Soil Fertility Research Articles

Biochar boosted high oleic peanut production with enhanced root development and biological N fixation by diazotrophs in a sand-loamy Primisol

Peanut yield and quality face significant threats due to climate change and soil degradation. The potential of biochar technology to address this challenge remains unanswered, though biochar is acknowledged for its capacity to enhance the soil microbial community and plant nitrogen (N) supply. A field study was conducted in 2021 on oil peanuts grown in a sand-loamy Primisol that received organic amendments at 20 Mg ha−1. The treatments consisted of biochar amendments derived from poultry manure (PB), rice husk (RB), and maize residue (MB), as well as manure compost (OM) amendment, compared to no organic amendment (CK). In 2022, during the second year after amendment, samples of bulk topsoil, rooted soil, and plants were collected at the peanut harvest. The analysis included the assessment of soil quality, peanut growth traits, microbial community, nifH gene abundance, and biological N fixation (BNF) rate. Compared to the CK, the OM treatment led to an 8 % increase in peanut kernel yield, but had no effect on kernel quality in terms of oil production. Conversely, both PB and MB treatments increased kernel yield by 10 %, whereas RB treatment showed no change in yield. Moreover, all biochar amendments significantly improved oilseed quality by 10–25 %, notably increasing the proportion of oleic acid by up to 70 %. Similarly, while OM amendment slightly decreased root development, all biochar treatments significantly enhanced root development by over 80 %. Furthermore, nodule number, fresh weight per plant, and the nifH gene abundance in rooted soil remained unchanged under OM and PB treatments but was significantly enhanced under RB and MB treatments compared to CK. Notably, all biochar amendments, excluding OM, increased the BNF rate and N-acetyl-glucosaminidase activity. These changes were attributed to alterations in soil aggregation, moisture retention, and phosphorus availability, which were influenced by the diverse physical and chemical properties of biochars. Overall, maize residue biochar contributed synergistically to enhancing soil fertility, peanut yield, and quality while also promoting increased root development, a shift in the diazotrophic community and BNF.

Inoculation of Native Arbuscular Mycorrhizae and Bacillus subtilis Can Improve Growth in Vegetable Crops.

Arbuscular mycorrhizal fungi (AMF) and some rhizobacteria are known as plant growth-promoting microorganism (PGPM) as they play significant roles in improving soil fertility structure, plant nutrition, growth, and health. However, little is known about the PGPM potential of AMF and rhizobacteria native to the Rift Valley and highland regions of Ethiopia. Hence, this study aimed to investigate the PGPM effect of single and co-inoculation of AMF and the Bacillus subtilis ALCR46 strain, on tomato (Lycopersicum esculentum L.), onion (Allium cepa L.), and squash (Cucurbita pepo L.) plants. The experimental setup was a randomized complete block design with three replications of the following treatments: (i) inoculation with a consortium of AMF, (ii) co-inoculation with a consortium of AMF and the Bacillus subtilis, (iii) inoculation with Rhizophagus clarus, (iv) co-inoculation with R. clarus and B. subtilis, (v) inoculation with B. subtilis, (vi) plants without inoculation (negative control), and (vii) plants treated with chemical fertilizer (positive control). Plants were maintained in a greenhouse for 60 days, and after harvest, plant growth parameters, percentage of AMF root colonization, and spore number were analyzed. The result shows that the growth of crops significantly increased by co-inoculation with the consortium of AMF and B. subtilis. AMF spore density and root colonization rate were also increased in co-inoculated plants. Highest root colonization, spore number, and mycorrhizal dependency were observed in A. cepa. Our results suggest that there is a synergistic effect between the AMF and B. subtilis ALCR46, and between AMF inoculants. However, the application of present findings under field conditions is required to be confirmed by further studies.

Cow Based Inputs for Sustainable Agriculture: A Review

Food safety is of prime importance at present because the consumption of food products with chemical residues above the threshold levels is causing dreadful diseases in living beings and deteriorating soil health too. The current global scenario firmly emphasizes the need to adopt agricultural practices that are ecologically safe for sustainable food production. Hence, it is necessary to adopt organic farming which improves the health of Agro-ecosystems besides providing safe food and conserving the soil fertility and soil biota. There is a need to identify a suitable substitute in place of chemical fertilizers which are economically cheaper and ecofriendly. In this context, Cow-based inputs (dung, urine, ghee, milk) play an important role in organic farming as an alternative to chemical fertilizers which help in the growth of the crop and provide eco-safety food

Occurrence of Stem Rot on Acacia mangium Caused by Amauroderma subresinosum.

