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Improving the Soil Fertility Based on Soil Texture and Climate Change
... Computer-based systems that allow users to make complex decisions using data, analytical models, and related knowledge. DSS integrates various information and resources in agriculture, such as weather data, soil conditions, cropping patterns, and market prices, to advise farmers or policymakers [18]. In general, the main objectives of DSS in agriculture are to improve operational efficiency, optimize agricultural output, minimize risk of losses, and support the long-term sustainability of food production. ...
Selecting the right crop for a particular land condition is one of the significant challenges in the agricultural sector. Each crop type has specific needs related to environmental factors such as soil type, pH, humidity, rainfall, and temperature. Mistakes in determining the appropriate crop type can result in decreased production, wastage of resources, and losses for farmers. This paper aims to determine the best model for use as a knowledge base to choose suitable plants for soil conditions. Machine learning algorithms were used to identify patterns of relationships between land conditions and the success of certain crop types to assist in selecting suitable crops and then made a knowledge-based decision support system. Algorithms such as Decision Tree, Random Forest, Support Vector Machine (SVM), and k-Nearest Neighbor (k-NN) have been applied to solve this problem. In this paper, 30 experiments were conducted to test the stability of the model in determining suitable crops based on land conditions. The results of the experiments showed that the Support Vector Machine (SVM) has a more stable performance than other algorithms, with accuracy values of mean and standard deviation of 1 and 0, respectively.
... ML-powered crop recommendation systems evaluate soil quality together with climate information and historical yield data to supply sustainable recommendations that suit individual farmer needs. The systems optimize crop decision-making while resource management for better agricultural productivity [5]. To achieve sustainable agriculture, it becomes essential to concentrate on maintaining healthy soil conditions because these conditions depend on NPK levels and pH values and climate factors. ...
Global economic expansion and food security rely heavily on agriculture since it influences various systems that support millions of people and ecosystems across the world. Evolution in food consumption has become vital because of accelerating demand which stems from population expansion alongside urban transitions. We present a consolidated agricultural technology solution that uses computer vision together with machine learning and top-tier data analysis methods to handle agricultural necessities. The platform contains three major components including a crop recommendation system which makes crop suggestions based on soil analysis together with a soil analysis module that uses advanced data processing for accurate prediction needs and personalized recommendations as well as a Convolutional Neural Network (CNN) model to analyze crop leaf images for disease identification. Weather-based crop recommendations along with market price predictions appear within the system to assist farmers in launching their yield according to market conditions. This system allows farmers to execute timely decisions through accurate predictions as well as a single-user platform which unifies all models using a straightforward interface for improved crop management and sustainable productivity.
The twenty-first century marks a significant shift in soil fertility evaluation, driven by advancements in pedometrics and
Digital Soil Mapping (DSM). Pedometrics introduces quantitative methods to assess soil variability using statistical and
geostatistical techniques, enhancing understanding of soil properties. DSM builds on this by creating high-resolution predic
tive maps, offering valuable data for researchers and practitioners. An in-depth bibliometric analysis on the Scopus platform
(2000–2023) revealed 133 articles on pedometrics and an impressive 1,172 on DSM, underscoring growing interest in these
technologies.The integration of Geographic Information Systems (GIS) and Remote Sensing (RS) has further advanced
these fields, enabling extensive geospatial data collection and real-time monitoring. Machine Learning (ML) has also been
transformative, facilitating complex pattern recognition and predictive analysis to improve soil fertility mapping and manage
ment. A review of 364 studies from 2000 to 2023 highlights the development and impact of these technologies, detailing their
advantages and limitations. The surge in related publications and citations since 2000 reflects a rising interest in sustainable
agriculture and environmental management. Significant milestones occurred in 2019 and 2022 with the introduction of new
soil management technologies, while RS and GIS technologies surged in popularity in 2016 and 2020, driven by satellite
advancements like Sentinel and Landsat. The capabilities of ML techniques were notably effective in 2019 and 2022. Coun
tries like India, China, and Iran have been key adopters, transforming soil fertility mapping into a non-invasive, large-scale
process that enhances agricultural decision-making.This transition emphasizes the value of specialized publications that
advocate for GIS, RS, pedometrics, and DSM, which are crucial for addressing environmental challenges. In conclusion,
integrating traditional and advanced methodologies provides a holistic, adaptable approach to sustainable land management,
supporting data-driven decisions to enhance agricultural and environmental sustainability.
