Soil Fertility Research Articles

Plant growth promoting Rhizobacteria for sustainable tomato production

Numerous phosphate solubilizing bacteria (PSB) are found in the rhizosphere, benefiting the host plant in different mechanisms and promoting sustainable agriculture. They improve soil fertility with minimum cost requirements using an eco-friendly approach, which is an essential attribute for small-scale farm production. Thus, isolation, characterization, and evaluation of symbiotic effectiveness are hierarchical procedures to develop bioinoculants. Using a dual (plate and liquid medium) screening technique and a greenhouse trial, four potential PSB strains (Mk-1–25, Mk-13–16, Mk-20–7, and Mk-20–20) were selected from tomato rhizosphere soil. All isolates exhibited the following traits: produced colony clear-zone, lowered liquid medium pH, gram-positive, produced urease and IAA, dissolved substantial P from various substrates, symbiotically effective, and improved tomato growth and yield. Taxonomically, they belong to Bacillus and Priestia species (i.e., Mk-1–25 Bacillus halotolerance, Mk-13–16 Bacillus amyloliquefaciens, Mk-20–7 Bacillus megaterium, and Mk-20–20 Priestia megaterium). Among the current strains, Bacillus halotolerance recorded higher SI (3.11), was able to grow in extreme conditions (10% salt, up to 45 °C), produced HCN and siderophore, and improved tomatoes’ shoot length and weight, in contrast, Mk-20–20 produced HCN, siderophore, was able to fix nitrogen, improved tomato germination, shoot dry weight, and fruit weight. Various P-supplements (Ca3(PO4)2, bonemeal, FePO4, AlPO4, compost, and DAP fertilizer) were added to induce tomato-strain symbiotic interaction; hence, compost substantially promoted the interaction and resulted in higher symbiotic effectiveness. Ca3(PO4)2 was a good media composite preferred by most PSB strains; consequently, a higher concentration (219 µg/ml) of dissolved P was recorded from the liquid medium after 10 days of incubation than other substrates. Based on the data obtained from laboratory and greenhouse trials, the current strains were found to be potential candidate. Future work should confirm their efficacy at the field level using model host crops at different sites to recommend them as farm inputs and biofertilizer.

Dynamics of Soil Properties under Jhum Cultivation: A Review

A staple of many indigenous cultures, shifting agriculture is coming under more and more scrutiny for its role in soil degradation and deforestation, especially in light of climate change. This study investigates the effects of jhum agriculture in Arunachal Pradesh, with a particular emphasis on the detrimental effects on soil qualities and its contribution to deforestation. Along with considerable nutrient loss from frequent forest clearing and burning, jhum farming causes severe soil degradation, including soil erosion and changes in the physical and chemical properties of the soil. In the diverse climates of Arunachal Pradesh, characterized by heavy rainfall, soil fertility and moisture are especially vulnerable. The shortening of fallow periods further destabilizes soil moisture and fertility, despite the potential benefits of carbon dynamics and sequestration during extended fallows. This research underscores the urgent need for sustainable practices, such as improved soil moisture conservation and extended fallow periods, to align traditional agricultural practices with the goals of climate resilience, soil health, and long-term sustainability.

Effect of Artificial Humic Acids Derived from Municipal Sludge on Plant Growth, Soil Fertility, and Dissolved Organic Matter

Due to its high nutrient utilization efficiency, liquid organic fertilizer has become a research hotspot in the field of agricultural planting. Artificial humic acids, which are near-nature products, can be deemed as a green liquid organic fertilizer, but few studies have been reported, which has limited their further application. In this study, artificial humic acids were derived from municipal sludge, and their effect on rice growth, soil fertility, and dissolved organic matter was investigated using multi-chamber root box experiments. The shoot and root biomass of rice can be significantly enhanced by artificial humic acids, and the heavy metal concentration in rice was within safe limits. Artificial humic acids can limit the decrease in soil pH, especially in the far-rhizosphere zone, and improve the distribution of nutrients in the rhizosphere, near-rhizosphere, and far-rhizosphere zones. The use of artificial humic acids led to a significant decrease in soil electrical conductivity. The dissolved organic carbon content in the root zone was significantly increased, and the fluorescence intensity of dissolved organic matter in the rhizosphere was significantly increased. The proportion of specific components of dissolved organic matter was just slightly changed in the rhizosphere and near-rhizosphere zones. Artificial humic acids promoted the humification of dissolved organic matter in the near-rhizosphere and far-rhizosphere zones. The findings indicate that the environmental impact of artificial humic acids is significantly different from conventional chemical fertilizers, and they show huge potential in the agriculture field.