Acacia mangium has the characteristics of developed root system, nitrogen fixation and soil improvement, fast growth and high yield, and improvement of soil fertility. It is often used as a windbreak tree species in rubber plantations, a highway shade tree, for coastal and mountain restoration in Hainan . In October 2021, a stem rot disease with an incidence of 3% was found in Baisha city(19°22'18″N,109°16'58″E), Hainan Province, China. In the early stage of the disease, the crown showed chlorotic leaves, followed by defoliation. In later stages, whole tree dieback was observed. The basal tissue of the stem of the diseased tree had white rot, and black-brown basidiocarps were observed about 1 m away from the ground. The basidiocarps surface of fresh was disinfected with 75 % ethanol, the epidermal tissue was removed, and the inner tissue blocks were transferred to PDA medium. After culturing in dark at 28°C for 3 days, a colony with white aerial mycelium was isolated and designated: HNBSMZXS20211011001. The basidiocarp was dark brown, sessile, mostly one-year-old, and the cap is nearly semi-circular, wooden, slightly shiny, with a size of 14.7 to 18.1cm × 9.5 to 10.1 cm. The base is thick (5 to 6.5 cm) and the edge is thin (0.3 to 0.7 cm). The basidiospores are oval, 10.7 to 13.65μm × 6.7 to 9.06μm in size, with a double-layer wall. The outer wall is transparent and the inner wall is light yellow. The basidiospores contain 1~2 oil droplets. The morphological features are consistent with those of Amauroderma subresinosum (Murrill) Corner (Zhang et al., 2000). The basidiocarps and type strain cultures were stored as accessions in the Laboratory of Plant Pathogen Fungus Biology, Hainan University. For pathogenicity tests, sawdust culture medium was used (soft sawdust 82%, wheat bran 15%, glucose 2%, gypsum 1%, mixed with water in proportion, sterilized at 121°C for 40min). The mycelium plug from a fresh culture (d=5mm) was taken from the edge of the colony of type strain, and transferred to the sterilized sawdust medium. When mycelium has colonized the media, it was used to inoculate plants. Media without mycelium was used as a control. Naturally growing seedlings (three year old) of A.mangium were selected from the teaching nurseries of Hainan University (20°6'25''N,110°32'24''E). First, 75 % alcohol was sprayed on the stem of the base of A.mangium for surface disinfection. After the surface was dried, a slight wound (about 4×2cm) was made on the surface with a sterilized scalpel. A inoculated and control sawdust media rods were tightly attached to the wound, moistened with cotton balls soaked in sterile water, and then fixed with plastic wrap, and the outer layer was wrapped with newsprint. Inoculation and controls were replicated three times. Two months after inoculated, the stems of the plants inoculated with the isolated fungus grew white hyphae and showed white rot symptoms, and the leaves became chlorotic and defoliated with complete tree decline in six months, which was consistent with the original symptoms observed. By comparison, white callus had grown on the edge of the stem wounds of the control plants. The same fungus was re-isolated from the inoculated plants and confirmed as A.subresinosum based on the internal transcribed spacer (ITS), the ribosomal large subunit(LSU), and the translation elongation factor 1-α(EF1-α) gene sequence, the fungus was not isolated from control plants thus fulfilling Koch's postulates. The ITS region of r-DNA, the ribosomal large subunit(LSU), the translation elongation factor 1-α gene(EF1-α) were amplified using ITS1/ITS4(White et al. 1990), LR0R/LR5(Hu et al. 2021), EF1-983F/EF1-1567R(Buckley et al. 2005) primers, respectively. The sequences of ITS (OQ674500), LSU (OQ674502) and EF1-α gene (OQ883944) were submitted to GenBank. Through with BLAST, the identities of the ITS, LSU and EF1-α sequences to A.subresinosum (GenBank Accession no. ITS: LC176755; LSU: MK119903 and EF1-α: MK121572) was 99.82%; 99.15% and 99.82%, respectively, the identities were more than 99 %. It was reported that A.subresinosum could infect Casuarina equisetifolia and Areca catechu(Chen et al., 2016; Cheng. 2017; Wu et al., 2019). However, this is the first report of Amauroderma subresinosum causing stem rot of Acacia mangiumin Hainan, China. This report will facilitate field diagnosis and provide scientific reference for further research on the disease.

