Journal of Soil and Water Conservation最新文献

{"title":"Stability and splash erosion characteristics of lateritic red soil aggregates in the South Subtropical Zone of China","authors":"Juan Huang, Juhui Li, N. Leng, Y. Deng","doi":"10.2489/jswc.2023.00115","DOIUrl":"https://doi.org/10.2489/jswc.2023.00115","url":null,"abstract":"This study analyzed lateritic red soils developed from sand shale and Quaternary red clay to investigate the relationship between aggregate stability and splash erosion characteristics under different land use modes in the South Subtropical Zone of China. The mean weight diameter (MWD) values of soils were ranked slow wetting (SW) > stirring after prewetting (WS) > fast wetting (FW) by the Le Bissonnais (LB) method, indicating that the soil aggregates were least stable under continuous simulated rainfall. The contents of clay, soil organic matter (SOM), and particulate organic carbon (POC) were highly significantly positively correlated with soil stability. There was a highly significant negative correlation between the aggregate splash erosion amounts and MWD values, and the erosion amounts of the orchard and cultivated land soils were 1.20 to 8.38 and 1.53 to 6.68 times those of the woodland soil, respectively. The splash erosion amounts were negatively exponentially correlated with the splash erosion distances, which were mostly distributed at the distance of 0 to 10 cm (accounting for 71.17% to 89.32% of the total splash erosion). The splash erosion amounts on the downhill side were 3.85 to 30.44 times those on the uphill side. The mean weight distance (MWS) values were negatively correlated with the stability of the soil aggregates under the different fragmentation mechanisms, and the correlation coefficients were 0.79, 0.65, and 0.73. During simulated rainfall, the splash erosion rates first increased, then decreased and tended to be stable after reaching the peak, and the rainfall duration to reach the peak decreased with increasing rainfall intensity. At the rainfall intensities of 30 to 60 mm h−1, the splash erosion rates peaked at 24 to 36 min. At the rainfall intensities of 90 to 120 mm h−1, the splash erosion rates peaked at 12 to 30 min. With increasing rainfall duration, the amounts of large aggregates in the splash transport increased. These results can provide a theoretical basis for the formulation of soil and water conservation measures in the South Subtropical Zone of China.","PeriodicalId":50049,"journal":{"name":"Journal of Soil and Water Conservation","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2023-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88840823","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sediment delivery ratios from forest road networks and harvesting operational features by physiographic region in the southeastern United States","authors":"C. N. Horton, S. Barrett, W. Aust, B. S. Hawks, M. Bolding","doi":"10.2489/jswc.2023.00093","DOIUrl":"https://doi.org/10.2489/jswc.2023.00093","url":null,"abstract":"Mechanized forest harvesting and associated access networks can accelerate soil erosion. Forestry best management practices (BMPs) for water quality are used to minimize soil erosion from forest operations and to trap eroded materials on-site before stream entry. Sedimentation provides multiple threats to water quality, but research indicates that BMPs are generally effective at reducing erosion. However, BMP effectiveness for reducing sediment from specific operational features (skid trails, decks, harvest areas, stream crossings, and haul roads) and regions is insufficiently quantified. Sediment delivery ratios (SDRs) are needed to evaluate efficiencies and effects of BMPs. SDR is the ratio (or percentage) of eroded sediment that reaches streams. Soil erosion modeling and sediment trapping were applied to 183 operational features on 58 recent harvests across the Mountains, Piedmont, and Coastal Plain regions of Virginia and North Carolina to determine SDRs. For all regions combined, mean SDRs were highest for stream crossings (34%), followed by skid trails (21%), haul roads (16%), and decks (4%). Harvest areas, not including access features, had SDRs averaging 11%. SDR values were weighted by areas, and the highest weighted SDR was for the Coastal Plain (19%), followed by the Mountains (13%) and Piedmont (6%). The overall average SDR for all regions and operational features across the southeast was 12%, which corresponds with previously reported values. The highly variable SDRs were influenced by site conditions, climatic factors, and a wide range of BMP implementation across sites, yet reasonable estimates were developed. Major recommendations include additional emphases regarding stream crossing, skid trail, and Streamside Management Zone (SMZ) BMPs.","PeriodicalId":50049,"journal":{"name":"Journal of Soil and Water Conservation","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2023-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82588854","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Gully erosion susceptibility prediction in Mollisols using machine learning models","authors":"Yansong Wang, Yue Zhang, Education. Hongrui Chen, H. Chen, N. 127°0'E127°30'E","doi":"10.2489/jswc.2023.00019","DOIUrl":"https://doi.org/10.2489/jswc.2023.00019","url":null,"abstract":"In recent years, gully erosion has caused soil loss, land degradation, and a large sediment yield in the Mollisols in northeastern China, threatening agricultural development and national food security. Moreover, the prediction of gully erosion remains a great challenge owing to the difficulty of determining suitable environmental indicators and identifying