Study Of Fertilization With Fertilizer Applicator On Nitrogen Absorption, Distribution And Growing Characteristics Of Peach Tree

¹⁵N tracer elements were used to study the effects of fertilization either using a fertilizer applicator or broadcast application in the radial ditch (CK) on nitrogen absorption, utilization, and distribution, and fruit quality and yield of five-year-old trees of the early-maturing peach'Yuhualu'and ten-year-old trees of the late-maturing cultivar'Chinese Peach'. The main results were as follows:1. After fertilization with the fertilizer applicator, the Ndff value (the percentage nitrogen derived from the fertilizer) of new shoot leaves increased significantly from the new shoot growth stage and throughout the growing season the Ndff value of new shoot leaves were maintained at high levels. After the fruits were harvested, the Ndff value of the fruit flesh and stone were 3.64 and 4.73 times higher, respectively, than those of CK. The nitrogen absorption and utilization efficiency of the plant was 20.35 % at the end of the growing season, which increased 5.87 percentage points than that of CK. The distribution efficiency of new shoot leaves was 9.00 %, which decreased significantly than that of CK. In the next year, The nitrogen absorption and utilization efficiency of the plant was 20.95 % at the end of the growing season, which increased 2.41 percentage points than that of CK. The distribution efficiency of new shoot leaves was 20.85 %, which decreased significantly than that of CK. The nitrogen absorption and utilization efficiency of the two years was 24.73 %, which increased 4.84 percentage points than that of CK. These results indicated nitrogen was absorbed more quickly and transported to newly developing organs following fertilization with the fertilizer applicator and, in addition, nitrogen utilization efficiency was significantly improved. The nitrogen loss with the fallen leaves decreased significantly at the end of the growing season.2. After fertilization with the fertilizer applicator, the percentage residual nitrogen fertilizer was 49.33 % at the end of the growing season, whereas with broadcast fertilization in the radial ditch, the residual nitrogen fertilizer was 50.46 %. In the next year, Fertilization with the fertilizer applicator and broadcast fertilization in the radial ditch, respectively, the percentage residual nitrogen fertilizer was 15.86 %, 17.71 %. The difference between the two methods was not significant. These results indicated the contents of the residual nitrogen were no difference, and the maintenance of soil fertility was consistent under the two methods of fertilization.3. After fertilization with the fertilizer applicator, the nitrogen distribution in soil space was relatively more uniformly. The concentration of NH4⁺-N, NO3^–-N, available phosphorus and available potassium significantly increased. The soil nutrient levels was kepe of the best solution and the fertilizer utilization efficiency was also significantly increased. Fertilization with the fertilizer applicator can reduce the amount of fertilizer to save cost. The SPAD value of new shoot leaves increased significantly from the new shoot growth stage and throughout the growing season the chlorophyll content of new shoot leaves were maintained at high levels, while the growth rate of new shoots was accelerated significantly at the new shoot growth stage. Fertilization with the fertilizer applicator was beneficial to improve yield. The fruit weight, fruit diameter and the content of soluble solids of peach fruit were also improved, but the difference was not significant.