Soil Quality Index Values Research Articles

Changes in soil quality during different ecological restoration years in the abandoned coal mine area of southern China

AbstractUnderstanding the effects of abandoned coal mine ecological restoration on soil quality and function is important to protect the regional ecological environment. This study aims to evaluate the ecological restoration effects of soil quality in abandoned coal mine area. Taking Fengcheng County, a typical coal‐rich area in southern China, as a case, this study took 120 soil samples to investigate the influence of restoration years on soil quality by using an integrated soil quality index (SQI). Results indicated that restoration years had significant effects on the saturated hydraulic conductivity (Ks) by affecting the soil bulk density, clay content, and soil water content. Furthermore, clay, soil organic matter, Ks, and pH were selected to assess the effect of ecological restoration years on soil quality. It was found that the ecological restoration 8 years (ER8) site had higher SQI value, indicating ecological restoration years showed a positive correlation with SQI in abandoned coal mine area. Since there was a 4‐year gap between ecological restoration 4 years site and ER8 site, the ecological restoration may be effective between 5 and 8 years. The results of this study are of great significance for improving the effects of ecological restoration and management in abandoned coal mine area.

Soil quality index: a tool to detect the sensitivity to soil erosion in an agricultural catchment from the Middle Atlas of Morocco.

Abstract The present paper focuses on the application of the Soil Quality Index (SQI) within the Tiguert catchment, situated in the Middle Atlas of Morocco. The studied catchment, covering approximately 10.2 km², experiences a semi-arid climate with irregular rainfall and is designated as an agricultural area, making it an ideal site for studying the intricate interactions between natural processes and human activities. The SQI developed as part of the Mediterranean Desertification and Land Use (MEDALUS) project is tailored to the unique conditions of the Mediterranean region. In the case of the Tiguert catchment, SQI is calculated using a formula that considers topographical slope, horizontal depth of soil, parental material, and soil brightness. Consequently, the results depict a promising scenario, with 61% of the soil classified as “High Quality,” indicating robust soil health and resilience despite the challenges posed by a semi-arid climate. The 31% categorized as “Moderate Quality” underscores areas requiring specific management attention, while the 8% identified as “Low Quality” signals localized challenges potentially influenced by irregular rainfall patterns. Furthermore, the SQI results are closely linked to soil erosion dynamics, with higher SQI values associated with improved resistance to erosion. The dynamic connection between precipitation patterns and SQI over a 40-year analysis indicates the impact of varying rainfall on soil health. Extreme rainfall events correspond to higher SQI percentages in the “High Quality” category, while drier periods align with lower SQI percentages, emphasizing the dynamic relationship between climate and soil quality. A comprehensive analysis of SQI across diverse ecosystems in Tiguert reveals variations in soil health, emphasizing the importance of tailored land management approaches for different land use types to optimize overall soil sustainability.

Soil quality assessment in the Araban plain across various land use types

BackgroundSoil is an important resource for improving the quality of human well-being and creating sustainable environmental awareness. Therefore, it is imperative to protect the soil health. This study determined quality of the soils in the Araban plain, Türkiye using three different methods, i.e., principal component analysis (PCA), analytic hierarchy process (AHP), and expert opinion (EO). The major aim was to determine the most appropriate method for determining soil quality and recommending soil protection practices for improving quality. MethodsThis study was conducted on an area of approximately 25,000 ha. A total of 230 soil samples (7 pasture areas, 56 orchards, and 167 arable crops) were analyzed to determine key soil quality indicators. A minimum dataset consisting of parameters that best represent the soils of the region was created. Subsequently, PCA was used to predict soil quality with the optimal accuracy using the least amount of data. The EO was incorporated to validate the PCA results. The AHP was used to assign weights to the parameters. Indicators at all sampling points were converted to unitless scorers. These scores were then formulated as soil quality index (SQI) using the weighted summation method. ResultsOrganic matter (OM) exerted the highest impact on soil quality. Significant variations in SQI values were observed among arable land, orchards land and pastureland (P < 0.01). Significant variations were recorded in SQI values of the assessment methods employed in this study. The lowest (0.552) and highest (0.829) SQI values were recorded for AHP and EO, respectively. Overall, streamlining indicators through PCA gave the most accurate result for SQI value. Subsequently, SQI determination should involve weighing with AHP, particularly towards EO. ConclusionThe AHP was found to be the most appropriate method for evaluating soil quality in Araban. This integrated approach ensures a robust evaluation of soil quality, facilitating more accurate and nuanced insights for informed land management decisions. Overall, 92.61 % of the region’s soil had poor and medium soil quality. Therefore, increasing OM content and aggregate stability are suggested to improve soil quality in the study region.