the best models for predicting gully erosion prone areas. Therefore, the objective of this study was to quantify the contributions of the main factors controlling gully erosion and to identify the best model for predicting areas susceptible to gully erosion in Hailun City, northeastern China. Initially, the spatial distribution of the gully erosion was investigated through visual interpretation of GaoFen-1 satellite images. The analyzed gullies were evenly distributed in the study region, and we selected 70% of the gullies as the training data set and the remaining 30% as the validation data set. Subsequently, 12 variables, including the elevation, slope, aspect, plan curvature, profile curvature, topographic wetness index (TWI), soil type, land use, normalized difference vegetation index (NDVI), precipitation, distance from rivers, and distance from existing gullies, were selected as the indicators of gully erosion. Then, multicollinearity analysis was conducted to determine the main indicators without linearity. Finally, the contributions of the indicators and the areas susceptible to gully erosion were determined using machine learning models, including support vector machine (SVM), multilayer perceptron neural network (MLPNN), random forest (RF), and extreme gradient boosting (XGBoost) models. The results revealed that there was no multicollinearity among the 12 indicators, so they were all employed in the machine learning models for the gully erosion susceptibility prediction. The XGBoost model had the highest R2 and lowest root mean square error (RMSE) values in the model validation stage (0.81 and 0.60, respectively), followed by the RF (0.78 and 0.61, respectively), MLPNN (0.65 and 0.70, respectively), and SVM (0.62 and 0.70, respectively). The gully distance had the largest relative importance score (>35%) for gully erosion, followed by the profile curvature, plan curvature, land use, elevation, and soil type, which had relative importance scores of 10% to 15%. The gully erosion susceptibility map revealed that the central part of the study area was more susceptible to gully erosion than the other regions. These results can help managers to identify the regions that are prone to gully erosion and to design soil conservation practices to slow down the soil erosion process.","PeriodicalId":50049,"journal":{"name":"Journal of Soil and Water Conservation","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2023-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87633776","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of economic and climatic factors on agricultural water use in arid regions","authors":"B. McGreal, B. Colby","doi":"10.2489/jswc.2023.00130","DOIUrl":"https://doi.org/10.2489/jswc.2023.00130","url":null,"abstract":"Throughout the arid American West, agriculture is the dominant consumptive use of water, with farming operations dependent on finite groundwater resources or limited surface flows for necessary irrigation. This study makes use of climatic, economic, and remote-sensed land cover data to model those factors that contribute to farmers’ water use decisions in central Arizona. Growers’ water needs are met through a combination of groundwater, Colorado River water delivered via the Central Arizona Project, and additional surface flows. The modeling approach presented is applicable to a wide range of agricultural communities that are dependent on irrigation for agriculture. This study specifically examines water deliveries to and irrigation intensity within irrigation districts in central Arizona. Econometric analysis of integrated panel data finds that climate, the prices of December cotton (Gossypium hirsutum L.) futures, water costs, and fallowed land area have significant impacts on at least one of the two outcomes of interest. Understanding irrigators’ water use decisions is useful to those concerned with the impact of water availability on local economies, ecosystems, and aquifers.","PeriodicalId":50049,"journal":{"name":"Journal of Soil and Water Conservation","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2023-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90342999","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Understanding barriers to adoption of sustainable nitrogen management practices in California","authors":"J. Rudnick, S. Khalsa, M. Lubell, M. Leinfelder-Miles, K. Gould, P. H. Brown","doi":"10.2489/jswc.2023.00109","DOIUrl":"https://doi.org/10.2489/jswc.2023.00109","url":null,"abstract":"Achieving sustainability in agricultural nitrogen (N) management relies on farmers’ decisions to reduce fertilizer inputs and adopt conservation management practices. Understanding the drivers and barriers to farmers’ adoption of improved N management practices is critical to developing effective management and policy approaches on this intractable challenge. Existing research on farmer behavior has assumed that any barrier to adoption will result in lower practice adoption rates, without fully understanding how barriers may vary across different management practices, farm and farmer types, and stages of adoption. By leveraging two farmer survey data sets (total n > 1,900), this study diagnoses key barriers to adoption across 11 different N management practices and a large diversity of farmer and farm types across the California Central Valley. We find resource constraints, technical knowledge, and uncertainty emerge as key barrier types that differentially affect farmers at various stages of adoption. On a practice-by-practice basis, uncertainty barriers appear greatest for nonadopters of a practice, whereas practice adopters are more likely to report