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Mechanical site preparation (MSP) is widely used in forestry to improve plantation success. Although it is known to alter soil properties, its direct effects on soil structure have rarely been described. The cultivation profile is a visual soil evaluation (VSE) method developed in agricultural research to analyse the impacts of cultivation practices on soil structure. The objective of the study was to adapt the method to forest plantations in order to analyse the effects of MSP on soil quality. Cultivation profiles were performed in six experimental plantation sites located in Northern France. The method made it possible to compare the impacts on soil structure of three MSP methods. It provided a schematic representation of the soil structural quality and a quantitative estimation of the volume of soil favourable to seedling root growth. It also highlighted unexpected negative effects of some MSP methods on soil structure, such as the creation of small cavities, the presence of compacted soil volumes due to wheel tracks or smeared soil volumes due to tool pass, and the pseudogleisation of soil zones due to changes in water circulation in the soil. The relevance and limitations of VSE methods in the context of forest plantation as well as the expected future development of the methods are discussed. [ABSTRACT FROM AUTHOR]

This study, based on vegetable production fields, combined soil quality assessed by three approaches (qualitatively by farmers, semi-quantitatively by a researcher and quantitatively by laboratory analyses) with the aim of improving the integration of the different approaches. We interviewed 79 peri-urban vegetable growers in two communities within the Sunyani Municipality, Ghana. Eight of the farmers were selected to participate in the farmer-based assessment of soil quality. Further, visual evaluation of soil quality was conducted by the researcher, followed by laboratory analyses of soil properties to corroborate the farmers' assessment of good and poor soils in their fields. Results showed that the farmers used locally-defined characteristics to describe the physical, biological and crop performance indicators of soil quality. There was, in general, limited use and understanding of soil chemical properties as indicators of soil quality. The farmers' perception on soil quality of their fields largely influenced their decision on the type of crops they cultivate, and application regimes of mineral fertilizers. Results from the visual evaluation by the researcher agreed in some respects with the farmers' assessment of soil quality of the good and poor soils in their respective farms. Laboratory analyses did not show specific trends for the content of chemical properties for neither good nor poor soils. The study highlighted that none of the approaches of soil quality assessment is necessarily superior in and of itself. We emphasized the need for integration to capitalize on the strengths of each approach, enhance mutual learning between farmers and soil scientists, build the capacity of farmers, and improve their decision on soil use for agricultural production. [ABSTRACT FROM AUTHOR]

A near real-time evaluation of the management system's impact on soil conditions requires a quick and straightforward framework to help farmers with a reliable on-farm assessment. The visual soil evaluation methods can potentially be used as a reliable on-farm approach for assessing soil physical quality. This research aims to better understand the importance of visual soil evaluation for productivity in semi-arid climates. The objectives were to evaluate the ability of Visual Evaluation of Soil Structure (VESS) and Double Spade (DS) under agricultural systems in a semi-arid region and to assess the relationship between soil structural quality and crop yield. Forty arable sites under rain-fed and irrigated farming with crop rotation and mono-cropping systems were studied, and twenty-one physical and bio-chemical soil properties were determined at two depths (0–20 cm and 20–40 cm). VESS and DS were conducted at each farm. The reliability of visual approaches was evaluated using measured soil properties and their capability to detect the impact of management systems. Soil quantitative measurements and crop yield information were deployed to assess soil productivity and its relationship with soil physical quality. The overall assessment of soil properties indicated a better soil condition for irrigated farming with crop rotation. The visual scores were in a range of 1.5–3.4 for VESS and a range of 1.9–3.5 for DS. The mean scores of VESS and DS were different between rain-fed and irrigated farms (P < 0.05), and visual methods were able to differentiate between mono-cropping and crop rotation (P < 0.05). The best soil structural quality was associated with the highest level of crop yield, and visual approaches were able to detect the differences in wheat yield levels (P < 0.05). The scores of VESS and DS were significantly correlated with soil properties (r > 0.6). Both VESS and DS indicated good efficiency for a practical on-farm assessment of soil conditions under agricultural management in northwest Iran and similar ecosystems. A close relationship between crop yield and soil structural quality was obtained, which indicated that the optimum soil structural condition plays an important role in the sustainability of crop production in semi-arid cultivation. • Impact of crop rotation on soil quality was detectable using visual soil evaluation. • Visual soil scores were significantly correlated with soil quality indicators. • Soil structural quality affected soil productivity and crop yield. • Visual soil evaluation can be used for assessing soil productivity. [ABSTRACT FROM AUTHOR]