Restoration of soil multifunctional indicators requires more than thirty years in degraded shrubland of a semi-arid mountainous ecosystem

Vegetation degradation in natural environments leads to considerable fluctuations in soil function indicators, particularly in the sensitive and delicate habitats of semi-arid regions. In this study, the dynamic of both litter and soil properties was examined in northern Iran, in sites with Crataegus melanocarpa and Berberis integerrima dominance. The chosen sites have been degraded in 1993 due to exploitation for fuel production. Litter and soil (0–10, 10–20 and 20–30 cm depths) samples were collected in sites that have been degraded [i.e., 10-years post-degradation (2003), 20-years post-degradation (2013), and 30-years post-degradation (2023)]. A site not to exposed to degradation (year 2023) was also included as a control. In total, 48 litter samples (4 study sites × 12 samples) and 144 soil samples (4 study sites × 3 depths × 12 samples) were collected. Our findings showed a significant reduction of approximately 60–70% in the chemical characteristics of the litter, such as phosphorus (P) and magnesium (Mg) after 10-years post-degradation (2003) compared to the control site. Soil fertility indicators were also reduced 2–6 times as a result of habitat degradation. Aligned with this, the biota population in the 10-year post-degradation site showed a decrease of 70–90% with respect to the control. Moreover, the densities of fungi and bacteria decreased by approximately 30%–70% and 45–80% respectively compared to the 30-year post-degraded site. The peak activation of soil enzymes including urease, acid phosphatase, arylsulfatase, and invertase was found in the site that was not subjected to degradation, being 3.5, 5.8, 6.7 and 6.7- times higher in comparison to the 10-year post-degradation site. Overall, the results showed that in the non-degraded ecosystems, the input of plant-based organic matter was accompanied by an increase in soil fertility, organism population and soil function. This pinpoints the importance of protecting plant species in these areas, while in degraded areas planting native species adapted to the region's climate and fertilization could significantly contribute to restoring these areas.

Implementasi Pertanian Berkelanjutan melalui Pembuatan Pupuk Organik Cair di Karot, Kabupaten Manggarai

Excessive use of synthetic fertilizers causes a decrease in soil fertility, which can reduce crop production. Making liquid organic fertilizer (POC) from vegetable and fruit waste can reduce the use of synthetic fertilizers and support sustainable agriculture. The Golo Curu Permai farmer group has never implemented sustainable agriculture. This activity aims to reduce synthetic fertilizers' use to support sustainable agriculture and increase the knowledge and skills of farmer groups in producing liquid organic fertilizers independently. This activity was carried out at the Golo Curu Permai farmer group in Karot Village, Langke Rembong District, Manggarai Regency, with a total of 15 participants and through activity methods in the form of coordination and field surveys, extension, training or demonstration and evaluation. Evaluation is carried out by analyzing the initial test results before training (pre-test) and after training (post-test). The results of this activity show that the knowledge and skills of farmer groups after participating in training in making POC from organic waste increased by 30% from 50% to 85%.

Effects of microbial communities during the cultivation of three salt-tolerant plants in saline-alkali land improvement.

