关键词: 纳米碳, 桃幼树, ¹⁵N, 氮素利用率, 氮素损失率

Abstract:

【Objective】 In order to clarify whether carbon nanoscale could promote the growth of peach trees and to screen out the optimum application ratio of carbon and urea, it was expected to provide a theoretical basis for the application of carbon nanomaterials to improve the nitrogen fertilizer efficiency in the process of fruit tree cultivation. 【Method】 The experiment was conducted by using isotope tracer technology. The 2-year-old Rui pan 21/peaches was used as a test material and ¹⁵N urea was used in different doses under potting conditions (5 treatments: CK: 0 mL, T1: 5 mL, T2: 10 mL, T3: 15 mL, and T4: 20 mL). And the nano-carbon sol was tested to investigate the effects of nanocarbon on soil physical and chemical properties, peach growth and development, and nitrogen absorption and utilization. The pH value, redox potential and electrical conductivity of the soil, the dry diameter of 2 cm at the upper part of the plant and the dry weight of each part of the plant, the chlorophyll SPAD value of the leaf, the net photosynthetic rate, the structure of the root system, the total N content, and the ¹⁵N abundance of each part of the plant were measured. 【Result】 Application of nano-carbon significantly reduced soil pH value, increased soil oxidation-reduction potential, and affected the redox state of soil solution; with the increase of the amount of nano-carbon, the soil conductivity showed a tendency of decreasing at the early stage of treatment and increasing at a later stage. The application of nano-carbon promoted the growth of the root system of young peach trees. The net photosynthetic rate, chlorophyll content of peach leaves and diameter were increased. The total biomass accumulation of peach trees was highest under T3 treatment, which was 778 g and was 28.4% higher than that under CK. The application of nano-carbon increased the Ndff value of fine roots, coarse roots, lateral branches, spring shoot leaves and other organs of peach trees. Compared with CK, T1 treatment significantly increased the nitrogen distribution rate of the main trunk and the central trunk, while T3 and T4 treatment decreased the nitrogen distribution rate of the main trunk. The nitrogen utilization rate of peach plants was increased significantly with the application of nano-carbon, and the treated with T3 was the highest, being 45.2%, which was 66.5% higher than that under CK. With the increase the amount of carbon nanoscale, the nitrogen residue rate of soil increased. The treatments of T1, T2, T3 and T4 were 1.06 times, 1.35 times, 1.62 times and 1.70 times of CK, respectively, and the nitrogen loss rate decreased significantly. 【Conclusion】 The application of urea with nano-carbon could improve soil physical and chemical properties, effectively adsorb nitrogen in soil, significantly reduce nitrogen loss rate, increase plant nitrogen utilization and soil nitrogen residue, and promote root growth and plant morphology of peach trees.

Key words: nano-carbon, peach, ¹⁵N, nitrogen utilization rate, nitrogen loss rate