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Soil in short-term crop rotation systems (STCR) is still in the initial development stage of farmland soil, whereas after long-term crop rotation treatment (LTCR), soil properties are significantly different. This study compares STCR (4 years) and LTCR (30 years) rice-rice-fallow, rice-rice-rape rotation practices under the same soil type background and management system. To reveal ecosystem mechanisms within soils and their effects on rice yield following LTCR, we analyzed the physical, chemical, and microbiological properties of soils with different rotations and rotation times. Relative to STCR, LTCR significantly reduced soil water-stable aggregate (WSA) content in the < 0.053-mm range, while > 2 mm WSA content significantly increased. Soil organic matter increased in fields under LTCR, mainly in > 2 mm, 2–0.25 mm, and < 0.053 mm soil WSA in 0–10 cm soil layer. LTCR was associated with significantly increased total soil organic matter, at the same time being associated with increasing the amount of active organic matter in the 0–20 cm soil layer. The two crop rotation regimes significantly differed in soil aggregate composition as well as in soil N and P, microbial biomass, and community composition. Relative to STCR, LTCR field soils had significantly higher soil organic matter, active organic matter content, soil enzyme activities, and overall microbial biomass, while soil WSA and microbial community composition was significantly different. Our results demonstrate that LTCR could significantly improve soil quality and rice yield and suggest that length of rotation time and rice-rice-rape rotation are critical factors for the development of green agriculture.

PurposeExcessive application of nitrogen fertilizers on farmland widely occurs in China, which has been recognized as one of the main sources of non-point pollution. To reduce the nitrogen loss in agricultural soils, some specific biochar can be introduced to increase the water-holding capacity of soils and to reserve soil nutrition. The effects and mechanisms of biochar application on decreasing nutrient losses after fertilization were systematically evaluated and understood through both pot and field experiments.Materials and methodsThis study was objected to investigate the effects of neutral biochar (NBC, pH 6.6–7.1) and its combination with urease inhibitor (UI) on nitrogen mitigation and reservation in farmland soil, and the interactions among the mixed soils (biochar, nitrogen fertilizer, and soil) under both pot and field experiments.Results and discussionThe application of straw biochar could reduce the amount of ammonia volatilization in soil. The maximum inhibition of ammonia volatilization loss accounted for 27.67% of fertilizer applications. In field experiments, neutral biochar could reduce the leaching of soil NH4+-N and NO3—-N, and this effect was more evident for NO3—-N (68 mg/kg) compared to no fertilization in the soil layer 20–40 cm. With the addition of neutral biochar and urease inhibitors, the content of soil total nitrogen increased greatly with 1.70 g/kg.ConclusionNeutral biochar from waste agricultural straw and commercial urease inhibitors were applied for nitrogen reservation in pot and field experiments. The application of neutral biochar played a positive role in lower volatile ammonia loss and higher nitrate content compared to urease inhibitor application only. These findings reveal the potential of neutral biochar for the improvement of agricultural soil.

Intercropping has been widely used to control disease and improve yield in agriculture. In this study, maize and peanut were used for non-separation intercropping (NS), semi-separation intercropping (SS) using a nylon net, and complete separation intercropping (CS) using a plastic sheet. In field experiments, two-year land equivalent ratios (LERs) showed yield advantages due to belowground interactions when using NS and SS patterns as compared to monoculture. In contrast, intercropping without belowground interactions (CS) showed a yield disadvantage. Meanwhile, in pot experiments, belowground interactions (found in NS and SS) improved levels of soil-available nutrients (nitrogen (N) and phosphorus (P)) and enzymes (urease and acid phosphomonoesterase) as compared to intercropping without belowground interactions (CS). Soil bacterial community assay showed that soil bacterial communities in the NS and SS crops clustered together and were considerably different from the CS crops. The diversity of bacterial communities was significantly improved in soils with NS and SS. The abundance of beneficial bacteria, which have the functions of P-solubilization, pathogen suppression, and N-cycling, was improved in maize and peanut soils due to belowground interactions through intercropping. Among these bacteria, numbers of Bacillus, Brevibacillus brevis, and Paenibacillus were mainly increased in the maize rhizosphere. Burkholderia, Pseudomonas, and Rhizobium were mainly increased in the peanut rhizosphere. In conclusion, using maize and peanut intercropping, belowground interactions increased the numbers of beneficial bacteria in the soil and improved the diversity of the bacterial community, which was conducive to improving soil nutrient (N and P) supply capacity and soil microecosystem stability.

