Soil Biological Activity Research Articles

Cu-tolerant Klebsiella variicola SRB-4 increased the nanoparticle (NP) stress resilience in garden peas (Pisum sativum L.) raised in soil polluted with varying doses of copper oxide (CuO)-NP.

Utilizing metal/nanoparticle (NP)- tolerant plant growth-promoting rhizobacteria (PGPR) is a sustainable and eco-friendly approach for remediation of NP-induced phytotoxicity. Here, Pisum sativum (L.) plants co-cultivated with different CuO-NP concentrations exhibited reduced growth, leaf pigments, yield attributes, and increased oxidative stress levels. Cu-tolerant (800µM) Klebsiella variicola strain SRB-4 (Accession no. OR715781.1) recovered from metal-contaminated soils produced various PGP traits, including IAA, EPS, siderophore, HCN, ammonia, and solubilized insoluble P. The PGP substances were marginally increased with increasing CuO-NP concentrations. When applied, Cu-tolerant SRB-4 strain increased root length (18%), root biomass (15.3%), total chlorophyll (29%), carotenoids (30%), root N (21%), root P (23%), total soluble protein (20%) nodule number (32%), nodule biomass (39%) and leghaemoglobin content (18%) in 50µM CuO-NP-exposed peas. Furthermore, proline, malondialdehyde (MDA), superoxide radical, hydrogen peroxide (H2O2) content, and membrane injury in K. variicola-inoculated and 50µM CuO-NP-treated plants were maximally and significantly (p ≤ 0.05) reduced by 70.6, 26.8, 60.8, and 71.6%, respectively, over uninoculated but treated with similar NP doses. Moreover, K. variicola inoculation caused a significant (p ≤ 0.05) decline in Cu uptake in roots (71%), shoots (65.5%), and grains (76.4%) of peas grown in soil contaminated with 50µM CuO-NP. The multivariate i.e. heat map and pearson correlation analyses between the NP-treated and PGPR inoculated parameters revealed a significant and strong positive corelation. The NP-tolerant indigenous beneficial K. variicola could be applied as an alternative to enhance the production of P. sativum cultivated in nano-polluted soil systems. Additionally, more investigation is required to ascertain the seed/soil inoculation effect of K. variicola SRB-4 on soil biological activities and different crops under various experimental setups.

Agroforestry Systems Based on Anacardium occidentale L. (Anacardiaceae): Socio-Economic Yield and Environmental Insights from the Peripheries of Benoué National Park, Cameroon

Biodiversity, a natural biological capital of the earth that presents important opportunities for all societies, provides goods and services essential for human livelihoods and aspirations. Thus, this study aims to investigate agroforestry models of western Anacardium parks in the southern and western zones of the Bénoué National Park (North Cameroon), in order to determine the most appropriate system for the study area. More specifically, the aim is to: characterize the diversity of crops associated with Anacardium occidentale; estimate crop yields obtained in Anacardium occidentale parks; assess the socio-economic and environmental impact of the Anacardium occidentale parks established. The Ishikawa tool enabled us to analyze and visualize the socio-economic and environmental impact of the agroforestry parks established, and using the KoboCollect tool, the survey form was drawn up and administered to the producers. Crops associated with Anacardium occidentale include maize, soya, cowpeas, groundnuts, cotton, yams, cassava, millet and sesame. The most common are cashew-peanut (27 %), cashew-maize (24 %), cashew-cassava (21 %) and cashew-millet (17 %). The results showed that the cashew-rachis system produced 42,800 kg, the cashew-maize system 36,700 kg and the cashew-manioc system recorded the highest production of 46,100 kg. The study also highlighted the potential socio-economic benefits of collaboration between trees and crops associated with the preservation of soil biological activity by cashew trees. In the environmental level, the equipment used by growers is traditional and has no impact on soil quality. Western Anacardium plantations offer growers numerous partnership opportunities, with cashew by-products widely consumed, sold and recycled. This integration can have mutual benefits for both partners (trees and crops). This research topic provides added value in the environmental field, in that it provides a solution to the problem of soil degradation from which many farmers suffer, and increases production while maintaining the soil in a healthy state. It also contributes to achieving the goals of sustainable development, which are to protect biological diversity (ODD15), ensure food security (ODD2) and the living conditions of human populations (ODD3).

