This study assessed the interactive effect of selenium (Se) and farmyard manure (FYM) on soil microbial activities, growth, yield, and Se accumulation by wheat grains. Preliminarily, the effect of Se (0–250 µg kg⁻¹ soil) and FYM (0–12.5 g kg⁻¹ soil) was assessed on soil microflora. Selenium exhibited an adverse impact on soil microflora; respiration was decreased at ≥ 10 µg kg⁻¹ soil while dehydrogenase and urease activities were decreased at ≥ 125 µg kg⁻¹ soil. At 250 µg Se kg⁻¹ soil, respiration, dehydrogenase and urease activities were decreased by 81, 40 and 35%, respectively, on unamended soil, and by 9, 47 and 22%, respectively, on FYM-amended soil. The subsequent plant experiments were conducted with same Se and FYM rates; one was harvested 42 days after sowing and other at crop maturity. The application of 125 µg Se kg⁻¹ and 12.5 g FYM kg⁻¹ soil improved seedling biomass by 12.6 and 22%, respectively, while their combined use lacked synergistic effect. Similarly, at maturity Se and FYM increased grain yield while their combined effect was not synergistic. The Se-induced suppression in microbial activities was not related to yield which was improved (11% at the highest rate in unamended soil) by Se application. Selenium application increased grain Se content in a rate-dependent manner, it increased from 0 to 1025 µg kg⁻¹ by applying 250 µg Se kg⁻¹ soil. Moreover, FYM application decreased Se accumulation in grains. It is concluded that FYM application increased soil microbial activities and yield but reduced grain Se accumulation in wheat on Se-applied soil.

本研究评估了硒 (Se) 和农家肥 (FYM) 对土壤微生物活动、生长、产量和小麦籽粒硒积累的交互作用。初步评估了Se（0-250 µg kg ^-1土壤）和FYM（0-12.5 g kg ^-1土壤）对土壤微生物群落的影响。硒对土壤微生物区系有不利影响；≥ 10 µg kg ^-1土壤呼吸减少，而脱氢酶和脲酶活性减少 ≥ 125 µg kg ^-1土壤。250 µg Se kg ^-1土壤、呼吸、脱氢酶和脲酶活性在未改性土壤上分别降低了 81%、40% 和 35%，在 FYM 改性土壤上分别降低了 9%、47% 和 22%。随后的植物实验以相同的 Se 和 FYM 比率进行；一种在播种后 42 天收获，另一种在作物成熟时收获。125 µg Se kg ^-1和 12.5 g FYM kg ^{-1 的应用}土壤分别使幼苗生物量提高了 12.6% 和 22%，而它们的联合使用缺乏协同效应。类似地，成熟时硒和 FYM 增加了谷物产量，但它们的联合作用没有协同作用。硒诱导的微生物活动抑制与通过硒应用提高的产量无关（在未经改良的土壤中最高为 11%）。硒应用以速率依赖的方式增加谷物硒含量，通过应用 250 µg Se kg ^-1土壤，硒含量从 0 增加到 1025 µg kg ^-1。此外，FYM 施用减少了籽粒中硒的积累。结论是，在施硒土壤上，施用 FYM 增加了土壤微生物活性和产量，但降低了小麦籽粒硒的积累。