Planting vegetation on saline-alkaline land enhances soil fertility and sustainability by improving salt-alkali tolerance. Different salt-tolerant plant species interact with soil microorganisms, enriching bacterial communities and promoting nutrient availability. In this study, mechanisms affecting microbial communities in severely saline-alkaline soils planted with salt-tolerant plants are investigated. Over 4 years, the potential to cultivate three salt-tolerant plant species (tall wheatgrass Agropyron elongatum, chicory Chicorium intybus, and alfalfa Medicago sativa) in severely saline-alkaline soils is compared with a non-cultivated control. Bacterial and fungal communities were characterized through high-throughput sequencing of the 16S rRNA gene V3-V4 region and the V4 region, respectively. Cultivating these three plant species significantly reduces soil electrical conductivity values. Chicory cultivation notably increased soil nutrients, bacterial alpha richness, and fungal alpha diversity and richness. Microbial community structures vary considerably between the control and treatments, significantly correlating with the soil quality index. This index enables an assessment of soil health and fertility by integrating variables such as nutrient content, microbial diversity, and salinity levels. In each plant treatment, particularly alfalfa, the relative abundances of fungal pathogens like Neocosmospora and Gibellulopsis increase, which may pose risks to subsequent crops such as tomatoes, requiring careful consideration in future planting decisions. Conversely, in alfalfa and tall wheatgrass treatments, there was an increase in the relative abundances of fungal genera (e.g., Alternaria and Podospora) that antagonize fungal pathogens, while Paraphoma increased in the chicory treatment. The strong relationship between microorganisms and the rise in pathogen-resistant fungi across different plant treatments highlights robust and beneficial structural characteristics. According to soil quality index scores, each treatment, but especially that of chicory, improved the severely saline-alkaline soil environment.

Evaluating the Impact of Integrated Nutrient Management Practices on Land Productivity, Crop Residue Decomposition and Abundance of Soil Organisms in a Banana Plantation in Sri Lanka

The fertilization practices heavily influence the decomposition rate of organic materials added to soil. Hence, the nutrient management strategies that aim to improve crop yields may not necessarily support organic carbon accumulation in soil and overall soil fertility. This study investigated how land productivity, crop residue decomposition and diversity of soil organisms were affected by the combined use of chemical fertilizers (CF) and poultry manure (PM) in a banana plantation in Buttala, Sri Lanka. Banana yield, soil properties and decomposition of crop residues were studied in six treatments as, CF1+PM1, CF1+PM2, CF1+PM3, CF2 +PM1, CF2+PM2, and CF2+PM3. CF1 and CF2 correspond with 75% and 100% of recommended CF application rate. PM1, PM2 and PM3 correspond with PM application rates of 0, 2.5 and 5 kg/plant. Crop residue decomposition was assessed using litter bags containing two litter materials as banana pseudo-stem pieces and banana leaves and placed at two depths (surface and at 7.5 cm depth). Litter bags were recovered at 17, 31 and 45 days after placement (DAP) and weight loss of crop residues was determined. The application of poultry manure significantly increased (P<0.01) banana yield at first harvest and decreased (P<0.1) bulk density. Type of material and time of exposure to decomposition had significant effects (P<0.05) on litter decomposition but depth of placement and nutrient management strategy had no significant effect (P>0.05) on decomposition. By 45 DAP pseudo-stems were degraded more than leaves (67.47±13.99 % and 46.90±5.76 %, respectively). The abundance of culturable bacteria and cellulose decomposers in soil and the abundance of soil fauna in decomposing litter were significantly (P<0.1) increased with the PM application to soil. In conclusion, in the studied banana plantation, incorporation of PM in nutrient management increased land productivity and had positive impact on some soil properties, which are important determinants of soil fertility but did not register any effects on crop residue decomposition during the study period.

Multi-year performance of white clover oversown into eastern North Island hill country

Animal performance on summer-dry North Island hill country pastures is limited by soil fertility and the challenge of establishing and retaining a strong legume base in swards on steeper slopes. However, this can be overcome by 1. selecting legume species adapted to the various slope, aspect and soil type combinations; and 2. following well-recognised establishment and management techniques developed in the 1980s. We broadcast white clover in two large southerly aspect paddocks on Tangihanga Station, Gisborne, in the autumn of 2019. Establishment methods involved resident pasture control by hard grazing and selective herbicide to supress dominant low-fertility grasses, broadcasting at high sowing rates and trampling of seed with sheep. We followed white clover persistence and animal performance over the subsequent 5 seasons of rotational cattle grazing with heifers and steers, in comparison with adjacent unsown paddocks. The cost of establishment was c. $220/ha. White clover abundance remained high throughout the 5 years, between 25-40% of cover, compared with 7-17% in unsown paddocks. This increase in clover content of the pastures translated into both increased stocking rates and per head growth rates, with overall annual LWG increasing by 67-169% depending on season. The investment was paid back within the first year.