Influence of Annual Ryegrass (Lolium multiflorum) as Cover Crop on Soil Water Dynamics in Fragipan Soils of Southern Illinois, USA

Fragipans are dense subsurface soil layers that severely restrict root penetration and water movement. The presence of shallow fragipan horizons limits row crop production. We hypothesized that the roots of cover crop might improve soil physiochemical properties and biological activity, facilitating drainage and increasing effective soil depth for greater long-term soil water storage. To evaluate annual ryegrass as one component of a cover crop (CC) mix for promoting the characteristics and distribution of soil water, on-farm studies were conducted at Marion and Springerton in southern Illinois, USA. Soil samples were collected at 15 cm increments to 60 cm (Marion) and 90 cm (Springerton) depths during the fall of 2022. Both sites had low total soil carbon and nitrogen contents and acidic soil pH (≤6.4). A soil water retention curve was fitted using the van Genuchten equation. At Springerton, the CC treatment increased saturated (thetaS) and residual (thetaR) soil water contents above those of the no cover crop (NCC) at the 60–75 cm and 75–90 cm depths. Changes in volumetric soil water content were measured using a multi-depth soil water sensor for the Springerton site during late July to early August of the soybean growing phase of 2022; NCC had higher soil water than CC within the 0–15 cm depth, but CC had higher soil water than NCC at the 30–45 cm depth. These findings indicate that cover crop mix has the potential to improve soil water movement for soils with restrictive subsoil horizon, possibly through reducing the soil hydraulic gradient between the surface and restrictive subsurface soil layers.

Toxicity evaluation and degradation of cypermethrin-contaminated soil using biochar and Bacillus cereus amendments

Cypermethrin (Cyp), a persistent synthetic pyrethroid insecticide widely used for insect control. The persistence of Cyp creates toxicity to both humans and the environment This study investigates biochar and Bacillus cereus distinct and collective effects on Cyp -contaminated soil during a 90-day incubation. This study also investigates the effects of different concentrations of Cyp (50, 100, ,500 to 1000 mg kg−1) on soil physicochemical and biological activities during a 90-day incubation period. Microbial biomass carbon and soil respiration rates decreased significantly across all cypermethrin concentrations, with the most substantial reductions observed at 1000 mg kg−1. However noticeable variations in soil enzymes and MBC over time during the entire incubation period. On 1st day, the GMean Enz and MBC rate for Cyp treatments (50, 100, ,500 to 1000 mg kg−1) ranged from 0.98 to 0.63, and 9.06, to 5.03, respectively. Under Cyp pollution, microbial biomass carbon exhibited significant decreases, with the highest inhibition (86.2%) at 1000 mg kg−1 on 1st day of incubation. Soil respiration rates dropped 77%, at 1000 mg kg−1, and Integrated biomarker response (IBR) values peaked on day 30, indicating environmental stress. Biochar and Bacillus cereus effectively facilitated the degradation of Cyp, achieving approximately 85% degradation within the first 45 days of the experiment. The combined application of biochar and Bacillus cereus increased soil pH to a neutral level from 5.9, to 7.1, reduced electrical conductivity from 1.41 µS cm− 1 to 1.20 µS cm−1, and elevated cation exchange capacity from 1.54 ± 0.04 to 6.18 C mol kg−1, while also improving organic carbon content to 3.135%. However, the dehydrogenase activity was decresed upto 47% in the combined application and all other enzymes including urasese catlayse and phostasese enzymes with Gmean enzymeatic activities were significantly improved. These findings suggest biochar and bacterial interaction for soil management to enhance soil resilience against pesticide stress.

Limited effect of mycorrhizal inoculation depending on soil type and fertilization level in a central European field trial

AbstractRecent trends indicate a substantial increase in the application of mycorrhizal inoculants (Myc) across Central Europe. These inoculants are projected to contribute to a reduction in fertilizer dependency and to facilitate the mobilization of soil nutrients. Nevertheless, most studies are conducted in tropical or arid regions with very few data on wether mycorrhizal inoculants affect soil biological activity and cereal growth in temperate climates. A 4-year field trial was set up to assess the effects of Myc treatments (Funneliformis, Clariodeoglomus, Rhizophagus)on two different soil types. Myc was applied in combination with conventional fertilization in the first three years (sowing corn-wheat-corn) and substantially reduced fertilizer application in the fourth year (sowing corn). Weather conditions and fertilizer application rates had the highest impact on crop yields and shoot biomass throughout the four-year period. Mycorrhizal inoculants consistently caused significantly greater root colonization than the control each year, regardless of the fertilization rate. Myc also enhanced root capacity, phosphatase enzyme activity, and yield, but these benefits were most pronounced when combined with reduced fertilization and Luvisol with nutrient deficiency. In contrast, higher levels of soil organic matter and microbial activity in Gleysol led to a greater yield and diminished the impact of Myc compared to Luvisol. In this experiment, the Myc’s capacity to increase yield was not enough to compensate for the yield decrease caused by reduced fertilization. Our results indicate how critical soil types and fertilizer application rates are in determining the effectiveness of Myc in Central European cereal production.

