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The aim of this study was to quantify the effects of different mulch planting patterns on soil enzyme activity and organic carbon mineralization in a tea plantation. The cover crop diversity experiment was conducted in the Tanjiawan tea garden, Yunyang District, Shiyan City, Hubei Province. Four cover crop planting modes were set up, namely no crop cover(A0), two cover crops(A1), four cover crops (A2), and eight cover crops(A3). The enzyme activity, organic carbon mineralization rate, and cumulative mineralization of the 0~20 cm and 20~40 cm soil layers in the tea plantation were measured, and the data was fitted to the first order kinetic equation to obtain the mineralization potential(Cp)and mineralization constant(k)of organic carbon. The results showed that, the soil enzyme activity in the mulch plot was generally higher than that in the control plot, and the enzyme activity in the 0~20 cm soil layer was higher than that in the 20~40 cm layer. Different mulch types had significant effects on soil catalase and urease activity(PPCp/k value was as follows:A1 > A2 > A3 > A0. In the 20~40 cm soil layer, the Cp/k value was as follows:A1 > A2 > A0 > A3. This suggests that the organic carbon mineralization of A1 was the strongest in both soil layers. Moreover, the microbial biomass carbon and soluble organic carbon of A1 were higher than those of the other treatments, thereby providing sufficient nutrients for crop growth and development. A1 had the highest pH value, which was conducive to soil acidification.

This study was performed in a tea garden in Xupingsi Village, Tanjiawan Town, Yunyang District, Shiyan City, Hubei Province, to evaluate the effects of different mulching crop patterns on soil microbial community functions in 0~15 and 15~30 cm soil layers of the tea garden. Four treatments were selected:Natural grasses(CK), ryegrass+white clover(EZ), ryegrass+white clover+bluegrass+red clover(SZ), and ryegrass+white clover+bluegrass+red clover+purple fescue+hairy raccoon+cosmos+zinnia(BZ). The results showed that the activities of urease, invertase, catalase, and phosphatase in the 0~15 cm soil layer treated with SZ were higher than those in the other treatments; The activities of urease, catalase, and phosphatase in the 15~30 cm soil layer treated with SZ were higher than those in the other treatments, whereas the activity of invertase was lower than that in the other mulching treatments. The mulching crops increased the average well color development(AWCD)of microbial communities in the 0~15 cm soil layer; AWCD was the highest in the SZ treatment, indicating the highest utilization efficiency of the carbon source. The mulching crops improved the soil microbial richness index, evenness index, and dominance index in the 0~15 cm soil layer, but had few effects on these parameters in the 15~30 cm soil layer. The results indicate that the mulching crops can improve soil enzyme activity and microbial community functional diversity, and SZ treatment had the best effect on the 0~15 cm soil layer. The findings of this study would be able to provide a theoretical basis for analyzing the effects of different mulching crop patterns on soil functional diversity of microbial communities in tea plantations in the future.

The effect of different arrangements of grasses, flowering plants(Asteraceae), and legume crops on the number and diversity dynamics of arthropod communities was determined in a tea orchard in Xupingsi Village, Tanjiawan Town, Yunyang District, Shiyan City, Hubei Province. For this, 4 treatments were established:Natural grasses(CK), ryegrass+white clover(EZ), ryegrass+white clover+bluegrass+ red clover(SZ), and ryegrass+white clover+bluegrass+red clover+purple fescue+hairy raccoon+cosmos+zinnia(BZ). The community composition and dynamics of richness index, divesity index, and evenness index of arthropods were determined. The results showed that the arthropod community composition in the tea orchard with different cover crops was similar to that in the tea orchard with CK, with the largest number of Diptera and the least number of Araneae insects. Compared with that in the CK, the number of Lepidoptera increased significantly under the different cover crop treatments(PP>0.05). Homoptera insects increased significantly by 92.47%(PP>0.05). The dynamics of diversity, evenness, and richness indices of arthropod communities in the tea orchard with different cover crops were basically the same; The richness index was the highest on August 26 and was higher in the tea orchard with different cover crops than in that with natural grasses on September 30. The arthropod community diversity index for EZ treatment, the diversity, richness, and evenness indices for SZ treatment, and the diversity and evenness indices for BZ treatment were significantly higher than those of the CK in the tea orchard.

Farmland management measures can have a significant impact on the carbon cycle of farmland ecosystems, which can affect soil fertility, agricultural production, and food security, and more broadly, climate change and environmental health. In this paper, the effects of different farmland management measures(fertilization methods, planting systems, and farming models)on soil organic carbon, greenhouse gas emissions, and soil microorganisms were reviewed. The increase in soil organic carbon was fastest when organic and inorganic fertilizer were applied. Moreover, there was a threshold effect between the amount of fertilizer applied and the soil carbon inventory. The application of organic fertilizer increased the CO2 emissions flux in the soil, and the application of phosphorus and potassium fertilizers reduced the globe warming potential of farmland soil more than nitrogen fertilizer. Increasing the application ratio of organic fertilizer to phosphate fertilizer was beneficial, leading to an increase in microbial richness in the soil and accumulation of microbial biomass carbon. Planting structure and planting density both affected the carbon storage of farmland soil, and planting structure had a significant impact on greenhouse gas emissions in farmland ecosystems. Compared with traditional monoculture planting, crop rotation and intercropping could effectively reduce the greenhouse gas emissions of farmland. At the same time, crop rotation was more conducive to increasing soil microbial diversity than continuous cropping. Conservation tillage improved the efficiency of farmland soil carbon, reduced greenhouse gas emissions, and had a positive impact on microbial activity, diversity, community structure, and carbon source utilization. Finally, we summarized the application of international mainstream carbon models to farmland ecosystems, and present future development prospects.