Soil Science最新文献

{"title":"Spatial distribution of argan tree influence on soil properties in southern Morocco","authors":"Mario Kirchhoff, Tobias Romes, I. Marzolff, M. Seeger, Ali Aït Hssaine, J. Ries","doi":"10.5194/soil-7-511-2021","DOIUrl":"https://doi.org/10.5194/soil-7-511-2021","url":null,"abstract":"Abstract. The endemic argan tree (Argania spinosa) populations in southern Morocco are highly degraded due to overbrowsing, illegal firewood extraction and the expansion of intensive agriculture. Bare areas between the isolated trees increase due to limited regrowth; however, it is unknown if the trees influence the soil of the intertree areas. Hypothetically, spatial differences in soil parameters of the intertree area should result from the translocation of litter or soil particles (by runoff and erosion or wind drift) from canopy-covered areas to the intertree areas. In total, 385 soil samples were taken around the tree from the trunk along the tree drip line (within and outside the tree area) and the intertree area between two trees in four directions (upslope, downslope and in both directions parallel to the slope) up to 50 m distance from the tree. They were analysed for gravimetric soil water content, pH, electrical conductivity, percolation stability, total nitrogen content (TN), content of soil organic carbon (SOC) and C/N ratio. A total of 74 tension disc infiltrometer experiments were performed near the tree drip line, within and outside the tree area, to measure the unsaturated hydraulic conductivity. We found that the tree influence on its surrounding intertree area is limited, with, e.g., SOC and TN content decreasing significantly from tree trunk (4.4 % SOC and 0.3 % TN) to tree drip line (2.0 % SOC and 0.2 % TN). However, intertree areas near the tree drip line (1.3 % SOC and 0.2 % TN) differed significantly from intertree areas between two trees (1.0 % SOC and 0.1 % TN) yet only with a small effect. Trends for spatial patterns could be found in eastern and downslope directions due to wind drift and slope wash. Soil water content was highest in the north due to shade from the midday sun; the influence extended to the intertree areas. The unsaturated hydraulic conductivity also showed significant differences between areas within and outside the tree area near the tree drip line. This was the case on sites under different land usages (silvopastoral and agricultural), slope gradients or tree densities. Although only limited influence of the tree on its intertree area was found, the spatial pattern around the tree suggests that reforestation measures should\u0000be aimed around tree shelters in northern or eastern directions with higher soil water content or TN or SOC content to ensure seedling survival, along with measures to prevent overgrazing.\u0000","PeriodicalId":22015,"journal":{"name":"Soil Science","volume":"51 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88284384","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":"Application of the governance disruptions framework to German agricultural soil policy","authors":"B. Bartkowski, Stephan Bartke, N. Hagemann, B. Hansjürgens, C. Schröter‐Schlaack","doi":"10.5194/SOIL-7-495-2021","DOIUrl":"https://doi.org/10.5194/SOIL-7-495-2021","url":null,"abstract":"Abstract. Governance of natural resources is inherently complex and requires\u0000navigating trade-offs at multiple dimensions. In this paper, we present and\u0000operationalize the “governance disruptions framework” (GDF) as a tool for\u0000holistic analysis of natural resource governance systems. For each of the\u0000four dimensions of the framework (target adequacy, object adequacy,\u0000instrument adequacy, and behavioural adequacy), we formulate guiding\u0000questions to be used when applying the framework to particular governance\u0000systems. We then demonstrate the use of GDF by applying it to the core of\u0000German agricultural soil policy. We show that for each framework dimension,\u0000the governance system exhibits deficits, particularly with respect to object\u0000adequacy and instrument adequacy. Furthermore, we use the GDF-based analysis\u0000to highlight research gaps. We find that stakeholder analyses are a central\u0000gap across GDF dimensions.\u0000","PeriodicalId":22015,"journal":{"name":"Soil Science","volume":"47 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82074485","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":"Whole-soil warming decreases abundance and modifies the community structure of microorganisms in the subsoil but not in surface soil","authors":"C. Zosso, N. Ofiti, J. Soong, E. Solly, M. Torn, A. Huguet, G. Wiesenberg, M. Schmidt","doi":"10.5194/SOIL-7-477-2021","DOIUrl":"https://doi.org/10.5194/SOIL-7-477-2021","url":null,"abstract":"Abstract. The microbial community composition in subsoils remains understudied, and it is largely unknown whether subsoil microorganisms show a similar response to global warming as microorganisms at the soil surface do. Since microorganisms are the key drivers of soil organic carbon decomposition, this