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Purpose: Tillage practices and crop growth play important roles in the soil erosion of sloping farmland. This study aims to investigate the effects of tillage practices on soil erosion in response to different crop growth stages and to determine the primary factors that affected the runoff reduction benefit of tillage practices among different growth stages. Methods: A field study was carried out under natural rainfall conditions, and 12 runoff plots (20 m × 5 m) were established, including four treatments, i.e., flat planting (FP), flat planting with hedgerow intercropping (HG), longitudinal ridge (LR) and bare land (CK). Runoff and soil losses after each rainfall event were monitored during the peanut seasons of 2021 and 2022 and the effects of tillage practices and peanut growth stages on runoff and sediment yields were evaluated. Results: The total surface runoff depth and sediment yield decreased in the following order: CK > LR > FP > HG. As peanuts grew, the seedling, needling, podding, and full fruit stages contributed approximately 71.5%, 20.4%, 6.4%, and 1.7% of the total runoff depth, respectively, which could be attributed to the synergistic impact of rainfall, crop growth, and antecedent soil moisture. During the seedling stage of peanuts, which did not provide sufficient surface cover, concentrated rainfall in large amounts resulted in high soil moisture and consequently high runoff losses. As peanuts grew, the S-shaped growth curve for peanut aboveground parts and root systems and reduced rainfall depth and frequency resulted in less runoff loss and increased runoff reduction benefits of tillage practices. Conclusions: The early growth stage of peanuts, generally accompanied by high antecedent soil moisture and heavy rainfall, should attract more attention to improving water erosion conditions on sloping farmland with only longitudinal ridges. [ABSTRACT FROM AUTHOR]

Begonia × benariensis series varieties have high ornamental and economic value and are excellent varieties for large-area group planting in gardens and green areas. At present, the B. × benariensis series varieties grown in China rely on foreign imports, and the price of imported germplasm resources is expensive, which greatly increases the cost of flower enterprises. In view of this, B. × benariensis (2n = 2x = 34) was used as the material, the callus was treated with colchicine to induce polyploid plants, and the polyploid plants were subjected to morphology, DNA content identification, and stomatal identification, as well as comparisons of the morphophysiological indexes of the plants. The results showed that the polyploid was better induced with the treatment of 0.05% colchicine for 4 h, and the induction rate was 46.67%. Among the mutagenized plants, there were 42 triploids (2n = 3x = 51) and 98 tetraploids (2n = 4x = 68). The stomatal density of diploid leaves was about 1.09 times that of the triploid and 1.67 times that of the tetraploid, the defense cells of the leaves increased gradually, and the stomatal density decreased; with the increase in ploidy, the height of the plants increased, while the crown width decreased; the maximum length and width of the leaves decreased, the color of the leaves became darker, and the chlorophyll content increased. This study provides abundant variation materials and technical support for the selection and breeding of new varieties of B. × benariensis in the future. [ABSTRACT FROM AUTHOR]

Purpose: Changes in climate and land use may disrupt the soil carbon (C), nitrogen (N), and phosphorus (P) cycles, which affect the availability of essential nutrients differently, including soil organic carbon (SOC), total nitrogen (TN), and total phosphorus (TP). Nevertheless, lithologic impact on soil C:N:P stoichiometry over a broad climatic gradient remains largely unknown. We aimed to determine the variation in nutrient limitations between karst and non-karst forests and croplands across a climate gradient. Materials and methods: This study investigated soil C:N:P stoichiometry in mature forest (MF) and nearby cropland rotation (CR) (as a control) soils on limestone (karst) and clastic rock (non-karst) throughout a climatic gradient in southwest China through analysis of soil samples. Result and discussion: The SOC and TN contents in the karst MF were 1.3 and 1.6 times greater, respectively, than that in the non-karst MF. Consequently, the karst MF had a lower C:N ratio than did the non-karst MF. The SOC and TN contents were considerably higher in the MF than they were in the CR under both lithologies, leading to higher C:P and N:P ratios in the MF compared to those in the CR. The increasing temperature resulted in a shift from TN and TP to SOC limitation, due to the increased decomposition of SOC by microbes with an increase in temperature. Soil pH and Ca content are controlled by the lithology, and they were closely related to C:N:P stoichiometry in this study, whereas a combination of lithology and temperature controlled soil microbial activity and plant growth. Importantly, the magnitude of lithology-induced changes in the stoichiometry was greater as temperature increased, which was more pronounced in the non-karst than it was in the karst. Conclusions: These findings highlight the responses of soil C, N, and P to climate warming in relation to stoichiometry, and soil-microorganism-plant response strategies may be the key to the mitigating the effect of temperature increase on nutrient cycles in karst ecosystems. [ABSTRACT FROM AUTHOR]

