起垄覆膜垄沟覆草对山地果树氮肥吸收利用的影响

Effect of Ridge Ffilm Mulching Combined with Straw Mulching Technology on N Absorption and Utilization of Apple in Loess Hilly Area of Northern Shaanxi Province

为给起垄覆膜垄沟覆草集雨条件下氮肥的施用提供科学依据。以7年生红富士苹果树为试材,田间布设起垄覆膜垄沟覆草(FS)、常规管理(CK)两种田间管理措施,3个氮肥施用水平(N 201.53、403.05、604.58 kg/hm2,分别以N1、N2、N3表示),每株树施15N-尿素5 g,利用15N同位素示踪技术,研究不同处理对果树氮肥吸收、利用、产量和品质的影响。不同物候期FS的叶片氮含量高于CK,春梢旺长期差异达到显著水平,叶片氮含量随叶龄的增加而降低,N2水平叶片含氮量高于N1和N3;不同物候期FS的叶片Ndff值高于CK,生长季内叶片的Ndff值呈现"先增后降"的趋势,但是N2水平的Ndff值始终高于N1和N3;在果实采收期,FS的叶片、新稍、多年生枝、主枝、主干和果实的Ndff值均明显高于CK,且各器官N2的Ndff值均高于N1和N3;FS的15N-尿素利用率较CK处理提高6.65%~13.41%,FS的N2水平的氮肥利用率显著高于N1、N3水平(P<0.05)。FS的单株产量、单果质量、优果率均高于CK,可溶性固形物、硬度、可滴定酸与CK接近,但不同施氮水平都表现为N2最大,N3次之,N1最小。在干旱贫瘠的山地苹果园,采用起垄覆膜垄沟覆草管理措施可以提高果树对氮肥的吸收、利用率,提高产量和改善品质。

The purpose of this paper is to provide a scientific basis for the application of nitrogen fertilizer under the condition of ridge film mulching combined with straw mulching technology. In this study,seven-year-old Fuji apple trees and15 N trace technique were used to explore the characteristic of15 N-urea absorption,utilization,fruit yield and quality under the condition of ridge film mulching combined with straw mulching technology and CK. The experiment had three application level of nitrogen fertilizer（ N 201. 53,403. 05,604. 58 kg/hm2,respectively,named N1,N2 and N3）,and each tree was15 N-urea 5 g. The results showed that： the nitrogen content of the leaves of FS was higher than that of CK in different phenological phase,and the difference reached a significant level in rapid growth stage of spring twig,the nitrogen content of leaves decreased with the increase of leaf age,and the nitrogen content of N2 was higher than that of N1 and N3. Ndff of the leaves of FS was higher than that of CK in different phenological phase,and Ndff of the leaves presented the trend of＂first increase and then drop＂in the growth season,but Ndff of N2 was higher than that of N1 and N3. In the period of harvest fruit,Ndffs of leaves,new shoots,branches of perennials,boughs,trunk and fruits under condition of FS were significantly higher than those of CK,and the Ndffs of N2 were higher than that of N1 and N3. The15 N-urea utilization ratio of FS was increased by 6.65% to 13.41% compared with CK,and the nitrogen fertilizer utilization rate of N2 was significantly higher than that of N1 and N3（ P0.05） under condition of FS. Yield,fruit quality and superior fruit rate of FS were higher than those of CK,and soluble solids,hardness,titratable acid were closed to those of CK,but under condition of different nitrogen levels,N2 showed the largest,followed by N3,and then N1. It can be concluded that in the arid and barren hilly apple orchards,FS can improve the absorption,utilization of nitrogen fertilizer and yield and fruit quality.