This study investigated the effects of adding mature compost (MC) and vermicompost (VC) on controlling gas emissions and compost quality during food waste (FW) composting. In addition to a control treatment (only food waste), four treatments were designed to mix the initial FW with varying rates of MC and VC (5.0% and 7.5%). The composting process was monitored for 84 days. Results indicate that the addition of MC and VC resulted in higher temperature, prolonged the thermophilic stage and reduced NH₃ and greenhouse gas (GHG) emissions. Compared to the control, the loss of NH₃-N was decreased by 29–69%, and the global warming impact was also mitigated by 49–61%. The largest reductions in NH₃ and global warming potential (GWP) were found for 7.5% VC and 5% MC, respectively. The treatments with additives more rapidly achieved the required maturity value. This research suggests that the addition of 7.5% MC and VC is suitable for food waste composting.

Phosphorus accumulation in soil leads to soil quality degradation and yield reduction. Therefore, effective phosphorus management is essential for maintaining a sustainable agroecosystem and ensuring crop productivity. This study aimed to evaluate the effects of various organic materials on phosphate availability in phosphorus-accumulated soil, identify suitable organic materials, and determine optimal application rates for solubilizing accumulated phosphate. The materials tested including organic acid, peat moss, zeolite, sulfur, hairy vetch, rice straw, wheat bran, expeller cake, and DTPA (a chelating agent). The treatment rates were applied on a weight/weight (w/w) basis, with DTPA and distilled water serving as the controls. Soil pH, available phosphate, water-soluble phosphate, and phosphatase activity were analyzed at 0, 7, 14, and 30 days through incubation experiments. The results indicated that sulfur, expeller cake, DTPA and hairy vetch effectively reduced soil pH. Available phosphate increased by 25% and 17% compared to the control with sulfur and expeller cake, respectively. Water-soluble phosphate increased by 21% to 75% compared to the control with sulfur, rice straw (1%), zeolite, expeller cake (2%), and wheat bran (2%). Acid phosphatase activity was enhanced by organic acid (0.5%, 1%), zeolite (1%), rice straw (2%), wheat bran, and hairy vetch (0.5%, 1%, 2%). This study demonstrated that organic materials have phosphate solubilization effects comparable to DTPA.

This study aimed to evaluate the greenhouse gas (GHG) emission rates and the stable organic carbon content in organic and conventional systems during rice-onion cropping season. Methane (CH 4) and nitrous oxide (N 2 O) emissions rates were investigated using the closed chamber method. As a stable carbon, mineralassociated organic matter (MAOM) and humic substances were selected and determined through physical and chemical fraction methods. During the rice and onion growing seasons, the CH 4 and N 2 O emissions patterns exhibited similar trends in both organic and conventional practices. However, the total greenhouse gas emissions in the organic was notably lower than conventional farm, and the impact of the rice season (70%) was much higher than onion. Furthermore, humic substances and MAOM were 14% and 13% higher, respectively, in the organic system compared to the conventional system (p < 0.05). This suggested that organic farming management could contribute to mitigating climate change by reducing GHG flux and increasing stable soil organic carbon.

Organic fertilization has been known to improve soil health by accelerating microbial activity, which mainly regulated the formation and decomposition of labile organic carbon (LOC). The objectives of this study were to: (1) analyze the effects of different fertilization on soil microbial activity; β-glucosidase, dehydrogenase, phosphatase, urease and soil respiration (RES) and LOC; particulate organic carbon (POC), permanganate oxidizable carbon (POXC), and microbial biomass carbon (MBC), and (2) evaluate the potential of LOC pool as a soil health indicator through correlation analysis. Treatments included chemical fertilizer (NPK), cattle manure compost (COM), green manure crops (GM), and an unfertilized control (NF). Soil chemical properties and microbial activity were higher in organic resource treatments (COM, GM) than in NPK. The COM treatment showed the highest values for pH, total nitrogen (T-N), soil organic matter, available phosphorus, and exchangeable cations. Also, microbial enzyme activities (β-glucosidase, dehydrogenase, phosphatase, urease) and RES were higher in organic fertilization, compared to NPK. In particular, COM treatment increased urease activity and respiration by 35% and 60%, respectively, relative to NPK. Significant positive correlations were observed between soil microbial activity and the LOC fractions, in particular, POC showed the strongest correlation ( p < 0.01). Particulate organic C could be suggested as a reliable indicator for soil health. Additionally, maize yield of the organic treatments was comparable to those of NPK, confirming organic fertilization could be an effective management for both soil health and crop yield.

Organic vegetable cultivation requires soil management strategies that improve carbon balance and suppress soilborne diseases. This study evaluated the efficacy of acidified microbial biochar pellets (ABPM) in enhancing net ecosystem carbon balance (NECB) and suppressing clubroot disease (Plasmodiophora brassicae) during organic Chinese cabbage (Brassica rapa ssp. pekinensis) cultivation. In a field-scale evaluation, three treatments were compared: guano fertilizer (control), ABPM 27 (inoculated with Pseudomonas fluorescens 22BCO027), and ABPM 86 (inoculated with Bacillus megaterium 22BCO086). Soil incorporation of ABPM 27 and ABPM 86 significantly increased soil carbon sequestration by 29.1% and 22.4%, respectively, while simultaneously reducing cumulative greenhouse gas emissions under the experimental conditions. This resulted in positive NECB values of 2.63 and 2.94 t CO₂-eq ha⁻¹, suggesting enhanced carbon retention potential within the studied cultivation system. Beyond its impact on carbon dynamics, ABPM 27 increased marketable yield by 8.6% (77.4 t ha⁻¹) and reduced clubroot incidence by 46.2%. Rhizosphere microbial analysis revealed that ABPM 27 promoted late-season microbial diversity and the persistence of beneficial Bacillus spp. and Pseudomonas spp. populations. These findings suggest the potential multifunctional role of microbially engineered biochar pellets in improving crop production, carbon retention, and pathogen suppression under organic cultivation conditions. However, these findings are based on a single-season field experiment and NECB-based carbon balance estimates, and therefore require validation across multiple growing seasons and cultivation environments.

Crop productivity in North Korea's farmland is low due to cold climate and low soil fertility. Green manure is strongly recommended to improve soil fertility and crop yield as an alternative to chemical fertilizer. However, the optimum sowing date of green manure under North conditions has not been investigated yet. Therefore the objective of this study was to select the sowing date for Hairy vetch and rye considering North Korea's climate conditions. The sowing period consisted of 6 times autumn sowing, three times winter sowing, and one time spring sowing. Average minimum temperature (°C), germination rate (%), over wintering survival rate (%), and plant height (cm) were surveyed. Dry matter weight (kg ha-1) and nutrient input (kg ha-1) were also analyzed. The soil temperature at the experimental site, located near North Korea, was 5°C lower on the average temperature during the cultivation period compared to the central region of South Korea. According to the growth survey and production analysis, it was appropriate to sow hairy vetch and rye no later than September 27th and October 7th, respectively. Late sowing was negatively impacted by low temperatures, resulting in reduced crop growth and nutrients production. Considering climate conditions, selecting a proper sowing date could be a useful agricultural practice for maximizing green manure biomass.