Cushion plants (as nurse species) can ameliorate soil conditions under their canopy in alpine environments. However, this amelioration (or the intensity of soil fertility islands) related with the size of plants is rarely studied. To assess size effects of Thylacospermum caespitosum on soil fertility islands, soil properties (pH; electric conductivity, EC; soil organic carbon, SOC; available nitrogen, AN; available phosphorus, AP; available potassium, AK) and microbial biomass (soil microbial biomass carbon, SMBC; soil microbial biomass nitrogen, SMBN) were investigated at three different elevations in the Qilian Mountains. Plant size significantly influenced (P < 0.001) soil properties (pH, EC, SOC, AN, AP, AK) and microbial biomass (SMBC and SMBN) at all three elevations. A size-dependent fertile island effect occurred beneath T. caespitosum, where the relative interaction index (RII) of soil properties and SMBC was affected (P < 0.001) by plant size at the three elevations. Moreover, most parameters of soil nutrition and microbial biomass under T. caespitosum were reduced (P < 0.001) with increases in elevation, but the RII was increased (P < 0.05). In short, soil amelioration by T. caespitosum was clearly dependent on plant size at all elevations, and this effect on soil increased with elevation. Thus, the existence of size-dependent fertility islands together with elevation should be regarded as a central mechanism of the nurse effect of T. caespitosum in harsh alpine ecosystems, where many ecological processes rely on the nurse effect of cushion plants.

was established in the West Ordos Region of northwest China approximately 140 million years ago. It plays an irreplaceable role in maintaining local ecosystem stability. This study aimed to evaluate the effects of planting on soil nutrition and microbial communities by comparing the root zone soil (Rz_soil) and bare soil (B_soil) across three different plant communitie. The results showed that decreased soil pH and Na while increasing available potassium, soil organic matter, organic carbon, total nitrogen, and potassium. significantly improved the diversity indices (Sobs and Ace), as well as the richness index (Chao), of bacterial and fungal communities across three plant communities. Meanwhile, the relative abundances of and norank_c_Actinobacteria in the bacterial communities declined significantly in the Rz_soil compared with the B_soil across all three plant communities. In contrast, the relative abundances of and were higher, whereas those of and were lower in Rz_soil than in B_soil in the two plant communities. decreased the soil bacterial co-occurrence networks while increasing the soil fungal co-occurrence networks. These results provide a new perspective to understand the role of in the desert ecosystems.

Abstract Purpose Mycorrhizal fungi are critical for the growth and survival of trees although the knowledge on the extent of their association with different tree species in the boreal forest remains limited.MethodsWe examined the vertical distribution and composition of the root mycorrhizal communities of black spruce (Picea mariana (Mill.) B.S.P) and trembling aspen (Populus tremuloides Michx) along three soil layers (organic, minerals top 0–15 cm and bottom 15–30 cm) in pure and mixed stands, using next generation sequencing.ResultsWe found that spruce and aspen differ in the composition of their mycorrhizal communities in respective pure stands. The difference was present also in mixed stands, despite a shift in the composition of species-specific mycorrhizal communities between pure and mixed stands. In mixed stands, the relative abundance of spruce-specialist mycorrhizae in the organic layer was higher than that of aspen-specialists. The opposite pattern was observed in the mineral soil. The mixed stands exhibited lower richness and abundance of generalist mycorrhizae in the organic and in the mineral soil layers.ConclusionThe results suggest that it is the soil chemistry that structure species-specific mycorrhizal communities between pure stands and along different soil depth within stands. However, in mixed stands, it is the identity of tree species that determines the structure of mycorrhizae communities within soil layers. We speculate that the differences in the richness and abundance of individual mycorrhizal communities of spruce and aspen along the soil profile would likely contribute to stronger partitioning of tree nutrient uptake between these two species in mixed stands.

PurposeThe environmental benefits of biochar application, ranging from improvements in crop yield to global change mitigation, have been extensively studied in the last decade. However, such benefits have not been profusely demonstrated under a Mediterranean climate and still less in combination with high pH soils. In our study, the short to medium effects of biochar application on a soil-plant system under Mediterranean conditions in an alkaline soil were assessed.Material and methodsBarley plants were grown in field mesocosms during three agronomical years at three biochar addition rates (0, 5, and 30 t ha−1). Related to soil, different physicochemical parameters were analyzed as well as microbial respiration, biomass, and functional diversity. In the plant domain, in vivo ecophysiology variables such as leaf transpiration rate, stomatal conductance, and photosynthesis rate were determined while photosynthetic pigment content and soluble protein concentrations were measured in the laboratory. Additionally, crop yield and nutrient composition were also analyzed. The soil-plant connection was investigated by the N content ratio in both fractions establishing the nitrogen efficiency in the system.Results and discussionThe highest rate of biochar amendment enhanced soil moisture and electrical conductivity combined with an increase of SO42−, Cl−, Mg2+, and K+, and decrease of NO3− and HPO4−. Notable variations regarding nutrition and moisture were induced in this Mediterranean alkaline soil after biochar addition although pH remained stable. Contrastingly, there were no major effects on microbial activity, but a lower abundance of the nosZ functional gene was found. Similarly, plant parameters were unaffected regarding chemical composition and ecophysiology although biochar induced a higher efficiency in the plant nitrogen uptake without increasing crop yield.ConclusionsBiochar addition at the highest rate (30 t ha−1) reduced soil-soluble nitrate although N uptake by the plant remained invariable, in turn coupled to no effects on crop productivity. Our study showed that, in a Mediterranean agroecosystem, a wood biochar produced by gasification was unable to increase crop yield, but enhanced soil water retention, decreased the need for N fertilization, and decreased soil-soluble nitrate concentrations, something that could help to mitigate the excessive nitrate levels associated with over-fertilization.

