Significant research has been conducted on the effects of fertilizers or agents on the sustainable development of agriculture in salinization areas. By contrast, limited consideration has been given to the interactive effects of microbial fertilizer (MF) and salinity on hydraulic properties in secondary salinization soil (SS) and coastal saline soil (CS). An incubation experiment was conducted to investigate the effects of saline soil types, salinity levels (non-saline, low-salinity, and high-salinity soils), and MF amounts (32.89 g kg⁻¹ and 0 g kg⁻¹) on soil hydraulic properties. Applied MF improved soil water holding capacity in each saline soil compared with that in CK, and SS was higher than CS. Applied MF increased saturated moisture, field capacity, capillary fracture moisture, the wilting coefficient, and the hygroscopic coefficient by 0.02–18.91% in SS, while it was increased by 11.62–181.88% in CS. It increased soil water supply capacity in SS (except for high-salinity soil) and CS by 0.02–14.53% and 0.04–2.34%, respectively, compared with that in CK. Soil available, readily available, and unavailable water were positively correlated with MF, while soil gravity and readily available and unavailable water were positively correlated with salinity in SS. Therefore, a potential fertilization program with MF should be developed to increase hydraulic properties or mitigate the adverse effects of salinity on plants in similar SS or CS areas.

The purpose of this study was to investigate the effects of combined treatment of Trichoderma harzianum and Phanerochaete chrysosporium on lignin degradation and humification during aerobic composting. Chicken manure (CM) and rice husk (RH) were used as organic raw materials for composting. The basic physicochemical analysis indicated that the combined addition of Trichoderma harzianum and Phanerochaete chrysosporium effectively improved lignin degradation rate (16.60%), increased humic acid (HA) content (22.70 g/kg), and the germination index (GI) reached 110.99%. Fungal community revealed that the relative abundance of Ascomycota was 37.46–68.85%, 9.57–60.35%, 58.02–91.76%, 0.98–91.60% in CK, T1, T2, T3 and Basidiomycota was 7.81–36.03%, 7.84–3.55%, 4.42–9.60%, 0.06–8.05% in CK, T1, T2, T3 (in phylum); the relative abundance of Kazachstania was 0.001–68.48%, 0.62–14.60%, 7.06–25.45%, 0.001–38.16% in CK, T1, T2, T3 and Diutina was 2.67–7.97%, 1.11–34.42%, 15.79–64.41%, 0.25–35.34% in CK, T1, T2, T3 (in genus) during the composting. Especially, the combined addition of Trichoderma harzianum and Phanerochaete chrysosporium had more negative impact on the activity of Basidiomycota compared with CK and other treatments and Trichoderma harzianum treatment had the strongest inhibitory effect on Tausonia abundance compared with CK and other treatments. Correlation analysis indicated that moisture content influenced fungal community structure (r = −0.740, p < 0.01) which affected lignin degradation (r = −0.952, p < 0.01) and compost maturity level in the composting process. Fungi Functional Guild (FUNGuild) and correlation heatmap demonstrated that T3 could enhance the relative abundance of endophyte which may had the potential to improve the degradation of lignin. This study confirmed the positive effects of the combination of Trichoderma harzianum and Phanerochaete chrysosporium in enhancing lignin degradation and promoting compost maturity, providing a foundation for a deeper understanding of the mechanisms involved in lignin degradation and humification processes influenced by the fungal community during composting, ultimately contributing to the efficient utilization of agricultural waste resources.

Southwestern China is receiving excessive chemical fertilizers to meet the challenges of continuous cropping. These practices are deteriorating the soil environment and affecting tobacco (Nicotiana tabacum L.) yield and quality adversely. A novel microbially enriched biochar-based fertilizer was synthesized using effective microorganisms, tobacco stalk biochar and basal fertilizer. A field-scale study was conducted to evaluate the yield response of tobacco grown on degraded soil amended with our novel biochar-based microbial fertilizer (BF). Four treatments of BF (0%, 1.5%, 2.5% and 5%) were applied in the contaminated field to grow tobacco. The application of BF_1.5, BF_2.5 and BF_5.0 increased the available water contents by 9.47%, 1.18% and 2.19% compared to that with BF₀ respectively. Maximum growth of tobacco in terms of plant height and leaf area was recorded for BF_1.5 compared to BF₀. BF_1.5, BF_2.5 and BF_5.0 increased SPAD by 13.18–40.53%, net photosynthetic rate by 5.44–60.42%, stomatal conductance by 8.33–44.44%, instantaneous water use efficiency by 55.41–93.24% and intrinsic water use efficiency by 0.09–24.11%, while they decreased the intercellular CO₂ concentration and transpiration rate by 3.85–6.84% and 0.29–47.18% relative to BF₀, respectively (p < 0.05). The maximum increase in tobacco yield was recorded with BF_1.5 (23.81%) compared to that with BF₀. The present study concludes that the application of BF_1.5 improves and restores the degraded soil by improving the hydraulic conductivity and by increasing the tobacco yield.

Continuous cropping causes soil degradation and decreases crop yield in the karst region of southwestern China. However, the relationship between continuous cropping systems and soil hydraulic and physicochemical properties remains incompletely elucidated. In this study, we performed a comparative investigation on the soil physicochemical properties and soil-water-characteristic-curve-derived parameters from sites subjected to 3, 5, or 7 years of continuous cropping (CC3, CC5, and CC7) and cropping rotation (CC0). Soil organic matter content, clay content, and pH were significantly greater in soils under CC0 and short-term cropping (CC3) than in soils under long-term cropping (CC5 and CC7). This finding illustrated that continuous cropping reduced soil organic matter content, clay content, and pH. Across all continuous cropping durations, soil water holding capacity at 40~60 cm was greater than the 20~40 cm and 0~20 cm layers. The significantly greater soil water characteristics (except saturated moisture) in CC0 and CC3 soils than in CC5 or CC7 soils at all soil depths demonstrated that soil water characteristics deteriorated with the prolongation of cropping duration. The same soil water characteristics were positively correlated with soil organic matter content, clay content, and pH. These correlations, when viewed within the context of continuous cropping, can inform the development of more sustainable cropping systems in similar karst regions.

This study aimed to determine the effect of irrigation amount and irrigation frequency on drip-irrigated flue-cured tobacco evapotranspiration (ETa), yield, and water use efficiency. Four irrigation treatment levels were imposed: 100% IRT (fully irrigated treatment, no stress), 85% IRT, 70% IRT, RFT (rainfed treatment), and high, medium, and low irrigation frequencies were set. The relationship between irrigation volume and yield is a quadratic curve. The evapotranspiration had a positive relationship with the irrigation amount. The yield of flue-cured tobacco was the highest in 2016 (wet year), and the corresponding ETa was the smallest. The irrigation water use efficiency (IWUE) in the driest year, 2017, was lower than IWUE in the wet years 2015 and 2016, and the crop water use efficiency (CWUE) had similar results for the three years. IWUE increased with irrigation amount. The effect of irrigation frequency on CWUE was not significant. The CWUE had a positive relationship with yield. No significant differences due to irrigation frequency were found for yield.