Biological Indicators Of Soil Quality Research Articles

FARManalytics – A bio-economic model to optimize the economic value of sustainable soil management on arable farms

Soil quality is an important determinant of agricultural productivity and environmental quality. Despite its importance, few economic models incorporate sustainable soil management. The objective of this study is to develop and illustrate FARManalytics: a bio-economic model to gain quantitative insight in the economic value of sustainable soil management. First, we defined a comprehensive set of chemical, physical and biological soil quality indicators and quantitative rules on how these indicators respond to farmers’ production management over time. Second, we introduce an economic calculation framework that enables accurate calculation of the contribution of different production management decisions towards farm income using Activity-Based-Costing. The set of soil quality indicators and economic calculations serve as the basis for the bio-economic model FARManalytics, which consists of two modules: (1) the PMcalculator, a module that calculates the impact of current production management on soil quality and farm economics and (2) the PMoptimizer, a module that uses Mixed-Integer-Linear-Programming to maximize farm incomewithin predefined soil quality indicator constraints. The decision variables are the crop rotation, cover crops, manure & fertilizer application and crop residue management. We illustrate the added value of the model by applying it to an extensive and intensive farm type, both on clay and sandy soil. These farm types are derived from the Farm Accountancy Data Network (FADN) in the Netherlands. FARManalytics demonstrates that it is possible to increase farm income with up to €940 ha−1 year−1 on clay soil and up to €683 ha−1 year−1 on sandy soil, while meeting all soil quality targets except subsoil compaction vulnerability. The latter was among the most limiting soil quality indicators for the farm types in this study, together with soil organic matter input, wind erosion vulnerability and plant-parasitic nematodes. FARManalytics integrates the impact of production management decisions on soil quality and economics at farm level. Combined with representative farm types, the bio-economic modeling approach of FARManalytics can provide useful information for policy support. FARManalytics can also be tailored to provide decision support for individual farms, based on data that is commonly available on arable farms at low cost.

Soil Quality under Polyhouse and Open Field Conditions as Affected by Continuous Fertilizer and Manure Applications

ABSTRACT Intensive cultivation coupled with scrupulous use of fertilizers could be detrimental to soil health and quality of the produce in the long run. Therefore, this study aimed to assess the predominant protected/polyhouse and open field vegetable production on soil quality. The changes in soil quality in comparison to control (fallow) indicate, whether the management practices being adopted under both the systems are sustainable or not. Thus, a study was conducted to identify the most appropriate soil quality indicators and finally to know about the status of soil quality both under polyhouse and open field system of cultivation in mid hills of North western Himalayas. Principal component analysis (PCA), a data reduction tool was employed to get the minimum data set for the assessment of soil quality. Geo-referenced soil samples were collected from 25 progressive farmers’ cultivating vegetables under polyhouse, as well as open field conditions and analyzed for various physical, chemical and biological indicators of soil quality. The PCA was performed which screened out the three principal components (PCs) with eigen value > 1. Average soil quality index (SQI) for different sites was observed to be on higher under polyhouse conditions (0.815) as compared to open field cultivation for vegetables (0.760) and control (0.703). Where, soil organic carbon contributed maximum to soil quality (75.6%) followed by pH (13.9%), water holding capacity (6.8%) and EC (3.6%). Conclusively, polyhouse cultivation system revealed high category of soil quality. Whereas, open field cultivation system revealed medium category of soil quality.