Eco-Sustainability of Soils in Baby-Leaf Crop Systems under Tunnel through the Application of C-Rich Inputs: Towards Combating Soil Degradation

Fresh-cut leafy vegetables are produced in Southern Italy in very intensive crop systems under tunnel greenhouses in which continuous cropping has triggered soil organic carbon (SOC) depletion and the risk of degradation of soil fertility. A two-year trial of soil organic amendment was carried out on a private farm producing baby-leaf crops on a very poor OC soil (<1%). Biowaste compost, two types of olive pomace composts and buffalo manure were compared to evaluate their ability to recover a positive SOC balance and sustain crop growth and yield. The effects on soil health and crop system were studied by measuring different aspects such as SOC stock change and SOC sequestration rate, soil microbial biomass and nine enzyme activities, yields of rocket and concentration of nitrates in leaves. Soil amendments were distributed once a year at doses of 15 and 30 Mg ha−1 as fresh matter without integration of mineral fertilizers. In our study, the SOC stock improved in the amended soils in a range of 4–6 Mg ha−1, except for dose 30 of buffalo manure, with the highest values where biowaste compost was applied. Our data showed an increase in biological parameters in all the amended soils with respect to Control. In soil amended with olive pomace, however, compost mineralization rates likely did not match crops’ nutrient needs so the yields of rocket were lower than with the biowaste compost and buffalo manure. Biowaste compost showed the best results as it balanced the best C conversion efficiency, the higher increment of SOC and yields of rocket.

Impact of diversified cropping systems and fertilization strategies on soil microbial abundance and functional potentials for nitrogen cycling

Diversified cropping systems and fertilization strategies were proposed to enhance the abundance and diversity of the soil microbiome, thereby stabilizing their beneficial services for maintaining soil fertility and supporting plant growth. Here, we assessed across three different long-term field experiments in Europe (Netherlands, Belgium, Northern Germany) whether diversified cropping systems and fertilization strategies also affect their functional gene abundance. Soil DNA was analyzed by quantitative PCR for quantifying bacteria, archaea and fungi as well as functional genes related to nitrogen (N) transformations; including bacterial and archaeal nitrification (amoA-bac,arch), three steps of the denitrification process (nirK, nirS and nosZ-cladeI,II) and N2 assimilation (nifH), respectively. Crop diversification and fertilization strategies generally enhanced soil total carbon (C), N and microbial abundance, but with variation between sites. Overall effects of diversified cropping systems and fertilization strategies on functional genes were much stronger than on the abundance of bacteria, archaea and fungi. The legume-based cropping systems showed great potential not only in stimulating the growth of N-fixing microorganisms but also in boosting downstream functional potentials for N cycling. The sorghum-based intercropping system suppressed soil ammonia oxidizing prokaryotes. N fertilization reduced the abundance of nitrifiers and denitrifiers except for ammonia-oxidizing bacteria, while the application of the synthetic nitrification inhibitor DMPP combined with mineral N reduced growth of both ammonia-oxidizing bacteria and archaea. In conclusion, this study demonstrates a strong impact of diversified agricultural practices on the soil microbiome and their functional potentials mediating N transformations.

