| 摘要: 本研究以线虫作为指示生物, 探索不同肥料长期施用对旱作盐碱瘠薄土壤微食物网的影响。依托5年定位试验, 设置醋糟/粉煤灰配施(VRF)、醋糟(VR)、有机肥(OM)、菌肥(BM)、有机肥/化肥配施(OCF)、化肥(CF)和不施肥(CK) 7个处理, 选取燕麦苗期、抽穗期和收获期3个时期的耕层土壤样品, 分析土壤线虫群落、土壤性状及燕麦产量。结果表明: 大部分施肥处理降低了土壤pH和容重, 显著提升了有效磷、有机质、硝态氮含量以及微生物数量(P<0.05)。除BM外，各施肥处理的燕麦均显著增产(P<0.05), 增幅为44.5%~92.3%, 其中OM和CF显著高于其他施肥处理(P<0.05)。施肥显著提高了土壤线虫的数量和丰富度, OM处理线虫群落达到结构化状态, 食物网稳定, 但植物寄生线虫占比较高(36.2%); CF则会显著增加线虫优势属数量, 显著降低线虫多样性(P<0.05); 而两者配施的OCF一定程度上弥补了各自的不足。VRF和VR均显著提高了食微线虫占比, 降低了植物寄生性线虫占比, VRF处理自由生活线虫成熟度指数显著最高(P<0.05)。土壤有机质、有效磷和微生物是土壤线虫数量变化的主要因素, 土壤pH、EC、容重是燕麦增产的主要限制因素, 而土壤线虫数量与燕麦产量无显著相关。有机肥/化肥和醋糟/粉煤灰配施较肥料单施更利于土壤微生态环境的健康稳定。 |
| 关键词: 肥料 燕麦 土壤线虫 盐碱地 土壤理化性状 |
| 中图分类号:S344.2 |
| 基金项目:国家自然科学基金项目（面上项目，重点项目，重大项目） |
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| Effects of different fertilizers application on soil nematode communities and oat yield in saline-alkali dryland |
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qiaoyuejing
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Shanxi Agriculture University
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| Abstract: Saline-alkali land is of great significance to the improvement of cultivated land quality, nematode is a critical fauna of the soil food web, which are morphologically and functionally diverse, widely used to indicate soil quality. However, the ecological indicator function of nematode community on oat saline-alkali land, especially the application of industrial waste on saline-alkali land, has not been reported. In this study, soil nematodes were investigated as an indicator of soil ecological environment to explore the effects of long-term application of different fertilizers on the micro-food web of saline-alkali barren soil under dry farming. Based on the 5-year experiment, seven treatments were set as: vinegar residue/ fly ash (VRF), vinegar residue (VR), organic manure (OM), bacterial manure (BM), organic manure/ chemical fertilizer (OCF), chemical fertilizer (CF) and no fertilizer (CK). Soil samples were collected from plough layer at seedling, heading and harvest stage of oat, the soil nematode community, soil traits and oat productivity under long-term application of different fertilizers were analyzed. The results showed that most fertilizers reduced soil pH and bulk density, and significantly increased available phosphorus, organic matter, nitrate nitrogen and microbial quantity (bacterial, fungi and actinomycete). With the exception of BM, the yield of oat increased significantly by 44.5%-92.3% under other fertilizer treatments, OM and CF had the significantly highest oat yield (P<0.05). The total number of soil nematodes were significantly increased by fertilization, OM was the highest at seedling and heading stage, and VR was the highest at maturity stage (P<0.05). The enrichment index (EI) of each treatment and the structure index (SI) of most treatments were lower than 50, indicating that the soil nutrient was poor, and soil food web was in a stress state or in a degraded state in this experimental field. While the nematode community under OM application reached a structured state at harvesting (SI>50), the food web was relatively stable, but the proportion of plant-parasitic nematodes was higher (36.2%). CF significantly increased the number of dominant species, and the nematode diversity was the lowest (P<0.05). The combined application of OCF made up for their shortcomings to some extent; VRF and VR significantly increased the proportion of microbial-feeding nematodes and decreased the proportion of plant-feeding nematodes. The Wasilewska index (WI) under VRF and VR treatments were higher than CK during 3 growth periods, the Maturity index (MI) of free-living nematodes under VRF treatment was always the highest (P<0.05), which indicated that the organic carbon mineralization was dominated by microbial-feeding nematodes under VRF and VR, and the food web was mature and stable with less disturbance under VRF treatment. Soil organic matter, available phosphorus and microorganisms were the main factors for the number of soil nematodes. Soil pH, EC and bulk density were the main limiting factors for oat yield, but there was no significant correlation between the number of nematodes and oat yield, but β-glucan content was negatively correlated with the number of plant parasitic nematodes (r=?0.52*). The combined application of organic manure/ chemical fertilizer and vinegar residue/ fly ash were more beneficial to the health and stability of soil micro-ecological environment. |
| Keyword: Fertilizer Oat Soil nematode Saline-alkali field Soil physical-chemical properties |