Soil functions as the active force managing diverse biogeochemical processes in tropical forest ecosystems, including storing and recycling nutrients and decomposing organic matter. Anthropogenic activities, mainly deforestation on charcoal production, have substantially disrupted these processes, leading to notable changes in microbial activities, enzyme functions, and the availability and soil nutrient status of the derived savannah in southwestern Nigeria. While there is increasing recognition of charcoal’s impact on soil properties, there remains a noticeable research gap in understanding its specific effects on some associated soil microbial properties, soil enzymes, and micronutrients in charcoal production sites. Our investigation assesses soil nutrition, microbial composition, and some selected associated P and S enzymes under charcoal production sites of derived Savanna, Nigeria. Soil samples were systematically collected at 0–15 cm, 15–30 cm, and 30–45 cm in locations associated with charcoal production (CPS) and non-production sites (NPS). The objective was to assess the microbial biomass content in phosphorus and activity levels of microorganisms in soil, focusing on their production of phosphorus and sulfur enzymes, and to examine the overall nutrient release in these diverse environments. The findings revealed Biomass phosphorus (B p ), Phosphatase (Pho), Thiosulfate dehydrogenase (Tsd), Dimethyl sulfoxide reductase (Dsr), and micronutrients (Mn, Zn, Cu, Co, Fe) were significantly higher in CPS than in NPS. Phytase (Phy) followed a consistent trend at both sites with significant differences among means. Except for copper (Cu), the cobalt (Co), iron (Fe), manganese (Mn), and zinc (Zn) concentrations declined as the soil depth increased in the CPS and NPS across the three locations. This indicates that charcoal production sites in the derived savannah forest of southwestern Nigeria significantly impact soil properties and microbial activities. The higher Bp, Pho, Tsd, and Dsr levels in CPS suggest increased microbial activity and nutrient availability compared to NPS. Additionally, the variation in micronutrient concentrations with soil depth indicates differences in nutrient distribution and availability between the two sites. These findings underscore the importance of further ecosystems to understand the effects of charcoal production on soil ecosystems and to fully develop sustainable management practices that mitigate these impacts.

Soil degradation, climate change, and water scarcity worsen the declining crop productivity. Plastic mulches provide a sustainable solution, yet comprehensive evaluations of their effects, particularly in vegetable production, remain limited. This meta-analysis synthesizes 97 studies and 789 observations across 25 vegetable species to assess the influence of plastic mulch colour on crop yields and soil properties. Ten plastic mulch colors were analyzed: black, blue, green, gray, yellow, transparent, white, silver, brown, and red. Results show that all mulch colors improved crop productivity and soil parameters compared to non-mulched soil. Green (effect size (ES) = 5.73, confidence interval (CI) = 3.92–7.93), transparent (ES = 6.52, CI = 5.17–7.87), and black (ES = 1.95, CI = 1.49–2.42) mulches produced the highest significant increase in yield, plant height, and stem diameter, respectively. The highest reduction in weed biomass occurred with red mulch (ES = -9.04, CI = -13.33–-4.76). Increases in soil temperature and water use efficiency were noted from black (ES = 0.82, CI = 0.69–0.94) and silver (ES = 0.68, CI = -3.16–4.53), while the black (ES = 0.19, CI = 0.03–0.35), blue (ES = 2.62, CI = 0.44–4.80), and gray (ES = 2.03, CI = 0.06–4) mulches exhibited improved soil organic carbon, pH, total nitrogen, available phosphorus, and potassium, respectively. Besides black, the impacts of other colors are still under-explored, which limits the understanding of their effects on soil properties. Further studies are essential, as soil chemical characteristics are essential in agricultural productivity.

Environmental conditions affect crop yield, and water deficit has been highlighted by the negative impact on soybean grain production. Radicial growth in greater volume and depth can be an alternative to minimize losses caused by a lack of water. Therefore, knowledge of how soybean roots behave before the chemical, physical, and biological attributes of the soil can help establish managements that benefit in-depth root growth. The objective was to evaluate the growth of soybean roots in response to chemical, physical, and biological variations in the soil, in different soil locations and depths. Six experiments were conducted in different locations. Soil samples were collected every 5 cm of soil up to 60 cm of soil depth for chemical, physical, and biological analysis. The roots were collected every 5 cm deep up to 45 cm deep from the ground. The six sites presented unsatisfactory values of pH and organic matter, and presented phosphorus, potassium, and calcium at high concentrations in the first centimeters of soil depth. The total porosity of the soil was above 0.50 m 3 m −3 , but the proportion of the volume of macropores, micropores, and cryptopores resulted in soils with resistance to penetration to the roots. Microbial biomass was higher on the soil surface when compared to deeper soil layers, however, the metabolic quotient was higher in soil depth, showing that microorganisms in depth have low ability to incorporate carbon into microbial biomass. Root growth occurred in a greater proportion in the first centimeters of soil-depth, possibly because the soil attributes that favor the root growth is concentrated on the soil surface.