The use of amendments in combination with Bacillus subtilis has been understudied as a strategy for rehabilitating acid soils and improving cropping systems. This study aimed to evaluate the effects of amendments and B. subtilis on the development, yield, and nutritional quality of the hard yellow maize Marginal 28 T variety. A randomized complete block design with a factorial arrangement was employed, considering five amendments, including biochar, alongside the application of B. subtilis. The combination of biochar and B. subtilis significantly increased plant and ear height (p < 0.01), achieved a grain yield of 4.11 t ha⁻¹, and reduced flowering time by seven days. Strong correlations were observed between male and female flowering (r = 0.99) and between stem diameter and leaf area (r = 0.95), indicating improved vegetative development. Soil pH and nutrient availability, such as phosphorus, were also enhanced. The combined use of amendments and B. subtilis optimizes yield and improves soil chemical properties. Thus, applying biochar and B. subtilis improves growth, yield, and soil quality, consolidating a promising strategy for sustainable agriculture in acid soils.

The study was conducted in Juan Guerra district, province and region of San Martin, Peru; it assessed two treatment sets: (1) nitrogen fertilizer dose (FN75, FN100); (2) green manure Crotalaria juncea (CroJ), Canavalia ensiformis (CanE), and without green manure. It was arranged in a split-plot design with four replications. During the experiment, we observed an important fluctuation in soil parameters. Notably, there was a decrease in soil carbon and nitrogen levels, likely attributed to microorganism metabolism. On the other hand, we observed that CanE significantly reduced the diseased tillers through “White Leaf Virus” (RHBV) by 2.82% compared to the control, and significant panicle fertility was achieved by CroJ (91.88%). No significant differences were obtained in yields during this first campaign; however, the highest reported yield was 8.36 t ha-1 with the CanE - FN100 treatment. Additionally, the nutritional quality of the rice was not affected by either green manuring or the application of chemical nitrogen fertilization. These findings allow deeper studies to consider strategic alternatives to reducing dependency on inorganic fertilizers among the poorest communities. Highlights: A reduced incidence of White Leaf Virus (RHBV) was observed with the use of green manures. Rice variety INIA 507 "La Conquista'' reached 8.36 t ha-1 under tropical climate conditions. Canavalia ensiformis accompanied by nitrogen fertilization produced the highest yield. Replacing 25% of chemical nitrogen fertilization with Canavalia or Crotalaria green manures did not significantly affect rice yield. Replacing chemical nitrogen fertilization with green manure did not affect the nutritional quality of rice.

Organic amendments provide a sustainable strategy to enhance soil quality in degraded environments while also helping to reduce greenhouse gas emissions, for example, by improving soil structure, minimizing the use of synthetic fertilizers, and promoting a green economy. This study assessed the comparative effects of two organic amendments—vermicompost leachate and biochar—on the performance of popcorn maize (Zea mays L. var. everta) cultivated in saline soil conditions. Four treatments were evaluated: T0 (Control), T1 (Vermicompost leachate), T2 (Biochar), and T3 (Vermicompost leachate + Biochar), each with 10 replicates arranged in a Completely Randomized Design (CRD). Although various soil physicochemical, microbiological, and agronomic parameters displayed no significant differences compared to the control, the application of biochar resulted in considerable improvements in soil total organic carbon, the microbial community (mesophilic aerobic bacteria, molds, and yeasts), and increased seed length and diameter. In contrast, vermicompost leachate alone negatively impacted plant growth, leading to decreases in leaf area, stem thickness, and grain yield. Specifically, grain yield declined by 46% with leachate alone and by 31% when combined with biochar, compared to the control. These findings emphasize the superior effectiveness of biochar over vermicompost leachate as a soil amendment under saline conditions and highlight the potential risks of widely applying compost teas in stressed soils. It is recommended to conduct site-specific assessments and screenings for phytotoxins and phytopathogens prior to use. Additionally, the combined application of leachate and biochar may not be advisable given the tested soil characteristics.

Background. The morphological quality of cocoa (Theobroma cacao L.) seedlings in the nursery is essential for the success of commercial plantations. Bioferments represent a sustainable alternative to improve the morphology and quality of seedlings. Objective. To evaluate the effect of bioferments on the morphology and quality of cocoa seedlings in the nursery. Methodology. Four treatments were used with different combinations of substrates and solid and liquid bioferments. A completely randomized design with four repetitions was used, measuring morphological and quality variables. Results. The traditional substrate treatment with the addition of solid and liquid bioferments (ST+BS+BL) showed the highest values in height, stem diameter, dry biomass and Dickson quality, surpassing the traditional substrate by 51%. Implications. Bioferments improve the availability of nutrients and the structure of the substrate, favoring the development of vigorous and better quality seedlings. Conclusions. The combination of solid and liquid bioferments represents an agroecological strategy to optimize the morphological attributes and quality of cocoa seedlings in the nursery.

Background: The utilization of organic fertilizers is put forward as an effective approach to address soil degradation and enhance crop yields. Objective: To assess the impact of applying microbial consortia, in combination with fermented liquid fertilizer (biol), on maize grain production, with a focus on fostering sustainable family farming in dry tropical conditions. Methodology: A randomized complete block design with three blocks and divided plots was employed, with the main plots featuring various maize cultivars, while the subplots consisted of four bioferments and a control treatment. The bioferments included Microbial Consortium (CM), BIOL+CM, and BIOL+EM-1, compared to the commercial product Efficient Microorganisms (EM-1) and a control with no application. Parameters such as days to male and female flowering, plant and ear height, leaf area, grain diameter, and yield, along with the physical and chemical soil characteristics, were evaluated following the bioferment application. Results: The application of BIOL+CM to the Marginal 28T variety resulted in increased plant height (164.17 cm) and cob size (65.83 cm), as well as a larger leaf area (361.17 cm²). It also enhanced the grain yield of the Marginal 28T variety (3.42 tꞏha-1) and the HS-1 hybrid (3.02 tꞏha-1). Implications: The combined use of locally-sourced microbial consortia and Biol significantly improves the agronomic performance of hard yellow corn and aids in maintaining the soil's physical and chemical conditions, thereby promoting its enhancement. Conclusion: The Marginal 28T variety and the HS-1 hybrid exhibited a favorable response to the application of microbial consortia, particularly BIOL+CM, making it a viable option for family farming in dry tropical conditions.

Organic amendments offer a sustainable strategy to enhance soil quality in degraded environments, while also contribute to reducing greenhouse gas generation and implementing a green economy. This study evaluated the comparative effects of two organic amendments—vermicompost leachate and biochar—on the performance of Popcorn maize (Zea mays L. var. everta) grown under saline soil conditions. Four treatments were tested: T0 (Control), T1 (Vermicompost leachate), T2 (Biochar), and T3 (Vermicompost leachate + Biochar), each with 10 replicates arranged in a Completely Random Design (CRD). Although several soil physicochemical, microbiological, and agronomic parameters showed no significant differences compared to the control, biochar application led to notable improvements in soil total organic carbon, microbial community (mesophilic aerobes bacteria, molds, and yeasts), and increased seed length and diameter. In contrast, vermicompost leachate alone had a detrimental effect on plant growth, including reduced leaf area, stem thickness, and grain yield. Notably, grain yield declined by 46% with leachate alone and by 31% when combined with biochar, compared to the control. These results highlight the superior performance of biochar over vermicompost leachate as a soil amendment under saline conditions and underscore the potential risks of broadly applying compost teas in stressed soils. Site-specific assessments and screening for phytotoxins and phytopathogens are recommended before use. Furthermore, the combined use of leachate and biochar may not be advisable under the tested soil characteristics.