Sustainable soil management: Insights from a 47-year maize-wheat cropping system study

Continuous monitoring of soil quality is vital to understand the effects and to identify best management practices for sustainable agroecosystems. This study focuses on evaluating the soil quality and crop yield sustainability in a long-term maize-wheat cropping system experiment spanning 47 years. Physical, chemical, and biological soil quality indicators were assessed at two soil depths (0–0.15 m and 0.15–0.30 m) under eleven fertilizer and amendment regimes i.e., 50 % NPK, 100 % NPK, 150 % NPK, 100 % NPK + Zn, 100 % NPK+ hand weeding, 100 % NP, 100 % N, 100 % NPK + farmyard manure (FYM), 100 % NPK(S), 100 % NPK + lime and control, laid out in a completely randomized block design. Principal component analysis (PCA) was employed to select a minimum data set (MDS) of indicators for soil quality assessment, followed by weighted additive approach to calculate the soil quality index (SQI). Results showed that balanced dose of NPK fertilizers, in combination with FYM or lime, enhanced average wheat grain yield by 39.9 and 29.4 % over sole 100 % NPK fertilizers, respectively. Treatment 100 % NPK + FYM recorded a significant improvement in aggregate stability, available nutrients, microbial biomass over control and 100 % NPK. The highest value of SQI (0–0.15 m) was recorded in 100 % NPK + FYM (0.99), followed by 100 % NPK + lime (0.86) and lowest in 100 % N (0.41). Omission of NPK, PK, K and S from fertilizer regime caused a decline of respective 33, 39, 22 and 6 % in the SQI, whereas, all the treatments recorded a decline in SQI in sub-surface layer. The average contribution of MDS towards the SQI of 0–0.15 and 0.15–0.30 m depth was labile carbon (LC) (30 %) > microbial biomass N (MBN) (28 %) > mean weight diameter (MWD) (17 %) > pH (16 %) > available K (6 %) and LC (33 %) > N mineralization (24 %) > MWD (22 %) > pH (21 %), respectively. The SQI positively correlated with average grain yield and SYI, highlighting the importance of soil quality for sustainable crop production. This research underscores the significance of continuous soil quality monitoring and use of balanced fertilization, organic manure and lime in maintaining soil health and crop productivity in agroecosystems.

Comparison of Biological Indicators of Soil Quality of Horticultural Crops Based on No-tillage and Non-synthetic Systems

Comparison of Biological Indicators of Soil Quality of Horticultural Crops Based on No-tillage and Non-synthetic Systems

Impact of long-term resource conservation techniques on biogeochemical characteristics and biological soil quality indicators in a rice green-gram farming system.

Nutrient management in resource conservation practices influence the structural and functional microbial diversities and thereby affect biological processes and biochemical properties in soil. We studied the long-term effects of resource conservation technologies on functional microbial diversity and their interactions with soil biochemical properties and enzymatic activities in tropical rice-green gram cropping system. The experiment includes seven treatments viz., conventional practice (CC), brown manuring (BM), green manuring (GM), wet direct drum sowing, zero tillage, green manuring-customized leaf colour chart based-N application (GM-CLCC-N) and biochar (BC) application. The result of the present study revealed that microbial biomass nitrogen (N), carbon (C) and phosphorus (P) in GM practice were increased by 23.3, 37.7 and 35.1%, respectively than CC. GM, BM and GM-CLCC-N treatments provide higher yields than conventional practice. The average well color development value, Shannon index and McIntosh index were significantly higher by 26.6%, 86.9% and 29.2% in GM as compared to control treatment. So, from this study we can conclude that resource conservation practices like GM, GM-CLCC N and BM in combination with chemical fertilizers provide easily decomposable carbon source to support the microbial growth. Moreover, dominance of microbial activity in biomass amended treatments (GM, GM-CLCC N and BM) indicated that these treatments could supply good amount of labile C sources on real time basis for microbial growth that may protect the stable C fraction in soil, hence could support higher yield and soil organic carbon build-up in long run under rice-green gram soil.