Innovative organic nutrient management and land arrangements improve soil health and productivity of wheat (Triticum aestivum L.) in an organic farming system

IntroductionSoil health is vital for ecosystems, but excessive use of fertilizers, chemicals, and irrigation harms soil fertility, leading to reduced yields and degradation. Thus, exploring innovative land arrangements and nutrient management for staple crops such as wheat is essential. Organic farming offers a promising solution. This study hypothesized that an appropriate land arrangement, combined with split applications of farmyard manure (FYM) and liquid organic fertilizer, can enhance wheat productivity while also improving soil health. The objective of this study was to investigate the effects of different sowing methods and organic nutrient management practices on the productivity of wheat and soil health.MethodsThis study aimed to examine the impact of sowing methods and nutrient management practices on soil health and organic wheat productivity during the winter seasons of 2021–22 and 2022–23 at the Organic Farming Unit (Agronomy), Rajasthan College of Agriculture, MPUAT, Udaipur. The experiment was arranged in a split-plot design, with three land arrangements/sowing methods in the main plot and eight nutrient management approaches in the subplots.ResultsConcerning different land arrangements, the furrow irrigated raised bed sowing (FIRB) method resulted in the maximum wheat yield (4.34 t ha−1) compared with flat row sowing and zero tillage sowing. With respect to nutrient management practices, 75% of the recommended dose of N (RDN) through the FYM was basal + 25% RDN with the 1st irrigation + Jeevamrut application at 500 L ha−1 during sowing, and the 1st irrigation + Panchagavya spraying at 5% during the booting stage resulted in the highest grain yield (4.47 t ha−1). Both the zero tillage and FIRB land arrangements resulted in better soil biological activities and microbial counts than did flat sowing. The results indicate that sowing wheat via the FIRB method, with the recommended nitrogen dose applied through split applications of FYM along with liquid organic manures such as Jeevamrut and Panchagavya, can be an excellent option for organic wheat cultivation. This approach can enhance both yield and soil health.ConclusionSeventy-five percent RDN through FYM as a basal + 25% RDN during the 1st irrigation + Jeevamrut at 500 L ha−1 during sowing and the 1st irrigation + spraying of Panchagavya at 5% during the booting stage effectively increased the growth and yield of organic wheat. With respect to land arrangements, both FIRB and zero tillage resulted in better growth, yield, and soil biological properties. The practical utility of this study is the optimization of split applications of FYM and land arrangements for organic wheat cultivation.

Effect of an insecticide, fungicide and plant growth regulator and their mixture on the survival of the springtail Folsomia candida and the potential reduction of toxicity by vitamins

A pesticide-free model soil was pretreated with field-realistic doses/applications of the insecticide, Biscaya 240 OD; the fungicide Tilmor; the growth regulator, Atonik and their mixture. Because Folsomia candida is eyeless, unpigmented, avoids light, and prefers dark, wet and cold conditions, we grew and tested it in the dark and at 18°C. Survival of springtails added to soil at 50 % moisture was assessed after 28 days. The experiments were repeated three times in order to confirm the validity of the test and results. The mixture decreased the survival most significantly. Bayesian statistics showed that pesticide treatment had a greater effect than repeating the experiment. Further tests revealed that the negative effect of the mixture on springtail survival was effectively suppressed by the application of biotin (vitamin B7), whereas riboflavin (vitamin B2) had little effect. Vitamins can reduce the toxicity of agrochemicals in the soil through potential effects on soil biological activity.

