Process Study of Dry Matter Accumulation and Nitrogen Absorption Use of Winter Wheat under Different N-fertilizer Rates on Dry Highland of Loess Plateau

The rule of plant nutrient absorption can help us to take effectively measure to regulate plant growth and to increase grain yield.A research of different N-fertilization rates on dry matter accumulation and the changes of nitrogen absorption was conducted on the bases of long-term positional fertilization experiment on dry highland of the Loess Plateau,and the results showed that the dry matter accumulation changed as a S curve during the whole growth period,and the dry matter accumulation of winter wheat was increased with the increasing of N-fertilizer amount,the accumulation rate showed clearly a single-peak curve,the fast rate of dry matter accumulation was found in the jointing-filling stage.N content of wheat plant and the accumulation of N nutrient were increasing with the increasing of N-fertilizer amount,two key periods of N accumulation were found in the before winter-jointing stage and the flowering-filling stage.