Keywords Soil fertility mapping · Remote sensing · Geographic Information Systems · Machine Learning · Pedometrics ·
Digital Soil Mapping · Sustainable land management · Traditional methodologie
Tomatoes are a globally cultivated and popular vegetable. The output and quality of tomatoes are significantly influenced by the use of organic fertilizers. It was discovered that organic fertilizers increase tomato productivity and improve fruit quality. The influence of organic fertilizers on tomato yield and quality is shown to be complex and dependent on soil organic matter, total soil nitrogen, organic fertilizers kinds, and other variables. In this review paper, we evaluated 769 data sets from 107 research papers and determined that organic fertilizers can enhance the tomato yield by 42.18%. Compared to the control group, soluble solids, soluble sugar, lycopene, vitamin C, and nitrate were raised by 11.86%, 42.18%, 23.95%, 18.97%, and 8.36%, respectively. In general, the soil organic matter >20 g·kg⁻¹ and organic fertilizers significantly improved the tomato sugar/acid content ratio and VC, whereas under total soil nitrogen >1 g·kg⁻¹, organic fertilizers had significant differences in tomato soluble solids, soluble sugar, lycopene, and vitamin C, with different organic-fertilizer types having different effects on tomato quality. When comparing animal and plant organic fertilizers to other forms of organic fertilizers, we observed that tomato quality varied significantly. We also evaluated the impact of different cultivation methods, soil organic matter, total soil nitrogen, soil pH, and types of organic fertilizers on the tomato yield and quality. The results gave valuable information and direction for the use of organic fertilizers in greenhouse production.
Overuse of chemical fertilizers to maintain tea production has caused many adverse effects in tea plantations and largely hampers the sustainable development of the tea industry. Applying bio-organic fertilizer (BOF) to achieve the goal of sustainable agriculture has become popular because of its advantages, such as its pollution-free nature, considerable amount of beneficial microbes and soil-friendly organic materials. However, the effects of BOF application on tea plantation soil remain an open question. Herein, we carried out a 3-year pot experiment with four treatments, including control without fertilization (CK), 100% chemical fertilizer (CF), 50% chemical fertilizer +50% BOF (CFOF) and 100% BOF (OF), to explore the effects of BOF application on soil fertility and bacterial community in tea plantations. The results showed that BOF application could increase soil fertility in both bulk and rhizosphere soils and improve the biomass of tea leaves. In addition, the nutrient level change caused by BOF application significantly changed bacterial community diversity and composition and accounted for 74.91% of the community variation. CFOF and OF treatments significantly increased the bacterial Chao1 and Shannon indices compared to CF treatment (p < 0.05). Moreover, bacterial community composition was dominated by Betaproteobacteria (46.88%), Acidobacteria (11.29%), Alphaproteobacteria (9.69%) and Gammaproteobacteria (9.59%). BOF application increased the relative abundance of Alphaproteobacteria, Acidobacteria, Deltaproteobacteria and planctomycetes and decreased the relative abundance of Betaproteobacteria (p < 0.05). Furthermore, bacterial function prediction revealed that BOF application improved the N and C cycling processes and enhanced the co-occurrence network complexity in the bulk soils. Bacterial community functions and co-occurrence networks in the rhizosphere did not show similar results, indicating that rhizosphere bacterial communities were more affected by the rhizosphere effect than BOF application. All these findings verified our hypothesis that applying BOF in tea plantations could increase the biomass of tea plants by improving soil fertility and influencing the soil bacterial function groups. In summary, we suggested that BOF application could be a promising way to achieve the sustainable development of the tea industry.