PENGARUH LARUTAN PUPUK HAYATI ENDOMIKORIZA ASAL AKAR MERANTI TERHADAP PERTUMBUHAN DAN PRODUKSI TANAMAN KANGKUNG

Water spinach (Ipomoea sp) is a plant that is widely consumed by people as a vegetable because it is cheap and easy to cultivate. The main problems in growing water spinach are soil fertility and attack by plant pests and diseases. To increase production from kale farming, farmers generally use inorganic fertilizers such as NPK which in reality can cause environmental pollution. For this reason, various efforts to use organic (environmentally friendly) fertilizers such as fungal and bacterial biofertilizers remain the focus of research to date. Mycorrhizal fungi are known to have quite a lot of benefits for plants, especially in providing phosphate and nitrogen nutrients for host plants. In the forestry sector, it is known that the roots of meranti plants (Shorea sp) and the roots of pine plants (Pinus sp) are natural hosts for the growth and development of mycorrhizal fungi. Therefore, the aim of this research is to determine the effect of endomycorrhizal solution fertilizer from meranti roots on the growth and production of water spinach plants. The results of the research show that the endomycorrhizal biofertilizer solution from meranti roots produces growth and production of water spinach plants that are not significantly different from the NPK fertilizer treatment, so from an environmental safety aspect, it is proposed that it is better to use endomycorrhizal biofertilizer because it is environmentally friendly.

The Productivity of Lumbricus rubellus Earthworms in Cow Manure Media with the Addition of Cricket Manure

Earthworms are one of the animals used as indicators to assess soil quality and fertility. In earthworm cultivation, several factors affect the life of earthworms, including temperature, pH, moisture, nutrient content, and media texture. This study aims to evaluate the productivity of earthworms (Lumbricus rubellus) in a mixed medium of cow manure and cricket manure. The method used in this study is a Completely Randomized Design (CRD) with 6 treatments and 3 replications, along with a Tukey posthoc test. The results showed that the addition of cricket manure to cow manure as a cultivation medium could increase earthworm productivity. The use of 90% cow manure with the addition of 10% cricket manure resulted in an average weight increase of 17 g, an average of 94 cocoons, and an average media reduction of 260.50 g. The addition of more than 10% cricket manure to cow manure could reduce earthworm productivity.

IMPACT OF FARMERS PERCPTION OF USING ORGANIC MANURE ON THE ONION PRODUCTION IN KUDAN LOCAL GOVERNMENT AREA OF KADUNA STATE, NIGERIA

This study assessed the impacts of farmers’ perception of using organic manure on the onion production in Kudan Local Government Area (LGA) of Kaduna State, Nigeria. The specific objectives were to: describe the socio-economic characteristics of onion farmers, assess the impacts of using organic manure on income and productivity, and perception of farmers in using organic manure. A multi-stage sampling procedure was employed to select 200 respondents for the study. Primary data were collected using structured questionnaires and analyzed through descriptive and inferential statistics. The findings revealed that the majority of respondents were male (89.5%) with a mean age of 40.76 years, and most households comprised 10-15 members. Compost manure (53%) was the most widely used organic input due to its availability and effectiveness in enhancing soil fertility. The results indicated that the use of organic manure had a positive impact on the productivity and income of onion farmers. Key socio-economic factors influencing productivity and income-included education, access to extension services where farmers received training on organic manure use, farming experience and the quantity of manure applied. For sustainability and continuous use of organic manure in Kudan LGA. Improving access to organic inputs, enhancing transportation infrastructure, and providing targeted education and training on organic farming practices are critical. These recommendations align with recent policies promoting sustainable agriculture in Nigeria.

Biochar as a strategy to manage stem rot disease of groundnut incited by Sclerotium rolfsii