Abstract: Visual evaluation of soil structure (VESS) is used for assessing arable management impact on soil quality. When used on pastures, operators have identified limitations because VESS does not consider a surface root‐mat typical of managed grassland. The structure of the root‐mat may be indicative of nutrient use efficiency, pollution potential and subsurface compaction. The objectives of this research were to develop GrassVESS for grassland soil management, to compare it with VESS and quantitative physical indicators and to assess its utility for soil management. GrassVESS maintained the methodological strengths of VESS, but uses a flow chart, grassland images and a new root‐mat score. A focus group found GrassVESS to be quicker, dealt better with technical information and made root‐mat evaluation easier. The range of structural quality scores assigned by the focus group for a site was less for GrassVESS than VESS, suggesting the procedure is more reproducible, thus suitable for use by a range of stakeholders. GrassVESS was also deployed at 30 grassland sites across Ireland. Results indicated that GrassVESS generated the same overall diagnoses as VESS, but the GrassVESS root‐mat structural quality score was better related to bulk density, total porosity at 5–10 cm and a visual estimation of damaged sward area. It was concluded that GrassVESS has improved the VESS method for the specific assessment of grassland soil structural quality and could be used in real‐time farm management decision support. [ABSTRACT FROM AUTHOR]

Visual Evaluation of Soil Structure (VESS) method assesses the status of soil structural quality through the examination of soil physical characteristics and biological features. Consistent relationships between VESS scores and quantitative soil physical properties have been demonstrated. However, how VESS scores correlate with quantitative soil biological properties remains unknown. This study assessed relationships between soil structural quality responses to land use change (LUC) and alterations in soil macrofauna in arable tropical soils. We simultaneously measured soil structural quality through VESS method and the abundance and community structure of macrofauna in chronosequences of land uses comprising pasture and sugarcane crop along a 1000-km-long transect through two major tropical biomes in Brazil. Correlation matrix and principal component analysis (PCA) were performed to elucidate correlations between the measured variables. Average VESS scores were 2.5 and 3.0 for pasture to sugarcane, respectively, showing a deterioration of soil structural quality following LUC. Soil macrofauna abundance and richness, as well as the abundance of individual dominant macrofauna groups, consistently decreased from pasture to sugarcane. PCA explained 56.5% of the variance, with pasture soils mostly associated with macrofauna variables, and sugarcane soils grouped near the VESS score. Correlation matrix and PCA showed positive correlation between the deterioration of soil structure after LUC and reductions in the size of macrofaunal community, especially termites ( r spearman = 0.36; P = 0.012). These results indicate that VESS scores correlate well with the abundance and richness of major soil engineers. [ABSTRACT FROM AUTHOR]

Highlights: [•] Reliable semi-quantitative methods to assess soil structural quality. [•] Visual examination methods as encouraging estimators of soil physical properties. [•] SOC per se is not always well related to the soil structural quality. [•] Evidence of tillage effect on soil structure from visual examinations. [ABSTRACT FROM AUTHOR]

Abstract: Soil structure plays a key role in the ability of soil to fulfil essential functions and services in relation to, e.g., root growth, gas and water transport and organic matter turnover. The objective of this paper was: (1) To quantify tillage effects on soil structural quality in the entire topsoil layer (0–20cm) using X-ray CT, visual evaluation and traditional core methods; and (2) To correlate pore network characteristics from X-ray CT imaging with the results from the visual evaluation and the core method. Samples were taken in May 2009 from a long-term rotation and tillage field experiment on a Danish sandy loam. The tillage treatments were direct drilling (D) and ploughing (P). For X-ray CT scanning, we sampled large soil cores (Ø =20cm, height=20cm) from the top layer. Small 100cm3 samples were taken from the 4–8 and 12–16cm layers for water content and bulk density measurements. Visual soil structure evaluation was carried out in the field at the same time as sampling. CT images (0.39×0.39×0.6mm3 voxels) were produced using a medical X-ray CT scanner. The visual assessment showed a good structural quality in the top 5–8cm for both treatments (Sq<2). A poorer soil structure was observed in lower part or the topsoil where a firm structure (Sq=2.9) was observed for D and relatively friable structure (Sq=2.2) for P. Lower bulk density was found for P than for D in the 4–8cm layer (1.34 and 1.52gcm−3, respectively), whereas relatively high bulk density values were observed for both treatments in the 12–16cm layers (1.50 and 1.56gcm−3, respectively). The X-ray CT image analysis showed that the P soil had more networks, branches and junctions but a lower degree of anisotropy and shorter average branch length than the D soil. The image data also confirmed a clear stratification of the 0–20cm topsoil layer for both tillage treatments. The stratification of the direct drilled soil was in accordance with our expectations whereas it was surprising for the ploughed soil. The dense lower topsoil layer for the ploughed soil was probably caused by compaction during secondary tillage and natural consolidation, and aggravated by a poor structural stability due to a low organic matter content. The visual soil evaluation scores were negatively correlated to soil porosity and number of pore networks estimated from X-ray CT imaging and positively correlated to the macropore characteristics of branch length and pore thickness. [Copyright &y& Elsevier]