resource barriers. Across management practices at the farm level, farmers with higher self-reported conservation orientations are more likely to report being affected by all barrier types, as compared to their peers with lower self-reported conservation orientations. Our findings demonstrate that barriers to adoption are more complex than simply the factors that predict lower adoption, as both adopters and nonadopters experience barriers. Furthermore, factors that typically predict higher adoption, such as conservation motivation, do not insulate a farmer from facing barriers to adoption. We consider how adopters are likely to go through a learning process while moving from considering to fully implementing a new practice, during which different barriers to behavior change may be encountered. We argue that interventions intended to motivate farmer adoption of improved management practices need to take more nuanced approaches to understanding how barriers to adoption are likely to vary across stages of adoption, farm and farmer type, and specific management practices.","PeriodicalId":50049,"journal":{"name":"Journal of Soil and Water Conservation","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2023-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76642658","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characteristics of the soil macropore and root architecture of alpine meadows during the seasonal freezing-thawing process and their impact on water transport in the Qinghai Lake watershed, northeastern Qinghai–Tibet Plateau","authors":"X. Hu, L. Jiang, Y.-D. Zhao, X. Li","doi":"10.2489/jswc.2023.00155","DOIUrl":"https://doi.org/10.2489/jswc.2023.00155","url":null,"abstract":"Low temperatures, freezing-thawing cycles, and short growing seasons characterize alpine soils. The mattic epipedon, a special diagnostic surface horizon with an intensive root network, is widely distributed in alpine ecosystems. Studies on the soil macropores and roots of the mattic epipedon layer in response to seasonal freezing-thawing processes on the Qinghai–Tibet Plateau are lacking. This study characterized the soil macropores and roots of alpine meadows during the seasonal freezing-thawing process using X-ray computed tomography and revealed the influence of soil macropores and roots structure on water transport in the mattic epipedon layer of the alpine meadows. The results showed that the soil pore distribution was more uniform during the unstable freezing stage (UFP) and the unstable thawing stage (UTP), whereas there was a clear mattic epipedon layer during the completely thawed stage (TP) and the completely frozen stage (FP). Soils in the TP stage had a higher total surface area density (0.1898 mm2 mm−3), length density (225.28 mm mm−3), node density (1,592 no. mm−3), and connectivity (0.3144) of soil macropores than those in the UFP, UTP, and FP stages. In the TP stages, the density, surface area density, branch density, length density, and node density of roots had significant correlations with the macroporosity, surface area density, length density, node density, and tortuosity of soil macropores. In the FP stage, there were no correlations between the root and soil macropore characteristics. Vertical water is expected to move more readily through the mattic epipedon in the TP stage than in the UFP and UTP stages. Roots were the preferential pathways for water transport into the soil layer of the alpine meadow. Therefore, the mattic epipedon is a key layer for water and nutrient storage and plays an important role in the water-holding function of the Tibetan Plateau due to its greater root development.","PeriodicalId":50049,"journal":{"name":"Journal of Soil and Water Conservation","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2023-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79956096","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of different vegetation restoration types on soil infiltration characteristics in severely eroded subtropical regions of South China","authors":"J. Peng, X. Xu, Haifang Wen, S. Ni, J. Wang, C. Cai","doi":"10.2489/jswc.2023.00047","DOIUrl":"https://doi.org/10.2489/jswc.2023.00047","url":null,"abstract":"Vegetation restoration could cause variations in soil and near-surface properties, altering soil structure directly or indirectly and consequently affecting soil infiltration characteristics. This study is aimed at exploring the variation of soil physicochemical properties and infiltration characteristics under five vegetation restoration types (including restored forest, restored orchard, restored scrubland, restored grassland, and unrestored eroded land, which are referred to as RF, RO, RS, RG, and EL, respectively) and the main factors affecting infiltration characteristics. The EL was taken as the control group. Five hydraulic heads (0, −3, −6, −9, and −12 cm) were set to continuously measure the soil infiltration characteristics through a disc infiltrometer. Results indicated that vegetation restoration types significantly affected initial infiltration rate (IIR), steady infiltration rate (SIR), and hydraulic conductivity (Ks), which ranged from 0.56 to 4.40, 0.32 to 2.86, and 6.48 × 10−3 to 0.47 mm h−1, respectively (mean value: 2.72, 1.35, and 0.32 mm h−1, respectively). The highest value of soil infiltration rate appeared in the EL, and the lowest value was observed in the RF. Root parameters including root length density and root surface density were highest in RG, and lowest in the control and RF, respectively. In addition, the conceptual path model explained 95%, 96%, and 96% of the variance in IIR, SIR, and Ks, with the goodness-of-fit index of 0.988, 