Soil microbial community composition and functions are disrupted by fire and land use in a Mediterranean woodland

The intersection of fire, land use transformations, and climate change is putting Mediterranean climate-type ecosystems at risk of soil degradation and loss of ecosystem services. Ondik et al. (2022b) showed that in a Mediterranean dry sclerophyll woodland of South Australia, high severity fire and clearing and grazing practices impacted both physicochemical and biological soil quality indicators. Building upon the work of Ondik et al. (2022b) this study aims to 1) identify soil physicochemical properties impacted by fire and land management that are indirect drivers of changes to soil microbial community composition and 2) determine whether the observed changes to soil microbial community composition affect soil microbial functions. Via a redundancy analysis, we identified fire and management-induced changes to pH, soil water repellency, nutrient stoichiometry, and total nutrient content as significant drivers of the composition of soil microbial communities. We then measured basal respiration, substrate induced respiration, and the carbon mineralisation quotient, and calculated functional trait distributions among microbial communities by linking 16S and 18S rRNA sequences to respiration modes and functional guilds, respectively. We found that fire reduced soil microbial respiration and the relative abundance (RA) of microbial symbionts, anaerobic bacteria, and microaerophilic bacteria, while increasing the RA of aerobic bacteria. Furthermore, management increased the RA of post-fire ectomycorrhizal fungi and may have reduced pathogenic load, microbial efficiency, and wood saprotrophs, while increasing litter, soil, and other saprotrophic species that are adapted to grasslands. This study shows that, through changes to microbial community composition, high severity wildfire and land management affected soil respiration rates, bacterial modes of respiration, prevalence of symbiotic bacteria and fungi, and microbial substrate preference. Having identified the main physicochemical drivers of changes to microbial community composition, we provide valuable insights into how fire and land management can impact soils in Mediterranean woodland.

Prediction of soil ecotoxicity against Folsomia candida using acute and chronic endpoints

ABSTRACT Soil invertebrates serve as great biological indicators of soil quality. However, there are very few in silico models developed so far on the soil toxicity of chemicals against soil invertebrates due to paucity of data. In this study, three available soil ecotoxicity data (pLC50, pLOEL and pNOEL) against the soil invertebrate Folsomia candida were collected from the ECOTOX database (cfpub.epa.gov/ecotox) and subjected to quantitative structure-activity relationship (QSAR) analysis using 2D descriptors. The collected data for each endpoint were initially curated and used to develop a partial least squares (PLS) regression model based on the features selected through a genetic algorithm followed by the best subset selection. Both internal and external validation metrics of the models’ predictions are well-balanced and within the acceptable range as per the Organization for the Economic Cooperation and Development (OECD) criteria. From the developed models, it has been found that molecular weight and presence of phosphate group, electron donor groups, and polyhalogen substitution have a significant impact on the soil ecotoxicity. The soil ecotoxicological risk assessment of organic chemicals can therefore be prioritized by these features. With the availability of additional data in the future, the models may be further refined for more precise predictions.

Comparison of biological soil quality indicators under different nutrient management techniques in semi-arid parts of India

Comparison of biological soil quality indicators under different nutrient management techniques in semi-arid parts of India

Microplastics in agricultural soil: Polystyrene fragments inhibit soil microbial and enzymatic activities but promote nutrient concentration of Cowpea (Vigna unguiculata)

The disintegration and fragmentation of plastics into microplastics (MPs) and their transport from aquatic and terrestrial ecosystems into agricultural soils have been reported to be hazardous to soil health and crop growth. However, it is unknown how biological soil quality indicators and agronomic indices of a C3 plant respond to MPs' ecotoxicity after short-term exposure. Here, we conducted two experiments to define the eco-toxicity impact of polystyrene-MPs (PS-MPs) exposure at concentrations of (i) non-amended control, (ii) 0.5% PS-MP (w/w), (iii) 1% PS-MP (w/w), (iv) 2% PS-MP (w/w), and (v) 4% PS-MP (w/w) on the soil microbial biomass, respiration, and enzymatic activity—indicators of soil quality, and cowpea (model C3 plant) growth and nutrient concentrations. Our results demonstrate that PS-MPs, generally considered nontoxic, negatively inhibit microbial biomass and extracellular enzymatic activities after 30 days of soil incubation. On the other hand, increasing concentrations of PS-MPs increased soil basal respiration and the microbial metabolic quotient (qCO2), indicating microbial stress. Cowpea growth, irrespective of PS-MPs concentration and exposure time, showed neutral or non-inhibitory responses after 60 days. However, PS-MPs at low concentration (0.5% w/w) promoted an increase in cowpea leghemoglobin content, total chlorophyll pigment, and shoot and root nutrient concentrations (N, P, Zn, and Fe) over the control. Overall, our findings affirm the short-term ecotoxicity effect of PS-MPs on soil biological indicators of soil quality but also indicate that PS-MP exposure may not always have negative impacts on the agronomic performance of certain C3 plant species, such as cowpea.

