Search

Land uses may shift soil biota community composition, and soil chemical traits. Our aims were to assess if the land uses may influence the soil biota community composition and soil chemical traits; if there are differences into soil biota biomass as influenced by land uses; and what are the plant-soil feedback among the land uses, soil biota, and soil chemical traits. We have collected soil samples and extracted soil biota individuals from four different land uses (e.g., natural ecosystem, conventional farming system, agroecological farming system, and fruticulture). Our results have revealed that land uses have influenced soil biota abundance (from 59.0 to 210.12 ind. trap− 1in the natural ecosystem and fruticulture system, respectively), richness (from 6.5 to 10.5 in the fruticulture system, and natural ecosystem, respectively), diversity (from 1.01 to 1.75 in the conventional farming system, and natural ecosystem, respectively), dominance (from 0.52 to 0.71 in the natural ecosystem, and conventional farming system, respectively), and its biomass. The studied land uses have decreased the soil organic carbon when compared with the natural ecosystem (5.75 g kg− 1). SOC, soil pH, Olsen’s available P, Mg2+, K+, and Na+were the main factors contributing to the variance of the samples accounting for 78% of the data variance. The results of our study highlight the importance of considering land uses as key factors influencing soil biota community and soil chemical traits. Thus, long-term experiments considering land uses (e.g., conventional farming system, fruticulture, and agroecological farming system) may exploit negative effects of land uses on soil biota abundance on the one hand, while positive effects on soil chemical traits on the other hand.

Changes in the soil fertility, physiological traits, and fruit quality of Morinda citrifoliawere investigated between January 2012 and December 2020. Soil samples, physiological properties, and fruits of M. citrifoliawere collected in a factorial scheme 2 × 2 × 2, with the use of intercropping with Musaspp., mulching, and biofertilization (e.g., presence and absence) within five blocks. We evaluated soil reaction (pH), P by Melich-1, soil exchangeable cations, potential acidity (H++ Al3+), sum of bases, CEC, SOC, Fm, F0, Fv, Fv/F0,Fv/Fm, photochemical quenching, non-photochemical quenching, apparent electron transport rate, firmness, refractometric index, soluble sugar content, acidity, ascorbic acid, total phenolic content, antioxidant activity, and fruit mineral content. Our results emphasized the influence of agroecological practices on soil chemical properties, plant physiological traits, and fruit quality of M. citrifolia. The combined use of intercropping, mulching, and biofertilization showed high values of soil pH, available P, Mg2+, electron transport rate, firmness, ascorbic acid, antioxidant activity, fruit Zn content, and fruit Na content and low values of Ca2+and K+under field conditions. The results of this study highlight the importance of considering agroecological practices as promoters of fruit quality, and thus improving fruit properties with high importance for human mental health, fruit palatability, fruit development, fruit postharvest storage, and redox state of the human body.

Green manure represents a crucial soil management practice for soil traits and potentially sequestering organic carbon (OC) within the soil profile. Understanding the biomass dynamics of Fabaceae and Poaceae plants has become essential for refining existing models of soil fertility and organic carbon. In this work, we have developed six models of the fertility and carbon stock of the soil collected from the plots where ten plant species were cultivated as green manuring crop. Two of them are named aboveground and belowground biomass models which use specific biomass production parameters α and adapted to both Fabaceae and Poaceae stands, and three other models are named Ca2+, K+and P models adapted to green manure stands. The last one is named soil organic carbon stock model, and it is adapted to both Fabaceae and Poaceae stands. A Bayesian inference was carried out to determine parameters values according to the 6-years field experiment database. The highest significant values for SOC stock, aboveground biomass model, and belowground biomass modes were found for the Fabaceae model with 9.99 t ha−1, 5.37 t ha−1, and 0.61 g cm−3, respectively. All proposed models into this study (density, soil, and biomass models) were explained by the geometric reliability index (GRI) and efficiency factor (EF) with a more dispersive fitting. This study underscores the importance of considering adapted models from the Fabaceae and Poaceae families, particularly those with high growth rate index (GRI) and efficiency factor (EF). We found that shoot dry biomass exhibited a polynomial decrease, whereas root density showed an exponential decrease over time for both Poaceae and Fabaceae plants. Furthermore, our study revealed that long-term cultivation of cover crops with green manure significantly augmented the contents of exchangeable cations (Ca2+and K+) as well as soil organic carbon (SOC) stock.

The soil physical-chemical changes in different land uses in a Tropical Cambisol at Apodi Plateau, Northeastern Brazil, were investigated between May 2017 and April 2018. Soil samples were collected at three soil layers (0–5, 5–15, and 15–25 cm) under three land uses: a 6-year agroecological farming system, a 10-year fruticulture farming system, and a 6-year conventional farming system. We evaluated: bulk density, soil porosity, weighted average diameter (WAD), geometric mean diameter (GMD), soil pH, soil organic carbon (SOC), P, and sum of bases. Soil quality index was built by considering four main functions: Water supply and storage, root growth capacity, nutrient cycling, and soil conservation. Our results emphasized the land use influence on the soil physical-chemical traits in a Tropical Cambisol. The PCA analyses showed that SOC, soil porosity, bulk density, WAD, GMD, soil pH, sum of bases, and soil P content were the main factors contributing to the data variance. We found the highest values of soil quality index in the conventional farming system (0.57 ± 0.03). The results highlight the importance to consider land uses that increase the sum of bases, WAD, GMD, and SOC content, and decrease bulk density. Our findings suggest that (1) a conventional farming system with liming and fertilizers’ input positively changed soil physical-chemical traits, which in turn improved soil quality in a tropical Cambisol; and (2) by altering soil functions land uses may create a sustainable cycle into the soil profile thus promoting soil quality.