Due to the pathogen’s ability to survive in the soil for longer durations, soil-borne diseases are often difficult to control. This study investigates the multifaceted impacts of biochar on the management of stem rot disease in groundnut and its influence on soil properties and microbial communities. The effects of biochar at different concentrations, such as 0%, 1%, 3%, and 5% on groundnut stem rot disease incited by Sclerotium rolfsii were evaluated thoroughly. Under laboratory conditions, biochar exhibited no direct inhibitory effects on S. rolfsii at varying concentrations but revealed an indirect suppression of sclerotial body production, suggesting a concentration-dependent influence on pathogen resting structures. Further, it was observed that biochar treatments effectively delayed symptom onset and reduced disease progression in groundnut plants, with significant variation observed among genotypes and biochar concentrations. Notably, interactions involving genotypes ICGV 171002 and ICGV 181035 with BC2 + Sr (3% conc. of biochar + S. rolfsii) and BC3 + Sr (5% conc. of biochar + S. rolfsii) treatments showed superior efficacy in disease reduction under controlled conditions. Field evaluations confirmed these findings, highlighting genotype-specific responses to biochar treatments. However, no significant difference was observed between BC2 + Sr (3%) and BC3 + Sr (5%) treatments in managing stem rot disease compared to controls. Biochar application significantly increased soil nutrient levels, including nitrogen, phosphorus, and potassium, and increased soil organic matter content, EC, pH, emphasizing its potential to improve soil fertility. Overall, these findings highlight the potential benefits of biochar for sustainable agriculture through disease management, soil nutrient enrichment, and microbial modulation, warranting further investigation into optimal application strategies across different agricultural contexts.

Effects of Fire on Physical and Chemical Properties of Soil in Fwangnin Bokkos District, Nigeria

Background: Vegetation burning, a common agricultural practice, has both positive and negative effects on soil fertility. Soil quality, which is critical for ecosystems, shapes biodiversity and productivity, while increased temperatures from vegetation burning can alter conditions for seed germination by reducing nutrient availability. Objectives: The study aims to assess the impacts of vegetation burning on soil fertility in Fwangnin, Bokkos, Nigeria, through experimental investigation of the effects of burning on both the chemical and physical properties of soil. The results are expected to contribute to the development of adaptive fire management strategies in land use, and the results will also help monitor soil changes in order to maintain long-term soil fertility. Methods: Using purposive sampling, four 500-gram soil samples were taken from 0 – 15 cm depth in burned and unburned areas. The samples were analysed for pH, electrical conductivity (EC), organic carbon (OC), organic matter (OM), nitrogen (N), phosphorus (P), and cation exchange capacity (CEC). Traditional well-proven methods were used for the analysis. Results: It was found that the pH of the burnt soil samples ranged from 6.10 to 5.90, while that of the unburnt samples ranged from 5.73 to 5.81; a significant increase in pH occurs at higher combustion temperatures, which increases the alkalinity of the soil due to the alkaline properties of ash. The electrical conductivity value for the samples in the burnt areas was significantly higher (0.08 mS/cm and 0.10 mS/cm) compared to the healthy soil (0.07 mS/cm and 0.09 mS/cm), which can be explained by the release of mineral ions due to the combustion of organic matter. The study found a decrease in organic carbon content in the burnt soil, a significant deficiency of nitrogen and a decrease in the cation exchange capacity, which contributes to the depletion of the fertile layer and a decrease in the ability of the soil to retain essential nutrients. Increased levels of organic phosphorus were also found in burnt soils, which contributes to improved crop growth and increased yields in the short term. Conclusion: The current study has filled the gap in deep understanding of the impact of vegetation burning on the fertile properties of agricultural soils. Namely, it has been experimentally established and confirmed by the results of similar studies and statistical analysis that while vegetation burning remains a common agricultural practice in Fwangnin, the long-term implications for soil fertility, structure, and ecosystem health are significant. The soil degradation observed in this study suggests that continued reliance on burning as a land-clearing method may undermine agricultural productivity and environmental integrity over time.

Dynamics of major plant nutrients and enzymatic activities in soil influenced by application of biochar and organic waste.

The concentration of salt ions influences the availability and plant nutrients dynamics in the soil. Proper management of these ions can enhance food grain production, helping to feed the growing population. In this experiment, nine fertility combinations were followed to enhance the soil organic carbon and reduce the salt toxicity and monitor the plant nutrient availability. An incubation experiment was conducted for the period of one year with different organic soil amendments in combinations including biochar (BC), pressmud (PM), and farm yard manure (FYM) as follow: T1-control, T2-RDF, T3-FYM (10 t/ha), T4-PM (10 t/ha), T5-BC (10 t/ha), T6-FYM (5 t/ha) + PM (5 t/ha), T7-FYM (5 t/ha) + BC (5 t/ha), T8-PM (5 t/ha) + BC (5 t/ha), T9-FYM (5 t/ha) + BC (2.5 t/ha) + PM (2.5 t/ha). Results showed that addition of organic substance (10 t/ha) significantly (p < 0.05) affected soil pH and electric conductivity. Plant nutrient availability (N, K, and S) was also influenced by application of organic substance (10 t/ha). Organic C and available N were recorded the highest in the treatment T7 (FYM-5 t/ha + BC -5 t/ha); whereas, the highest available K and S were observed in treatment T5 (BC-10 t/ha). The microbial soil fertility indicators (alkaline phosphatases, arylsulphatase, dehydrogenase activity and microbial biomass carbon) were measured the highest in FYM (5 t/ha) + BC (5 t/ha) applied treatment. In conclusion, application of organic substance 10 t/ha (biochar alone or with FYM) improved the plant nutrient availability and soil microbial activities in saline soil. It could be a suitable option for enhancing the soil fertility in saline soils.