Agricultural practices influence biological soil quality indicators in an irrigated semiarid agro-ecosystem

A study was conducted to investigate how soil biological measurements can be used to indicate differences in soil quality in arid and semiarid agroecosystems. The objectives were to assess soil biological quality indicators under different land management practices and at different depths and to explore the relationships between soil microbial community and organic matter fractions. Soil samples were collected from three replicates of six land management systems at 0–5 cm and 5–15 cm soil depths. Four management systems had medium to fine soil texture including a permanent grass field with tall fescue (Lolium arundinaceum [Schreb]; TFC), peach orchard with clover understory (Prunus persica with Trifolium repens L.; PCC), alfalfa field (Medicago sativa; ALF) and conventionally tilled soil with an annual crop rotation (CTC). Two management systems, including a young cottonwood tree orchard (Populus fremontii and Populus deltoides; CWS) and conventionally tilled soil in annual crop rotation (CTS), had coarse soil texture. Management systems had significant impacts on most of the soil biological indicators assessed at the two depths with both depths responding similarly to management practices. For the soil biological indicators that showed differences, the TFC generally had the most favorable indicator measurements compared to other management systems. The principal component analysis showed a clear separation between the management systems and microbial communities at both soil depths. The ordination pattern was structured by soil textural differences between medium to fine-textured soils from TFC, PCC, ALF, and CTC fields and coarse-textured soils (CWS, CTS). Spearman’s correlation coefficients (rs) showed that the soil organic matter (rs = 0.85, P = 0.001) and the permanganate oxidizable carbon (rs = 0.93, P = 0.001) were significantly correlated with the total microbial biomass at 0–5 cm soil depth. Also, the soil organic matter (rs = 0.84, P = 0.001) was significantly correlated with the total microbial biomass at 5–15 cm soil depth. This study suggests that in semiarid agroecosystems, management practices with permanent covers have the potential to improve soil quality, and soil texture may also influence the directional changes in soil quality within this region.

Physical, Chemical, and Biological Indicators of Soil Quality in Mediterranean Vineyards under Contrasting Farming Schemes

The soil of most Spanish vineyards is strongly eroded and carbon depleted and is very poor in biodiversity. Growing evidence of the negative impacts of soil degradation on climate change mitigation, water quality, and plant production is pushing a shift from intensive viticulture to more sustainable management strategies of the vineyards. Among them, minimum impact and regenerative viticulture are gaining ground. However, field data are still necessary to assess the real effect of these new farming schemes on soil carbon stocks and soil functional biodiversity. We compared soil quality at three vineyards managed under intensive, regenerative, and minimum impact strategies using physical, chemical, and biological indicators. Soil carbon stocks were 2.3 and 3.4 times greater in the regenerative and the minimal impact vineyards than in the intensive vineyard, respectively. Soil biota was particularly favored by regenerative viticulture, with 26.2 times more protists, 3.1 times more nematodes, and 29.4 more microarthropods in the regenerative than in the intensive vineyard. Our results indicate that the ecological intensification of agricultural practices is highly promising to restore degraded agricultural soils under Mediterranean conditions. We also propose cost-effective soil bioindicators sensitive to agricultural management for their possible inclusion in soil monitoring programs.