China's Grain‐for‐Green Program (GFGP) motivates conversion from steep slope cropland to forest or grassland to reverse serious land degradation. However, impoverished farmers potentially persist with inefficient slope farming for survival, thereby threatening the sustainable GFGP efforts. Consequently, a strategy for balancing farming and vegetation restoration from a spatial optimization perspective is necessary. Here, we selected two catchments with high and low agricultural intensity in the loess hilly and gully regions for a case study. Spatial analysis and binary logistic regression models were used to clarify the effects of topography, accessibility, and location factors on cropland distribution and explore spatially optimized cropland distribution. The results show that steep slope cropland is still widespread, of which cropland with slopes >15° accounts for 46.7% and 34.7% in the two catchments, respectively. Residences and roads significantly impact steep slope cropland distribution, and around 80% of cropland with slopes >15° is distributed within 200 m from residences or 100 m from roads. In cropland redistribution scenarios, cropland with slopes >25° and >15° can be redistributed to gentler slopes while maintaining cropland areas in catchments with high and low agricultural intensity. Correspondingly, 38.8% and 81.2%, respectively, of simulated cropland on gentle slopes needs optimized attributes such as accessibility in order to be priorities of farmers. Our research provides new insights into GFGP strategies for steep slope cropland restoration in catchments with different agricultural intensities, thereby advancing sustainable farming and vegetation restoration in China's mountainous regions. [ABSTRACT FROM AUTHOR]

China has implemented the world's largest‐ever vegetation restoration program in marginal mountainous areas to sustain life on land. However, land competition between the demand for grain and the need for green has threatened sustainable vegetation restoration. Here, focusing on China's marginal mountainous areas with the highest density of slope cropland, we explore the optimal solution in the trade‐offs between green and grain. We find that current vegetation restoration strategies are not sufficiently optimized, which may threaten the survival and development of local farmers and in turn destroy existing vegetation restoration achievements. Through adjusting vegetation restoration objectives carefully tailored to local conditions, the population experiencing grain shortages can be greatly reduced by 51–66% (from 18.26 million to 6.29–8.90 million) compared with the current scheme. The optimal design will alleviate the conflict between grain and green, thereby promoting sustainable ecological restoration in China. Our research provides an important reference for the world's mountainous areas to achieve a win‐win situation between green and grain. Plain Language Summary: Vegetation restoration in China has made remarkable achievements in recent years. However, the sustainability of these vegetation restoration programs has been questioned and challenged. Combined with spatial statistics and scenario analysis for analyzing the trade‐offs between green and grain, we find that the current vegetation restoration strategies in China's mountainous areas are not sufficiently optimized, which may affect the sustainability of vegetation restoration programs. Vegetation restoration strategies adapted to local conditions can reduce the risk of grain shortage for 9.30–11.97 million farmers, and contribute to a more balanced development and the sustainability of vegetation restoration in mountainous areas. Key Points: Chinese farmers rely heavily on slope cropland and self‐sufficient farming in marginal mountainous areasCurrent vegetation restoration strategies are not sufficiently optimized, which may affect farmers' livelihood in mountainous areasPlanning tailored to local conditions can alleviate the conflict between grain and green, and promote sustainable vegetation restoration [ABSTRACT FROM AUTHOR]