Cover crops (CCs) are a promising and sustainable agronomic practice to ameliorate soil health and crop performances. However, the complex of relationships between CCs, the soil, and the plant nutritional status has been little investigated. In this article, for the first time, we critically review, under a holistic approach, the reciprocal relationships between CCs and the soil physical and hydraulic properties, microbial, and faunal communities, soil nutrient availability, and plant nutritional status in temperate climates. For each of these topics, we report the current state of understanding, the influence of CC management options and suggested strategies, thus including both fundamental and applied aspects. In addition, we provide a detailed focus on the history of CCs and a list of the main temperate CCs. Cover cropping is a helpful practice in improving the physical, chemical, and biological soil properties, optimizing nutrient use efficiency and reducing the dependency of crops on external supplies of nutrients. The interactions between CCs and the nutritional status of soil and plants are complex and dynamic. Their understanding could be useful to set up an appropriate and site-specific management of fertilization. Management options play a key role in developing an effective and context-specific cover cropping.
The use of carbon nanoparticles (CNPs) as a fertilizer synergist to enhance crop growth has attracted increasing interest. However, current understanding about plant growth and soil response to CNPs is limited. In the present study, we investigated the effects of CNPs at different application rates on soil properties, the plant growth and nutrient use efficiency (NUE) of corn (Zea mays L.) in two agricultural soils (Spodosol and Alfisol). The results showed that CNPs affected corn growth in a dose-dependent manner, augmenting and retarding growth at low and at high concentrations, respectively. The amendment at the optimal rate of 200 mg CNPs kg−1 significantly enhanced corn growth as indicated by improved plant height, biomass yield, nutrient uptake and nutrient use efficiency, which could be explained by the higher availability of phosphorus and nitrogen in the amended soils. The application of CNPs largely stimulated soil urease activity irrespectively of soil types. However, the responses of dehydrogenase and phosphatase to CNPs were dose dependent; their activity significantly increased with the increasing application rates of CNPs up to 200 mg kg−1 but declined at higher rates (>400 mg kg−1). These findings have important implications in the field application of CNPs for enhancing nutrient use efficiency and crop production in tropical/subtropical regions.
High food demand for the world's teeming population necessitates the intensification of crop production in
modern agriculture, which requires the extensive use of synthetic fertilizers for higher crop yield. The excessive
use of chemical fertilizers, despite the high nutrients contents and ability to grow crops faster, discovered to be
dangerous to the health and environment besides polluting the groundwater and atmosphere in the future. The
alternative to these, biofertilizers arose today due to their attributes towards eco-friendly, cost-effective, and easy
to apply in the agricultural field. Biofertilizers are a batch of diverse microorganisms, which can induce plant
growth-promotion activities along with soil health, even under abiotic stress conditions. Biofertilizers maybe
plant growth-promoting rhizobacteria, arbuscular mycorrhizal fungi, and as well as the consortia of other
beneficial microbes. Biofertilizers can sustain plant growth performance, even in a challenging environment. The
performance of perfect-candidate-biofertilizer in the agricultural field depends on crop type, properties of inoculants,
technical background, and environmental condition. Biofertilizers can, directly or indirectly, help in
attaining food security compared to the harmful effect of chemical fertilizers. A direct mechanism of Biofertilizers
refers to phyto-stimulation and nutrient mobility, while an indirect mechanism poses bio-control activity.
Direct mechanisms involve phytohormone production and phosphate, potassium, zinc, etc. solubilization.
While, indirect-mechanism is HCN production, siderophore production, antibiotic production, etc. The present
review elucidates the diversity of microbial inoculants (biofertilizers), their impacts on agricultural production
through rising soil fertility, and overall crop yield. In line with related literature worked out by different
researchers.