knowledge gap causes uncertainty in the predictions of future carbon cycling in the subsoil carbon pool (> 50 % of the soil organic carbon stocks are below 30 cm soil depth). In the Blodgett Forest field warming experiment (California, USA) we investigated how +4 ∘C warming in the whole-soil profile to 100 cm soil depth for 4.5 years has affected the abundance and community structure of microorganisms. We used proxies for bulk microbial biomass carbon (MBC) and functional microbial groups based on lipid biomarkers, such as phospholipid fatty acids (PLFAs) and branched glycerol dialkyl glycerol tetraethers (brGDGTs). With depth, the microbial biomass decreased and the community composition changed. Our results show that the concentration of PLFAs decreased with warming in the subsoil (below 30 cm) by 28 % but was not affected in the topsoil. Phospholipid fatty acid concentrations changed in concert with soil organic carbon. The microbial community response to warming was depth dependent. The relative abundance of Actinobacteria increased in warmed subsoil, and Gram+ bacteria in subsoils adapted their cell membrane structure to warming-induced stress, as indicated by the ratio of anteiso to iso branched PLFAs. Our results show for the first time that subsoil microorganisms can be more affected by warming compared to topsoil microorganisms. These microbial responses could be explained by the observed decrease in subsoil organic carbon concentrations in the warmed plots. A decrease in microbial abundance in warmed subsoils might reduce the magnitude of the respiration response over time. The shift in the subsoil microbial community towards more Actinobacteria might disproportionately enhance the degradation of previously stable subsoil carbon, as this group is able to metabolize complex carbon sources.\u0000","PeriodicalId":22015,"journal":{"name":"Soil Science","volume":"16 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86717490","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":"The role of geochemistry in organic carbon stabilization against microbial decomposition in tropical rainforest soils","authors":"M. Reichenbach, P. Fiener, G. Garland, M. Griepentrog, J. Six, S. Doetterl","doi":"10.5194/soil-7-453-2021","DOIUrl":"https://doi.org/10.5194/soil-7-453-2021","url":null,"abstract":"Abstract. Stabilization of soil organic carbon (SOC) against microbial decomposition depends on several soil properties, including the soil weathering stage and the mineralogy of parent material. As such, tropical SOC stabilization mechanisms likely differ from those in temperate soils due to\u0000contrasting soil development. To better understand these mechanisms, we investigated SOC dynamics at three soil depths under pristine tropical\u0000African mountain forest along a geochemical gradient from mafic to felsic and a topographic gradient covering plateau, slope and valley\u0000positions. To do so, we conducted a series of soil C fractionation experiments in combination with an analysis of the geochemical composition of soil\u0000and a sequential extraction of pedogenic oxides. Relationships between our target and predicting variables were investigated using a combination of\u0000regression analyses and dimension reduction. Here, we show that reactive secondary mineral phases drive SOC properties and stabilization mechanisms\u0000together with, and sometimes more strongly than, other mechanisms such as aggregation or C stabilization by clay content. Key mineral stabilization\u0000mechanisms for SOC were strongly related to soil geochemistry, differing across the study regions. These findings were independent of topography in\u0000the absence of detectable erosion processes. Instead, fluvial dynamics and changes in soil moisture conditions had a secondary control on SOC\u0000dynamics in valley positions, leading to higher SOC stocks there than at the non-valley positions. At several sites, we also detected fossil organic\u0000carbon (FOC), which is characterized by high C/N ratios and depletion of N. FOC constitutes up to 52.0 ± 13.2 % of total SOC stock\u0000in the C-depleted subsoil. Interestingly, total SOC stocks for these soils did not exceed those of sites without FOC. Additionally, FOC decreased\u0000strongly towards more shallow soil depths, indicating decomposability of FOC by microbial communities under more fertile conditions. Regression\u0000models, considering depth intervals of 0–10, 30–40 and 60–70 cm, showed that variables affiliated with soil weathering, parent material\u0000geochemistry and soil fertility, together with soil depth, explained up to 75 % of the variability of SOC stocks and\u0000Δ14C. Furthermore, the same variables explain 44 % of the variability in the relative abundance of C associated with\u0000microaggregates vs. free-silt- and-clay-associated C fractions. However, geochemical variables gained or retained importance for explaining SOC target variables when controlling for soil depth. We conclude that despite long-lasting weathering, geochemical properties of soil parent material\u0000leave a footprint in tropical soils that affects SOC stocks and mineral-related C stabilization mechanisms. While identified stabilization\u0000mechanisms and controls are similar to less weathered soils in other climate zones, their relative importance is markedly different in the tropical soils\u0000investigated.