Soil erosion in cropland areas is mainly influenced by agricultural activities and natural conditions. Previous studies have largely focused on the biophysical processes or economic drivers of soil erosion. There have been few attempts to balance the impacts of population, agricultural production, and soil erosion to address the global socioecological predicament facing cropland. We combined the coupling coordination degree model (CCDM) with the Shapley additive explanations (SHAP) method to evaluate the coupling coordination level between population demand, agricultural production, and soil erosion as well as the influence of socioeconomic factors in 281 Chinese cities for the period from 1995 to 2010. Coupling between population, crop yield, and soil erosion was generally moderate across China during 1995–2010. Cities with a GDP in the range of 4.42–241.54 billion could fall into different coupling coordination phases that were identified by K-means clustering. The SHAP results showed that GDP and population density were the most important factors influencing the coordination level, while industrial structure was the key determinant that distinguished the different phases in cities with a similar economic status. Building on research on the evolutionary aspects of system coupling coordination, our study reveals for the first time the probable causes of changes in system coupling coordination via machine learning algorithms, providing a reference for future investigations. Our findings also provide a basis for developing policy recommendations to balance social demands, agriculture, and environmental protection. ● Nexus between population, crop yield, and soil erosion have a spatial zonality. ● Economic growth and coupling coordination are significant positively correlated. ● Economic structure is vital for breaching the phase change threshold. ● Development policies should target to different coupling phases. [ABSTRACT FROM AUTHOR]

• Anticlockwise hysteresis type was the dominating hysteresis type. • Complex hysteresis type generated more sediment than either of three other types. • Antecedent rainfall dominated clockwise type, along with time lag for complex type. • Intraday rainfall and sediment separately dominated clockwise and anti-clock types. • Largest patch index and grassland separately dominated complex and other types. This study aims to quantitatively evaluate the effects of hydrological and landscape characteristics on suspended sediment concentration and discharge (SSC-Q) hysteresis. Runoff and sediment data of 405 flood events were collected from 10 basins in Wudinghe River basin on the Loess Plateau of China. Hysteresis analysis is a key tool for the interrogation of transport of sediment, which have been shown to be important within catchments. It can provide insight into catchment function, allowing the development and testing of process-based hypotheses. The principal components and corresponding explanatory power were extracted quantitatively from hydrological and landscape characteristics via principal component analysis (PCA) and redundancy analysis (RDA), respectively. The most common hysteresis type was anticlockwise. The proportions of the total event sediment loads for different hysteresis types were not always generally correlated to the frequency of the corresponding events. Furthermore, the composition and explanatory power of controlling principal components varied among clockwise, anticlockwise, figure-of-eight, and complex hysteresis types. For hydrological principal components, the antecedent precipitation, intraday precipitation, and sediment principal components controlled clockwise, anticlockwise, and figure-of-eight hysteresis types, which had explained 47.03%, 58.82% and 52.05% of the variation of hysteresis index, respectively; the antecedent precipitation and time lag principal component controlled complex hysteresis type and accounted for 28.22% and 34.65% of the variation of hysteresis index, respectively. For landscape principal components, grassland principal component dominated clockwise, anticlockwise, and figure-of-eight hysteresis types, and accounted for 95.00%, 69.70%, and 92.00% of the variation of hysteresis index, respectively. Largest patch index principal component controlled complex hysteresis type and accounted for 100% of the variation of hysteresis index. Therefore, within this catchment, whereas hysteresis patterns varied due to all of the hydrological and landscape variables to some extent, precipitation, suspended sediment, area of grassland, and the largest patch area had stronger impact on hysteresis dynamics. [ABSTRACT FROM AUTHOR]

