基于磷脂脂肪酸（PLFA）技术的新疆灌漠土生物肥力形成机制研究

Understanding mechanism of microbial community structure formation in Xinjiang irrigation desert soil and the effect of the diversity of biological fertility is the key of oasis agricultural ecosystem stability in arid areas. This contribute to explore the necessary premise of agricultural carbon emission reduction mechanism in arid areas. We will establishing irrigation method was desert soil microbial community diversity based on phospholipid fatty acid (PLFA). The object of study is long-term fertility monitoring experiments: loess irrigation desert soil of shanshan county in southern Xinjiang and clay irrigation desert soil of fukang in northern Xinjiang. We choose four treatments: uncultivated, no chemical fertilizer, chemical fertilizer, chemical fertilizer plus manure. Analysis of long-term different fertilization interaction effect of carbon input and community diversity. Laboratory simulation experiments will be conducted to different processing the relation between soil respiration characteristics and community diversity. To explore carbon input, output, the impact on the microbial community structure change. at the same time ,we will collecte the climate factor parameters, and test the conventional soil fertility factor parameters, in order to study the action mechanism of natural and artificial. This study will help us to accurate evaluation biological fertility of irrigation desert soil in arid areas , provides basic data, and formation mechanism. In the mean time, we could deeply understand the microbiological mechanism of carbon emission reducing through human management measures.

了解新疆灌漠土微生物群落结构多样性对生物肥力形成的影响机制，是全面解析绿洲农业生态系统稳定性的关键环节，也是进一步探讨干旱区农业固碳减排机理的必要前提。本项目以新疆南部鄯善县黄土状灌漠土和北部阜康县红土状灌漠土两个长期肥力监测试验为对象，选择撂荒、长期不施肥但种植作物、施化肥、有机肥四个处理，应用气质联用方法测试其土壤磷脂脂肪酸（PLFA）含量及种类，建立灌漠土微生物群落多样性图谱；继而以微生物群落结构为主线，分析长期不同施肥碳投入与群落多样性的互作效应；室内模拟分析不同处理土壤呼吸特征与群落多样性的相关关系，探讨碳输入、输出对微生物群落结构变化的影响。同时收集研究区气候因子参数，并测试土壤常规肥力因子参数，研究自然和人为管理措施对土壤微生物群落结构建成机制，为准确评估干旱区灌漠土生物肥力提供基础数据，也对明晰灌漠土生物肥力形成机制，揭示人为管理措施固碳减排的微生物学机理具有重要意义

土壤生物肥力形成机制是近十年来土壤质量研究的热点问题之一，自然因素与人为措施对生物肥力的形成有其区域独特性。本研究依托黄土状灌漠土（鄯善）和红土状灌漠土（阜康）两个农业部长期肥力监测点，通过对两个样点不同处理土壤样品生物肥力指标检测，开展了灌漠土磷脂脂肪酸特征与群落结构多样性、灌漠土磷脂脂肪酸与土壤肥力因子的相关性、长期不同施肥对灌漠土葡萄产量与品质的影响和灌漠土土壤呼吸特征四个方面的研究，获得以下结果：.（1）长期施用有机肥PLFA总量及各类菌群含量均高于其他施肥方式；长期施用化肥表层PLFA总量降低，G-含量增加，土壤微生物量减少，低代谢能力种群增多，暗示土壤开垦后一定时期内表层土壤质量有下降趋势；化肥与有机肥配施可抑制真菌活性。长期撂荒土壤表层微生物活跃，真菌/细菌值较高，土壤微环境健康。.（2）化肥减施-有机肥配施及撂荒处理，表层土壤微生物总量、细菌、放线菌、真菌含量高于亚表层，而在有机肥、化肥施用量较高情况下，亚表层高于表层。聚类分析表明，化肥用量是影响土壤微生物群落分布的主要因素。化肥减施-有机肥配施是理想的土壤培肥模式。.（3）土壤有机质、速效氮与可溶性有机碳、可溶性有机氮以及微生物碳之间存在显著相关；与微生物氮、微生物物种个数、微生物种类数之间不相关，土壤养分更依赖土壤的矿质化过程。.（4）长期不同施肥处理条件下，葡萄产量、营养成分、土壤养分和微生物群落存在显著差异。可溶性固形物和还原糖含量与葡萄产量呈显著正相关，可滴定酸度和单宁含量与葡萄产量呈相反趋势。施肥对土壤养分和微生物群落的影响取决于施肥量。施肥占葡萄产量和营养成分变异的31.9%，其次是土壤养分，占19.7%，微生物群落占26.8%。施肥、土壤养分和微生物群落与葡萄产量、可溶性固形物和还原糖呈显著正相关，与可滴定酸度、单宁和酚类呈显著负相关。