Sustaining Soil Biological Activity: The Role of Extended Reduced and No-Tillage Techniques

Soil management techniques can have varying effects on various soil properties. This study investigated the impact of various tillage techniques on soil properties for 14 years. The experiment was conducted at the Çukurova University Research Station, located in a region with a dominant Mediterranean climate. The research aimed to assess the changes in soil organic matter (SOM) content, soil respiration (SR), dehydrogenase enzyme activity (DHA), and soil temperature (ST) under seven different long-term tillage practices. The results revealed significant increases (p ≤ 0.05) in SOM (17-115%), SR (19-37%), and DHA (63-142%), under conservation tillage compared to conventional tillage practices. Additionally, conventional tillage with stubble burned consistently had the lowest values across all measured properties. Seasons variations also significantly (p≤0.05) affected the observed values. These findings suggest that conventional tillage practices have a negative effect on the analyzed biological activities, with stubble burning further exacerbating this impact. Further research exploring the long-term effects of different tillage practices under varying crop rotations and soil conditions can contribute to the sustainable development of agricultural production in the region.

Long-term changes in soil biological activity and other properties of raised beds in Longan orchards.

The Longan fruit tree of the Vietnam Mekong Delta is grown in raised beds to improve water drainage during the rainy season and can live as long as 100 years. This research explores the extent to which the soil microorganisms as well as soil physical and chemical properties of these raised beds degrade over a period of 60 years under traditional management practices. Raised bed topsoil samples at depths of 0-20 cm were obtained from four different Longan orchards raised bed age groups: group 1) 15-25 years (L1-L5); group 2) 26-37 years (L6-L10); group 3) 38-45 years (L11-L15); and group 4) 46-60 years. Soil biological properties were tested for nitrogen-fixing bacteria, phosphorus solubilizing bacteria, potassium solubilizing bacteria, calcium solubilizing bacteria and silicate solubilizing bacteria, β-glucosidase, urease, phosphomonoesterase, and phytase. Soil samples were also tested for moisture content, soil texture, soil porosity, and bulk density as well as soil chemical properties including pH, electrical conductivity (EC), soil organic matter (SOM), total nitrogen (TN), total phosphorus (TP), total potassium (TK), available nitrogen (NH4 +, NO3 -), available phosphorus (AP), exchangeable potassium (K+), exchangeable calcium (Ca2+), available silicate (SiO2), available copper (Cu), zinc (Zn), boron (B) and manganese (Mn). Key findings: The results showed that soil moisture, soil porosity, sand content, SOM, TP, TK, available P, exchangeable Ca2+, available Si, nitrogen fixing bacteria number, β-glucosidase, urease, phosphomonoesterase, and phytase gradually and significantly decreased in the raised bed soil as the Longan orchard increased in age. Pearson correlation analysis between the ages of Longan orchards and soil properties revealed that raised bed ages were positively correlated with soil bulk density, but negatively correlated with soil moisture content, soil porosity, SOM, TN, β-glucosidase, urease, phosphomonoesterase, and phytase. Principal component analysis (PCA) showed Longan yields had a positive correlation with available NO3 - but negative correlation with NFB, exchangeable Ca2+, pH, and available B. These findings reveal that traditional long-term management of Longan trees in raised beds significantly reduce soil organic matter, moisture content, porosity, and soil fertility with impacts on soil microbial numbers and activity within raised bed soils. This suggests that more sustainable management practices, such as mulch and cover crops that decrease soil compaction and increase soil organic matter, improve soil porosity, total N, and feed soil microorganisms that are critical to nutrient cycling are needed to improve raised bed soil quality.

Post-Pyrogenic Restoration of the Biological Activity of Soils of Artificial Forest Plantations in the Arid Zone of the Shirinskaya Steppe in the Republic of Khakassia

Post-Pyrogenic Restoration of the Biological Activity of Soils of Artificial Forest Plantations in the Arid Zone of the Shirinskaya Steppe in the Republic of Khakassia

Healthcare waste management and antimicrobial resistance: a critical review.

The rapid growth of populations and urbanization has led to a significant increase in healthcare waste, posing serious health risks. A search on Google Scholar identified seven relevant articles from Ethiopia that examine the relationship between improper waste management in healthcare facilities (HCFs) and the rise of antimicrobial resistance (AMR) genes. This review aims to highlight key concepts, evidence sources, and knowledge gaps specific to the Ethiopian context. The unsafe disposal of antibiotics through leaks and solid waste has contributed to what some are calling a 'silent pandemic,' raising concerns about emerging infectious diseases. Studies have revealed alarming rates of infectious agents and AMR in healthcare wastewater. Isolates of C. jejuni, Escherichia coli, Enterococcus faecalis, and Enterococcus faecium from various healthcare waste sites in Ethiopia demonstrate high levels of AMR genes. Additionally, research indicates that HCFs produce significant amounts of waste, with high per-person daily waste production rates. Leachate from landfills containing this waste can negatively affect soil health, biological activity, water quality, agriculture, animal health, and human well-being. To mitigate these risks, effective waste management practices and the promotion of alternative antimicrobial use are essential strategies for reducing the emergence of pandemic diseases in developing countries.

