Soil carbon mineralization plays an important role in the carbon cycle of terrestrial ecosystems. When it comes to the soil carbon cycle, however, research on how carbon mineralization characteristics of fertilized Camellia oleifera forest soil respond to temperature changes remains limited. This study used an indoor constant temperature incubation method to examine the effects of the vermicomposting of cow dung by applying it at three different quantities (A: 0.8 kg earthworm + 62.5 kg cow dung/Camellia oleifera; B: 1.6 kg earthworm + 125 kg cow dung/Camellia oleifera; C: 2.4 kg earthworm + 187.5 kg cow dung/Camellia oleifera) and set a control group with Camellia oleifera forest not being fertilized (CK). This research was conducted with incubators set at 5 °C, 15 °C, 25 °C, and 35 °C, and with continuous monitoring of soil carbon mineralization characteristics and temperature sensitivity of organic carbon mineralization. The results showed significant increases in soil MBC, MBN, DOC, DON, NO₃⁻-N, and NH₄⁺-N in groups with applications of cow-dung vermicomposting compared to CK. Except at 35 °C, soil respiration in the Camellia oleifera of Group A was consistently the strongest. The maximum soil carbon emission (C₀) was determined through a simulation of potential carbon emissions, with all correlation coefficients exceeding 0.95. The contents of TC and TN were positively correlated with MBC and MBN (p <0.001), while the C: N_micro was negatively correlated with TN, AN, MBN, and inorganic nitrogen. Based on temperature sensitivity (Q₁₀), the influence of temperature on soil mineralization rate was observed. The vermicomposting of cow dung had a noticeable effect, as Group B showed significantly stronger enzyme activity compared to other groups. These results indicate that changes in MBC can impact the stability of soil carbon mineralization. The roles of soil moisture and microorganisms should be considered when predicting dynamic changes in the soil carbon pool of Camellia oleifera when applying fertilizers and improving its soil carbon sequestration capacity.

Field experiments were conducted on a four-year-old leaf-use ginkgo plantation in southern China to assess the impact of nine different fertilization strategies with varying N-P₂O₅-K₂O rates at three growth phases (FBD: March for bud development; FLG: May for leaf growth; FLS: July for leaf strengthening) on leaf-use ginkgo (Ginkgo biloba L.) leaf productivity and ecological economic benefits (EEBs). The results indicated that regardless of timing and rate, fertilizer application led to an increase in leaf area and thickness, resulting in higher ginkgo leaf yield. The highest fresh (215.14 g tree⁻¹) and dry (78.83 g tree⁻¹) yields were observed with 3 g N + 2.5 g P₂O₅ + 1.5 g K₂O tree⁻¹ in FLG. FLS was found to mitigate the decline in SPAD values of leaves during late summer. Furthermore, fertilized ginkgo trees exhibited higher flavonoid concentrations in leaves, enhancing profitability. However, higher fertilizer rates were associated with elevated greenhouse gas emissions, nitrogen losses and ecological costs. Despite these drawbacks, all fertilization treatments resulted in increased net economic income. Specifically, compared to no fertilization, FBD, FLG and FLS treatments boosted net income by 3.5~26.6%, 11.6~60.5% and 5.8~35.4%, respectively. Using the entropy weight TOPSIS method, it was concluded that optimizing the N, P and K fertilization rate and timing (applying 3–2.5–1.5 g tree⁻¹ of N-P₂O₅-K₂O in May) is a beneficial approach to maximize EEBs and industrial benefits in leaf-use ginkgo plantations in southern China. This study provides valuable insights into suitable fertilization patterns and management for leaf-use ginkgo plantations in southern China.

Co-application of sewage sludge (SS) with biochar in landscape/forestry soil is a common strategy for enhancing soil fertility and reducing the bioavailability of potential toxic elements (PTEs) derived from SS, such as Cd, Pb, Cu, Zn, and Ni. However, due to variability of biochar quality and uncertainties in responses of different plant species, whether the co-application benefits the landscape/forestry plant system remains elusive. Here, we tested the effectiveness of three types of biochar (SS-derived biochar (SB), rice straw-derived biochar (RB), and litter-derived biochar (LB)), which were added to soil amended with SS at 50% (w/w) at rates of 1.5%, 3%, and 4.5% as growth media for the landscape plant Aglaonema modestum (A. modestum). We analyzed the substrate’s physicochemical properties and assessed the alleviation of phytotoxicity by biochar application. A significant increase in the fertility index of substrate was observed in all the treatments with biochar addition. The addition of biochar reduced the potential mobility of PTEs while increasing their residual fraction in media. Nonetheless, it has been found that the addition of biochar has ineffective or even negative effects on A. modestum growth (height, biomass, root length) and nutrient absorption. Importantly, the reduction in root biomass and the increased activity of root antioxidant enzymes (SOD, POD, CAT, and MDA) indicate contamination stress of biochar on the roots of A. modestum. Toxic elements of concern—namely Cu, Cd, and Pb—were not significantly higher in tissues of A. modestum saplings planted in biochar-SS-amended soil. However, elevated levels of other elements that may pose toxicity concerns, such as Ni and Zn, increased in tissues at high biochar dosages. Based on the Entropy–Weight TOPSIS method, it was further confirmed that compared to the treatment without biochar, all treatments except for 3.0% LB application resulted in poorer A. modestum comprehensive growth. Our results emphasize the need for detailed research on the response of specific plants to biochar in specific environments, including plant adaptability and the unexplored toxicity of biochar, to understand the large variations and mechanisms behind these ineffective or negative effects before the large-scale co-utilization of SS and biochar in landscape/forestry soils.