Effect of the irregular shelterwood system on soil organic carbon stock and soil quality of Shorea robusta Gaertn. f. forest in Nepal

The effective management of forests relies on the crucial role played bysilvicultural systems. However there exist a significant knowledge gap regarding impact of these systems in Nepalese forests. Therefore, this research was conducted to assess the effects of the forest management activities under irregular shelterwood system on soil organic carbon (SOC) stock and the overall soil quality of Sal (Shorea robusta Gaertn. f.) forests in Terai region of Nepal. Stratified random sampling method with 1.67 % sampling intensity was adopted in this study where management of stands was used as basis of strata. A total of 30 composite soil samples (15 each from managed and unmanaged forest stands) were collected from a depth of 0–30 cm, taken from the four corners and the center of each plot. Soil quality index (SQI) method was used for soil quality assessment using indicators on the basis of prior studies conducted in Nepal. Our study found significant difference in soil parameters except organic carbon, pH, silt, and clay among the managed and unmanaged forest stands (p < 0.05). SOC stock of unmanaged forest stands (48.87 ± 1.34 ton ha−1) was significantly greater than managed forest stands (27.76 ± 1.27 ton ha−1). Similarly, unmanaged forest stands demonstrated better soil quality with higher SQI value (0.66) than managed forest stands (0.50). This negative impact of irregular shelterwood silviculture system highlights the necessity for management interventions to enhance SOC stock and overall soil quality. To establish a robust conclusion, further replication of similar studies at different soil depths and in other management regimes, along with longitudinal studies, is essential.

Soil quality index in some cropping systems in plot 17 of Wanagama forest, Gunungkidul, Yogyakarta, Indonesia

&lt;p&gt;&lt;span&gt;The Wanagama 1 Forest, owned by Universitas Gadjah Mada in Playen, is an educational and research forest that is home to different species of trees that are managed and treated differently. Finding the quality index values for different cropping strategies in plot 17 of Wanagama Educational Forest 1 was the aim of this study. The soil quality index was determined using three methods: simple addition, scoring and weighting, and summation. The results show that in plot 17 of the Wanagama forest, the highest soil quality index values were found for ebony species and the lowest soil quality index values were found for mahogany and &lt;/span&gt;&lt;em&gt;&lt;span&gt;Eucalyptus&lt;/span&gt;&lt;/em&gt;&lt;span&gt; species. The results showed that all land uses with different types of forest plants had lower soil quality indices. The stepwise analysis results showed that porosity, organic C, cation exchange capacity (CEC), P availability, K availability, and C biomass influenced the soil quality index. Measuring soil quality can help you learn more about soil properties and how to improve it through effective management.&lt;/span&gt;&lt;/p&gt;