Sandy soil often has low soil organic matter (SOM) content, cation exchange capacity (CEC), and water storage levels. Sandy soil requires specific management techniques to improve soil quality. The purpose of this study was to evaluate chemical characteristics and microbial activity of sandy soil, as well as the effects of different rotation systems on crop yield in these environments. The treatments consisted of cultivation with cover crops in the off-season. The following cover crop treatments were used: fallow, a single grass species (SG), two grass species (G + G), mixture of three or more crop species (MIX), and a grass and legume combination (G + L). Corn and sorghum yields were highest with the fallow treatment. Cotton yield was highest with fallow and G + G treatments. Soybean yield was lowest with the SG treatment. The use of SG resulted in the highest SOM content in the 0–10 cm layer. Phosphorus (P) content was highest in treatments with the lowest biomass content (fallow and G + L); potassium content and CEC levels were highest in treatments with cover crops. The G + L resulted in levels of dehydrogenase and enzyme activity (DEA) that were 50% higher than the fallow. When compared with the fallow, the MIX increased microbial biomass carbon (MBC) and nitrogen (MBN) by 66 and 90%, respectively. The implementation of cover crop systems in sandy soil under no-till improved microbial soil activity even in the first year, but benefits to yield and soil chemistry occurred only after the third year of cultivation.
Farmyard manure, an amendment traditionally used for improving the fertility of sandy soils in arid climates, is becoming scarce and expensive. Its shortage makes it necessary to evaluate, at field scale, the suitability and medium-term performance of other cheap, highly available substitutes. A field trial was established to analyze the effects of a single application of three organic residues on barley yield and nutrient uptake and selected soil properties after two consecutive harvests. Municipal solid waste compost (MSWC), sewage sludge compost (SSC) and farmyard manure (FYM) were tested at rates of 0, 20, 40 and 60 t ha⁻¹. Adding all three organic amendments increased organic matter, cation exchange capacity and available P, Ca, Mg and K in the soil, the grain yield (up to 51%), and the barley plants’ nutrient contents. After the second harvest, a positive residual effect of the amendment was observed in plant yield (up to 77%) and nutrient contents. MSWC and SSC induced slight increases on the extractable fractions (BCR protocol) of Co, Cu and Ni, relative to the unamended soil. The results demonstrate the positive immediate and residual effect of the amendments evaluated as fertilizers for agricultural purposes.
An exponential increase in the human population has drastically reduced the length of fallow period (<5 years) in widely spread shifting cultivation (Jhum). This has increased the invasion of weeds and decreased soil fertility and crop productivity, and consequently raised concern of food security for the local farming communities. The present study was conducted in two jhum fallows (FL-10 and FL-15) to understand the response of fallow length and applications of indigenous soil microbes and rock phosphate on the levels of soil fertility and crop productivity. The results showed greater soil physicochemical properties in FL-15 compared to FL-10. Burning significantly increased the levels of soil pH, avail P, avail N in the soil, whereas, the same decreased the levels of soil C, MBC and SM in both the sites. Among treatments, the synergistic effect of rock phosphate and microbial inocula showed greater improvement in soil biochemical properties, and showed a climactic increase over control in crop productivity and rice yield in all sites. Maximum rice grain yield and productivity was recorded in FL-15 followed by FL-10. This study concludes that a mixture of rock phosphate and microbial inocula from the rhizosphere soil of early regenerating plant is effective in increasing soil fertility and crop productivity, and can be used as an important tool to sustain crop productivity and food security in the region.
PurposeThis investigation assessed the responses of soil fertility, enzyme activity, and microbial community diversity to soil texture and land use type.Materials and methodsThe tested soils included five soil textures (sandy loam, medium loam, heavy loam, light clay, and medium clay soils) with two land use types (uncultivated and paddy soils) in the coastal zone of Zhejiang Province, China.Results and discussionSoil texture had a significant effect on soil pH, electrical conductivity (EC), organic carbon (OC), total nitrogen (TN), available nitrogen (AN), phosphorus (AP) and potassium (AK), catalase and protease activities, total phospholipid fatty acids (PLFAs), bacterial and actinomycetes PLFAs, and microbial diversity (MD). The clay content was significantly positively correlated to soil EC, OC, TN, AN, AP, AK, catalase activity, total PLFAs, bacterial and actinomycetes PLFAs, and MD but significantly negatively associated with soil pH and protease activity. Land use type also had significantly influenced soil pH, EC, OC, TN, AN, AP, AK, catalase, protease and urease activities, total PLFAs, bacterial, actinomycetes, and fungal PLFAs, and MD. The paddy soil had higher OC, TN, AN, AP, catalase, protease and urease activities, total PLFAs, bacterial and actinomycetes PLFAs, and MD but lower soil pH, EC, and AK than the uncultivated soil. The interaction with soil texture and land use type had significantly affected soil pH, EC, OC, TN, AN, AP, AK, catalase and protease activities, total PLFAs, bacterial and actinomycetes PLFAs, and MD.Conclusions
Soil texture and land use type could be considered important factors in improving soil fertility, enzyme activity, and microbial diversity in coastal saline soils.