Context Soil capacity to biomass production (SC) sheds light on soil health and its capacity to sustain high primary production. However, the currently existing models are based on rather local data, and thus there is a lack of predictive tools to monitor SC. Aims Our aim was to assess the influence of cover crops on soil chemical properties by considering their different behaviours (biomass production and root density). Methods We characterised soil chemical properties, and plant biomass production during 6years in field conditions at a tropical soil. Key results Our findings suggest that: (1) green manure practice improved Ca2+, K+, and soil organic carbon (SOC) stock, but none of the studied cover crops were able to improve soil P content; and (2) we found three groups of green manure by considering the SC reduction, namely G1 (low SC reduction) that comprises Crotalaria ochroleuca and Neonotonia wightii, G2 (medium SC reduction) that comprises Brachiaria decumbens, Pennisetum glaucum, and Crotalaria juncea, and G3 (high SC reduction) that comprises Mucuna pruriens, Canavalia ensiformis, Crotalaria spectabilis, Dolichos lablab, and Stizolobium aterrimum. Conclusion We concluded that after 3years during which soil parameters and the production of most, but not all, cover crops have increased, the deficiency in P did not allow plants to grow well anymore. Implications This study highlights the importance to consider predictive models as a tool to be used in soil management. Our study also provides a deeper view about the use of green manure and their influence on soil capacity to biomass production.

We aimed to analyse the effects of Cryptostegia madagascariensis’invasion on soil biota community composition from a tropical Fluvisol at the Brazilian Northeast. We collected soil organisms from two dissimilar environments (e.g., invaded and non-invaded) using Provid-type traps into transects. There was a positive correlation between the abundance of Araneae, Blattodea, Homoptera and, Pseudoscorpiones with the invaded environment. On the other hand, the frequency of occurrence of Hymenoptera was significantly higher in the invaded environment compared to the non-invaded one. The biological invasion process promoted by C. madagascariensisreduces soil biota diversity, and the frequency of occurrence of important functional groups, such as predators (e.g., Araneae, Dermaptera, and Scorpiones), and litter transformers (e.g., Coleoptera). This creates a negative plant-soil feedback that promote the functional redundancy process by soil organisms and the biological invasion process by the invader into the Caatinga ecoregion.

Positive feedback between arbuscular mycorrhizal fungal (AMF) and vascular plants can contribute to plant species establishment, but how this feedback affects plant invasion by Prosopis julifloraSW. (DC.), or resistance to invasion by Mimosa tenuiflora(Willd.) Poir in Brazilian semi-arid region is not well known. In this work, we tested how modified and native AMF communities affect the establishment of P. julifloraand M. tenuifloraplants. We examined the effects of inoculation with modified and native AMF communities on number of AMF spores, root colonization, number of N-fixing nodules, plant dry biomass, plant phosphorous concentration, and plant responsiveness to mycorrhizas of P. julifloraand M. tenuiflora. We found that the modified AMF community enhanced the root colonization, plant dry biomass, and plant phosphorous concentration of invasive P. juliflora, whereas native AMF enhanced M. tenuiflora. Our results demonstrate that the invasive P. julifloraalters soil AMF community composition, and this change generates positive feedback to the invasive P. julifloraitself and decreases AMF associations with native M. tenuiflora.

Here, we compare the arbuscular mycorrhizal fungal (AMF) community composition in soils from the root zone of the exotic invasive species Prosopis juliflora(EXO soils) and soils from the root zone of the native species Mimosa tenuiflora(NAT soils) from five locations in the Brazilian tropical seasonal dry forest, Paraíba, Brazil, using morphological analyses. AMF community composition in EXO and NAT soils were dissimilar. Available phosphorus, diversity index, spore abundance, and species richness were the main factors differing between the EXO and NAT soils. In general, the most dominant order present in the soils were Glomerales(44.8%) and Gigasporales(41.4%). The most abundant AMF genus in all studied soils was Funneliformis. Differences in AMF community composition were associated with (1) differences in the dominant plant species (P. julifloravs. M. tenuiflora) and (2) changes in soil chemical factors (soil, pH, total organic carbon, total nitrogen, and available P) in EXO soils. These results contribute to a deeper view of the AMF communities in exotic soils and open new perspectives for ecological processes involving AMF species and exotic plant species in the Brazilian tropical seasonal dry forest.

Many plant species from Brazilian semi-arid present arbuscular mycorrhizal fungi (AMF) in their rhizosphere. These microorganisms play a key role in the establishment, growth, survival of plants and protection against drought, pathogenic fungi and nematodes. This study presents a quantitative analysis of the AMF species associated with Mimosa tenuiflora, an important native plant of the Caatinga flora. AMF diversity, spore abundance and root colonization were estimated in seven sampling locations in the Ceará and Paraíba States, during September of 2012. There were significant differences in soil properties, spore abundance, percentage of root colonization, and AMF diversity among sites. Altogether, 18 AMF species were identified, and spores of the genera Acaulospora, Claroideoglomus, Dentiscutata, Entrophospora, Funneliformis, Gigaspora, Glomus, Racocetra, Rhizoglomusand Scutellosporawere observed. AMF species diversity and their spore abundance found in M. tenuiflorarhizosphere shown that this native plant species is an important host plant to AMF communities from Brazilian semi-arid region. We concluded that: (a) during the dry period and in semi-arid conditions, there is a high spore production in M. tenuifloraroot zone; and (b) soil properties, as soil pH and available phosphorous, affect AMF species diversity, thus constituting key factors for the similarity/dissimilarity of AMF communities in the M. tenuifloraroot zone among sites.