Improve Soil Conditions Research Articles

Ecological Assessment of Restored Rock Phosphate Mine Spoils in the Maldevta Area of Garhwal Himalayas

This research explores the complex interaction between vegetation restoration and soil recovery, with a particular focus on the ecological restoration of an area in Maldevta, Garhwal Himalayas, that was once mined. The Himalayan ecology, which is abundant in minerals and biodiversity, is under a great deal of stress from mining, building roads, and grazing. The research area experienced open-pit mining, which degraded the soil and eliminated vegetation from what had once been a tropical dry mixed deciduous forest. Analyzing the restored soil's physical and chemical properties reveals a varied profile that affects fertility, structure, and nutrient composition. The loamy sand is made up of different percentages of sand (72.4%), silt (16.96%), and clay (9.89%). The chemical characteristics of the soil include potassium (5.10%), phosphorus (0.33%), nitrogen (0.042%), and electrical conductivity (EC) of 0.21 ohms/cm. The pH of the soil is 7.80. Employing the quadrat method for vegetation analysis, the study underscores the dominance of key plant species like Lantana camara, Mallotus philippensis, and Bombax ceiba in the restored ecosystem. The results demonstrate how restoration initiatives improve soil conditions, vegetation structure, and species diversity. By highlighting the crucial relationship between soil and vegetation dynamics, this study adds insightful information that can improve the effectiveness of ecological restoration projects. The work supports the long-term establishment of self-sustaining ecosystems by offering a thorough grasp of the intricate biological mechanisms leading to the rehabilitation of degraded landscapes in the fragile Himalayan region.

Performance of wood waste biochar and food waste compost in a pilot-scale sustainable drainage system for stormwater treatment

Sustainable drainage system (SuDS) for stormwater reclamation has the potential to alleviate the water scarcity and environmental pollution issues. Laboratory studies have demonstrated that the capacity of SuDS to treat stormwater can be improved by integrating biochar and compost in the filter media, whereas their performance in scaled-up applications is less reported. This study examines the effectiveness of a pilot-scale SuDS, bioswale followed by bioretention, amended with wood waste biochar (1, 2, and 4 wt.%) and food waste compost (2 and 4 wt.%) to simultaneously remove multiple pollutants including nutrients, heavy metals, and trace organics from the simulated stormwater. Our results confirmed that SuDS modified with both biochar (2 wt.%) and compost (2 wt.%) displayed superior water quality improvement. The system exhibited high removal efficiency (> 70%) for total phosphorus and major metal species including Ni, Pb, Cd, Cr, Cu, and Zn. Total suspended solids concentration was approaching the detection limit in the effluent, thereby confirming its capability to reduce turbidity and particle-associated pollutants from stormwater. Co-application of biochar and compost also moderately immobilized trace organic contaminants such as 2,4-dichlorophenoxyacetic acid, diuron, and atrazine at field-relevant concentrations. Moreover, the soil amendments amplified the activities of enzymes including β-D-cellobiosidase and urease, suggesting that the improved soil conditions and health of microbial communities could possibly increase phyto and bioremediation of contaminants accumulated in the filter media. Overall, our pilot-scale demonstration confirmed that the co-application of biochar and compost in SuDS can provide a variety of benefits for soil/plant health and water quality.

Effect of cover crops on soil health at different landscape positions

AbstractSoil health is crucial to reaching high yields, and growing cover crops can help improve soil conditions. The goal of this study is to determine the effects of cover crops on soil health using potential respiration, potential nitrogen mineralization, and aggregates stability as indicators of soil health. The study has been conducted since 2019 at the University of Kentucky Spindletop Farm, Lexington, KY, and involves three landscape positions receiving a treatment with cereal rye, cereal rye–crimson clover mixture, and fallow soil. This study emphasized that cover crops can enhance potential respiration and microbial activity over landscape positions, with rye being more beneficial than the mixture treatment. However, cover crops were also beneficial for aggregate stability but not for potential nitrogen mineralization.