Accurate information on crop type spatial distributions is crucial for yield estimation, agroecological modeling, and agrarian policy development. In comparison with moderate resolution (10–30 m) satellite images, very high-resolution (VHR, ≤ 1 m) images are superior at describing the spatial details and complex texture features of agricultural land. However, VHR images generally suffer from insufficient spatiotemporal coverage and high spectral variation in crop type, making fine-scale crop type mapping at regional or larger scales challenging. In this study, we developed a novel data-driven residual attention U-shape network (RAUNet) to identify crop types at the regional scale based on VHR images. RAUNet was adapted from UNet by introducing a residual module and a gated attention mechanism to strengthen the multilevel representation of crop features from VHR images. We selected rice-crayfish fields (RCFs) in Hubei Province, China, as the case crop type and area to test the performance of RAUNet. Seven models, including RAUNet pan , ResUNet, AttnUNet, UNet, DeepLabV3 + and random forest at the pixel and object levels, were adopted for comparison with RAUNet. Moreover, the model transferability was evaluated over regions with different agricultural landscapes. Our results showed that RAUNet-derived RCF maps obtained an average F1-score and MCC of 0.90 and 0.85 at different cultivation stages, which significantly outperformed other methods. Additionally, RAUNet had good spatiotemporal transferability, with an average F1-score and MCC of 0.93 and 0.88 in four transfer areas. The visualization results of the attention weights indicated RAUNet's prominent capability in combining useful and relevant information from different feature levels to produce refinement predictions for the target crop type. Furthermore, the high-level features derived from RAUNet can well separate RCFs and non-RCFs over different landscapes, which were also consistent across different cultivation periods. These encouraging results suggest that RAUNet works well for fine-scale crop type mapping in smallholder farming systems, and it is an efficient method for land cover mapping based on VHR images at the regional scale. [ABSTRACT FROM AUTHOR]

Cropland soil erosion is primarily caused by agricultural production and indirectly altered by consumption patterns. A well-developed grain trade system transfers grain products to distant locations, away from their place of origin where soil erosion may have occurred. Evidence-based policies to control soil erosion can be developed by holding consumers responsible for the soil erosion caused by their consumption. However, there have been few systematic studies on cropland soil erosion that is embodied in grain trade. In this study, we estimated the soil erosion intensity (SEI) of grain production in each province of China from 1990 to 2020 by combining the Revised Universal Soil Loss Equation and socio-economic statistics. We also constructed an interprovincial grain trade network using linear programming techniques and analyzed the cropland soil erosion associated with the interprovincial grain trade. The results showed a rise in national cropland soil erosion attributed to grain production from 5.36×108 t in 1990 to 7.56×108 t in 2020. In particular, those embodied in interprovincial grain trade increased from 0.94×108 t in 1990 to 3.52×108 t in 2020. Nationally, about 10.72% of soil erosion exports in 2020 was from provinces with lower-than-average SEI, compared to 18.42% in 1990, indicating that current patterns of grain production and consumption are unfavorable for erosion control. Accordingly, measures have been proposed to build a soil erosion control system that includes consumers, such as changing farming practices, optimizing agricultural layout, promoting technology export and establishing a provincial compensation mechanism. [Display omitted] • Trade was prominent and insufficiently explored driver for cropland soil erosion. • RUSLE and grain trade network were utilized to estimate embodied soil erosion. • Mismatch between production and consumption increased embodied soil erosion. • Soil erosion burden mainly shifted from south with high SEI to north with low SEI. • Current provincial grain trade patterns were not conducive to soil erosion control. [ABSTRACT FROM AUTHOR]

In China, sloping farmland accounts for one-third of its total farmland, supporting ~330 million mountain people's livelihoods. Despite its long history of using soil conservation measures for reducing soil loss on sloping farmland, no comprehensive evaluation has ever been performed on their effectiveness. In this study, we reviewed the soil conservation measures on sloping farmland in China from ~2500 years ago to the present and examined their effectiveness under current and projected climate change scenarios based on 6909 plot-scale observations. For the sloping farmland across China, the average soil loss rate is 14.47 Mg ha−1 yr−1, with a quarter of the observed values exceeding the maximum tolerable soil loss rate (10 Mg ha−1 yr−1). Soil conservation measures can reduce soil loss by ~80%, with the highest effectiveness for the combination of biological and engineering measures (reduced by ~86%), followed by biological measures (reduced by ~84%) and engineering measures (reduced by ~82%) separately. However, the effectiveness of soil conservation measures shows a significant decrease in the farmland with a slope above 15° or a single rainfall event >25 mm. The effectiveness of currently applied soil conservation measures was also compared under the Shared Socioeconomic Pathways (SSP) 1, 2, and 5 in 2050, and their effectiveness is expected to decrease on over 27% of the sloping farmland. In particular, under the SSP1 scenario, the effectiveness of soil conservation measures is projected to diminish in 70%, 54%, and 54% of sloping farmland in Northeast China, Sichuan Basin and surrounding regions, and Yunnan-Guizhou Plateau, respectively, due to changes in rainfall, highlighting the need to consider the impact of climate change when implementing soil conservation measures. Overall, this study provides useful information for scientific strategies on the construction, management, and maintenance of soil conservation measures to control soil loss on sloping farmland. [ABSTRACT FROM AUTHOR]