Bioindicators for Assessing Soil Quality in Ecuador’s Jun Jun Micro-Watershed

The evaluation of soil quality in different altitudinal gradients, with vegetative and non-vegetative subareas, is crucial for proper soil functioning and optimal crop growth, thus contributing to the sustainability of agroecosystems. Although the altitudinal gradient significantly influences soil quality, the ability to predict this quality, expressed through an index, in soils with and without vegetative cover, is still insufficiently explored. This study employed the simple additive index (SQI) method to evaluate soil quality in Ecuador’s Jun Jun micro-watershed, Tungurahua region. Three altitude categories (&lt;2800, 2800–2900, &gt;2900 masl) were investigated, with 24 soil samples collected across both vegetated and non-vegetated areas. The indicators used included chemical and biological parameters such as soil organic carbon (OC), earthworm density (WD), earthworm biomass (WB), organic matter (OM), pH, and total nitrogen (TN). The results revealed that in areas with altitudinal gradients below 2800 masl, the soil quality index values were higher compared to other altitudes. In vegetated areas, a decrease in index values was observed as the altitudinal gradient increased, indicating a deterioration in soil quality with increasing altitude. These findings are significant in providing a quantitative assessment of the effects of altitudinal gradient and vegetative cover influence on soil quality.

Dependency of Long-Term Soil Quality Controls on Summer Fallow Tillage and Soil Layers for Dryland Winter Wheat in Loess Plateau

The capacity for winter wheat to produce sufficient yield may be influenced by soil tillage practices and soil quality. However, determining how to quantify the impact of long-term tillage on soil quality is crucial. Here, we address this issue by comparing soil properties and wheat yield under four tillage systems during summer fallow in the Loess Plateau. Twenty-two soil properties were explored to estimate soil quality. Results showed that a rotational tillage (PT/ST) during summer fallow decreased soil bulk density (ρb) and improved soil gravimetric water content (θg), soil organic carbon (SOC), soil capillary porosity (Pc), and total porosity (Pt) in 0–50 cm soil layers. A minimum dataset (MDS) of thirteen indicators was selected to calculate soil quality index (SQI). Treatment of PT/ST had higher SQI value in soil layers of 0–10 cm and 20–50 cm, and PT/ST showed a significant increase in yield since the third year. No tillage (NT) during summer fallow decreased soil physical and chemical indicators, thus decreasing soil quality. These findings suggest that a rotation tillage of PT/ST during summer fallow could enhance soil chemical and biological properties concurrently, and PT/ST may provide a promising management strategy to sustain soil quality and grain yield for dryland winter wheat in the Loess Plateau.

Comprehensive assessment of combined inorganic and organic fertilization strategies on cotton cultivation: implications for sustainable agriculture.

The integration of inorganic and organic fertilizers is increasingly being recommended to address the demand for sustainable cotton cultivation and to mitigate the ecological impacts of reliance on inorganic fertilizers. However, the nuanced effects of this combined fertilization approach on soil quality, cotton growth, yield, and their interaction mechanisms, remain unclear. To elucidate this, a 2-year field trial (2022-2023) was conducted, incorporating five fertilization treatments: low inorganic fertilizer (BI1), high inorganic fertilizer (BI2), organic fertilizer (BO), combined low inorganic and organic fertilizer (BIO1), and combined high inorganic and organic fertilizer (BIO2). This study aimed to evaluate the influence of these treatments on soil quality, cotton growth, and yield. The results indicate that the BO treatment significantly enhanced plant height growth rate, and BIO1 treatment increased leaf area index and dry matter accumulation growth rate. Critical soil parameters such as alkali-hydrolyzed nitrogen and available potassium emerged as pivotal determinants of soil quality over the trial period, corresponding to soil quality index (SQI) values of 0.482 and 0.478, and yields of 7506.19 kg ha-1 and 6788.02 kg ha-1, respectively. Water productivity reached optimum levels at SQI values of 0.461 and 0.462, with corresponding efficiencies of 13.31 kg (ha mm)-1 and 12.16 kg (ha mm)-1. Partial least squares path modeling revealed that integrating organic fertilizer with reduced inorganic fertilizer usage significantly boosts cotton yield by enhancing soil quality (path coefficient: 0.842). In conclusion, this integrated fertilization strategy not only improves soil health but also increases agricultural productivity. It presents a promising approach for optimizing crop yields while fostering sustainable agricultural practices. © 2024 Society of Chemical Industry.