This study investigates the dynamics of soil CO₂ emissions during the cover period of Phyllostachys violascens and the impact of different cover measures, aiming to provide references for reducing the environmental effects of bamboo cover. An L₂₇ (9¹³) orthogonal experimental design was employed, setting the following variables: (1) heating materials: chicken manure, straw cake, and wheat ash; (2) thickness of husk layer: 15 cm, 25 cm, and 35 cm; (3) soil moisture levels before covering: moisture to 10 cm, 15 cm, and 20 cm. The soil CO₂ emission rate showed a unimodal curve, with a significant overall increase during the cover period. Throughout the entire cover period, the average soil CO₂ emission rate (25.39 μmol·m⁻²·s⁻¹) was 5.1 times higher than that of the uncovered Lei bamboo forest (5.02 μmol·m⁻²·s⁻¹) during the same period. Thicker husk layers (25 cm and 35 cm) corresponded to higher soil CO₂ emission rates, with significant differences noted among the thicknesses. When the soil was moist to 10 cm, the CO₂ emission rate was highest (62.51 μmol·m⁻²·s⁻¹); moisture to 15 cm and 20 cm resulted in significantly lower emission rates. Chicken manure produced the highest peak CO₂ emissions in the third week, at 70.64 μmol·m⁻²·s⁻¹, while straw cake and wheat ash reached their peaks in the fifth week, at 66.56 μmol·m⁻²·s⁻¹ and 57.58 μmol·m⁻²·s⁻¹, respectively. The interactions between the three factors (heating materials, husk layer thickness, and moisture levels) significantly affected the soil CO₂ emission rates. By optimally configuring these factors, CO₂ emissions can be regulated. This study recommends using wheat ash or straw cake as heating materials, combined with a 25 cm husk layer thickness, and moistening the soil to 15 cm before covering. This approach effectively reduces the peak and total soil CO₂ emissions while ensuring suitable soil temperatures for the growth of bamboo shoots in spring. This research provides a scientific basis for the environmental management of bamboo forests, aiding in the optimization of covering measures to achieve low-carbon and sustainable bamboo management.

Efficient water management and soil salinity are major constraints on cotton (Gossypium hirsutum L.) production in southern Xinjiang. This study evaluated the impacts of three irrigation leaching regimes (W1: 75 mm + 80% ETc, W2: 150 mm + 80% crop evapotranspiration (ETc), W3: 240 mm + 80% ETc) applied at different stages (seeding, budding, flowering), compared with a control of 450 mm spring irrigation (CK), on cotton growth, yield, quality, and water-use efficiency (WUE). The optimal leaching amount was found to range between 155–240 mm, with the W2C and W3C treatments performing the best. To integrate eight fiber indices, five growth parameters, yield, and WUE, comprehensive assessment models were established Four integrated evaluation models (Broda, Copeland, fuzzy Borda, and overall difference-based evaluation) exhibited strong consistency (Spearman coefficient > 0.98). Results from the fuzzy Borda model indicated optimal performance under treatments W2C and W3C. Additionally, a regression model suggested that cotton production was optimized when cumulative irrigation and rainfall reached approximately 326.3 mm, with leaching amounts applied during seeding, budding, and flowering stages. These findings provide practical guidelines for effective leaching practices to reduce soil salinity and to sustainably enhance cotton productivity in southern Xinjiang.

Excessive and unregulated management of water and fertilizer limits the productivity of Chukrasia tabularis ( C. tabularis ) plantations in subtropical regions. A two-factor factorial potted experiment was conducted using one-year-old C. tabularis seedlings. Three soil water content levels (95%, 75%, and 55% field capacity) and four compound fertilizer rates (0, 6, 12, and 18 g pot ⁻¹ ) were established, with the treatment of 75% field capacity and 0 g pot ⁻¹ fertilizer serving as the control (CK). Soil water content emerged as the dominant factor controlling C. tabularis seedling growth; furthermore, water and fertilizer exhibited a highly significant interaction effect on total biomass and root dry weight ( p < 0.001). At the 12 g pot ⁻¹ fertilizer rate, seedlings grown at 55% field capacity produced 35% more total biomass than those at 75% field capacity, and 224% more than CK. It also raised root dry weight by 32% over the control. But 95% field capacity reduced growth under all fertilizer treatments. Under the 55% field capacity condition, nitrogen and potassium accumulation at the 12 g pot ⁻¹ fertilizer rate increased by 701% and 318%, respectively, compared to CK. In contrast, the 95% field capacity condition caused severe root hypoxia and nutrient leaching, effectively negating the benefits of fertilization and leading to negative apparent fertilizer use efficiency for phosphorus and potassium. At 55% field capacity, the observed CH ₄ patterns suggested a potential shift from net emission to net uptake under selected treatments. A combined PCA-EWM-TOPSIS model demonstrated that a field capacity of 55% combined with 12 g pot ⁻¹ compound fertilizer achieved an optimal balance among growth benefits, resource use efficiency, and ecological trade-offs.