Assessment of Effects of Amended Bioremediation of Toxic Metal-polluted Soil using Organic Composites and Bacillus sp on Plant Growth Parameters

It has become pertinent to develop improved bioremediation techniques, to avert the deleterious effects of heavy metal pollution on agricultural productivity, and safety of its produce. In this study, cow dung, poultry wastes and their composites used as organic amendments were collected and processed, while Bacillus sp used as plant growth promoting rhizosphere was isolated and identified. Then 24 kg of fertile soil was polluted by introducing 20 mL of 0.1M lead acetate solution, before bagging 5 kg of polluted soil into ten perforated nylons. Soil sample was then analyzed before and after treatment. After mixing with Bacillus sp suspension, two of the pot experiments were amended with each of 0.5 kg cow dung only, 0.5 kg poultry wastes only and 1:1 ratio of their composites. Control samples were set up without amendment, and they were bioremediated for 25 days. Following germination of sown corn seedlings, heights of their shoots and number of leaves were monitored on day 4, weeks 2, 4 and 7, before harvesting for analysis together with soil samples. Results obtained revealed that seedlings grown on treated samples as well as properties of treatment of soil were generally better than those of control samples. Highest percentage increase in organic matter content of soil was recorded in treatment with mixture of cow dung only and Bacillus sp, with 9.28% and 7.63% increase at 33.75 mg/kg and 52.55 mg/kg of lead (Pb) pollution. Seedlings grown on samples treated with poultry wastes only, recorded the highest protein content of 161.25±5.5 mg/g, 104.99±4.95 mg/g and 79.75±3.2 mg/g protein contents, at 32.75 mg/kg, 42.02 mg/kg and 52.44 mg/kg levels of Pb pollution, respectively. The amendments also reduced bioaccumulation of Pb in corn seedlings, which was in the order; stem<leaf<root. Therefore, these amendments can be exploited for improved bioremediation of heavy metals.

Use of organo-mineral amendments and Lupinus angustifolius to enhance mine tailings rehabilitation

Uncontrolled mine waste disposal globally poses severe environmental and health risks due to high concentrations of toxic substances like heavy metals and organic pollutants. This jeopardizes soil fertility and ecological balance. In this study, we adopted a novel approach based on the use of low-cost amendments that can be used in small to tailing sites for better plant growth and reducing health risks. On a 37-ha-old abandoned pyrrhotite mine site (Kettara) which was operated for 34 years near Marrakesh a high amount of tailing material low in organic C, high in salt contents, and contaminated by various heavy metals still exists. This material is low in fertility and is only patchily discovered by vegetation which should hinder the material of aeolian erosion. To increase the fertility of the material and improve vegetation growth, the soil material has to be improved by different organo-mineral amendments and their combinations as Marble waste (Mw), Clay (Cy), and Compost (Cp). To determine the impact of these amendments on plant growth the fast-growing Lupinus angustifolius L. a legume plant found close to the mining site, identified with the Regional Herbarium 'MARK' code: MARK-14861. This plant serves as a pivotal component in the comprehensive approach aimed at rehabilitating the soils surrounding the mining site. To identify the most effective organo-mineral amendment, we examined 65 combinations by mixing mine tailing soils with varying proportions (2.5%, 5%, 7.5%, or 10%) of the three distinct amendments and its combinations (Com), to identify the optimal rate for effective seeds germination and plant growth. Preliminary results on the germination index of L. angustifolius seeds revealed that four combinations (Com1: Cy2.5-Cp2.5-Mw10; Com2: Cy2.5-Cp5-Mw5; Com3: Cy7.5-Cp2.5-Mw7.5; and Com4: Cy10-Cp10-Mw10) maintained a high index due to improved soil properties. These combinations were used as the soil substrate material for a greenhouse experiment where plant growth, heavy metals accumulation, soil characteristics, and available metal content were determined. Our findings demonstrated that incorporating these four organo-mineral soil amendments into Kettara mine tailings led to a significant enhancement in plant growth. Notably, L. angustifolius plants exhibited a preferential accumulation of heavy metals in the root’s biomass (Cu: 565.60, Zn: 433.52, and Pb: 301.44 mg kg−1) with limited translocation to shoot parts (Cu: 37.44, Zn: 28.40, and Pb: 19.36 mg kg−1), particularly following the application of Com4. Furthermore, the properties of the mine soil were improved, including both neutralization of acidic soil pH (3 to ∼ 7) and reduction of metal elements bioavailability. Specifically, Com1, Com3, and Com4 effectively decreased the mobile fraction of metals in the tested mine tailings to exceptionally low levels achieving a reduction of 99% for copper, lead, and zinc, and 95% for arsenic. Our findings from this study indicated that our amendment holds promising potential for enhancing both plant growth and soil fertility, while simultaneously mitigating the mobility of heavy metals in heavy metal-contaminated acidic mine soils.