Development of a Low-Cost Sensor System for Accurate Soil Assessment and Biological Activity Profiling.

The development of low-cost tools for rapid soil assessment has become a crucial field due to the increasing demands in food production and carbon storage. However, current methods for soil evaluation are costly and cannot provide enough information about the quality of samples. This work reports for the first time a low-cost 3D printed device that can be used for soil classification as well as the study of biological activity. The system incorporated multiple physical and gas sensors for the characterisation of sample types and profiling of soil volatilome. Sensing data were obtained from 31 variables, including 18 individual light wavelengths that could be used to determine seed germination rates of tomato plants. A machine learning algorithm was trained using the data obtained by characterising 75 different soil samples. The algorithm could predict seed germination rates with high accuracy (RSMLE = 0.01, and R2 = 0.99), enabling an objective and non-invasive study of the impact of multiple environmental parameters in soil quality. To allow for a more complete profiling of soil biological activity, molecular imprinted-based fine particles were designed to quantify tryptophol, a quorum-sensing signalling molecule commonly used by fungal populations. This device could quantify the concentration of tryptophol down to 10 nM, offering the possibility of studying the interactions between fungi and bacterial populations. The final device could monitor the growth of microbial populations in soil, and offering an accurate assessment of quality at a low cost, impacting germination rates by incorporating hybrid data from the microsensors.

Different cropping systems impact soil health by improving soil biological activities and total organic carbon content

ABSTRACT This study assesses the impact of different cropping systems on changes in total organic carbon (TOC), its fractions and biological activities to evaluate the changes in soil health. The rice-wheat cropping system (RWCS) had significantly higher total organic carbon (TOC) (38.8%) and soil organic carbon (SOC, 43.6%) compared to the pearl millet-mustard cropping system (PMCS). Active C pools were significantly higher in soils under cotton-wheat (CW) and pearl millet-wheat cropping systems (PWCS) than RWCS, whereas passive C pools (63% of TOC), the microbial biomass carbon (MBC) and dehydrogenase activity (DHA) were highest under RWCS than other systems. Soils under these cropping systems exhibited a significant polynomial relationship of TOC with SOC and dissolved organic carbon (DOC). Two significant canonical discriminant functions involving TOC, SOC, DOC, very labile carbon (CVL), labile carbon (CL), less labile carbon (CLL), recalcitrant carbon (CR), MBC and DHA could distinguish the different cropping systems and contributed 94.7%. The principal component analysis identified that TOC, SOC, pH and EC were the most reliable and contributing variables for assessing soil health under different cropping systems. Three PCs explained the 79.2% variability of the total variance of the original data set.

Биологическая активность горных почв Западного Кавказа после сведения леса

A study of a set of indicators characterizing the ecological state of forest soils in the mountains of the North-Western Caucasus under broad-leaved and mixed forests has been conducted. The aim of the study has been to assess changes in the biological activity of soils of different genesis after deforestation. The objects of the study have been rendzina, gray forest and gray forest-steppe soils of forest and disturbed ecosystems of the Republic of Adugeya at altitudes from 500 to 1635 m above sea level. Logging plots of different ages (from 10 to 40 years old) after deforestation have been considered. The analyzed indicators have included: the content of total and active carbon, the activity of soil enzymes (catalase, invertase, dehydrogenase, urease, phosphatase), the number of bacteria, as well as an integral index of the biological properties of the soil. The correlation of these indicators with hydrothermal conditions, density of soil structure, penetration resistance, medium reaction, hydrolytic acidity, total absorbed bases and other soil parameters has been evaluated. The level of biological activity of soils in logging areas in the low mountains of Adygea depends on the relief and the timing of restoration after deforestation. Even after several decades of restoration of woody vegetation on the slopes of 12–15° there is no complete return of biological activity to the values of Greyic Phaeozem Eutric of the background forest area. 40 years after logging, the integral index of biological properties of gray forest soil is still 17 % lower than in the control plot. The biological activity of post-forest soils can change in three main directions. On steep slopes, with severe disturbance of the soil and vegetation cover due to the operation of heavy machinery, the integral index of the biological properties of soils decreases by 25–40 % or more without a tendency to recovery. At an average level of disturbance in plots with slight slopes, after an initial decrease, the soils are restored to control values. Restorative successions with intensive development of herbaceous flora and the turf process with slight disturbance can lead to an increase in biological activity above the control values in just 2–3 years. Comprehensive biodiognostic studies using an integral index of the biological state of the soil have revealed, in general, increased stability of low-mountain terrain soils (gray forest and forest-steppe) compared to the soils of the middle mountains of Adygea (rendzina soils). The main degradation factor that reduces the biological activity of soils disturbed by logging is erosion.