Mixed planting mode is the best measure to restore soil quality in alpine mines

In ecologically fragile areas heavily affected by human disturbance, it is imperative to restore soil quality to preserve nutrient cycling and ensure ecosystem stability. However, our understanding about the underlying mechanisms of dynamic change in soil quality associated with revegetation in alpine areas remains incomplete. In this study, data from 96 plots were collected to reveal the response of soil quality to vegetation restoration in alpine mines. The soil quality index (SQI) was developed utilizing 19 measured indicators to assess differences in soil quality between various vegetation restoration modes (natural restoration (CK), planting with Elymus dahuricus (ED), Medicago sativa (MS), and multi-plant mixed (Avena fatua L. + Elymus dahuricus + Medicago sativa + Oxytropis coerulea, MM)) and restoration periods (1, 3, 4, and 6 years). A partial least squares structural equation model (PLS-SEM) was constructed to recognize the impact of 14 variables related to topographical features, plant biodiversity and community stability, aboveground plant productivity characteristics, root functional traits, and soil erosion on soil quality. The results revealed significant variations in soil quality among different vegetation restoration modes. Within the initial four years following vegetation restoration, the discernible discrepancies in SQI values were as follows: ED > MM > MS > CK; by the sixth year, the order shifted to MM > ED > MS > CK. Aboveground plant productivity characteristics and functional root traits significantly contribute to soil quality. In contrast, plant biodiversity and community stability had no significant effects on soil quality. Topographical features and soil erosion adversely affected soil quality, with soil erosion exerting the most prominent effect.

Long-term straw return enhanced crop yield by improving ecosystem multifunctionality and soil quality under triple rotation system: An evidence from a 15 years study

ObjectiveRice-rice-oilseed rape rotation is a typical triple cropping system in Asia, and the development of rice-oilseed rape rotation plays an important role in ensuring global food and oil security. With the intensive cropping rotation and frequent changes between paddy and upland farming under anaerobic and aerobic conditions, whether tillage and straw return would be benefit for both agronomic and environmental perspectives remained to be tested. MethodTherefore, we used a long-term locational experiment (15 years) employing four treatments of conventional tillage without straw incorporation (CT); conventional tillage with straw incorporation (CTS); no-tillage without straw mulching (NT); no-tillage with straw mulching (NTS), to assess the relationships among soil quality, ecosystem multifunctionality, and crop yields under the straw-returning and tillage strategies, based on both agronomic and environmental perspectives. ResultThe results showed that long-term straw return to the field could increase the yield of early rice by 6.24–8.80%, late rice by 3.81–7.13%, and oilseed rape by 9.55–14.45%. Long-term straw return enhanced soil quality index (SQI) by 22.21–40.74% and ecosystem multifunctionality (EMF) by 104.19–141.14% in the 0–20 cm soil layer. Long-term conventional tillage (i.e., CT and CTS) showed higher SQI and EMF values especially in the oilseed rape season. Structural equation modelling (SEM) indicated that straw return and tillage mainly increased crop yield by increasing the SQI in the oilseed rape season. ConclusionIn conclusion, long-term straw return with conventional tillage would be more benefit for the improvement of soil quality and the multifunctionality of soil ecosystems under triple paddy-upland rotation system, offering an effective approach for sustainable soil management and crop production.

Diffuse reflectance spectroscopy for assessing soil quality indicators in cocoa production system validated using multi‐year data