Effectiveness of Soil-amended Biochar in Improving Crop Production, Soil Health and Environmental Aspects

Effectiveness of Soil-amended Biochar in Improving Crop Production, Soil Health and Environmental Aspects

ASSESSMENT OF THE QUALITY OF LAND IN THE SARATOV TRANS-VOLGA REGION WHEN INVOLVING UNUSED ARABLE LAND IN PRODUCTION

ASSESSMENT OF THE QUALITY OF LAND IN THE SARATOV TRANS-VOLGA REGION WHEN INVOLVING UNUSED ARABLE LAND IN PRODUCTION

Effectiveness of sod and humus soil maintenance and biologized protection in intensive apple orchards (Malus domestica Borkh.) in the south of Russia

Application of intensive technologies in horticulture with a high mechanical and chemical load on soils and fruit plants leads to deterioration of soil properties, environmental pollution, and development of resistance among pathogens and phytophages. In this study, we aim to developing a biologized technology for apple tree cultivation using a sod and humus system of inter-row maintenance and biopreparations based on active strains of microorganisms, entomoacariphages, and pheromones. The research was conducted in 2019-2023 in intensive apple orchards of the central plain-steppe region of Crimea by the methods conventionally used in soil science, agrochemistry, horticulture, and plant protection. The use of a mixture of cereal-legume grasses in combination with microbiological fertilizers based on nitrogen-fixing microorganisms was found to increase apple yields by 11–12 t/ha, or 64 % compared to the control, by increasing the number of fruits and the average weight of one fruit. A positive balance of nutrition elements in soil with an intensity of 135-270 % was established. The efficiency of controlling the number of phytophages and pathogen harmfulness through the integrated use of biological and biotechnical methods was shown. Thus, the “attract-and-kill” method for Cydia pomonella L. pheromones demonstrated a 98 % efficiency along with a reduction in pesticide load to 7.7 kg/ha season by the preparation. Release of phitoseiid mites for control of tetranychus mites by the method of seasonal colonization provides for a reduction and retention of phytophagous population at the economic threshold of harmfulness during the entire vegetation period. The use of fungicides based on pathogenic bacteria of the Bacillus genus and antagonist fungi of the Trichoderma genus against scab is eff ective only in the years unfavorable for the development of the disease. The results obtained form the basis for a biologized resource-saving technology for exploitation of intensive apple orchards. This technology contributes to increased soil fertility, reduced chemical and pesticide load, and increased productivity of horticultural agrocenosis under the conditions of the Crimea and southern Russia.

Manufacturing Process for Ameliorant Plus Mycorrhizal Powder Using Local Raw Materials for Soil Improvement

The development of ameliorant powder enriched with indigenous arbuscular mycorrhizae for soil amendment has been limited. This study presents a formulation process for creating a high-quality ameliorant powder using local raw materials. The powder incorporates a culture of Glomus mosseae isolate MAA-01, which constitutes 25% of the mixture, combined equally with compost powder, cattle manure powder, and rice husk charcoal powder. This formulation results in a product containing 2500 spores per 20 g of powder, achieving a 95% colonization rate, a moisture content of 5.002 % db, and a shelf life of 12 months. Laboratory tests confirm that this ameliorant powder significantly enhances soil fertility, as well as plant growth and yield, particularly in suboptimal land conditions. The production method is straightforward, making it highly suitable for local farmers seeking to improve agricultural productivity.