Machine learning and remote sensing techniques applied to estimate soil indicators – Review

• Machine learning to process remote sensing data to estimate soil quality indicators. • Use of unmanned aerial vehicle (UAV) and satellite platforms to estimate soil indicators. • Selection of machine learning algorithms for processing agro-industrial systems databases. • Model for estimating soil quality in agricultural systems at a local scale. The demand for food based on intensive agriculture has decreased soil quality, posing great challenges such as increasing agricultural productivity and promoting environmental sustainability. Thus, researchers have focused on developing models for estimating soil quality based on artificial intelligence techniques for the processing of multidimensional data from agro-industrial systems, which provide useful information for farmers about soil management and crop conditions. However, a model for the application of these new technologies in medium and low-scale agricultural systems has not been identified. Therefore, a review of recent studies of crop yield prediction based on the estimation of chemical, physical, and biological soil quality indicators (SQI), which incorporate different machine learning (ML) techniques to process data from remote sensing (RS) systems, is presented. The advantages and disadvantages are also analyzed for: SQI estimates at regional and local scale, spectral bands used for analysis of plowed soils (bare soils) of cultivation plots, selection of minimun data set (MDS), use of unmanned aerial vehicle (UAV) and satellite platforms, data pre-processing, and selection of ML algorithms for processing biological systems databases (agro-industrial systems). Finally, we present a model to help estimate soil quality in agricultural systems at a local scale, based on ML to process RS data, in the model the inputs to the ML unit come from four different class data sets (RS, SQI, environmental data and crop management data). Crop management uses the production of the ML unit to adjust agricultural management practices and therefore improve crop yield.

Biological Soil Quality Indicators in an Irrigated Semiarid Agroecosystem

Biological Soil Quality Indicators in an Irrigated Semiarid Agroecosystem

Microarthropods and vegetation as biological indicators of soil quality studied in poor sandy sites at former military facilities

AbstractBiota play major roles in soil function and are highly sensitive to any disturbances including land degradation. However, it is not fully understood which organisms and what parameters can be useful in assessing soil quality. To fill this research gap we searched for good indicators of changes in environmental quality that could help to assess land degradation. Next to indicators using physical and chemical parameters, biological agents can also provide a lot of information. To obtain such knowledge we compared the soil quality of former military sites, which differed mainly in the texture, nutrients and organic carbon content based on fauna and vegetation indices. Among the fauna indices were Collembola and Acari abundance, Soil Biological Quality index (QBS‐ar), decomposition rate and feeding activity. The Ellenberg index was used as a vegetation indicator, in which the response to pH, nutrients, and moisture was analysed. The experiment was conducted at 2 former military sites in the Czech Republic. Site 2 was characterised by higher nutrient content and a more compact soil structure in comparison to site 1. It was found that almost all fauna and vegetation indices showed better soil quality in site 2. The significant changes were indicated by the Collembola abundance, QBS‐ar index and feeding activity, as well as response to pH considering vegetation indicators. Finally, we conclude the usefulness of biological indicators for monitoring the quality of soil, which can be adopted when making decisions concerning land use.

Effect of Different Agricultural Farming Practices on Microbial Biomass and Enzyme Activities of Celery Growing Field Soil.

