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Intercropping has the potential to enhance yields and nutrient availability in resource-limited agricultural systems. However, the effects on crop yield nutrients and soil properties can vary considerably depending on the specific plant combinations and intercropping ratios used. In this study, the advantages and impacts of intercropping C. esculentus with legumes were investigated by measuring their biomass, nutrient content, and soil properties. The experiment included five intercropping treatments: monoculture of C. esculentus (MC), intercropping of C. esculentus with Medicago sativa L. (alfalfa) at row spacing ratios of 4:4 (4:4CM) and 8:4 (8:4CM), and intercropping of C. esculentus with Glycine max (L.) Merr. (soybean), also at row spacing ratios of 4:4 (4:4CG) and 8:4 (8:4CG). Our results demonstrated that all four intercropping treatments (4:4CM, 4:4CG, 8:4CM, and 8:4CG) significantly increased the biomass of C. esculentus by approximately 41.05%, 41.73%, 16.08%, and 18.43%, respectively, compared with monoculture cultivation alone, among which the 4:4CG treatment was optimum. However, no significant differences were observed in alfalfa or soybean biomass across different intercropping ratios. A notable increase was found in the total nitrogen (TN) and total phosphorus (TP) contents in the leaves, roots, and tubers of C. esculentus under intercropping, along with increased soil organic carbon (SOC), alkaline-hydrolyzed nitrogen (AN), available phosphorus (AP), microbial biomass carbon (MBC), microbial biomass nitrogen (MBN), and soil water content (SWC), and significantly reduced the soil pH. Among the intercropping treatments, the 4:4CG treatment also exhibited the most favorable soil properties. In particular, compared with MC, the 4:4CG treatment resulted in significant increases of 163.8%, 394.6%, and 716.8% in SOC, AN, and AP contents, respectively. The same treatment also led to significant increases of 48.34%, 46.40%, and 208.65% in MBC, MBN, and SWC, respectively. Overall, the findings suggest that the use of 4:4CG intercropping is an effective approach for sustainable farming management in Xinjiang.

IntroductionSolar radiation plays a crucial role in the decomposition of litter and the cycling of nutrients. Previous studies have investigated that the net effect of solar radiation on litter decomposition depends on the balance of its facilitative and inhibitory effects on microbial activity; however, a gap in understanding the mechanism by which precipitation affects the net effect of solar radiation and the mechanism of litter decomposition on a global scale was observed.MethodsIn addressing this gap, a comprehensive meta-analysis of 351 data points from 37 published studies was conducted to estimate the sole radiation effect and interactive effect of solar radiation and precipitation on a global scale, as well as how they vary at different precipitation levels. In addition, the importance of influential factors regulating the net effect of solar radiation on litter decomposition was assessed to identify the key drivers of the response of mass loss to solar radiation at different precipitation levels.ResultsOur findings indicated that solar radiation largely regulates litter decomposition, and the direction and magnitude are potentially dependent on the precipitation regime. In addition, solar radiation significantly increased mass loss and decreased the nutrient remaining. Furthermore, the effects of solar radiation on mass loss, C remaining, and N remaining were found to be similar among areas with precipitation levels below 200 and above 800 mm and greater than in areas with precipitation levels between 200-400 mm and 400-800 mm. The effect of solar radiation on CO2 emissions varied from 13.97% when precipitation was below 200 mm to −0.707% when precipitation was between 200 and 400 mm.ConclusionClimatic factors determine the response ratio of mass loss to solar radiation in arid lands, whereas the initial litter characteristics have a great influence on the response of mass loss to solar radiation in ecosystems that are not moisture limited. The effect of precipitation on the photodegradation mechanism of litter was primarily achieved by influencing the decomposition of lignin, and the main effect of solar radiation on litter decomposition will shift from the positive effect of “photopriming” to the negative effect of “microbial inhibition” with the increase of precipitation. Our findings can provide a comprehensive understanding of litter decomposition patterns on a global scale, and our results showed that CO2 emissions from photodegradation will be lessened by precipitation, which is important in predicting CO2 emission and separating sources of CO2 under future increasing precipitation scenarios, particularly in arid lands.

IntroductionThe productivity and community structures of terrestrial ecosystems are regulated by total precipitation amount and intra-annual precipitation patterns, which have been altered by climate change. The timing and sizes of precipitation events are the two key factors of intra-annual precipitation patterns and potentially drive ecosystem function by influencing soil moisture. However, the generalizable patterns of how intra-annual precipitation patterns affect the productivity and community structures of ecosystems remain unclear. MethodsWe synthesized 633 observations from 17 studies and conducted a global meta-analysis to investigate the influences of intra-annual precipitation patterns on the productivity and community structures of terrestrial ecosystems. By classifying intra-annual precipitation patterns, we also assess the importance of the magnitude and timing of precipitation events on plant productivity.ResultsOur results showed that the intra-annual precipitation patterns decreased diversity by 6.3% but increased belowground net primary productivity, richness, and relative abundance by 16.8%, 10.5%, and 45.0%, respectively. Notably, we found that the timing uniformity of precipitation events was more important for plant productivity, while the plant community structure benefited from the increased precipitation variability. In addition, the relationship between plant productivity and community structure and soil moisture dynamic response was more consistent with the nonlinear model.ComclusionsThe patterns of the responses of plant productivity and community structure to altered intra-annual precipitation patterns were revealed, and the importance of the timing uniformity of precipitation events to the functioning of production systems was highlighted, which is essential to enhancing understanding of the structures and functions of ecosystems subjected to altered precipitation patterns and predicting their changes.

Introduction: Solar radiation plays a crucial role in the decomposition of litter and the cycling of nutrients. Previous studies have investigated that the net effect of solar radiation on litter decomposition depends on the balance of its facilitative and inhibitory effects on microbial activity; however, a gap in understanding the mechanism by which precipitation affects the net effect of solar radiation and the mechanism of litter decomposition on a global scale was observed. Methods: In addressing this gap, a comprehensive meta-analysis of 351 data points from 37 published studies was conducted to estimate the sole radiation effect and interactive effect of solar radiation and precipitation on a global scale, as well as how they vary at different precipitation levels. In addition, the importance of influential factors regulating the net effect of solar radiation on litter decomposition was assessed to identify the key drivers of the response of mass loss to solar radiation at different precipitation levels. Results: Our findings indicated that solar radiation largely regulates litter decomposition, and the direction and magnitude are potentially dependent on the precipitation regime. In addition, solar radiation significantly increased mass loss and decreased the nutrient remaining. Furthermore, the effects of solar radiation on mass loss, C remaining, and N remaining were found to be similar among areas with precipitation levels below 200 and above 800 mmand greater than in areas with precipitation levels between 200-400 mm and 400-800 mm. The effect of solar radiation on CO2 emissions varied from 13.97% when precipitation was below 200 mm to -0.707% when precipitation was between 200 and 400 mm. Conclusion: Climatic factors determine the response ratio of mass loss to solar radiation in arid lands, whereas the initial litter characteristics have a great influence on the response of mass loss to solar radiation in ecosystems that are not moisture limited. The effect of precipitation on the photodegradation mechanism of litter was primarily achieved by influencing the decomposition of lignin, and the main effect of solar radiation on litter decomposition will shift from the positive effect of "photopriming" to the negative effect of "microbial inhibition" with the increase of precipitation. Our findings can provide a comprehensive understanding of litter decomposition patterns on a global scale, and our results showed that CO2 emissions from photodegradation will be lessened by precipitation, which is important in predicting CO2 emission and separating sources of CO2 under future increasing precipitation scenarios, particularly in arid lands. [ABSTRACT FROM AUTHOR]