微生物肥料在改良盐渍土方面具有高效环保的特点,功能性微生物肥料的施用对沿海地区绿色消除盐渍屏障和改善土壤质量具有重要意义。该试验以河北省沿海地区的中度盐渍土壤为基础,以玉米为指示作物,在常规化肥施用的基础上。不同的微生物肥料处理,即,T1(常规化肥750kg·hm-2+复合微生物剂75kg·hm-2),T2(常规化肥750kg·hm-2+巨大芽孢杆菌300kg·hm-2),T3(常规化肥750kg·hm-2+粘胶芽孢杆菌300kg·hm-2),T4(常规化肥750kg·hm-2+有机硅肥600kg·hm-2),T5(常规化肥750kg·hm-2+生物有机肥600kg·hm-2),T6(常规肥料750kg·hm-2+活性微藻15kg·hm-2),和CK(仅肥料750kg·hm-2),用于这七种治疗,研究不同微生物肥料对土壤养分的影响,盐度,细菌群落,玉米的两个关键时期(V12期和成熟期)的产量和经济效益。结果表明,与CK相比,T1显著增加了整个生育期土壤全氮(TN)和速效磷(AP)的含量。在整个生育期,与CK相比,V12期土壤有机质(OM)增加了10.35%,但是治疗之间没有显着差异。与CK相比,T5和T6显著降低了整个生育期土壤全盐和Ca2+含量,平均降低了14.51%-18.48%和24.25%-25.51%。与CK相比,T1使整个生长期的细菌多样性指数显着提高了45.16%。土壤门的优势是放线菌,变形杆菌,酸杆菌,和氯氟,优势属为芽孢杆菌属和双孢杆菌属。研究区细菌群落功能最丰富的是化学异养和需氧化学异养,平均相对丰度为28.89%和27.11%,T3和T6显著提高了土壤氮素循环功能。冗余分析(RDA)结果表明Na+,SO42-,pH值,和EC是驱动细菌群落结构的重要因素,和相关热图显示Na+,SO42-,pH值,和EC呈显著正相关,主要与植物门,而土壤OM和TN与蓝藻呈显著正相关。与CK相比,T6增加了蓝藻的相对丰度,优化了整个生长期的细菌群落结构。使用推荐剂量的菌肥T1和T6可提高玉米产量7.31%-24.83%,经济效益9.05%-23.23%,分别。土壤化学性质和产量相关分析的初步结果表明,AP,HCO3-,和Mg2是限制沿海地区土壤生产力的障碍因子。总之,在推荐剂量下使用复合菌剂(T1)和活性微藻(T6)可以显著增强土壤养分,降低盐度,并改善土壤细菌群落的结构多样性,这不仅保证了玉米产量和效率的提高,而且实现了微生物肥料的高效利用和土壤质量的改善。
Microbial fertilizers have the characteristics of high efficiency and environmental protection in improving saline soils, and the application of functional microbial fertilizers is of great significance for the green abatement of saline barriers and the improvement of soil quality in coastal areas. The experiment was based on moderately saline soil in the coastal area of Hebei Province, with corn as the indicator crop, on the basis of conventional chemical fertilizer application. Different microbial fertilizer treatments, namely, T1 (conventional chemical fertilizer 750 kg·hm-2 + compound microbial agent 75 kg·hm-2), T2 (conventional chemical fertilizer 750 kg·hm-2 + Bacillus megaterium 300 kg·hm-2), T3 (conventional chemical fertilizer 750 kg·hm-2 + B. mucilaginosus 300 kg·hm-2), T4 (conventional chemical fertilizer 750 kg·hm-2 + organic silicon fertilizer 600 kg·hm-2), T5 (conventional chemical fertilizer 750 kg·hm-2 + bio-organic fertilizer 600 kg·hm-2), T6 (conventional fertilizer 750 kg·hm-2 + active microalgae 15 kg·hm-2), and CK (only fertilizer 750 kg·hm-2), were used for these seven treatments, to study the effects of different microbial fertilizers on soil nutrients, salinity, bacterial community, and corn yield and economic efficiency during two critical periods (V12 stage and maturity stage) of corn. The results showed that compared with that in CK, T1 significantly increased soil total nitrogen (TN) and available phosphorus (AP) contents during the whole growth period. Over the whole reproductive period, soil organic matter (OM) at maturity increased by 10.35% over the V12 stage compared to that in CK, but there was no significant difference between treatments. Compared with that in CK, T5 and T6 significantly reduced soil total salinity and Ca2+ content during the whole growth period by an average of 14.51%-18.48% and 24.25%-25.51%. T1 significantly increased the bacterial diversity index over the whole growth period by 45.16% compared to that in CK. The dominant soil phyla were Actinobacteria, Proteobacteria, Acidobacteria, and Chloroflexi, and the dominant genera were Bacillus and Geminicoccaceae. The most abundant functions of the bacterial community in the study area were chemoheterotrophy and aerobic chemoheterotrophy, with average relative abundances of 28.89% and 27.11%, and T3 and T6 significantly improved soil N cycling function. The results of redundancy analysis (RDA) indicated that Na+, SO42-, pH, and EC were important factors driving the structure of the bacterial community, and correlation heatmaps showed that Na+, SO42-, pH, and EC were significantly and positively correlated mainly with the phylum Planctomycetota, whereas soil OM and TN were significantly and positively correlated with Cyanobacteria. Compared with that in CK, T6 increased the relative abundance of Cyanobacteria and optimized the bacterial community structure during the whole growth period. Using recommended dosages of bacterial fertilizers T1 and T6 increased maize yield by 7.31%-24.83% and economic efficiency by 9.05%-23.23%, respectively. The preliminary results of soil chemical properties and yield correlation analysis revealed that EC, AP, HCO3-, and Mg2+ were the obstacle factors limiting soil productivity in coastal areas. In conclusion, the use of the compound bacterial agent (T1) and active microalgae (T6) at the recommended dosage can significantly enhance soil nutrients, reduce salinity, and improve the structural diversity of soil bacterial communities, which not only ensures the increase in maize yield and efficiency but also realizes the efficient use of microbial fertilizers and the improvement of soil quality.