Data_Sheet_1_Trichoderma-Inoculation and Mowing Synergistically Altered Soil Available Nutrients, Rhizosphere Chemical Compounds and Soil Microbial Community, Potentially Driving Alfalfa Growth.docx

Trichoderma spp. are proposed as major plant growth-promoting fungi (PGPF) to increase plants growth and productivity. Mowing can stimulate aboveground regrowth to improve plant biomass and nutritional quality. However, the synergistic effects of Trichoderma and mowing on plants growth, particularly the underlying microbial mechanisms mediated by rhizosphere soil chemical compounds, have rarely been reported. In the present study, we employed Trichoderma harzianum T-63 and conducted a pot experiment to investigate the synergistic effect of Trichoderma-inoculation and mowing on alfalfa growth, and the potential soil microbial ecological mechanisms were also explored. Alfalfa treated with Trichoderma-inoculation and/or mowing (T, M, and TM) had significant (P 2 = 0.3451, P = 0.045). However, Pseudomonas, Flavobacterium, Arthrobacter, Bacillus, Agrobacterium, and Actinoplanes were not significantly correlated with alfalfa biomass. According to structure equation modeling (SEM), Trichoderma abundance and available P served as primary contributors to alfalfa growth promotion. Additionally, Trichoderma-inoculation and mowing altered rhizosphere soil chemical compounds to drive the soil microbial community, indirectly influencing alfalfa growth. Our research provides a basis for promoting alfalfa growth from a soil microbial ecology perspective and may provide a scientific foundation for guiding the farming of alfalfa.</p

Analysis of variance (ANOVA) for the response surface quadratic model of the T-E5 population based on the Box-Behnken design (BBD).

Analysis of variance (ANOVA) for the response surface quadratic model of the T-E5 population based on the Box-Behnken design (BBD).</p

Pearson correlation between physicochemical and FRI parameters.

Pearson correlation between physicochemical and FRI parameters.</p

Plackket-Burman design matrix and the results of the six variables (coded and actual levels) with T-E5 population levels as a response.

<p>Plackket-Burman design matrix and the results of the six variables (coded and actual levels) with T-E5 population levels as a response.</p

The effects of different treatments on the biomasses of cucumber, tomato and pepper plants on the harvest day (30 d after transplantation) during the pot experiment.

<p>The effects of different treatments on the biomasses of cucumber, tomato and pepper plants on the harvest day (30 d after transplantation) during the pot experiment.</p

Fluorescence EEM contours of WEOM from composts during composting process in the optimized condition.

<p>Peak A, peak B and peak C represent protein-like, fulvic-like and humic-like substances, respectively. (a) 0 d; (b) 3 d; (c) 6 d; (d) 8 d; (e) 11 d; (f) 14 d.</p

Analysis of variance (ANOVA) for the response surface quadratic model of the T-E5 population based on the Plackett-Burman design (PBD).

<p>Analysis of variance (ANOVA) for the response surface quadratic model of the T-E5 population based on the Plackett-Burman design (PBD).</p

Dynamic changes of Pi, n in the five regions during composting process in the optimized condition.

<p>Dynamic changes of Pi, n in the five regions during composting process in the optimized condition.</p

Box-Behnken design (BBD) matrix of variables (coded and actual levels) for T-E5 population optimization.

<p>Box-Behnken design (BBD) matrix of variables (coded and actual levels) for T-E5 population optimization.</p

Data_Sheet_1_Trichoderma Biofertilizer Links to Altered Soil Chemistry, Altered Microbial Communities, and Improved Grassland Biomass.docx

In grasslands, forage and livestock production results in soil nutrient deficits as grasslands typically receive no nutrient inputs, leading to a loss of grassland biomass. The application of mature compost has been shown to effectively increase grassland nutrient availability. However, research on fertilization regime influence and potential microbial ecological regulation mechanisms are rarely conducted in grassland soil. We conducted a two-year experiment in meadow steppe grasslands, focusing on above- and belowground consequences of organic or Trichoderma biofertilizer applications and potential soil microbial ecological mechanisms underlying soil chemistry and microbial community responses. Grassland biomass significantly (p = 0.019) increased following amendment with 9,000 kg ha−1 of Trichoderma biofertilizer (composted cattle manure + inoculum) compared with other assessed organic or biofertilizer rates, except for BOF3000 (fertilized with 3,000 kg ha−1 biofertilizer). This rate of Trichoderma biofertilizer treatment increased soil antifungal compounds that may suppress pathogenic fungi, potentially partially responsible for improved grassland biomass. Nonmetric multidimensional scaling (NMDS) revealed soil chemistry and fungal communities were all separated by different fertilization regime. Trichoderma biofertilizer (9,000 kg ha−1) increased relative abundances of Archaeorhizomyces and Trichoderma while decreasing Ophiosphaerella. Trichoderma can improve grassland biomass, while Ophiosphaerella has the opposite effect as it may secrete metabolites causing grass necrosis. Correlations between soil properties and microbial genera showed plant-available phosphorus may influence grassland biomass by increasing Archaeorhizomyces and Trichoderma while reducing Ophiosphaerella. According to our structural equation modeling (SEM), Trichoderma abundance was the primary contributor to aboveground grassland biomass. Our results suggest Trichoderma biofertilizer could be an important tool for management of soils and ultimately grassland plant biomass.</p