The effect of recreational load on the biological activity of urban park soils

Currently, there are fewer and fewer healthy and strong plantings in urban parks due to various anthropogenic changes. One of these factors is the recreational load exerted on the soil, which causes adverse effects on the stand and ground cover. The rich component of the parks with numerous trees and beautiful ground cover is an integral part of the place for cultural recreation in the city. In addition, the park is a special green area that provides oxygen, absorbs road noise, traps dust and improves the atmosphere. The work was based on nine samples buried in the park, at three sites with different levels of recreational load under different tree species. The influence of recreational load on the biological activity of the soils of the urban park is shown.

Positive influence of apple trees on soil chemical and biological activities in agroecological garden orchard system

Positive influence of apple trees on soil chemical and biological activities in agroecological garden orchard system

Land use change from rice paddies to upland fields aggravates soil microbial metabolic limitation and reduces soil quality index and ecosystem multifunctionality

AbstractWith rapid urbanization and economic development, the area of paddy fields has seriously declined in rice‐producing region. However, the impacts of land use change (LUC) on soil enzymatic stoichiometry, microbial metabolic limitations and ecosystem multifunctionality (EMF) have not been well‐documented. Hence, four adjacent paired soil samples were collected in rice‐producing areas. Soil microbial carbon (C), phosphorus (P) and nitrogen metabolic limitations were assessed via vector model. The impacts of LUC on soil structure, microbial activity, quality and multifunctionality were evaluated via soil structure stability index (SSI), soil biological activity (SBA), soil quality index (SQI) and EMF, respectively. Result showed that LUC from rice paddies to upland fields markedly decreased soil structure stability by 19.6%. Soil microbial biomass carbon (MBC), microbial biomass nitrogen (MBN), microbial biomass phosphorus (MBP) and nutrient‐acquiring enzymes activities in the paddy soils were significantly higher than that in upland soil. Compared with paddy soil, microbial relative C and P limitations in upland soil were significantly aggravated by 10.9% and 4.2%, respectively. Additionally, variation partitioning and redundancy analyses revealed that soil pH, available P and P‐acquiring enzymes were the crucial edaphic factors affecting microbial metabolic limitations. Comprehensive assessment showed that LUC from rice paddies to upland fields significantly reduced SBA, SQI and EMF by 5.2%, 17.4% and 17.2%, accordingly. Overall, LUC from rice paddies to upland fields significantly destroyed soil structure, aggravated microbial relative C and P limitations and reduced soil quality. Therefore, artificial managements should be strengthened to counteract the adverse effects of LUC on soil quality and EMF. This study deepened our understanding of sustainable development and efficient management of field under LUC condition.

Rice straw biochar and NPK minerals for sustainable crop production in arid soils: a case study on maize-wheat cropping system