Impact of biogas adoption on household energy use and livelihood improvement in Kenya: an overview on a roadmap toward sustainability

Purpose This study assesses the impact of biogas adoption on household energy use and livelihood improvement. Also, this study aims to clarify the benefits of biogas adoption as a pathway to sustainable household energy. Design/methodology/approach The study explored the benefits of adopting biogas uptake. Fourteen sustainability indicators were identified, validated and categorized. Findings Adopting biogas technology provides numerous benefits, including better air quality, reduced deforestation and lower greenhouse gas emissions. Households can replace up to 4.5 tons of wood fuel, cutting CO2 emissions by around 6.75 tons annually. This shift saves approximately US$25 (Ksh.3223) monthly and frees up 45.5 h per week, enabling families to pursue additional income-generating activities. Biogas also produces digestate, a natural fertilizer that improves soil fertility, water retention and reduces erosion while minimizing the need for chemical fertilizers. Integrating biogas in livestock housing reduces odors, pathogens and methane emissions. Research limitations/implications The findings demonstrate numerous social, economic and environmental implications of biogas use. Social implications Health benefits include lower exposure to smoke and particulate matter, particularly benefiting women and children by reducing respiratory issues, improving lighting and enhancing educational opportunities. Biogas further improves hygiene, promotes cleanliness, strengthens energy security and alleviates energy poverty. In addition, the construction, operation and maintenance of biogas systems create jobs, and the use of digestate enhances agricultural productivity. Originality/value This study provides a unique and thorough analysis of the benefits of biogas, offering valuable insights and outlining a sustainable approach.

Phytoremediation of Mercury Contamination: Bibliometric Analysis

Mercury is classified as one of the world’s most toxic and dangerous pollutants as it tends to bioaccumulate and biomagnify within the trophic chain and is persistent. Various approaches are available to remediate Hg-affected sites including phytoremediation, which includes the use of plants to clean up contaminated environments. The phytoremediation of mercury contamination is attracting increasing attention because of its advantages: it is environmentally friendly, inexpensive, simple, and can improve soil fertility. In this report, VOSviewer (version 1.6.1) and Bibliometrix (version 4.16) software were used to analyze 457 and 697 documents published from 2000 to 2023, retrieved from the databases WoS and Scopus, respectively. China, India, the United States, and Spain were the top four most productive countries. The largest topic area was environmental sciences, and the Chinese Academy of Sciences was the organization that contributed the most to the overall number of publications. The keywords with the highest frequency excluding phytoremediation and mercury in WoS were heavy metals, accumulation, cadmium, soils, and phytoextraction. In Scopus, the most frequent keywords were bioremediation, heavy metals, soil pollution, bioaccumulation, biodegradation, and environmental. From the above analysis, we concluded that future research should focus on (1) finding native plants, (2) genetic engineering applications, (3) increasing remediation ability through assisted phytoremediation, and (4) the detoxification mechanism of mercury. This study provides insights into trending themes and serves as a reference for future research.