[Display omitted] • Accurate quantification of soil erosion sub-process by remote sensing and check dam. • Vegetation restoration significantly reduced soil erosion modulus. • Check dams effectively reduce sediment delivery on the watershed scale. • The variation of erosion and deposition changes the sediment delivery ratio. China has implemented a series of ambitious soil and water conservation (SWC) projects on the Chinese Loess Plateau, which have significantly changed the erosion, transport, and deposition of sediment. As a result, the sediment flux of the Yellow River, once the largest carrier of fluvial sediment worldwide, has been reduced by approximately 85 % in the past 60 years. However, the effects of SWC measures on erosion, transport, and deposition of sediment are still difficult to quantify, which greatly limits the further planning and adjustment of SWC measures. Here, we determined soil erosion, sediment deposition, and sediment yield at different historical stages in a 187 km2 hilly and gully watershed on the Chinese Loess Plateau using the unmanned aerial vehicle (UAV) photogrammetry technology combined with check dam surveying and hydrologic monitoring. The results show that the construction of check dams and vegetation restoration significantly reduced the soil erosion rate, from 21,144 t km−2 yr−1 at Stage-1 (1960–1969) to 13,819 ± 3,622 t km−2 yr−1 at Stage-2 (1970–1999) and further to 4,723 ± 1,278 t km−2 yr−1 at Stage-3 (2000–2018). The sediment deposition rate was estimated to be 5,989 and 2,582 ± 351 t km−2 yr−1 at Stage-2 and Stage-3, respectively. The variation in the erosion and deposition of sediment led to a significant change in the sediment delivery ratio, from 1 at Stage-1 to 0.57 at Stage-2 and 0.45 at Stage-3. Our research results provide an important reference for further SWC planning. [ABSTRACT FROM AUTHOR]

Cropland soil erosion is a major threat to global agricultural sustainability. Compared with the well-studied natural factors of soil erosion, socioeconomic factors have just begun to be considered. The major obstacle is that the soil erosion of different crops has not been accounted for and connected to socioeconomic activities. This study adopted the revised universal soil loss equation (RUSLE) and the environmentally extended multiregional input-output (EE-MRIO) model to account for soil erosion on cropland from the production, consumption, and income perspectives at the provincial and sectoral levels in China. The results showed the major responsible agents in a synthetic view. On the production side, the Yunnan-Kweichow Plateau and surrounding hills of the Sichuan Basin, the Chinese grain bases located in northeastern and central China, and the Loess Plateau were the major regions that caused the most cropland soil erosion. On the consumption side, the national final demand for Sichuan, Yunnan, Shandong, Henan, and other provinces with high production-based cropland soil erosion (PBE) values per se pulled remarkable cropland soil erosion. On the income side, the crucial provinces into which the national primary input enabled notable cropland soil erosion were still those areas with serious cropland soil erosion. From the industrial perspective, the direct effects of human primary inputs into agriculture and the demand for agricultural products played the dominant role. In addition, Cereal and BOP (beans, oil and potatoes) were the most important among the agricultural sectors. The effects of the nonagricultural sectors, especially the manufacture of foods and tobacco (MFT) and the chemical industry (CI), on cropland soil erosion also cannot be ignored. Our results indicated that accounting from multiple perspectives could inform the better management of cropland soil erosion from a more comprehensive perspective. To the best of our knowledge, this study is the first to consider the accounting of cropland soil erosion in China from multiple perspectives. Tailored packages of measures should be established based on different patterns of areas with serious cropland soil erosion. [Display omitted] • Cropland soil erosion accounting was based on a multi-regional input-output table. • Multiple perspectives' accounting shows the major responsible agents for soil loss. • Crops in different regions also were the key to tackle cropland soil erosion. • Cropland soil erosion control cannot just narrow down to four agricultural sectors. • Cropland soil erosion is not a local phenomenon but a macroscopic problem. [ABSTRACT FROM AUTHOR]

