Growth parameters, nutrient status and colonization density of beneficial microbes in winter rye grown organically and conventionally - Plant traits

The study focuses on the impact of a beneficial microbial consortium on the plant performance of winter rye under different farming practices during the vegetation period, including the winter growing season. Winter rye plants grown in a long-time field trial (Thy_ABS; 52°15’ N, 13°14’ E, 44 m a.s.l.) under conventional or organic farming practices were inoculated after plant emergence in autumn 2020 with a beneficial microbial consortium containing Pseudomonas sp. (RU47, drench inoculation with 2 L per m² of 7.5 x 107 CFU mL-1), Bacillus atrophaeus (ABi03, drench inoculation with 2 L per m² of 7.5 x 107 CFU mL-1) and Trichoderma harzianum (OMG16, soil inoculation with 100 mg inoculum per m²). The density of the microbial inoculants in the rhizosphere and root-associated soil as well as the plant performance and nutrient status was quantified in autumn and the following spring. Selective plating demonstrated that the beneficial microbes successfully colonized the rhizosphere and root-associated soil of winter rye throughout its early growth cycle. The inoculation with a beneficial microbial consortium enhanced the biomass of winter rye, especially under organic farming practices at the second sampling in spring. The consortium significantly improved the nutrient status of the winter rye plants, providing an effective way to overcome nutrient limitations often found in organic farming.

Research domain: Plant Cultivation and Agricultural Technology

Research question: We hypothesized that (i) early inoculation of winter rye enables sufficient colonization of each BMc member at
early plant developmental stage, supporting its persistence in the rhizosphere throughout the vegetation period; (ii) the application of BMc shapes the composition of the rhizosphere bacterial community depending on the farming practice and thus differentially affects the plant performance.

本研究聚焦于有益微生物联合体（beneficial microbial consortium）在生育期（含冬季生长期）内，不同耕作模式对冬黑麦植株生长性状的影响。本研究依托一处长期田间定位试验（Thy_ABS；北纬52°15′，东经13°14′，海拔44米），分别在常规耕作与有机耕作模式下种植冬黑麦，并于2020年秋季植株出苗后，接种包含以下菌株的有益微生物联合体：假单胞菌属（Pseudomonas sp.，菌株RU47，以每平方米2升浓度为7.5×10^7 CFU·mL^-1的菌液灌根接种）、萎缩芽孢杆菌（Bacillus atrophaeus，菌株ABi03，以每平方米2升浓度为7.5×10^7 CFU·mL^-1的菌液灌根接种）及哈茨木霉（Trichoderma harzianum，菌株OMG16，以每平方米100毫克菌剂进行土壤接种）。
分别于秋季及次年春季，对根际与根围土壤中的微生物接种剂定殖密度、冬黑麦植株生长性状及养分状况进行定量检测。选择性平板培养实验证实，该有益微生物可在冬黑麦整个早期生长周期内成功定殖于根际与根围土壤。
有益微生物联合体接种可显著提升冬黑麦生物量，尤其在春季第二次采样时的有机耕作模式下效果最为突出。该联合体可有效改善冬黑麦植株的养分状况，为克服有机耕作中普遍存在的养分限制问题提供了可行方案。
研究领域：植物栽培与农业技术
研究假说：本研究提出两项核心假说：（i）冬黑麦早期接种可使各有益微生物组分在植株发育早期完成充分定殖，并在整个生育期内持续存活于根际环境中；（ii）有益微生物联合体的施用会根据耕作模式重塑根际细菌群落组成，进而对植株生长性状产生差异化影响。