AbstractDiffuse reflectance spectroscopy is emerging as a reliable soil testing approach. However, few studies reported on the applicability of DRS for estimating the overall soil quality index (SQI) in smallholder farms. Specifically, the DRS approach has not been evaluated in cocoa production systems with multi‐year soil data. We evaluated the DRS approach in typical cocoa production systems from Papua New Guinea (PNG) by collecting soil samples before and after implementing soil test‐based nutrient recommendations. Specifically, 379 soil samples were collected in 2017 from cocoa farms in East New Britain, New Ireland, and Bouganville provinces of PNG. A second soil testing campaign was undertaken in 2019 to analyse 432 soil samples from the same farms to test the consistency of the DRS approach for SQI assessment. In all these samples, 15 soil parameters were measured using the conventional wet chemistry approach. Reflectance spectra in each sample were also measured over the visible to near‐infrared (wavelength: 350–2500 nm). A minimum dataset approach was followed to estimate SQIs from laboratory‐measured soil properties. With available N, clay content, available P, and available Zn adjudged as significant soil quality parameters for the cocoa plantations of PNG, estimated mean SQI values ranged from 0.30 in the cocoa farm from Bouganville province (BOKA‐PAN) in 2017 to 0.46 for the New Ireland province (LAU‐PAN) soil samples collected during 2019. Overall, SQI values increased from about 13%–21% following the nutrient applications. Based on the validation of two commonly‐used chemometric models (PLSRFS: partial‐least‐squares regression with feature selection, SVR: support vector regression), the SQI values were estimated with the coefficient of determination (R2) values as high as .94. Our results showed that a DRS model calibrated in soil samples collected in a specific year can be used for estimating SQI values in soil samples collected in different years. These results suggest that the principal component analysis (PCA) based SQI may be estimated from the DRS data with good accuracy and SQI values may potentially capture the management effects in smallholder farms.

Assessment of soil quality in irrigated arid lands under organic agriculture systems

The process of evaluating the soil quality is complex and is impacted by a variety of physical, chemical, and biological indicators as well as how they interact over time, particularly throughout different cultivation periods. The main objective of the current investigation is to examine how various organic farming practices affect the soil quality indicators at selected organic farms throughout various cultivation times. The study sites in Egypt were selected to represent two great soil groups (Torripsamments and Haplotorrerts). Moreover, the selected farms have different organic cultivation periods and management practices. Soil samples were collected from five different farms and uncultivated soil in each soil great soil group as control. After analyzing soil samples in the lab, physical, chemical, and biological indicators were assessed and used to calculate the Soil Quality Index (SOI). Principal Component Analysis (PCA) was used to obtain the minimum data set needed for soil quality evaluation. The length of organic cultivation in Torripasament raised the SQI value for physical and chemical indicators in the following order: 2 years &gt; 6 years &gt; 10 years &gt; 13 years. Similar to Torripsament, the most sensitive indicators for SQI assessment in Haplotorrert were found to be soil respiration, microbial biomass C, microbial quotient, organic matter, and physical characteristics of soil quality. Results also indicated that organic farming improves most of the studied soil quality indicators of both soils (Torripsamment and Haplotorrerts). Soil respiration, Microbial Biomass (MBC), Microbial Quotient (MQ), organic matter, and physical aspects of soil quality were the most sensitive indicators of soil quality evaluation. Soil quality index (SQI) for Torripsamment was affected mostly by soil biological indicators, while soil physical indicators were the main indicators affecting SQI in Haplotorrerts. The best score for the soil quality index was at 13 years of organic cultivation periods in Torripsamment and at 17 years in Haplotorrerts.

Soil Quality Assessment of Sesame-Growing Soils with Different Productivity in the Northern Telangana Zone, India

Present study was carried out in major sesame growing areas of Northern Telangana zone in districts namely; Nizamabad, Jagtial, Nirmal and Kamareddy. The main objective of this study is to assess the soil quality and to find out the relation between sesame yield and soil quality index. Based on the seed yield data of sesame, the above-mentioned districts were divided into high, medium and low productivity zones. 50 samples from each productivity zone with a total of 150 surface soil samples (0-15 cm were collected and analysed for various physical, physico-chemical, chemical and biological properties. Physical properties included texture, bulk density and water holding capacity. Physico-chemical properties like pH, EC and organic carbon were analysed. Chemical properties of soil namely available nitrogen, available phosphorus, available potassium, available sulphur, exchangeable bases like exchangeable calcium and magnesium, potassium and sodium, available micronutrients like iron, copper, manganese and zinc were analysed. Biological properties like urease, acid and alkaline phosphatase and labile carbon were analysed. Principal component analysis, minimum dataset was derived which contained available nitrogen, sand, pH, available phosphorus, exchangeable calcium and magnesium and urease with 70.81% variance. These are identified as the key indicators of soil quality. Mean soil quality index values were 0.669, 0.549 and 0.443 for high, medium and low sesame productivity zones respectively and is in the order of high&gt;medium&gt;low sesame productivity zones. Percent contribution of MDS to SQI are in the order of, available nitrogen (44.44%&gt; pH (16.85% &gt;exchangeable calcium (9.87%&gt; exchangeable magnesium (8.89%&gt; urease (7.86%&gt; available phosphorus (7.38% &gt; sand (4.89%. This study concluded that the SQI was more significantly positively correlated with sesame yield, which revealed that soil variables from the minimum data set had biological significance and effectively evaluated the status of the sesame growing soils of Northern Telangana Zone.