0.988, and 0.997, respectively. This modeling determined biological crust thickness, soil organic matter content, root length density, and sand content as the major factors affecting the process of soil infiltration. These results enhance our understanding of the water erosion process under different vegetation restoration types in the severely eroded subtropical regions of South China.","PeriodicalId":50049,"journal":{"name":"Journal of Soil and Water Conservation","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2023-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87866981","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Long-term drainage water recycling affects soil health and soil properties","authors":"H. Kaur, K. Nelson, G. Singh, R. Udawatta","doi":"10.2489/jswc.2023.00159","DOIUrl":"https://doi.org/10.2489/jswc.2023.00159","url":null,"abstract":"Drainage water recycling (DWR) using drainage and subirrigation (DSI) has increased the resiliency of crop production and improved water quality in the midwestern United States, but the effects on soil properties and soil health parameters have not been determined. This research evaluated (1) reservoir nutrient concentrations of a long-term DWR site over time, (2) the effects of a DWR system on soil properties at four depths in a corn (Zea mays)–soybean (Glycine max L.) rotation compared to free drainage (FD) and nondrained (ND) soil, and (3) the influence of DWR on soil health parameters after a 17-year corn–soybean rotation compared to ND. Different laboratory methods for estimating these soil health parameters were compared. In the initial years of the study (2002 to 2007), concentration of salts (potassium [K] and sodium [Na]) and dissolved nutrients (nitrogen [N] and phosphorus [P]) were higher in the reservoir water. Mean concentrations were 1.8 mg L−1 for nitrate-N (NO3-N) and 0.36 mg L−1 for orthophosphate (PO4-P) in the reservoir during the study. The concentration of salts and ions in the reservoir were not restrictive for use as irrigation water for plants. The DWR treatment had a soil texture that was 11% lower in silt (P < 0.001) and 13% higher in clay (P < 0.001) concentration at 21 to 30 cm soil depth compared to ND. The water table fluctuations appeared to influence cation (calcium [Ca], magnesium [Mg], and K) movement in soils while the FD and DWR treatments had lower soil test P in the topsoil. No significant interaction in soil analysis methods × treatments were observed (P > 0.1), indicating the absence of an effect of analysis methods (Haney soil test, Soil Health Management Assessment Framework, and Cornell Soil Health Assessment) on assessment of soil properties. DWR did not alter soil properties or soil health parameters.","PeriodicalId":50049,"journal":{"name":"Journal of Soil and Water Conservation","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2023-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84554981","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Scaling up agricultural conservation: Predictors of cover crop use across time and space in the US upper Midwest","authors":"T. Guo, S. Marquart-Pyatt, K. Beethem, R. Denny, J. Lai","doi":"10.2489/jswc.2023.00084","DOIUrl":"https://doi.org/10.2489/jswc.2023.00084","url":null,"abstract":"Scaling up cover crop use will increase crop diversity on agricultural lands and help achieve sustainable production and environmental wellbeing. To increase the total acreage planted to cover crops, more farmers need to use cover crops on a larger proportion of their farms (extent) and for a longer time (longevity), suggesting the importance of spatial and temporal scales of adoption. The adoption literature lacks attention to the spatial and temporal precision of practice measures and misses opportunities to identify consistent or diverse mechanisms for scaling up conservation practices. To fill this gap, we used data from 1,724 corn (Zea mays L.) and soybean (Glycine max [L.] Merr.) farms in Illinois, Indiana, Michigan, and Ohio to study three measures of cover crop usage: the use of cover crops in a single year on a specific field, the percentage of acres planted to cover crops on a farm in a single-year, and years of cover crop use. Our models included key biophysical, operational, policy, social, and psychological factors. We hypothesize that predictors of cover crop adoption and intensity and longevity of use differ. Our results revealed five factors that performed consistently across measures (perceived benefits of cover crops, knowledge, profitability goals, no-till, and rotational diversity), while the effects of the other seven factors varied, including sustainability goals that were only associated with the longevity of use. Policy programs that aim at increasing cover crop use should consider which aspect of scaling-up is being targeted, then focus on corresponding factors that can better tailor policy and education programs to farmer motivations and decision-making contexts.","PeriodicalId":50049,"journal":{"name":"Journal of Soil and Water Conservation","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2023-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72541066","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Smart climate initiatives for United States cropland","authors":"C. Ogg","doi":"10.2489/jswc.2023.0322a","DOIUrl":"https://doi.org/10.2489/jswc.2023.0322a","url":null,"abstract":"","PeriodicalId":50049,"journal":{"name":"Journal of Soil and Water Conservation","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2023-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88992353","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}