Influence of Decomposed Stubble Return on the Soil Microbial Community Under Perennial Crop Rotation

The aim of this study was to understand how the application of decomposed stubble return (DSR), a type of bio-organic fertilization, affects soil microbial communities under crop rotation. The changes in microbial composition and diversity related to DSR were investigated based on metagenomic sequencing and comparative analysis of two groups of soil samples after a 3-year tomato-pepper-papaya rotation: the DSR and no-DSR (i.e., without DSR) groups, with the soils before crop rotation as the control group. Inter-group comparisons of the crop performance (growth and yield) and physicochemical soil properties (pH value, nutrient elements, and heavy metals) were also conducted to reveal the effects of DSR application on the soil. The relative abundance of bacteria was higher than 90% in all soil samples. Proteobacteria and Actinobacteria in the DSR group and Proteobacteria and Firmicutes in the no-DSR group, whereas Acidobacteria and Proteobacteria in the control, were the two most abundant phyla. The abundance of Proteobacteria decreased, whereas that of Actinobacteria increased, in the DSR-amended soil compared to the no-DSR soil. At genus level, Acidobacterium dominated in the control and genera Pseudomonas, Burkholderia, and Bacillus in the no-DSR group, while Burkholderia, Pseudomonas, and Bacillus in the DSR-amended soil comprised the majority of their microbiomes. The DSR soil had higher microbial diversity and relative abundance of Ascomycota fungi than the no-DSR group after the crop rotation. Along with higher diversity of microbial community, more favorable soil pH, better crop growth, higher crop yields, higher abundance of soil nutrient elements, and lower accumulation of heavy metals in the soil were found in the DSR group compared to the no-DSR one. Furthermore, the DSR soil had more similarities with the control than with the No-DSR soil, in aspects of microbial composition and microbe-derived potential gene functions. It was indicated that decomposed stubble return may improve soil conditions or prevent them from degradation incurred by long-term crop cultivation. It was suggested that the application of the compost derived from fermented post-harvest plant residue may be a general strategy for developing more sustainable agricultural systems.

Unveiling a Technosol-based remediation approach for enhancing plant growth in an iron-rich acidic mine soil from the Rio Tinto Mars analog site

This paper explores the potential of Technosols made from non-hazardous industrial wastes as a sustainable solution for highly acidic iron-rich soils at the Rio Tinto mining site (Spain), a terrestrial Mars analog. These mine soils exhibit extreme acidity (pHH2O = 2.1–3.0), low nutrient availability (non-acid cation saturation < 20 %), and high levels of Pb (3420 mg kg−1), Cu (504 mg kg−1), Zn (415 mg kg−1), and As (319 mg kg−1), hindering plant growth and ecosystem restoration. To address these challenges, the study systematically analyzed selected waste materials, formulated them into Technosols, and conducted a four-month pot trial to evaluate the growth of Brassica juncea under greenhouse conditions. Technosols were tailored by adding varying weight percentages of waste amendments into the mine Technosol, specifically 10 %, 25 %, and 50 %. The waste amendments comprised a blend of organic waste (water clarification sludge, WCS) and inorganic wastes (white steel slag, WSS; and furnace iron slag, FIS). The formulations included: (T0) exclusively mine Technosol (control); (T1) 60 % WCS + 40 % WSS; (T2) 60 % WCS + 40 % FIS; and (T3) 50 % WCS + 16.66 % WSS + 33.33 % FIS. The analyses covered leachate quality, soil pore water chemistry, and plant response (germination and survival rates, plant height, and leaf number). Results revealed a significant reduction in leachable contaminant concentrations, with Pb (26.16 mg kg−1), Zn (4.94 mg kg−1), and Cu (2.29 mg kg−1) dropping to negligible levels and shifting towards less toxic species. These changes improved soil conditions, promoting seed germination and seedling growth. Among the formulations tested, Technosol T1 showed promise in overcoming mine soil limitations, enhancing plant adaptation, buffering against acidification, and stabilizing contaminants through precipitation and adsorption mechanisms. The paper stresses the importance of tailoring waste amendments to specific soil conditions, and highlights the broader implications of the Technosol approach, such as waste valorization, soil stabilization, and insights for Brassica juncea growth in extreme environments, including Martian soil simulants.