Effect of different organic amendments on phosphorus dynamics of blackgram (Vigna mungo)

Legumes play a significant role in sustainable agriculture through their ability to improve soil fertility and health. With a mutual symbiotic relationship with some bacteria in soil, they can improve nitrogen (N) amount through biological N-fixation (BNF). But to maximize such functions, legumes need more phosphorus (P) as it is required for energy transformation in nodules. Besides, P also plays a significant role in root development, nutrient uptake and growth of legume crops. A field experiment was conducted during rainy (kharif) season of 2019 at IFS unit, College of Agriculture, (University of Agricultural Sciences, Dharwad), Vijayapur, Karnataka to study the effect of different combination of organic sources on phosphorus dynamics of blackgram [Vigna mungo (L.) Hepper]. Among different treatments, the application of vermicompost + ghanajeevamrutha @ 100% RDP + Rhizobium + PSB recorded significantly higher soil available phosphorus (36.30 kg/ha) and uptake by blackgram (16.08 kg/ha). This study has demonstrated the dynamics of phosphorus through different organic sources in blackgram.

A potential slow-release fertilizer based on biogas residue biochar: Nutrient release patterns and synergistic mechanism for improving soil fertility

The large yield of anaerobic digestates and the suboptimal efficacy of nutrient slow-release severely limit its practical application. To address these issues, a new biochar based fertilizer (MAP@BRC) was developed using biogas residue biochar (BRC) to recover nitrogen and phosphorus from biogas slurry. The nutrient release patterns of MAP@BRC and mechanisms for enhancing soil fertility were studied, and it demonstrated excellent performance, with 59% total nitrogen and 50% total phosphorus nutrient release rates within 28 days. This was attributed to the coupling of the mechanism involving the dissolution of struvite skeletons and the release of biochar pores. Pot experiments showed that crop yield and water productivity were doubled in the MAP@BRC group compared with unfertilized planting. The application of MAP@BRC also improved soil nutrient levels, reduced soil acidification, increased microbial populations, and decreased soil heavy metal pollution risk. The key factors that contributed to the improvement in soil fertility by MAP@BRC were an increase in available nitrogen and the optimization of pH levels in the soil. Overall, MAP@BRC is a safe, slow-release fertilizer that exhibits biochar-fertilizer interactions and synergistic effects. This slow-release fertilizer was prepared by treating a phosphorus-rich biogas slurry with a nitrogen-rich biogas slurry, and it simultaneously addresses problems associated with livestock waste treatment and provides a promising strategy to promote zero-waste agriculture.

Assessment of soil fertility and nutrient management strategies in calcareous soils of Khuzestan province: a case study using the Nutrient Index Value method.

Soil fertility (SF) is a crucial factor that directly impacts the performance and quality of crop production. To investigate the SF status in agricultural lands of winter wheat in Khuzestan province, 811 samples were collected from the soil surface (0-25cm). Eleven soil properties, i.e., electrical conductivity (EC), soil organic carbon (SOC), total nitrogen (TN), calcium carbonate equivalent (CCE), available phosphorus (Pav), exchangeable potassium (Kex), iron (Fe), copper (Cu), zinc (Zn), manganese (Mn), and soil pH, were measured in the samples. The Nutrient Index Value (NIV) was calculated based on wheat nutritional requirements. The results indicated that 100%, 93%, and 74% of the study areas for CCE, pH, and EC fell into the low, moderate, and moderate to high NIV classes, respectively. Also, 25% of the area is classified as low fertility (NIV < 1.67), 75% falls under medium fertility (1.67 < NIV value < 2.33), and none in high fertility (NIV value > 2.33). Assessment of the mean wheat yield (AWY) and its comparison with NIV showed that the highest yield was in the Ramhormoz region (5200kg.ha-1), while the lowest yield was in the Hendijan region (3000kg.ha-1) with the lowest EC rate in the study area. Elevated levels of salinity and CCE in soils had the most negative impact on irrigated WY, while Pav, TN, and Mn availability showed significant effects on crop production. Therefore, implementing SF management practices is essential for both quantitative and qualitative improvement in irrigated wheat production in Khuzestan province.