Carbon Sequestration in a Changing Climate: Management Techniques and Strategic Solutions

Carbon sequestration in agriculture plays a critical role in mitigating climate change by capturing and storing atmospheric carbon dioxide (CO2) in soil and biomass. This process involves various strategies and management practices aimed at enhancing soil organic carbon (SOC) levels while maintaining or improving agricultural productivity. Key strategies include no-tillage or reduced tillage, which minimizes soil disturbance and promotes residue retention, thus slowing down decomposition and enhancing carbon storage. Crop rotation and the use of cover crops further contribute to carbon sequestration by diversifying root structures and improving soil health. Organic farming practices, such as applying farmyard manure and compost, provide essential organic matter that enriches soil quality and increases carbon retention. Additionally, the incorporation of deep-rooted plants and biochar enhances carbon storage in deeper soil layers, making them more resilient to climate variability. The integration of these practices not only sequesters carbon but also improves soil fertility, water retention, and overall ecosystem health. Effective management of carbon sequestration in agricultural systems requires a holistic approach that considers local conditions, crop diversity, and sustainable land use practices. By adopting these strategies, agriculture can become a significant carbon sink, contributing to global efforts to reduce atmospheric CO2 concentrations while ensuring food security and environmental sustainability.

Metagenomic Analysis Reveals the Effects of Different Land Use Types on Functional Soil Phosphorus Cycling: A Case Study of the Yellow River Alluvial Plain

Phosphorus (P) is a crucial limiting nutrient in soil ecosystems, significantly influencing soil fertility and plant productivity. Soil microorganisms adapt to phosphorus deficiency and enhance soil phosphorus effectiveness through various mechanisms, which are notably influenced by land use practices. This study examined the impact of different land use types (long-term continuous maize farmland, abandoned evolving grassland, artificial tamarisk forests, artificial ash forests, and wetlands) on soil phosphorus-cycling functional genes within the Tanyang Forest Farm in a typical region of the Yellow River alluvial plain using macro genome sequencing technology. The gene cluster related to inorganic phosphorus solubilization and organic phosphorus mineralization exhibited the highest relative abundance across different land use types (2.24 × 10−3), followed by the gene cluster associated with phosphorus transport and uptake (1.42 × 10−3), with the lowest relative abundance observed for the P-starvation response regulation gene cluster (5.52 × 10−4). Significant differences were found in the physical and chemical properties of the soils and the relative abundance of phosphorus-cycling functional genes among various land use types. The lowest relative abundance of soil phosphorus-cycling functional genes was observed in forestland, with both forestland types showing significantly lower gene abundance compared to wetland, farmland, and grassland. Correlation analysis and redundancy analysis (RDA) revealed a significant relationship between soil physicochemical properties and soil phosphorus-cycling functional genes, with ammonium nitrogen, organic carbon, total nitrogen, and pH being the main environmental factors influencing the abundance of these genes, explaining 70% of the variation in their relative abundance. Our study reveals land use’s impact on soil phosphorus-cycling genes, offering genetic insights into microbial responses to land use changes.

Soil Biocrusts May Exert a Legacy Impact on the Rhizosphere Microbial Community of Plant Crops

Biological soil crusts (biocrusts) play important ecological roles in many ecosystems, but their legacy effects in subtropical agricultural systems are poorly understood. This study investigated how biocrusts impact soil properties and subsequent crop rhizosphere microbiomes. Soil with (+BC) and without (−BC) biocrusts was cultivated and used to grow pepper plants in a greenhouse experiment. Soil physicochemical properties and microbial communities in the pre-planting soils, and microbial communities in crop rhizosphere were analyzed. The results showed that soils with biocrust had significantly higher organic matter, total nitrogen, alkaline hydrolyzable nitrogen, total phosphorus, and total potassium content. Microbial community structures differed significantly among treatments, with −BC soils exhibiting higher microbial diversity in pre-planting conditions, while +BC soils showed higher diversity in crop rhizosphere soils. Soil properties, especially extractable potassium, total nitrogen, and organic matter content, were significantly correlated with rhizosphere microbial community structure. Additionally, our results showed that the first principal coordinate (PCoA1) of soil microbial community structure was significantly correlated with rhizosphere microbiota. Multiple regression analysis revealed that pre-planting soil microbial diversity indices and certain soil physicochemical properties could predict crop rhizosphere soil microbial diversity. Our results demonstrate that biocrusts can enhance soil fertility and alter microbial communities in subtropical agricultural soils, with persistent effects on the crop rhizosphere microbiome. This study provides new insights into the ecological legacy of biocrusts in managed subtropical ecosystems and their potential agricultural implications.

Soil micro-food web composition determines soil fertility and crop growth

Soil micro-food web composition determines soil fertility and crop growth