Soil quality is directly affected by alterations in its microbiological, biological, biochemical, physical, and chemical aspects. The microbiological activities of soil can affect soil fertility and plant growth because it can speed up the cycling of nutrients, enzymes, and hormones that are needed by plants for proper growth and development. The use of different agricultural management practices can influence microbial biomass and enzyme activities by altering soil microclimate, soil microorganism habitat, and nutrient cycling. Based on this, the present work planned to evaluate the impact of conventional, low-input, and organic farming systems in a vegetable field growing celery on microbial biomass and different soil enzyme activities. The present study showed a comparison of the effect of different practices on biological soil quality indicators during two sampling times, i.e., one month after colonization and one month before harvesting. It was observed that the soil microbial biomass in the organic farming system was significantly higher than that found in conventional and low-input practices. Under an organic farming system, the soil microbial biomass in December was significantly higher than that in October. The soil microbial biomass carbon in the 0–20 cm soil layer showed higher variation compared to that in the 20–40 cm layer for all the three of the farming management practices that were used in the study. Additionally, the soil total carbon and total organic carbon were recorded as being higher in the December samples than they were in the October samples. Under all the three of the management practices that were applied, the soil catalase activity was higher in the October samples than it was in the December soil samples that were collected the from 20–40 cm soil layer compared to those that were taken from the 0–20 cm layer. The application of organic fertilizer (chicken and cowmanure compost) resulted inincreases in the soil urease and in the protease activity. The protease activity of the soil samples that were extracted from the 0–20 cm and 20–40 cm soil layers in October was higher in the samples that were taken from farms using conventional practices than it was in the samples that were taken from farms using organic and low-input practices, while the samples that were collected during December from both of the soil layers showed higher protease activity when organic methods had been used. No significant variation in the soil urease activity was observed between the two soil layer samples. Urease activity was the highest when organic management practices were being used, followed by the low-input and the conventional modes. For the conventional and low-input practices, the soil urease activity showed an obvious trend of change that was related to thetime of sampling, i.e., activity in December was significantly higher than activity in October. The novelty of this study was to determine the microbial biomass carbon and enzymatic activity in a six-field crop rotation (tomato, cucumber, celery, fennel, cauliflower, and eggplant) using three management practices: low-input, conventional, and organic systems. The present study showed that the long-term application of organic fertilizers plays a large role in maintaining excellent microbial and enzyme activitythat result in improved soil quality.

Use of Organic Materials to Maintain Soil Quality by Thai-Lao Rice Farmers in Northeast Thailand

Maintaining soil quality is a major problem for traditional farmers in the tropics. Many rely on organic amendments to enhance the productivity of their fields. However, indigenous knowledge about soil organic matter (SOM) and its management has received relatively little attention from researchers. This paper describes the use of organic materials to maintain soil quality by Thai-Lao farmers in a rice-growing village in Northeast Thailand. In-depth semi-structured interviews were conducted with twelve farmers to: 1) identify the indicators of soil fertility they employed; 2) inventory the organic materials they used; 3) determine changes in the use of amendments over time; and 4) understand their concept of SOM. They used many physical and biological indicators of soil quality. They used nine different organic materials: rice straw and stubble, cattle, buffalo and pig manure, rice husks, sunn hemp plants as green manure, charcoal, commercial compost, homemade compost, and tree leaf litter. Recently, use of livestock manure, rice husks, charcoal, and leaf litter has declined because of supply shortages. They do not appear to have a general concept of organic matter nor is there a commonly used word for “organic” in their language. Most of the farmers would use larger quantities of organic amendments but are constrained by their scarcity and high cost. Ways to increase local supplies of organic materials must be found if the government’s efforts to encourage the adoption of organic agriculture are to be successful.

Biological Indicators of Soil Quality under Different Tillage Systems in Retisol

Soil microorganism diversity has a close relation with soil function, and the changes in the composition of the soil microbial population can directly affect it. The aim of this study was to identify the bacterial community composition and determine the main soil chemical and physical properties formed by the different tillage systems. In the experiment, we analyzed the combination of three tillage systems and four organic fertilizers. Soil samples were taken from the two layers of the soil profile: the upper 0–10 cm and the lower 10–20 cm. The composition and diversity of soil bacterial communities were assessed by the sequencing of 16S rRNA genes. Results revealed that the highest biodiversity was found in the soil with shallow ploughless tillage and enriched with farmyard manure. Actinobacteria and Proteobacteria were the dominant bacterial species across all treatments. Their total abundance varied between 26% and 36% in the different analyzed agroecosystems. For the Dystric Bathygleyic Glossic Retisol, shallow ploughless tillage is the most suitable tillage system, as it creates favorable conditions for the accumulation of organic carbon in the soil under the Western Lithuania climate conditions.