Patterns and determinants of calcium concentrations in forest litter and different soil horizons in warm-temperate China

Calcium is an essential nutrition for the integrity and structure of plant cells, and is generally neglected because of its high abundance in temperate forest soil. To date, little is known about the changes in soil Ca and the main natural drivers in the conserved forests. Here, the concentrations of Ca in forest litter and different soil horizons (0–10, 10–20, 20–30, and 30–50 cm) from 234 forest plots were measured. Spatial variations in litter and soil Ca concentrations beneath different forest types were determined, and a structural equation model (SEM) was constructed to evaluate the causal pathways of the biotic and abiotic drivers. The results showed that litter Ca concentration beneath broadleaved forests and mixed broadleaf-conifer forests (22.62 and 19.76 mg/g, respectively) were significantly greater than that beneath the coniferous forest (15.35 mg/g). The Ca concentrations in the soil significantly increased with latitude (soil depth < 30 cm) and longitude. However, litter and soil Ca concentrations significantly declined with elevation. The basal area of the forest and soil C/N were the dominant factors regulating the concentration of Ca in litter and soil profiles, respectively. The SEM highlighted the important effects of Ca concentration in deep soil (soil depth > 20 cm) on litter Ca concentration. The basal area and soil C/N had negative and positive direct effects on Ca concentration in topsoil (soil depth < 20 cm), respectively. The precipitation and temperature in the growing season had indirect effects by affecting the soil C/N and basal area. These results collectively suggest that different forest types influence the redistribution of Ca belowground, and the process is mainly mediated by the basal area and soil C/N. The afforestation in the study area with admixture of conifers and broadleaved trees is a desirable management for the improvement of forest productivity and soil fertility.

Assessing the efficacy of utilizing biochar derived from oil palm biomass as a planting medium for promoting the growth and development of oil palm seedlings

The recent adoption of biochar in Malaysia's oil palm industry offers numerous benefits, including soil enhancement, resource efficiency improvement, pollution remediation, and greenhouse gas mitigation. With approximately 66.15% of agricultural land dedicated to oil palm cultivation, a substantial amount of biomass, mainly from empty fruit bunch (EFB) and mesocarp fibre (MF), is generated. This study focused on carbonizing MF and EFB at temperatures ranging from 580 to 695 °C to produce biochar. The assessment of biochar's effectiveness as a planting medium in nurseries revealed significantly accelerated growth rates in seedlings cultivated in a composite of biochar and soil. At 8 months-after-treatment (MAT), the BMF-75 treatment showed remarkable growth enhancements, with the highest increase in height (64.9%), number of leaflets (60.5%), and girth size (55.3%) compared to the initial values at 3 MAT, indicating its effectiveness in promoting growth in oil palm seedlings. Additionally, compared to the control group, the biochar-mixed media resulted in favourable outcomes regarding the assimilation of both macro- and micro-nutrients. For instance, nitrogen uptake increased by 2.7% with BMF-50, magnesium by 25.2%, phosphorus by 24.1% with BEFB-75, calcium by 36.8% with BMF-75, chlorine by 10.5% with BMF-50, iron by 25.5% with BEFB-25, copper by 20.1% with BMF-25, and zinc by 6.3% with BMF-25. Additionally, biochar-treated soil exhibited higher organic carbon content, improved cation exchange capacity (CEC), enhanced nitrogen retention with greater biochar proportions, and likely improved soil fertility due to biochar's porous structure. Further potential research can be explored to investigate its long-term effects on oil palm plantation.

Dryland soil recovery after disturbance across soil and climate gradients of the Colorado Plateau

Drylands impacted by energy development often require costly reclamation activities to reconstruct damaged soils and vegetation, yet little is known about the effectiveness of reclamation practices in promoting recovery of soil quality due to a lack of long-term and cross-site studies. Here, we examined paired on-pad and adjacent undisturbed off-pad soil properties over a 22-year chronosequence of 91 reclaimed oil or gas well pads across soil and climate gradients of the Colorado Plateau in the southwestern United States. Our goals were to estimate the time required for soil properties to reach undisturbed conditions, examine the multivariate nature of soil quality following reclamation, and identify environmental factors that affect reclamation outcomes. Soil samples, collected in 2020 and 2021, were analyzed for biogeochemical pools (total nitrogen, and total organic and inorganic carbon), chemical characteristics (salinity, sodicity, pH), and texture. Predicted time to recovery across all sites was 29 years for biogeochemical soil properties, 31 years for soil chemical properties, and 6 years for soil texture. Ordination of soil properties revealed differences between on- and off-pad soils, while site aridity explained variability in on-pad recovery. The predicted time to total soil recovery (distance between on- and off-pad in ordination space) was 96 years, which was longer than any individual soil property. No site reached total recovery, indicating that individual soil properties alone may not fully indicate recovery in soil quality as soil recovery does not equal the sum of its parts. Site aridity was the largest predictor of reclamation outcomes, but the effects differed depending on soil type. Taken together, results suggest the recovery of soil quality - which reflects soil fertility, carbon sequestration potential, and other ecosystem functions - was influenced primarily by site setting, with soil type and aridity major mediators of on-pad carbon, salinity, and total soil recovery following reclamation.