• A UAV-based method estimating sediment deposited behind check dams was developed. • Errors of the optimal model for single and regional check dams are 12–13% and 2–3%. • This method avoids limitations of tedious field surveys and historical records. • This method can evaluate sediment retained by check dams in areas as large as 211,800 km2. The estimation of sediment deposited behind dams and reservoirs is of great significance for quantifying soil erosion rate and sediment flux. However, existing methods of sediment volume estimation often require detailed field measurements and historical topographic data, limiting the broader application of these methods. In this paper, focusing on the region that suffers the world's most severe soil erosion, we combine unmanned aerial vehicle (UAV) photogrammetry and simulate submerging analysis to propose a novel method for estimating sediment silted by check dams under complex topography. We obtained 1339 groups of topographic factors and ascertained the corresponding volumes of sediment deposited behind check dams in the loess hilly region of China (LHRC), and established five different models combined with regression analysis. Two different sets of data were used for method validation and optimal model determination. The results showed that the error of the optimal model in the volume estimation of single check dam and regional check dams is 12–13% and 2–3%, respectively. Additionally, the area-volume model has the potential to evaluate the sediment retention capacity of check dams (in the order of billions of cubic meters) in the whole LHRC, because the variables are easy to obtain and the model accuracy is relatively high. The further application of this method will help to evaluate the watershed sediment yield and regional soil and water conservation benefits, and is of great significance for explaining the future changes in water and sediment in the Yellow River basin. [ABSTRACT FROM AUTHOR]

The collapse of the plastic waste trade (PWT) amplifies the threats of mismanaged plastic waste to the ecological system and human health, posing a risk as well as an opportunity to the global circular economy. Although trade barriers in the PWT continue to impact waste management systems, there are few analyses that propose global mitigation strategies in response to trade fluctuations. Here, we show that most countries have been overloaded with plastic waste compared to their ordinary capacity since China's import ban in 2017. We apply a cascading failure model to quantify the collapse process worldwide and find that 183 countries become overloaded as this collapse cascades, with nearly 6% of countries experiencing over 1.5 times their ordinary load. However, this overload could be greatly alleviated if leading countries were to sharply increase their capacity to treat plastic waste based on scenario analysis. Although waste exporters should take more responsibility and scenario analysis results show that top exporters could effectively mitigate global plastic waste levels by increasing their treatment capacity, cooperation between key exporters, importers, and intermediators has the best mitigation effects. Our analysis suggests that key countries should as soon as possible take responsibility for and cooperate in mitigating potential plastic waste pollution related to trade fluctuations. • Many countries show plastic waste overloading due to China's import ban. • Structural change of plastic waste trade could lead cascading failure worldwide. • Overload situation will be greatly alleviated, if leading countries work for it. • The cooperation strategy has the best mitigation effect. [ABSTRACT FROM AUTHOR]

The effective control of cropland soil erosion is urgent for all countries because of its threat to global food security. Cropland soil erosion is caused by agricultural production and driven indirectly by consumption. Analyzing the causes and preventive strategies from the consumption side is essential for soil erosion control. However, there is not yet sufficient research or practice. In this study, we estimated global cropland soil erosion with the revised universal soil loss equation, allocated it to specific types of crops, and quantified the cropland soil erosion footprint of the economies with a multiregional input-output analysis model. Our results showed that developed economies, usually importing cropland soil erosion from developing or agriculturally developed economies, are the beneficiaries in the current crop trading system. The European Union is the largest net importer, while Brazil is the largest exporter. The indirect and induced sectors are the main contributors, consuming approximately 70.48% of the total cropland soil erosion. Our results revealed the region- and product-specific contributors that could inform the reduction of global cropland soil erosion for sustainable food production and consumption.