Abstract: Despite major advances in remote sensing and soil-landscape modelling, the use of visual soil examination and evaluation (VSEE) techniques in the field remains a crucial component of soil assessment and management packages for farmers in rural Australia. Of particular value are techniques for the rapid assessment of soil structural form and stability, which are fundamental issues affecting the ability of soil profiles to accept and store water in farming systems constrained by drought. An improved soil appraisal framework for farm evaluation, usable for all crops, derived from the successful VSEE-based ‘Cotton SOILpak’ system, is proposed. It has the potential to enhance the ability of farm businesses to deal with four soil-related issues; annual profitability, maximising land values, minimising the impact of increasing input costs, and negotiation of favourable outcomes for themselves and the local community when confronted by competing land uses. An overview is given of the proposed technical contents of the new scheme for ‘whole-farm soil assessment and management planning’, which is based on a blend of VSEE methods, modern soil databases, and extra laboratory testing where appropriate. Also outlined are the associated human resource requirements and organisational structures required to deliver practical and ethical soil management outcomes to farmers and the nation. [Copyright &y& Elsevier]

• Visual soil evaluation scores are highly correlated with soil physical properties. • Visual methods can detect structural changes from different land use. • Natural forest has better visual scores compared to cropland. • Top layer has better scores compared to sub layer. Soil quality is indicated by the interaction of physical, chemical and biological soil properties. The importance of physical properties, for example soil structure, lies in the fact that they enhance chemical and biological soil functions. Consequently, periodic assessment of structural quality is an important aspect of soil quality management. Quantitative soil properties can be used as indirect indicator parameters for soil structural changes. However, measuring these properties is not applicable, especially for smallholder farmers who cannot afford to pay for laboratory tests. This study contributes to the validation of visual field assessments by comparing the performance of such methods on 'tropical' soils. The study was conducted across two regions with contrasting soil types and land use, in the sub-humid with clay Nitiosl and semi-arid with sandy loam Cambisol locations of Kenya. At both locations, visual methods were tested on soils under cropland and under natural forests (NF). Under the cropland, evaluation sites were selected from researcher and farmer managed sites. Visual scores from visual soil assessment (VSA), visual evaluation of soil structure (VESS) and visual evaluation of soil structure using the core (coreVESS) were correlated with soil physical and chemical properties measured in the laboratory. Under the clay Nitisol, absolute values of Pearson r between VSA scores and laboratory measured soil properties ranged from 0.84 to 0.54, for VESS, they varied between 0.75 and 0.37 while for coreVESS, they ranged from 0.84 to 0.60. For the sandy loam Cambisol, absolute Pearson r values between laboratory measured soil properties and VSA scores ranged from 0.83 to 0.29, the r values were between 0.88 and 0.45 for VESS and between 0.81 and 0.40 for coreVESS. From the obtained correlations, we concluded that the visual methods tested are capable of distinguishing structural quality due to different land use and are therefore suitable for assessing soil structural quality of tropical soils in Africa. Management thresholds were determined using bulk density (BD). The target value for good soil quality (Sq<2) for the Kibugu Nitisol was BD = 0.0012*SOC+0.6476 (r = 0.71; SOC is soil organic carbon), while the trigger and remediation values were 0.93 Mg m−3 (Sq = 2) and 0.99 Mg m−3 (Sq = 3), respectively. In the absence of SOC data, the target mean BD for Sq<2 is 0.79 Mg m−3. For Machang'a Cambisol, the target, trigger and remediation values were 1.48 Mg m−3 (Sq = 2), 1.56 Mg m−3 (Sq = 3) and 1.64 Mg m−3 (Sq = 4), respectively. [ABSTRACT FROM AUTHOR]

• Silvopastoral systems contribute to the restoration of degraded pastures in Amazon region. • Integrated farming systems recovery soil quality in tropical region. • Agroforestry systems improve soil physical properties through increasing soil C. Cattle ranching is the main land use after deforestation in Amazon region of Colombia. Those poor-managed pasture system typically induces soil compaction, acidification, organic matter losses and soil erosion, leading to soil health degradation and ecosystem service losses. To mitigate this problem, alternative production systems such as silvopastoral systems, where trees, forage, and cattle are combined in an integrated and intensively managed system, have been established in the last years. Hence, we conducted a field study that aimed to assess soil physical quality changes due to the traditional management of livestock and the subsequent transition to a silvopastoral system in two sites in Caquetá state, northwestern Colombian Amazon. In each site, soil samplings were performed in a chronosequence conformed by three areas following the typical land-use change at the region: i) native vegetation, ii) traditional pasture and iii) silvopastoral system. The soil physical properties quantified were: soil bulk density, porosity, penetration resistance, visual evaluation of soil structure, aggregate stability as well as soil organic carbon. Compared to native vegetation, traditional pasture management causes a degradation in soil physical quality, with increases in soil bulk density in subsoil from 1.10 to 1.33 g cm−3 and penetration resistance, which reached values around 5 MPa, affecting the distribution of pores and soil structural quality. When pastures were replaced by silvopastoral systems, we observed a recovery in the physical soil attributes with bulk density reaching values of 1.09 g cm−3 and penetration resistance of 3.77 MPa. Those improvements as well as the enhacement in visual evaluation soil structure could be associated with increases in soil C content since diversified and greater above and belowground biomass production are expected, as well as improved animal/pasture management. Thus, the implementation of silvopastoral systems is highlighted as an efficient strategy to restore soil physical quality of degraded pastures, contributing to increase pastureland productivity, and indirectly decrease deforestation pressure in the Amazon Basin. [ABSTRACT FROM AUTHOR]