Alternative use of soil conditioners for cotton cultivation

Some production environments may present low pH and high levels of Al3+, thus making this element a limiting factor in the productivity of the cotton crop, which makes it necessary to use agricultural gypsum as a soil conditioner and even shell dust as sources low-cost alternatives to improve soil chemical attributes. The objective of this work was to know the responses of the use of alternative soil conditioners with aluminum in the cotton crop. The experiment was carried out in August 2022, at Faculdades Integradas Stella Maris (FISMA). The design was completely randomized, with six treatments, namely: no use of soil conditioners, agricultural gypsum (3.0 t ha-1); golden mussel shell powder (3.0 t ha-1); snail powder (3.0 t ha-1); agricultural gypsum (1.5 t ha-1) with golden mussel shell powder (1.5 t ha-1) and agricultural gypsum (1.5 t ha-1) with snail powder (1.5 t ha-1) and with four replications, totaling 24 plots or pots. The use of agricultural gypsum at a dose of 1.5 t ha-1 associated with golden mussel shell powder at a dose of 1.5 t ha-1 showed better responses in cotton development. The use of agricultural gypsum at a dose of 1.5 t ha-1 associated with golden mussel shell powder at a dose of 1.5 t ha-1 improves soil conditions for cultivation. The pyrolysis method at high temperatures to break the crystalline structures of mollusc shells was efficient.

Influence of tillage methods and soil crust breakers on cotton seedling emergence in silty-loam soil

Soil crusting is a common problem that affects crop emergence and growth worldwide across different soil and climate conditions. This study aimed to investigate the impact of various tillage methods on soil crust formation and assess the effectiveness of soil crust breakers in enhancing cotton seedling emergence. The research was conducted on Silty-Loam soil, examining the impact of four tillage methods: Method A, a conventional tillage approach employing a moldboard plow, disc harrow, and roller; Method B, a conservation tillage method involving a chisel plow, disc harrow and roller; Method C, another conventional tillage method utilizing a chisel plow, powered rotary tiller, and roller; and Method D, another conservation tillage approach utilizing a disc harrow and roller. Two types of crust breakers, a rolling type, and a skid blade type, were tested. The results showed significant variations in soil crusting hardness among the tillage methods, with conservation tillage methods B and D being the most effective in reducing penetration resistance. The post-crust-breaking penetration resistance declined, decreasing from 305 to 408 kPa in the control plots to 60–93 kPa in the treated plots. Breaking the soil crust with the crust breakers considerably reduced penetration resistance, improving soil conditions for seedling emergence and root growth. Seedling emergence was significantly influenced by tillage methods, with conservation tillage methods B and D promoting the highest emergence rates. The mean percent emergence of subplots (with crust breaker applications) was 77.8% when the chisel plow, disc harrow, and roller were applied (Method B) and 78.2% when the disc harrow and roller were applied for tillage (Method D). The percentage of emerged cotton seedlings in the control plots ranged from 51.1% to 86.2%, with the tillage method order of C < A < B < D. However, the soil crust-breaking treatments were effective in increasing the percentage of emerged cotton seedlings for all tillage methods. The rolling-type crust breaker was particularly effective in breaking the crust and enhancing emergence for methods A and C. It increased the emergence percentage by 27.1% for method A and 34% for method C. The study also revealed that the hardness of the soil crust significantly affected emergence time and emergence rate index. Harder soil crusts resulted in longer mean emergence times and lower emergence rate indices. The conventional tillage method involved a chisel plow, powered rotary tiller, and roller, contributing to a harder soil crust with the highest penetration resistance recorded at 408 kPa for the control plot (without soil crust breaking). This resulted in the longest emergence time of 9.8 days and the lowest emergence rate index of 0.38 seedlings/m·day. However, after the soil crust-breaking treatment, the differences in emergence time and emergence rate indices among different tillage methods and crust breakers became statistically insignificant (P>0.05).

Monitoring soil quality of different land use systems: a case study in Suha watershed, northwestern highlands of Ethiopia

The problem of soil quality degradation has been becoming more severe in the highlands of Ethiopia due to soil erosion; land use and land cover change, and poor land management. The level of soil quality degradation was not well known and documented in the study area and the results of this study could provide new information to improve soil conditions. The present study was conducted to evaluate soil quality in terms of its physical and chemical fertility under different land use types in the Suha watershed, northwestern highlands of Ethiopia. A total of 27 composite surface soil samples (0–30 cm) were collected from adjacently located land-uses in three replications from two elevation gradients. Standard procedures were followed to analyze selected soil physical and chemical quality indicators. The differences in the mean values of the parameters were tested using a two-way analysis of variance. In addition, Soil Quality Degradation Index was evaluated to see the direction and magnitude of change in soil quality indicators. The analysis of variance results revealed that soil quality indicators such as index of soil aggregate stability, organic carbon (OC), total nitrogen (TN), and C:N ratio were significantly decreased in the cultivated land use system compared to other land use systems. On the other hand, the content of available Phosphorus was significantly higher in the cultivated land. Soil quality deterioration index values were highly negative for SOC (− 71.3%) and TN (− 67.7%) in the cultivated land, followed by grazing land (SOM = − 35.5% and TN = − 27.7%). Aggregated Soil Quality Index values also indicated that the status of soil quality under cultivated fields is rated as low, grazing land as optimal, and forest land as high. Generally, results indicated that land use and cover changes had adverse effects on soil quality indicators. Hence, soil management strategies, mainly Integrated Soil Fertility Management which integrates soil and water conservation strategies, are required to alleviate the problem of soil quality deterioration and improve agricultural productivity.