Effects of different tillage and fertilizer on soil quality under wheat‐maize rotation in the North China Plain

AbstractThe North China Plain plays an important role in China's crop cultivation regions, with the wheat‐maize rotation serving as the predominant cropping system. Nonetheless, a dearth of research refers to the impact of tillage and fertilizer employment on soil quality (SQ) in this region. In this study, the primary objective centered on utilizing the soil quality index (SQI) derived from both minimum and total datasets (MDS, TDS) by the linear and nonlinear scoring criteria to assess SQ. The results indicated that there was a significant correlation between wheat‐maize yield and SQI, revealing a significant association between yield and key soil parameters such as bulk density, soil porosity, total phosphorus, alkali‐hydrolyzed nitrogen, available phosphorus and cation exchange capacity at 0–60 cm soil layer. The study identifies that substantially elevated SQI mean values were completely under T8 whose values were 0.980 (linear), 0.672 (nonlinear) under MDS and 0.908 (linear), 0.701 (nonlinear) under TDS at 20–40 cm. Importantly, the annual yields were the highest when the SQI values were the maximum. Furthermore, SQ levels within this locale demonstrate a moderate to highly favorable status, ultimately underscoring the area's propitious conditions for crop cultivation. This research provides indispensable theoretical guidance for agricultural practitioners and offers a foundational framework supporting enhanced yields in local grain crops.

Monitoring soil quality of different land use systems: a case study in Suha watershed, northwestern highlands of Ethiopia

The problem of soil quality degradation has been becoming more severe in the highlands of Ethiopia due to soil erosion; land use and land cover change, and poor land management. The level of soil quality degradation was not well known and documented in the study area and the results of this study could provide new information to improve soil conditions. The present study was conducted to evaluate soil quality in terms of its physical and chemical fertility under different land use types in the Suha watershed, northwestern highlands of Ethiopia. A total of 27 composite surface soil samples (0–30 cm) were collected from adjacently located land-uses in three replications from two elevation gradients. Standard procedures were followed to analyze selected soil physical and chemical quality indicators. The differences in the mean values of the parameters were tested using a two-way analysis of variance. In addition, Soil Quality Degradation Index was evaluated to see the direction and magnitude of change in soil quality indicators. The analysis of variance results revealed that soil quality indicators such as index of soil aggregate stability, organic carbon (OC), total nitrogen (TN), and C:N ratio were significantly decreased in the cultivated land use system compared to other land use systems. On the other hand, the content of available Phosphorus was significantly higher in the cultivated land. Soil quality deterioration index values were highly negative for SOC (− 71.3%) and TN (− 67.7%) in the cultivated land, followed by grazing land (SOM = − 35.5% and TN = − 27.7%). Aggregated Soil Quality Index values also indicated that the status of soil quality under cultivated fields is rated as low, grazing land as optimal, and forest land as high. Generally, results indicated that land use and cover changes had adverse effects on soil quality indicators. Hence, soil management strategies, mainly Integrated Soil Fertility Management which integrates soil and water conservation strategies, are required to alleviate the problem of soil quality deterioration and improve agricultural productivity.