\u0000","PeriodicalId":22015,"journal":{"name":"Soil Science","volume":"94 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85498865","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":"An underground, wireless, open-source, low-cost system for monitoring oxygen, temperature, and soil moisture","authors":"Elad Levintal, Y. Ganot, G. Taylor, P. Freer-Smith, K. Suvočarev, H. Dahlke","doi":"10.5194/SOIL-2021-72","DOIUrl":"https://doi.org/10.5194/SOIL-2021-72","url":null,"abstract":"Abstract. The use of wireless sensor networks in the measurement of soil parameters represents one of the least invasive methods available to date. Wireless sensors pose the least disturbance to soil structure and having fewer aboveground cables reduce the risk of undesired equipment damage and potential data loss. However, implementing wireless sensor networks in field studies usually requires advanced and costly engineering knowledge. This study presents a new underground, wireless, open-source, low-cost system for monitoring soil oxygen, temperature, and soil moisture. The process of system design, assembly, programming, deployment, and power management is presented. The system can be left underground for several years without the need for changing the battery. Emphasis was given on modularity so that it can be easily duplicated or changed if needed, and deployed without previous engineering knowledge. Data from this type of system have a wide range of applications, including precision agriculture and high-resolution modelling.\u0000","PeriodicalId":22015,"journal":{"name":"Soil Science","volume":"4 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81958375","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":"Nutrient limitations regulate soil greenhouse gas fluxes from tropical forests: evidence from an ecosystem-scale nutrient manipulation experiment in Uganda","authors":"J. Tamale, R. Hüppi, M. Griepentrog, L. Turyagyenda, M. Barthel, S. Doetterl, P. Fiener, O. van Straaten","doi":"10.5194/SOIL-7-433-2021","DOIUrl":"https://doi.org/10.5194/SOIL-7-433-2021","url":null,"abstract":"Abstract. Soil macronutrient availability is one of the abiotic controls that alters the exchange of greenhouse gases (GHGs) between the soil and the atmosphere in tropical forests. However, evidence on the macronutrient regulation of soil GHG fluxes from central African tropical forests is still lacking, limiting our understanding of how these biomes could respond to potential future increases in nitrogen (N) and phosphorus (P) deposition. The aim of this study was to disentangle the regulation effect of soil nutrients on soil GHG fluxes from a Ugandan tropical forest reserve in the context of increasing N and P deposition. Therefore, a large-scale nutrient manipulation experiment (NME), based on 40 m×40 m plots with different nutrient addition treatments (N, P, N + P, and control), was established in the Budongo Central Forest Reserve. Soil carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) fluxes were measured monthly, using permanently installed static chambers, for 14 months. Total soil CO2 fluxes were\u0000partitioned into autotrophic and heterotrophic components through a root\u0000trenching treatment. In addition, soil temperature, soil water content, and\u0000nitrates were measured in parallel to GHG fluxes. N addition (N and N + P) resulted in significantly higher N2O fluxes in the transitory phase (0–28 d after fertilization; p<0.01) because N fertilization likely increased soil N beyond the microbial immobilization and plant nutritional demands, leaving the excess to be nitrified or denitrified. Prolonged N fertilization, however, did not elicit a significant response in background (measured more than 28 d after fertilization) N2O fluxes. P fertilization marginally and significantly increased transitory (p=0.05) and background (p=0.01)\u0000CH4 consumption, probably because it enhanced methanotrophic activity. The addition of N and P (N + P) resulted in larger CO2 fluxes in the transitory phase (p=0.01), suggesting a possible co-limitation of both N and P on soil respiration. Heterotrophic (microbial) CO2 effluxes were significantly higher than the autotrophic (root) CO2 effluxes (p<0.01) across all treatment plots, with microbes contributing about two-thirds of the total soil CO2 effluxes. However, neither heterotrophic nor autotrophic\u0000respiration significantly differed between treatments. The results from this study suggest that the feedback of tropical forests to the global soil GHG budget could be disproportionately altered by increases in N and P\u0000availability over these biomes.