Agriculture is one of the largest contributors to greenhouse gas emissions, derived from livestock farming (enteric fermentation and manure management) and emissions from agricultural soils (i.e. application of excessive N fertilizers and decomposition of organic material). The review covers contribution of integrated fertility management to mitigate climate change and sustain agricultural production. Combined application of farmyard manure and mineral fertilizer is very economical than sole NP application in maintaining sustainable agricultural productivity. Maximum sustained crop production (2.88 t/ha) was obtained when 69 kg of NP fertilizer was applied with 10 t/ha farmyard manure. Combined application of tie ridge, farmyard manure and NP fertilizer contribute for agricultural sustainability. Applying integrated soil fertility increase total nitrogen and available phosphorus in the soil for agricultural sustainability. The highest carbon (12 mg/kg) was sequestered when farmyard manure was applied with NP fertilizer on maize and wheat cropped alfisoils. Application of integrated fertility management reduces N2O emissions by increase nitrogen-use efficiency. Application of animal manure and NPK fertilizer reduce CH4 into the atmosphere contributing for climate change mitigation. Integrated soil fertility management improves soil fertility contributing for agricultural sustainability. Crop yield was improved by application of integrated fertility management which sustains agriculture. Integrated soil fertility management was on option for climate change mitigation.
The emission of nutrients and pesticides from agricultural soils endangers natural habitats. Here, we review to which extent carbon-rich organic amendments help to retain nutrients and pesticides in agricultural soils and to reduce the contamination of surrounding areas and groundwater. We compare straw, compost, and biochar to see whether biochar outperforms the other two more traditional and cheaper materials. We present a list of criteria to evaluate the suitability of organic materials to be used as soil amendments and discuss differences in elemental compositions of straw, compost, and biochar to understand, how soil microorganisms utilize those materials. We review their effects on physical and chemical soil characteristics, soil microbial communities, as well as effects on the transformation and retention of nutrients and pesticides in detail.
It becomes clear that for all three amendments their effects can vary greatly depending on numerous aspects, such as the type of soil, application rate, and production procedure of the organic material. Biochar is most effective in increasing the sorption capacity of soils but does not outperform straw and compost with regards to the other aspects investigated. Nevertheless, the possibility to design biochar properties makes it a very promising material. Finally, we provide critical comments about how to make studies about organic amendments more comparable (comprehensive provision of material properties), how to improve concepts of future work (meta-analysis, long-term field studies, use of deep-insight microbial DNA sequencing), and what needs to be further investigated (the link between structural and functional microbial parameters, the impact of biochar on pesticide efficiency).