Unveiling the Ecological Ramifications of Aerial Pesticide Application by Drones on Soil Microbiota in Rice

The ecological consequences of aerial pesticide application by drones on soil microbiota in rice fields were investigated in this study. The quantitative and qualitative effects of different pesticide treatments, both applied via drones and power sprayer, were examined on soil bacteria, actinomycetes, and fungi. The average population of total bacteria and pseudomonas in the rhizosphere soil tended to be slightly higher in the drone-sprayed treatments compared to the power sprayer treatments. It is evident that the drone spraying treatments resulted in higher average populations of actinomycetes and fungi (124.75 CFU × 105 g-1 soil and 21.12 CFU × 104 g-1 soil, respectively) compared to the power sprayer treatments with average populations of 127.75 CFU × 105 g-1 soil for actinomycetes and 22.5 CFU ×104 g-1 soil for fungi. Qualitative assessment of microbial groups revealed that, the abundance of G -ve bacterial groups are higher when compared to G +ve bacterial groups in rhizospheric soil before harvest of the crop. The distribution of fungal genera varied due to pesticide applications. The mean per cent occurrence of Curvularia spp., Penicillium spp., and Trichoderma spp. was slightly higher in the drone-sprayed treatments (9.85%, 8.51%, and 8.33%) compared to the power-sprayed treatments (2.48%, 2.24%, and 2.00%). However, the mean per cent occurrence of Aspergillus species (A. ochraceous, A. niger, and A. flavus) was relatively higher in the power sprayer treatments (9.14%, 12.81%, and 4.09%) when compared to the drone-sprayed treatments (3.75%, 2.31%, and 0.83%). Overall, this study underscores the need for further research to comprehensively understand the implications of different pesticide application methods on soil microbial communities and their potential impact on soil fertility and ecosystem functioning over time.

Estimation of redox-sensitive metals in Lafarge cement company’s area in Akamkpa Nigeria: Assessment of ecological health risk

Toxic compounds such as redox-sensitive metals usually contaminate the soil. They are implicated in the causation of oxidative stress, a precursor of human diseases and ecological extinction. Having uncontaminated soil serves as the link between plant and animal health quality, and a sustainable ecosystem. Geological accumulation and spatial distribution of redox-sensitive metals in agricultural land can significantly hinder soil fertility, ecological health, food safety, and food security. This study used the soil samples from farmlands near the Lafarge industrial area at Mfamosing, Akamkpa local government area of Cross River State, Nigeria, to assess eight redox-sensitive metals (Cadmium, Chromium, Copper, Nickel, Lead, Arsenic, Cobalt, and Zinc), their spatial distribution, and geo-accumulation. The redox-sensitive metals were screened with an atomic absorption spectrophotometer connected with mass spectroscopy. A geographic information system (GIS) and ArcMap version 10:8:2 was used to infer the risk of the industrial area regarding geo-accumulation, and spatial distribution of redox-sensitive metals in the farmlands. The result shows Cd, Cr, Cu, Ni, Pb, As, Co and Zn have different concentrations among the samples. Three samples - MS2, MS3, and MS8, had the highest arsenic concentration, while samples Ms1, Ms2, Ms5, and Ms8, had the second-highest concentrations of Cadmium, Lead, and Chromium, respectively. The polluted area was moderately contaminated and distributed with other metals - Cu, Ni, and Co, respectively. Comparing these results with those of non-industrial areas, one can infer that the Lafarge industrial area is more contaminated with redox-sensitive metal. To advance this investigation, some microorganisms within the area can be used to verify a metal-hazard impact on the ecosystem and monitor the rise in redox-sensitive metals to predict the risk.