Vegetation establishment in soils polluted by heavy metal(loid)s after assisted natural remediation

Background and aimsThis field-base study evaluates the long-term effectiveness of in-situ remediation measures applied to soils residually polluted by potentially toxic elements (PTEs) in an area affected by a mining spill in SW Spain.MethodsTo evaluate the remediation treatments success, their influence on key soil properties and on the development of spontaneous vegetation in the treated soils was investigated. The treatments were based on human derived by-products valorization, and consisted of: biopiles, marble sludge and gypsum mining spoil addition, and their combination with an organic amendment (vermicompost).ResultsAmendments application improved the soil properties and reduced PTEs availability. As a result, an enhancement in spontaneous development of vegetation cover and diversity of plant species in the treated soils was followed. Spergularia rubra and Lamarckia aurea, two primary plant species growing in the studied area and that exhibit strong association to soils with the highest levels of pollution, showed high Pb and As accumulation in shoots ande in roots. Exceptionally, accumulation of these pollutants occurred in L. aurea roots, which can explain its high presence in soils with more limited vegetation development and in which no additional plant species can thrive.ConclusionsThe occurrence of S. rubra and L. aurea in the amended soils may be indicative of improved soil conditions and reduced toxicity induced by the remediation measures implemented. They may also be considered key species in the area since their presence can promote the recolonization of the degraded soils by species less tolerant to their residual pollution.

Farmyard Manure Integrated with Triple Superphosphate for Improved Soil Conditions and Yield of Bio-Fortified Common Beans

Increasing prices of fertilizers and low nutrient concentration in organic manure are highly contributing to poor soil conditions and increased yield gap of bio-fortified common beans. A field study was carried out to assess the effect of farmyard manure integrated with triple superphosphate on soil conditions and yield of bio-fortified common bean Genotypes in central Uganda. The experiments were set in a Randomized Complete Block Design (RCBD) conducted at Mukono Zonal Agricultural Research Institute (MUZARDI) in two rainfall seasons. Treatments included; Cattle manure + TSP, Swine manure + TSP, Chicken manure + TSP, TSP alone and control replicated five times. Bio-fortified common bean genotypes studied were: Naro bean 1, Naro bean 3 and NABE16 a local check. Data was collected on; organic matter, soil pH, nitrogen, potassium and phosphorus content, harvest index, number of pods, pod length, number of seeds per pod, weight of 100 seeds, and grain yield of bio-fortified common beans. Data was subjected to statistical test and analysis of variance using GenStat statistical package (15th edition). Results showed that amending field plots with Swine manure + TSP significantly increased Organic matter by; 1.51% and potassium 1.22% than Chicken manure + TSP, Cattle + TSP, TSP alone and a control respectively. Chicken manure + TSP increased soil pH and Nitrogen by 1.80 and 2.20% while, TSP alone improved Phosphorus by 5.2 PPM than other treatments. Yield parameters were not significantly (P&gt;0.05) affected by treatments except weight of 100 seeds. However, bean genotypes grown in Swine manure + TSP recorded maximum yield of 14 pods, 4 seeds per pod, 32.93 g weight of 100seeds, grain yield was (1843 kgha-1) and lowest (1253 to 650 kg/ha) in TSP+ cattle manure and control. It was therefore, concluded that swine manure + TSP significantly improved soil conditions and yield of bio-fortified common beans. Therefore, basing on these findings, farmers should adopt amendment of swine manure with TSP for improved soil conditions and yields of Naro bean 1

Pyrolysis of different organic feedstock combinations as soil amendments enhances the reclamation of saline-sodic soil