Gradual depletion in soil nutrients has affected soil fertility, soil nutrients, and the activities of soil enzymes. The applications of multifarious rhizobacteria can help to overcome these issues, however, the effect of co-inoculation of plant-growth promoting rhizobacteria (PGPR) and biochar on growth andnutrient levelsin soybean and on the level of soil nutrients and enzymes needs in-depth study. The present study aimed to evaluate the effect of co-inoculation of multifarious Bradyrhizobium japonicum USDA 110 and Pseudomonas putida TSAU1 and different levels (1 and 3%) of biochar on growth parameters and nutrient levelsin soybean and on the level of soil nutrients and enzymes. Effect of co-inoculation of rhizobacteria and biochar (1 and 3%) on the plant growth parameters and soil biochemicals were studied in pot assay experiments under greenhouse conditions. Both produced good amounts of indole-acetic acid; (22 and 16 µg mL⁻¹), siderophores (79 and 87%SU), and phosphate solubilization (0.89 and 1.02 99 g mL⁻¹). Co-inoculation of B. japonicum with P. putida and 3% biochar significantly improved the growth and nutrient content ofsoybean and the level of nutrients and enzymes in the soil, thus making the soil more fertile to support crop yield. The results of this research provide the basis of sustainable and chemical-free farming for improved yields and nutrients in soybean and improvement in soil biochemical properties.
Biochar, carbon-rich materials produced during the thermochemical processing of biomass, are receiving increased attention given their potential value as soil amendments. Biochar are formed through pyrolysis processes—heating to several hundred degrees Celsius under oxygen-limited environments—and both the source feedstock and the reaction conditions affect the quality of the resulting chars. Biochar can enhance soil physical and chemical properties and increase agricultural systems’ productivity through direct and indirect effects on crop growth and soil quality. Biochar also may directly help mitigate climate change by sequestering stable carbon compounds in the soil and perhaps indirectly through increased C uptake by trees. As the world faces growing challenges from soil degradation and climate change, biochar application to soils represents a potential pathway forward. Although a large volume of literature exists regarding the use of biochar under favorable climatic conditions, information regarding biochar applications in semiarid and arid climates has been more limited. Evidence of greater water holding capacity and reduced infiltration suggests these materials have potential to improve the productivity of such lands and provides a basis for considering its wider application in the arid environments such as Saudi Arabia. Challenges and limitations for biochar use on a mass scale are also briefly discussed. To move this technology forward, crop and soil scientists should involve economists and agricultural extension educators in studies that consider economic as well as biophysical implications for biochar’s application on a mass scale.
Humic acid, as a natural organic matter, is widely distributed in surface soil, oceans, rivers, and other ecological environments throughout the whole earth ecosystem. Humic acid provides abundant organic carbon and helps to maintain a hydrated, pH and redox buffered environment hosting the soil microbiome. Humic acid is however also a largely ignored polymer material full of exciting functional properties, and its scale is enormous. This perspective article discusses its synthesis and management as a tool to tackle parts of the climate crisis as well its use in technological applications, as made by chemical conversion of agricultural side products to artificial humic acids. Carbon bound to the topsoil as humic matter exceeds by overall mass the carbon of biosphere as well as in the atmosphere. While binding CO2 in biomass is a subsidized tool, binding CO2 in fertile soils is rarely done, despite its breath‐taking potential. Herein, the “artificial humification” to shift 200 Gt of carbon from the atmosphere to soil is discussed.
Soil fertility provides the foundation for nutritious food production and resilient and sustainable livelihoods. A comprehensive survey and summit was conducted to understand barriers to enhancing soil fertility in sub-Saharan Africa and provide evidence-based recommendations. The focus regions were West Africa, East Africa, Great Lakes, and Ethiopia. Overall recommendations were developed with four emerging themes: 1) strengthening inorganic fertilizer based systems, 2) access to and use of quality organic inputs, 3) capacity building along the entire knowledge transfer value chain, and 4) strengthening farming systems research and development across biophysical and socioeconomic factors. The evidence-based process and methodology for prioritizing these recommendations makes these findings useful for setting forth action plans for future investments and strategies. Inorganic fertilizer access, use, and related implementation issues were prominent; nevertheless, biophysical and socioeconomic barriers and solutions were identified as equally important to building soil fertility and natural resources. Soil management initiatives should focus on providing holistic solutions covering both biophysical and socioeconomic aspects along the entire value chain of actors and creating an enabling environment for adoption. A broader view of soil fertility improvement using all available options including both inorganic and organic sources of nutrients and farming system approaches are highly recommended.