Chemical and biological indicators of soil quality in cultivation areas of the Cerrado

The present study aimed to evaluate the interference of the management adopted in Cerrado cultivation areas on the chemical and biological soil attributes. Four soil management systems were studied (MC, NT3+SM, NT6+MB, and NT6+SMB), with different years of adoption and cover crops, and one area of native vegetation (NV). In each soil management system and in the NV, soil samples were collected at the depths of 0.0-0.05m, 0.05-0.10m, and 0.10-0.20m, 5 replications. The effects of the treatments on the response variables were evaluated by ANOVA, and the means were compared by the Scott-Knott test at 5% of significance. Soil management with crop rotation and succession improved soil fertility since all chemical elements studied presented higher values when compared to the NV. The soil contents of organic carbon, macronutrients, microbial biomass carbon (Cmic), and soil basal respiration (SBR) were generally higher on the surface, with the lowest contents of Cmic being observed for the NT6+MB, and the NV presenting high SBR in all studied depths. The metabolic quotient was higher in depth. In general, our results revealed that the use of no-tillage systems, besides providing soil cover, also increases and maintains the chemical and biological attributes, respectively, thus improving soil quality.

Epigeal invertebrate fauna in monoculture and integrated systems in the cerrado biome Piauí

Epigeal fauna are considered key biological indicators of soil quality, which can be used as parameters for determining sustainable agricultural production systems. This study aimed to evaluate the epigeal fauna under different monoculture and integrated production systems in a Yellow Latosol in the Cerrado biome. The epigeal fauna was sampled using pitfall traps in areas of no-tillage, pasture, exclusive eucalyptus cultivation, integrated livestock-forest system and in a native cerrado. The following variables were determined: number of individuals trap-1 day-1, total richness and the indices of Shannon and Pielou. The number of individuals trap-1 day-1 and richness were higher in native cerrado, while the no-tillage area presented the lowest values. For the Shannon and Pielou indices, native cerrado and integrated livestock-forest system presented the highest values while exclusive eucalyptus cultivation and no-tillage presented the lowest values. The pasture, exclusive eucalyptus cultivation and integrated livestock-forest system favored the ecological indexes of the epigeal fauna, while no-tillage was the system that least contributed to the establishment of these organisms. In areas explored with pasture, exclusive eucalyptus cultivation and integrated livestock-forest system, the community and the diversity of groups of fauna tend to increase. The association with different groups of fauna is more expressive in environments of native cerrado and exclusive eucalyptus cultivation.

Chemical and biological indicators of soil quality in organic and conventional Japanese plum orchards

ABSTRACT To evaluate the effect of the management system on soil quality, chemical and biological properties were measured in soils (0–20 cm depth) from Japanese plum orchards managed under organic and conventional conditions. The experiment was conducted between 2005 and 2014 in orchards established at the agricultural research station at Alcalá del Río, Seville, Spain. Overall, the soil chemical parameters in the organic orchard showed higher concentrations of soil organic matter, total N, available P and Mg. There was a trend of higher concentrations of K and Na, though for these elements the differences were significant only in two and one years, respectively. Similarly, concentrations of Mn and Zn tended to be higher in the organic plots, whereas contradictory trends were shown for Fe and Cu. No differences were found between the treatments for other physicochemical parameters such as pH and electrical conductivity. Regarding soil biological properties, the organic system was characterised with a significantly greater abundance of bacteria and fungi compared with the conventional system. The rhizobia population and the legume biomass were also higher in the organic orchard and the plants had more nodules. Likewise, the number of earthworms was higher in the organic system. The results showed that long-term organic management, including the use of cover crops and compost, resulted in a significant shift of the chemical and biological characteristics of the soil compared with the conventional management practice, thus improving soil quality and suggesting that organic farming may provide a potential solution to achieve sustainable agricultural systems.