绿洲灌区绿肥还田配施化学氮肥对小麦干物质积累及产量的影响

针对西北干旱绿洲灌区小麦长期连作、生产过程中化学氮肥依赖程度高等问题，探讨绿肥还田配施化学氮肥对小麦干物质积累特征及产量的影响，以期为区域小麦施氮制度优化及产量提升提供理论依据。2020至2021年，在河西绿洲灌区设置绿肥还田量和施氮水平的不同组合，即G1N1、G2N1、G3N1、G4N1、G1N2、G2N2、G3N2、G4N2,其中G1、G2、G3、G4分别代表绿肥还田7 500 kg/hm²、15 000 kg/hm²、22 500kg/hm²、30 000 kg/hm²,N1、N2分别代表传统施氮减量15%(153 kg/hm²)、减量30%(126 kg/hm²),以传统施氮不复种绿肥为对照(CK),研究了不同绿肥还田量结合化学氮肥减量条件下小麦干物质积累及产量表现。结果表明，绿肥还田量及减氮水平对干物质积累量、群体生长速率均有显著影响，二者的互作效应显著。N1较N2干物质积累量、群体生长速率分别提高8.9%、9.7%;G4较G3、G2、G1干物质...

Effect of Combined Green Manure Return and Chemical Nitrogen Fertilizer on Dry Matter Accumulation and Wheat Yield in Oasis Irrigated Area

Focusing on the challenges associated with continuous cropping and excessive reliance on chemical nitrogen fertilizer in wheat production in an oasis irrigated area,this study investigated the effects of combining green manure return with chemical nitrogen fertilizer application on wheat yield. The aim is to provide a theoretical basis for optimizing regional wheat nitrogen application system and enhancing overall yield. In 2020 and 2021,different combinations of green manure return and nitrogen application levels were set in Hexi Oasis Irrigated Area,namely G1N1,G2N1,G3N1,G4N1,G1N2,G2N2,G3N2 and G4N2. Here,G1,G2,G3,G4 represent 7 500 kg/hm₂,15 000 kg/hm₂,22 500 kg/hm₂ ,30 000 kg/hm₂ of green manure return,respectively. Additionally,N1 and N2 indicate 15% and 30% reduction of traditional nitrogen application,respectively. Compared with control group (CK),this study investigated the dry matter accumulation and yield performance of wheat under different treatment. The results showed that nitrogen fertilizer reduction level and green manure return amount had significant effect on dry matter accumulation and growth rate,with a significant interaction between the two factors. During the whole growth periods,N1 significantly increased dry matter accumulation and growth rate by 8.9% and 9.7% ,respectively,compared with N2.Similarly,G4 compared with G3,G2 and G1,significantly increased dry matter accumulation and growth rate by 7.4%- 23.5% and 10.6%-27.4%,respectively.Both nitrogen reduction level and green manure return amount had significant effect on grain yield and biological yield. Compared with N2,N1 significantly increased grain yield and biological yield by 8.7% and 5.6%,respectively; Compared with G3,G2 and G1,G4 significantly increased grain yield and biological yield by 6.5%-23.8% and 8.6%-20.6%,respetively. G4N1 significantly increased the maximum dry matter growth rate (V_max) and delayed its emergence time (t₅₀),the Vmax increased by 12.4%-26.8% and the t50 delayed by 8-13 days on average. In terms of the combination of green manure return and nitrogen reduction,G4N1 significantly increased the dry matter and yield by 36.4% and 32.7%,respectively.The maximum growth rate of dry matter was delayed by 13 days compared with CK. The path analysis results showed that the increase of grain number per ear was the major factor contributing to the overall increase in grain yield under G4N1. In general,returning green manure at 30 000 kg/hm₂ combined with a 15% reduction in nitrogen fertilizer can improve grain yield,which is a suitable method for nitrogen application and green manure incorporation in wheat production in oasis irrigated area.