Analisis Indeks Kualitas Tanah pada Tipe Penggunaan Lahan Berbeda di Kecamatan Maginti

Soil quality is the ability of the soil to function to maintain plant productivity, maintain and maintain water availability and support human activities. The purpose of this study was to determine the Soil Quality Index (SQI) and determine the management direction for improving soil quality on different land uses in the Maginti sub-district. A field study and laboratory analysis were carried out from March to May 2022. The method used in this study was a free survey method through field observations conducted on 2 types of land use, namely irrigated rice fields and dry land. In irrigated rice fields, 3 sample points were taken and 3 sample points in dry land, then composited into 1 sample in order to represent the total amount of each land use. In calculating the value of the soil quality index using the formula by Bajracharya (2006) which has been modified by Ghimire (2018). The soil quality index is analyzed using the indicators that best represent soil functions. The variables observed included Texture, pH, C-Organic, N-Total, P-Available and K-Available. Soil quality index values range from 0-1, the higher the index value, the better the quality. The results of the analysis of the selected soil functions (minimum data set/MDS) and the MDS scoring were summed to determine the value of the soil quality index (SQI). The conclusion of this research is that the criteria for medium soil quality are irrigated rice fields with SQI (0,56) and dry land with low criteria with SQI (0,36). To improve soil quality in irrigated paddy fields and dry lands is to increase organic matter through the application of organic fertilizers with the right dosage according to the type and level of soil fertility.Keywords: Soil Quality Index, Irrigated Rice Fields, Non-Irrigation, Soil Management, Physical Properties of Soil Chemistry.

Differences in the soil and hydrology responses of two revegetation chronosequences in the Loess Plateau, China

Vegetation restoration has been widely implemented to restore degraded land. However, vegetation expansion may result in the overconsumption of soil moisture and soil desiccation, which in turn exacerbates land degradation. To ensure the sustainability of ecological restoration, it is necessary to optimise restoration patterns. Two restoration patterns (afforestation with Robinia pseudoacacia L. (RP) and abandoned farmland (AL)) along a revegetation chronosequence (0, 9, 17, 27, and 42 years) were selected to analyse variations in soil and hydrological characteristics on the Loess Plateau, China. The results showed that for the two revegetation types, the soil quality index (SQI) increased markedly (p < 0.05) and the soil loss (SL) and surface runoff (R) decreased significantly (p < 0.05) over time, indicating that vegetation restoration improves soil quality and prevents soil and water erosion. The annual increments of soil moisture storage (Ws) within a 200 cm depth notably decreased during the late restoration stage (>27 years) for the artificial forest. Moreover, forest also showed increasing actual evapotranspiration (ET) trends and decreasing Ws trends. These results suggest that afforestation might lead to overconsumption of water and soil water depletion during the late restoration stage. Although RP sites had higher SQI (22.2–36.7 %) values and lower SL (47.0–81.4 %) and R (86.5–196.8 %) values when compared with AL sites, the change rates of the SQI, R, and SL at RP sites were stable or decreased over a period of restoration, while these rates showed increasing tendencies under AL sites. These suggests that natural grasslands may be more beneficial than artificial forests during the late restoration stage. Therefore, naturally restored grasslands are highly recommended for sustainable ecological restoration in the semiarid and arid areas of the Loess Plateau or in similar areas elsewhere.