\u0000","PeriodicalId":22015,"journal":{"name":"Soil Science","volume":"65 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83946513","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":"Assessing soil redistribution of forest and cropland sites in wet tropical Africa using 239+240Pu fallout radionuclides","authors":"F. Wilken, P. Fiener, M. Ketterer, K. Meusburger, Daniel Muhindo, K. Van Oost, S. Doetterl","doi":"10.5194/SOIL-7-399-2021","DOIUrl":"https://doi.org/10.5194/SOIL-7-399-2021","url":null,"abstract":"Abstract. Due to the rapidly growing population in tropical Africa, a substantial rise\u0000in food demand is predicted in upcoming decades, which will result in higher\u0000pressure on soil resources. However, there is limited knowledge on soil\u0000redistribution dynamics following land conversion into arable land in\u0000tropical Africa that is partly caused by infrastructure limitations for\u0000long-term landscape-scale monitoring. In this study, fallout radionuclides 239+240Pu are used to assess soil redistribution along topographic\u0000gradients at two cropland sites and at three nearby pristine forest sites\u0000located in the DR Congo, Uganda and Rwanda. In the study area, a\u0000239+240Pu baseline inventory is found that is higher than typically\u0000expected for tropical regions (mean forest inventory 41 Bq m−2).\u0000Pristine forests show no indication of soil redistribution based on 239+240Pu along topographical gradients. In contrast, soil erosion and\u0000sedimentation on cropland reached up to 37 cm (81 Mg ha−1 yr−1)\u0000and 40 cm (87 Mg ha−1 yr−1) within the last 55 years,\u0000respectively. Cropland sites show high intra-slope variability with\u0000locations showing severe soil erosion located in direct proximity to\u0000sedimentation sites. This study shows the applicability of a valuable method\u0000to assess tropical soil redistribution and provides insight into soil\u0000degradation rates and patterns in one of the most socio-economically and\u0000ecologically vulnerable regions of the world.\u0000","PeriodicalId":22015,"journal":{"name":"Soil Science","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73621081","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":"Aluminous clay and pedogenic Fe oxides modulate aggregation and related carbon contents in soils of the humid tropics","authors":"M. Kirsten, R. Mikutta, D. Kimaro, K. Feger, K. Kalbitz","doi":"10.5194/SOIL-7-363-2021","DOIUrl":"https://doi.org/10.5194/SOIL-7-363-2021","url":null,"abstract":"Abstract. Aggregation affects a wide range of physical and biogeochemical soil\u0000properties with positive effects on soil carbon storage. For weathered\u0000tropical soils, aluminous clays (kaolinite and gibbsite) and pedogenic Fe\u0000(oxyhydr)oxides (goethite and hematite; termed “Fe oxides”) have been\u0000suggested as important building units for aggregates. However, as\u0000aluminosilicates, aluminum hydroxides, and Fe oxides are part of the\u0000clay-sized fraction it is hard to separate how certain mineral phases\u0000modulate aggregation. In addition, it is not known what consequences this\u0000will have for organic carbon (OC) persistence after land-use change. We\u0000selected topsoils with unique mineralogical compositions in the East\u0000Usambara Mountains of Tanzania under forest and cropland land uses, varying\u0000in contents of aluminous clay and Fe oxides. Across the mineralogical\u0000combinations, we determined the aggregate size distribution, aggregate\u0000stability, OC contents of aggregate size fractions, and changes in\u0000aggregation and OC contents under forest and cropland land use. Patterns in\u0000soil aggregation were rather similar across the different mineralogical\u0000combinations (high level of macroaggregation and high aggregate stability).\u0000Nevertheless, we found some statistically significant effects of aluminous\u0000clay and pedogenic Fe oxides on aggregation and OC storage. An aluminous\u0000clay content > 250 g kg−1 in combination with\u0000pedogenic Fe contents < 60 g kg−1 significantly\u0000promoted the formation of large macroaggregates > 4 mm. In\u0000contrast, a pedogenic Fe content > 60 g kg−1 in\u0000combination with aluminous clay content of < 250 g kg−1\u0000promoted OC storage and persistence even under agricultural use. The\u0000combination with low aluminous clay and high pedogenic Fe contents displayed\u0000the highest OC persistence, despite conversion of forest to cropland causing\u0000substantial disaggregation. This indicates that aggregation in these\u0000tropical soils is modulated by the mineralogical regime, causing moderate\u0000but significant differences in aggregate size distribution. Nevertheless,\u0000aggregation was little decisive for overall OC persistence in these highly\u0000weathered soils, where OC storage is more regulated by direct\u0000mineral–organic interactions.