ABSTRACT Soil microorganisms play important roles in crop growth and nutrient cycling. This study investigated the influence of the temporal changes in soil fatty acids (FAs) mainly derived from microorganisms by the incorporation of different green manures on the subsequent crop yield of winter wheat. Plants (Sesbania rostrata or Sorghum bicolor) as green manure were cultivated as the preceding crop, followed by the cultivation of winter wheat. Soil FA structure was characterized by the analysis of the relative abundance of FA methyl esters (FAMEs). Principal component (PC) analysis of the abundance of FAME signatures indicated that the composition of soil FAs was clearly altered by different soil management regimes. The amount of soil FAMEs increased with the incorporation of green manure, and this increase was maintained during wheat cultivation. A positive correlation was observed between wheat yield and the ratio of FAMEs derived from Gram-positive and Gram-negative bacteria at stages of tiller emergence and heading. FAMEs from Gram-positive bacteria and protozoa also positively correlated with one of the wheat yield components, 1,000 grain weight. These results may suggest that the amount of bacterial and protozoan FAs at tiller and heading stage following green manure incorporation is useful to predict the winter wheat productivity.

中文翻译：

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不同绿肥改良剂对冬小麦产量与细菌和原生动物脂肪酸的影响

摘要 土壤微生物在作物生长和养分循环中起着重要作用。本研究通过掺入不同的绿肥，研究了主要来源于微生物的土壤脂肪酸 (FAs) 的时间变化对冬小麦后续作物产量的影响。种植绿肥植物（田菁或双色高粱）作为前茬作物，随后种植冬小麦。通过分析 FA 甲酯 (FAME) 的相对丰度来表征土壤 FA 结构。FAME 特征丰度的主成分 (PC) 分析表明，不同土壤管理制度明显改变了土壤 FA 的组成。土壤 FAME 的数量随着绿肥的掺入而增加，这种增长在小麦种植期间一直保持。在分蘖出苗和抽穗阶段，小麦产量与源自革兰氏阳性菌和革兰氏阴性菌的 FAME 的比例呈正相关。来自革兰氏阳性菌和原生动物的 FAME 也与小麦产量组成部分之一（1,000 粒重）呈正相关。这些结果可能表明，绿肥掺入后分蘖期和抽穗期细菌和原生动物 FA 的数量可用于预测冬小麦生产力。000 粒重。这些结果可能表明，绿肥掺入后分蘖期和抽穗期细菌和原生动物 FA 的数量可用于预测冬小麦生产力。000 粒重。这些结果可能表明，绿肥掺入后分蘖期和抽穗期细菌和原生动物 FA 的数量可用于预测冬小麦生产力。