Soil Quality Indicators in Peasant Agroecosystems in Paraíba State, Brazil

Background and Research Aims: Soil quality (SQ) is the basis for the Sustainability of Peasant Farming Systems (PFS). We hypothesized that different land uses modify soil quality through changes that can be analyzed by determining the Soil Quality Index (SQI). Methods: Soil samples were collected from the 0-20 cm layer in five subsystems of peasant agroecosystems located in the municipalities of Solânea (A), Casserengue (B), and Serraria (C). SQI was calculated using non-linear scoring, while a principal component analysis was performed using all data (bulk and particle density, total porosity, particle size, pH, macronutrients, and soil organic carbon) to determine a Minimum Data Set (MDS). Results: The MDS composed of P available, Ca+2, Al+3, sand, silt, H+Al, base saturation (BS%), and the aluminum saturation (AS%) indicate that these parameters can serve as indicators for soil quality assessment in peasant agroecosystems. Sand and silt are related to pedogenic processes and parent material, while the remaining indicators reflect management practices. Land conversion from forest to cropland decreased nutrient availability and soil organic matter in agroecosystems A (Arenosol) and B (Luvisol) and increased the cation exchange capacity in agroecosystem C (Lixisol). Conclusions: All agroecosystems showed low SQI values, highlighting the need to expand conservation practices in the studied agricultural subsystems, especially regarding the increase of soil organic matter. Our results contribute to improving the use and management of soils and the vulnerability assessment in peasant farming, an essential requirement for the sustainability of agroecosystems. Implications for Conservation: Our results also demonstrated that agroforestry practices can significantly increase soil quality and soil carbon sequestration, a viable alternative for maintaining organic matter in areas susceptible to degradation.

Quality of Soils in Soybean Producing Areas in Caraga Region

This study aims to determine the soil quality of selected soybean producing farms in the Caraga region using soil quality index (SQI) measurements. Five sites were selected in the municipalities of San Miguel, Surigao del Sur and Trento, Agusan del Sur. Three 10×10 m soil monitoring plots were established within soybean fields in each site. Within each monitoring plot, three composite samples were collected coming from 10 subsamples using a soil probe. SQI was calculated following three general steps, (1) selection of minimum dataset (MDS) via Principal Components Analysis (PCA), (2) Scoring of MDS via linear method, and (3) Calculation of weighted overall SQI. Out of the 16-soil property indicator, a total of five soil properties (exchangeable Ca, % Sand, Electrical conductivity, available P, and Soil respiration) were extracted and used as the MDS for the calculation of SQI in each site. The main indicator properties for determining the quality of the soils in the area were Exchangeable Ca and % Sand contents offering a 68% and 26% weights over other soil properties, respectively. High SQI classification was found on four out of five sites evaluated, these were the two sites in the Municipality of Trento (Cebolin.M (61%) &amp; Cebolin.T (54%)) and two sites in the Municipality of San Miguel (Libag-Gua (68%) &amp; Upper Carromata (93%)). One site in San Miguel revealed a low SQI (Lower Carromata (41%)). These SQI values indicate that in these areas, soils with very high Exchangeable Ca and Sand content could have a low-quality condition, and sites with optimal Exchangeable Ca (400 - 600 ppm) contents and loamy to sandy loam texture could be classified as high quality soils. Proper drainage system could be best done to manage the very high exchangeable Ca content in these soil and thus, could improve its quality.

Changes in soil quality under long‐term rice‐crayfish farming in the Dongting Lake Plain, China

AbstractRice‐crayfish (RC) integrated cultivation, as a sustainable agricultural system, could significantly improve soil fertility. However, the soil quality under the long‐term RC farming system is still unclear. To examine the effects of RC cultivation on soil quality in paddy fields, this study utilized an integrated soil quality index (SQI) for examining the soil quality at different soil profiles (0–10, 10–20, and 20–30 cm depth) in rice monoculture (RM) and RC farming systems (after 1, 6, 10, and 15 years) scattered in Nanxian County, Hunan Province, China. The minimum datasets for evaluating soil quality were assembled using the soil pH, bulk density, total nitrogen, microbial biomass carbon, microbial biomass nitrogen, and β‐d‐glucosidase. The findings demonstrated that soil quality was greatly impacted by RC farming, which improved with the increase of years under RC management. The soil quality of 10‐ and 15‐year RC farming systems were significantly higher than RM system. Besides, soil quality declined with increasing soil depth. The SQI value, which may be used as an indicator to assess the soil quality of RC systems, was dominated by total nitrogen, which contributed 27.60% to the SQI value. On the whole, long‐term RC farming affected the soil quality of paddy fields through management methods including non‐rice season flooding, feeding, and no tillage. Through this study, it was found that MDS and SQI composed of appropriate physical, chemical, and biological indicators could more objectively analyze the soil quality of long‐term RC system and provide guidance for sustainable development of RC farming.