The soil, Soul of Infinite Life, is the entity responsible for sustaining life on earth. In spite of significant advances in the service sector, agriculture remains the major provider of employment and source of revenue in India. Soil testing is a valuable tool for evaluating the available nutrient status of soil and helps to determine the proper amount of nutrients to be added to a given soil based on its fertility and crop needs. In the current study, the soil test report values are used to classify several significant soil features like village wise soil fertility indices of Available Phosphorus (P), Available Potassium (K), Organic Carbon (OC) and Boron (B), as well as the parameter Soil Reaction (pH). The classification and prediction of the village wise soil parameters aids in reducing wasteful expenditure on fertilizer inputs, increase profitability, save the time of chemical soil analysis experts, improves soil health and environmental quality. These five classification problems are solved using the fast learning classification technique known as Extreme Learning Machine (ELM) with different activation functions like gaussian radial basis, sine-squared, hyperbolic tangent, triangular basis, and hard limit. After the performance analysis of ELMs with diverse activation functions for these soil parameter classifications, the gaussian radial basis function attains the maximum performance for four out of five problems, which goes above 80% in most of the accuracy rate calculations in every problem, followed by hyperbolic tangent, hard limit, triangular basis, and sine-squared. However, the performance of the final classification problem, i.e. the pH classification, gives moderate values with the gaussian radial basis and best performance (near 90%), with the hyperbolic tangent. Keywords: Extreme learning machine, Activation functions, Soil fertility indices, Soil pH, Classification, Prediction
Climate‐smart agriculture (CSA) management practices (e.g., conservation tillage, cover crops, and biochar applications) have been widely adopted to enhance soil organic carbon (SOC) sequestration and to reduce greenhouse gas emissions while ensuring crop productivity. However, current measurements regarding the influences of CSA management practices on SOC sequestration diverge widely, making it difficult to derive conclusions about individual and combined CSA management effects and bringing large uncertainties in quantifying the potential of the agricultural sector to mitigate climate change. We conducted a meta‐analysis of 3,049 paired measurements from 417 peer‐reviewed articles to examine the effects of three common CSA management practices on SOC sequestration as well as the environmental controlling factors. We found that, on average, biochar applications represented the most effective approach for increasing SOC content (39%), followed by cover crops (6%) and conservation tillage (5%). Further analysis suggested that the effects of CSA management practices were more pronounced in areas with relatively warmer climates or lower nitrogen fertilizer inputs. Our meta‐analysis demonstrated that, through adopting CSA practices, cropland could be an improved carbon sink. We also highlight the importance of considering local environmental factors (e.g., climate and soil conditions and their combination with other management practices) in identifying appropriate CSA practices for mitigating greenhouse gas emissions while ensuring crop productivity.
This 2-year field experiment investigated the effects of full straw incorporation on soil fertility and crop yield in a rice-wheat (Oryza sativa L.–Triticum aestivum L.) rotation on sandy, loamy soil. Two treatments were tested: (i) straw removal (CK) and (ii) straw incorporation (STR). The STR significantly increased the wheat yield by an average of 58% compared with CK; however, no significant difference was found in the rice yield. Soil available nitrogen, phosphorus, and potassium in the 0–20 cm soil layer increased by more than 15% with STR compared to CK. The soil cation exchange capacity and organic carbon in the 0–20 cm soil layer increased by 8% and 22%, for STR compared to CK, respectively. Straw incorporation significantly elevated the soil saturated water content but decreased the soil bulk density compared with CK. Soil aggregates >2 mm were significantly increased after straw return. STR also notably increased the soil urease, invertase, and catalase activities in the 0–15 cm soil layer by 11.4%, 41.0%, and 12.9%, respectively, and the soil microbial carbon and nitrogen contents in the 0–20 cm soil layer by 59% and 54%. Therefore, full straw incorporation could significantly improve soil fertility and maintain crop yields for the study area.