\u0000","PeriodicalId":22015,"journal":{"name":"Soil Science","volume":"36 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79644022","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":"Predicting the spatial distribution of soil organic carbon stock in Swedish forests using a group of covariates and site-specific data","authors":"K. O. Hounkpatin, J. Stendahl, Mattias Lundblad, E. Karltun","doi":"10.5194/SOIL-7-377-2021","DOIUrl":"https://doi.org/10.5194/SOIL-7-377-2021","url":null,"abstract":"Abstract. The status of the soil organic carbon (SOC) stock at any position in the landscape is subject to a complex interplay of soil state factors operating at different scales and\u0000regulating multiple processes resulting either in soils acting as a net sink or net source of carbon. Forest landscapes are characterized by high spatial variability, and key drivers of SOC stock might be specific for sub-areas compared to those influencing the whole landscape. Consequently, separately calibrating models for sub-areas (local models) that collectively cover a target area can result in different prediction accuracy and SOC stock drivers compared to a single model (global model) that covers the whole area. The goal of this study was therefore to (1) assess how global and local models differ in predicting the humus layer, mineral soil, and total SOC stock in Swedish forests and (2) identify the key factors for SOC stock prediction and their scale of influence. We used the Swedish National Forest Soil Inventory (NFSI) database and a\u0000digital soil mapping approach to evaluate the prediction performance using\u0000random forest models calibrated locally for the northern, central, and\u0000southern Sweden (local models) and for the whole of Sweden (global model).\u0000Models were built by considering (1) only site characteristics which are\u0000recorded on the plot during the NFSI, (2) the group of covariates (remote sensing, historical land use data, etc.) and (3) both site characteristics and group of covariates consisting mostly of remote sensing data. Local models were generally more effective for predicting SOC stock after\u0000testing on independent validation data. Using the group of covariates\u0000together with NFSI data indicated that such covariates have limited\u0000predictive strength but that site-specific covariates from the NFSI showed\u0000better explanatory strength for SOC stocks. The most important covariates\u0000that influence the humus layer, mineral soil (0–50 cm), and total SOC\u0000stock were related to the site-characteristic covariates and include the\u0000soil moisture class, vegetation type, soil type, and soil texture. This study showed that local calibration has the potential to improve prediction\u0000accuracy, which will vary depending on the type of available covariates.\u0000","PeriodicalId":22015,"journal":{"name":"Soil Science","volume":"19 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87599229","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":"Significant soil degradation is associated with intensive vegetable cropping in a subtropical area: a case study in southwestern China","authors":"Ming Lu, D. Powlson, Yi Liang, D. Chadwick, Shengbi Long, Dunyi Liu, Xin-ping Chen","doi":"10.5194/SOIL-7-333-2021","DOIUrl":"https://doi.org/10.5194/SOIL-7-333-2021","url":null,"abstract":"Abstract. Within the context of sustainable development, soil degradation driven by land use change is considered a serious global problem, but the conversion from growing cereals to vegetables is a change that has received limited attention, especially in subtropical regions. Here, we studied the effects of the conversion from paddy rice to an oilseed rape rotation to vegetable production in southwestern China on soil organic carbon (SOC), total\u0000nitrogen (TN), the C/N ratio, pH, phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg) based on face-to-face farmer surveys and soil analysis. In the vegetable cropping system, fertilizer application often exceeds the crop demand or levels recommended by the local extension service several times over. Thus, the crop use efficiency of N, P, K, Ca, and Mg was only 26 %, 8 %, 56 %, 23 %, and 28 %, respectively. In the vegetable cropping system studied, SOC, C stock, TN, and N stock were decreased significantly due to low organic inputs from crop residues and high tillage frequency. Furthermore, the soil C/N ratio decreased slightly; available P (AP) in the topsoil increased by 1.92 mg kg−1 for every 100 kg ha−1 of P surplus, and\u0000the critical levels of AP and CaCl2-soluble P in P leaching were 104\u0000and 0.80 mg P kg−1. Besides, compared to the current paddy–rape\u0000rotation system, a clear trend of soil acidification was observed in the\u0000vegetable fields. However, increasing the contents of soil Ca and Mg\u0000significantly alleviated topsoil acidification, with the effect increasing\u0000over time. Given our findings, the potential benefits of conservation\u0000agricultural practices, integrated soil–crop system management strategies,\u0000and agricultural technology services for recovering the degraded soil and\u0000improving the vegetable productivity are discussed here.\u0000","PeriodicalId":22015,"journal":{"name":"Soil Science","volume":"3 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91159456","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}