Maize and wheat are the main cereals grown in Egypt. However, the country relies on grain imports to meet its local demands. In order to improve their production, appropriate fertilization programs are needed. The present study investigates the effects of amending a clayey soil of an arid region with rice straw biochar and NPK mineral fertilizers, individually or in combination, for increasing growth and productivity of maize and wheat crops. Additionally, impacts of these additives on soil biological activities and carbon (C) transformations in soil were a matter of concern herein. To achieve this objective, a field research of a randomized block design was conducted during the summer (maize) and winter (wheat) seasons of 2020/2021. The following treatments were considered: unmodified control (CK), 100% N inputs in the form of biochar (reference organic treatment, RSB) (T1), 100% mineral treatment (reference inorganic treatment, T2), 75% RSB + 25% NPK minerals (T3), 50% RSB + 50% NPK minerals (T4) and 25% RSB + 75% NPK minerals (T5). Additional doses of mineral fertilizers were added to treatments from T3 to T5 to maintain NPK inputs within the recommended doses. Key results showed that all additives significantly enhanced plant growth parameters and productivity. They also increased soil organic carbon level by the end of the growing season hence reduced soil bulk density, even for the treatment that received only mineral NPK applications (T2). All additives also upraised soil cation exchange capacity (CEC), soil available nitrogen (N), and soil salinity. However, sole application of biochar recorded the least increase in soil salinity. Combined mineral-organic treatments not only recorded the highest increases in soluble and microbial fractions of organic carbon and nitrogen in soil; but also noted the greatest improvements in growth and grain productivity of maize and wheat versus sole applications of mineral fertilizers or biochar. The alkaline nature of biochar was buffered by soil while no significant differences were observed in harvest index among treatments. In conclusion, combined use of biochar and mineral fertilizers, especially T5 is recommended for increasing soil fertility and wheat and maize grain productvity.

Soil profile distribution of organic, inorganic, and labile carbon and nitrogen fractions vary in semi‐arid drylands under long‐term conservation tillage systems

AbstractChanges in soil carbon (C) and nutrients considerably influence soil health and agricultural sustainability. However, how agricultural management affects C and N allocation among various soil organic matter pools and their linkages with soil health are not clear for arid and semi‐arid regions. This study aimed to evaluate the soil profile distribution of selected C and N fractions and associated soil health properties in conventional tillage (CT), no‐tillage (NT), and strip tillage (ST) fields and quantify the relationship of labile and inorganic C and N fractions to soil organic carbon (SOC) sequestration in semi‐arid dryland cropping systems. Crop rotation was a 4‐year cycle of corn (Zea mays L.)—sorghum (Sorghum bicolor L. Moench)—winter wheat (Triticum aestivum L.)—fallow across all tillage systems. Soil samples were collected from 0–20, 20–40, and 40–60 cm depths of each plot in July 2022, after 9 years of plot establishment, and analysed for potentially mineralizable carbon (PMC), microbial biomass carbon (MBC), SOC, soil inorganic (SIC), soil total carbon (STC), soil inorganic nitrogen (SIN), total labile nitrogen (TLN), total organic nitrogen (SON), and labile organic nitrogen (LON) and other soil health indicators. The results indicate that PMC was 31% more and LON was 23% more in NT than in CT, whilst ST resulted in lower pH and had only 10%, 9%, and 24% more SON, STN, and LON, respectively, than CT in 0–60 cm profile. The SIC stock was negatively correlated with MBC, PMC, SON, STN, LON, TLN, and SIN, whilst positively correlated with depth, STC, and pH. After 9 years of conservation tillage, whilst depth‐wise distribution varied among tillage systems, soil C sequestration rate was negative in the 0–60 cm profile under both NT and ST compared with CT, mainly owing to more SIC accumulation in deeper depth of conventional system. These results show the complexity of soil C and N allocation under different tillage systems, with NT and ST supporting greater C and N storage in the surface soil and CT supporting more C and N storage in the deeper depth. Soil biological activity indicators appear to drive surface SOC accumulation, whilst soil pH and N availability influenced SIC accumulation in lower depths.

Plant probiotic microbes – trending microbes for plant growth and value addition of compost- a review

New agricultural approaches, including natural and organic farming, have developed organic and microbiological goods. Beneficial microbes known as plant probiotic microorganisms (PPM) are primarily found in soil and have coevolved with plants in a symbiotic or free-living relationship. By encouraging plant growth and health, these bacteria lessen the need for artificial fertilizers, support environmentally friendly agricultural practices, and improve plant health. Agroecosystem vigour, biodiversity, biological cycles, and soil biological activity are all enhanced by using plant probiotic bacteria in biologically based agriculture. By using beneficial bacteria to support the health and function of the host organism, plant probiotics aim to lessen the demand for toxic pesticides and fertilizers. Using these probiotic microorganisms will have a synergistic and advantageous effect on crop production. Plant probiotic microorganisms improve the overall quality of compost throughout the composting process by accelerating the breakdown of organic materials and introducing helpful bacteria. This rich compost adds beneficial bacteria to the soil, creating a healthy and productive environment. This review looks at the common plant probiotic bacteria, how they work, how they complement each other to improve compost quality and plant growth, how they might be used in agriculture, and how they could change how composting is done.