A sustainable solution to biomass burning by converting agricultural residues into biochar was provided. Biochar application was investigated to improve soil fertility, sequester carbon, and increase crop production. Rice husk (RHBC) and corn stover (CSBC) biochars were obtained by slow pyrolysis at 650° and 550 °C, respectively. RHBC and CSBC were characterized (SEM, SEM-EDX, TEM, FTIR, XRD, elemental analyses, and SBET). Unpyrolyzed husks and stover were also used for soil amendments and compared to biochars in different proportions under a controlled incubation environment over 107 days. Fertilizers were not applied. An increase in water holding capacity, total organic carbon, cation exchange capacity, and a decrease in soil CO2 emission were observed after biochar application to soil versus the application of the parent husks or stover. These biochars improved soil fertility and enhanced eggplant crop growth (height, leaf number, fresh and dry weight). In addition, carbon mitigation was achieved because the biochar remained stable in the soil achieving longer term carbon sequestration. Both chars can be used for carbon sequestration and soil amendments.
Organic and inorganic fertilization management in intensive cropping system is important to achieve long-term high crop yield sustainability. We quantitatively investigated crop yield sustainability through soil fertility and nutrients balance in 34-years long-term experiment under double rice cropping system in acidic paddy soil. Seven treatments were studied: CK (no fertilization); NPK (Chemical nitrogen, phosphorus and potassium fertilizer); NPM (Chemical N, P and manure); NKM (Chemical N, K and manure); PKM (Chemical P, K and manure); NPKM (Chemical N, P, K and manure) and M (Manure). Manure was applied at the rate of 45,000 kg ha −1. Results showed that crop yield and sustainability yield index under combined application of manure and chemical fertilizers was significantly higher than chemical fertilization and highest crop yield was under NPKM treatment. Long-term combined manure and chemical fertilization improved soil fertility as compared to CK and NPK treatments. Soil organic C sequestration rates under NPM, NKM, PKM and NPKM treatments were increased , while decreased under CK and NPK over the fertilization years. The uptake of N, P and K was increased over the fertilization years in all the treatments that received manure, compared with CK and NPK. Apparent K balance was negative in all the treatments. N balance (except CK and NPKM) and P balance (except CK) was positive in all fertilization treatments. P balance was exceeded the environmental risk threshold under combined application of chemical P fertilizer and manure. Boosted regression tree indicated that soil available N (AN), orgnaic carbon (OC) and total N (TN) were the most influencing factors of crop yield, accounted 36.5 %, 17.8 %, 13.4 % of variations of relative yield, respectively. Path analysis showed that long-term fertilizer inputs increased soil nutrient contents and C input directly affected soil OC. C input and soil pH indirectly influenced the relative crop yield. This study concluded that long-term combined application of manure and inorganic fertilizers increased crop yield sustainability, organic carbon sequestration rate compared to the inorganic fertilization. But long-term combined application of manure and inorganic phosphorus fertilizer increased the P balance. Therefore, rate of P inputs should be reduced under combined application of manure and inorganic P fertilizers in acidic paddy soil.
The main objectives of this paper were 1) to estimate soil organic carbon (SOC) using remote sensing covariates, soil properties, and topographic factors , and 2) to evaluate the interaction and the relative influence of the selected factors on the spatial variation of SOC. Thirteen factors were considered for digital mapping of SOC in the west Urmia Lake in Iran. To quantify multicollinearity among the predictor variables, Variance Inflation Factor (VIF) was calculated. Among them, nine independent factors were remained including silt, sand, slope, enhanced vegetation index (EVI), brightness, wetness, land cover, and latitude and longitude. A machine learning algorithm called Gradient Boosting Machine (GBM) was calibrated for understanding the spatial dynamic and prediction of SOC. Model performance showed that GBM explained 43.5% (R 2) of the SOC variation, and root mean square error (RMSE) was 0.23%. Results showed that EVI and sand were the most influential factors of the SOC variation while slope and land cover were the least important ones. Furthermore, significant interaction among EVI-wetness-SOC and EVI-sand-SOC was detected. On the other hand, 45.2% of SOC variation was estimated by remote sensing covariates. These results suggested that GBM was a promising approach for an in-depth understanding of the SOC variation over space.