51.2%,And the absolute value of nitrogen utilization efficiency were increased 17.3%,increased by 42.6%.And the nitrogen harvest index increased 9.0%.