Nitrogen reduction, in association with increased planting density and irrigation management, has been widely adopted in super rice cultivation systems to pursue higher yield with lower input. Here, soil microbial community structures under accurate N and water management were investigated after four years of experiments. Plot experiments were conducted with three treatments, including conventional farming practice (CF), reduced nitrogen with increased plant density (RNID), and reduced nitrogen with increased plant density and precise irrigation (RNIDPI). The results showed that RNID treatment increased soil bacterial diversity, enriched biomarker bacterial taxa, and altered bacterial community structure, with pH as the influential factor. The phylum Chloroflexi was enriched in the treatment of N reduction, while a higher ratio of Firmicutes was present in CF treatments. RNID treatment witnessed a low proportion of bacterial functional groups involved in nitrification and nitrate reduction. N fertilizer reduction with irrigation management increased rice yield (up to 22%) without changing the major soil fertility properties except for the increased pH and decreased ammonium N. The results suggest that N reduction, in association with increased plant density and accurate irrigation, is beneficial for super rice production.

Plastic film mulching is widely used in protected agriculture. However, the residues of various types of plastic films, as a consequence, severely affect soil quality. The most widely promoted alternative strategy is the use of biodegradable plastic films. Nevertheless, the research on the effects of different types of plastic films on soil properties remains insufficient. This study explored the impacts of different plastic film mulching on the physicochemical properties and microbial communities of soils for pepper cultivation, with three treatments: traditional polyethylene film (PE-Ctr), PBAT biodegradable film (PBAT bio), and reinforced polyethylene film (RPE). The results showed that the soil pH value was the highest in PE-Ctr treatment, and the soil organic matter content was higher in the biodegradable film treatment, while the electrical conductivity (EC), nitrate, and some cations (Ca²⁺, Mg²⁺) were higher in the RPE treatment. The contents of available trace element Zn, Fe, and Mn increased in the PBAT bio treatment. The bacterial richness and evenness indices were higher in PBAT bio treatment than those of other treatments. The fungal community had a relatively high richness, but a lower evenness, compared to the PE-Ctr and PBAT bio treatments. The use of different plastic films significantly affected the composition of soil bacteria, while differences in the composition of soil fungi were only observed between the PBAT bio and RPE treatments. Proteobacteria, Acidobacteriota, and Actinobacteriota were the most dominant bacterial phyla, and Ascomycota and Mortierellomycota were the dominant fungal phylum across all treatments. FAPROTAX functional prediction showed that the abundances of multiple functions of soil bacteria were higher in the RPE treatment, and the chemoheterotrophy function was higher in the PE treatment. FUNGuild analysis indicated that the trophic types and ecological function groups of soil fungi were more abundant in the PBAT bio treatment.

Researchers have previously described the response of crop productivity and greenhouse gas (GHG) emissions to fertilizer nitrogen (N) additions, but they have not determined how to maximize yields while minimizing GHG emissions. We conducted an experiment at 2293 sites with four N levels to simulate both grain yield and yield-scaled GHG emissions in response to the N addition. The yield-scaled GHG emissions decreased by 16% as the N rate increased from treatments without the N addition to the minimum yield-scaled GHG emissions, which was comparable to the values associated with the maximum grain yields. The sites with both high soil productivity and high crop productivity had the highest yield and lowest yield-scaled GHG emissions, with 43% higher yield and 38% lower yield-scaled GHG emissions than sites with low soil and low crop productivity. These findings are expected to enhance evaluations of wheat production and GHG emissions in China, and thereby contribute to addressing disparities in the global food and GHG budget.

To identify a suitable plastic film type for broccoli cultivation in the subtropical humid region of southern China, a field experiment was conducted with four treatments, including no film control (CK), reinforced polyethylene film (RF), biodegradable film PBAT + starch (BDF1), and biodegradable film PBAT + PLA (BDF2). Soil physiochemical properties, temperature and humidity dynamics, microbial community structure, and film degradation status were investigated. The results showed that the RF treatment improved available P and K contents, while the BDF2 treatment significantly increased soil organic matter, NH4⁺-N, water-soluble Ca^2+, and Mg²⁺ contents. The soil temperature followed the order of RF > BDF1 > BDF2 > CK, and the humidity was BDF1 > RF > CK > BDF2, with RF treatment showing a more stable soil temperature, while BDF2 treatment fluctuated the most. There were no significant differences in bacterial diversity among the treatments, while the highest fungal diversity was observed in the BDF2. Water-soluble Mg was the key factor driving the changes in microbial community structure (p < 0.05). The film degradation rate followed BDF2 > BDF1 > RF. Collectively, RF is suitable for targeting short-term yield improvement, while BDF2 has significant advantages in sustainable cultivation in the long-term.

Micronutrient limitation and rhizosphere imbalance often constrain the productivity and quality of leafy vegetables in intensively managed greenhouse soils. This study evaluated the effects of conventional fertilization (CK), micronutrient supplementation (Mi), and micronutrient supplementation combined with a compound microbial inoculant (MM) on bur clover (Medicago polymorpha L.) yield, quality, rhizosphere chemical properties, and soil microbial communities. Compared with CK, Mi increased yield by 26.53%, whereas MM increased yield by 40.77%. MM also significantly increased SPAD, soluble protein, and soluble sugar, while reducing plant nitrate content by 22.86%; Mi had no significant effect on nitrate reduction. MM decreased soil pH from 8.62 to 8.34 and increased EC, available P and K, water-soluble Ca, Mg, and K, and available Zn and B, indicating improved rhizosphere chemical conditions. Mantel analysis showed that yield and plant nitrate were significantly associated with several soil variables. MM also markedly reshaped rhizosphere microbial communities, with clear treatment separation for both bacteria and fungi. The bacterial community was significantly explained by selected soil variables, whereas the fungal model was not significant. Overall, micronutrient supplementation mainly promoted yield, while its combination with microbial inoculation further improved rhizosphere conditions, crop quality, and nitrate control.