Avoidance of intensive rice cultivation (IRC) and soil amendments are potential practices to enhance soil properties. There is only limited information on the effects of reduced IRC and its mixture with compost or silicate fertilizer (Si) on the soil nematode community in salt–affected soils. This study aimed to assess the shifts of soil nematode community by reducing a rice crop from triple rice system (RRR) to a double rice system and mixed with compost or Si in paddy fields in acid sulfate soil (ASS) and alluvial soil (AL) in the Mekong Delta, Vietnam. Field experiments were designed with four treatments in four replicates, including RRR and a proposed system of double–rice followed by a fallow (FRR) and with 3 Mg ha^–1 crop⁻¹ compost or 100 kg ha^–1 crop⁻¹ Si. Soils were collected at harvest after the 2 year experiment, reflecting the fifth and third consecutive rice crop in RRR and FRR system, respectively. Results showed that reduced IRC gave a significant reduction in abundance of plant–parasitic nematodes (PPN), dominated by Hirschmanniella and increased abundance bacterivorous nematodes when mixed to compost and silicate fertilizer in ASS. In addition, reduced IRC increased nematode biodiversity Hill’s indices and reduced herbivorous footprint in ASS. Proposed system having compost or Si had strongly increased in bacterivorous and omnivorous footprints. Particularly, reduced IRC mixture with Si increased abundance of Rhabdolaimus, Mesodorylaimus and Aquatides, metabolic footprints (structure footprint, bacterivorous, omnivorous and predator) and diversity Hill’s N1 index in ASS. Our results highlighted that reduced IRC was a beneficial practice for decreasing abundance of PPN in salt-affected soils and increasing abundance of FLN in ASS. IRC mixture with compost or Si had potential in structuring the nematode communities with increasing biodiversity, trophic structure, and metabolic footprints.

中文翻译：

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越南湄公河三角洲的酸性硫酸盐和冲积土壤中，休耕条件，堆肥和硅酸盐肥料对盐害水稻田土壤线虫群落的影响

避免密集的水稻种植（IRC）和土壤改良剂是增强土壤特性的潜在做法。关于减少的IRC及其与堆肥或硅酸盐肥料（Si）的混合物对受盐影响的土壤中线虫群落的影响的信息很少。这项研究旨在通过将水稻作物从三联水稻系统（RRR）减为双水稻系统并在酸性硫酸盐土壤（ASS）和冲积土壤（AL）的稻田中与堆肥或硅混合来评估土壤线虫群落的变化在越南湄公河三角洲。设计了田间试验，采用四种处理方式，一式四份，包括RRR和拟议的双水稻体系，其次是休耕（FRR），采用3 Mg ha ^–1作物⁻¹堆肥或100 kg ha ^–1作物^-1 Si。经过2年试验后，收获时收集了土壤，分别反映了RRR和FRR系统中连续第五和第三次水稻收成。结果表明，降低的IRC给丰植物寄生线虫的（PPN）一个显著减少，由主导潜根和增加的丰度食细菌线虫混合时堆肥和ASS硅酸盐肥料。此外，减少的IRC增加了线虫生物多样性Hill的指数，并减少了ASS中的草食性足迹。提出的具有堆肥或Si的系统的细菌和杂食足迹显着增加。特别是，IRC混合物与Si的减少会增加Rhabdolaimus，Mesodorylaimus和ASS中的水化物，代谢足迹（结构足迹，细菌，杂食和捕食者）和多样性Hill的N1指数。我们的结果强调，减少IRC是减少盐分土壤中PPN含量和增加ASS中FLN含量的有益方法。与堆肥或硅混合的IRC混合物具有构成线虫群落的潜力，具有增加的生物多样性，营养结构和代谢足迹。