Utilizing agricultural wastes (e.g., straw, bagasse, manure) as amendments to remediate saline-sodic soils can be beneficial for improving soil quality and better waste management. In this study, we investigated the impact of raw and pyrolyzed feedstocks on salt leaching potential and physical and chemical properties in a saline-sodic silt loam soil. Utilizing a column experiment within a completely randomized design, we evaluated five feedstock combinations (i.e., rice husk, pine wood, cow manure, sugarcane bagasse) as amendments (69 Mg ha–1), including variations of raw feedstock and feedstock pyrolyzed at 300 and 500 °C, alongside a control (CT). For both the amended soil and the leachate, we measured electrical conductivity (EC), sodium adsorption ratio (SAR), pH and cations. Soil saturated hydraulic conductivity (KS) and bulk density (BD) were also measured. The BWR treatment (i.e., sugarcane bagasse, pine wood, and rice husk) exhibited notable improvements in soil physical quality (i.e., decreased BD and enhanced KS). Raw feedstock significantly (p < 0.01) increased soil leachate EC SAR, except for WM (i.e., pine wood and cow manure). The BWR treatments expedited the reduction of soil salinity and sodicity, evident in lower SAR/SARmax and EC/ECmax ratios, indicative of increased leaching potential. The amendments consistently demonstrated a trend of reducing soil SAR compared to the control, with raw feedstock exhibiting a more pronounced effect. Soil ECe decreased after amending with feedstock pyrolyzed at 500 °C compared to raw feedstock and pyrolyzed at 300 °C. Feedstock pyrolyzed at 300 °C did not significantly alter soil pH after leaching, and there was a decrease in the soil Na+/K+ ratio, especially with pyrolyzed feedstock. After leaching, the pyrolyzed feedstock treatments showed better soil aggregate stability (Mg2+/Ca2+<1) compared to raw feedstock. Based on the aggregated amelioration score for each amendment combination, BWR treatments consistently outperformed other combinations, with BWR300 being the most favorable option due to its lower production cost compared to BWR500. This study highlights BWR pyrolyzed at 300 °C as a suitable amendment for improving soil conditions, reducing salinity and sodicity, and increasing leaching potential.

Do agri-environment schemes enhance carbon sequestration? Quantifying the effort in the Czech Republic

In the Czech Republic, there are several agri-environment schemes focused on biodiversity and improved soil conditions with added benefits contributing to carbon sequestration introduced by the Common Agricultural Policy (CAP) in 2002. In this study, our aim was to analyse historical data of implemented measures with the highest potential for carbon sequestration, assess their outputs and determine which of the agri-environment measures contributed the most during the programming periods and over the twenty years. Apart from analysing historical data (e.g. number of applications, enrolled area and received payment) and assessing their outputs based on sequestration coefficients published in the literature, we have created an algorithm that predicted carbon sequestration over a twenty-year period to assess the contribution of specific measures beyond the duration of programmes. All the sub-measures monitored contributed to carbon sequestration, with the resulting value determined by the amount of land on which the measure was implemented. The results indicate that, over the period under study, the Conversion from Arable Land to Grassland sub-measure was the highest contributor, reaching values of 555,803–606,330 t C and 1,129,317–1,538,235 t C over twenty years. However, the conversion from arable land to grassland is limited by the land suitable for conversion, so it can be assumed that the Catch Crops sub-measure will make a higher contribution in the future. For the period under study, Catch Crops contributed 359,352–598,920 t C. An increase is also expected for the Flower Strips sub-measure. The study advances knowledge on the contribution of agri-environment measures to carbon sequestration and their modelling, a topic that has not been addressed by many researchers to date and is the first of its kind in Central Europe.

Роль биомелиорантов в снижении электропроводности и засоленности почв

This study aimed to evaluate the impact of biomeliorants on soil electrical conductivity and salinity under the arid conditions of the Syrian Arab Republic. Field experiments were conducted using compost, biopreparations based on Bacillus bacteria, and their combination. Electrical conductivity was measured at four depths: 0-25 cm, 26-50 cm, 51-75 cm and 76-100 cm. The methodology included the use of graphite electrode cells and a conductometer calibrated with standard potassium chloride (KCl) solutions. Soil samples were collected from various depths, dried at 105°C, sieved through a 2 mm sieve, mixed with distilled water in a 1:2 ratio, stirred, and left for 24 hours. Three measurements of electrical conductivity were then taken for each sample. The results showed a significant reduction in soil electrical conductivity with the application of biomeliоrants particularly at the 0-25 cm depth. Two-factor ANOVA and Tukey’s test confirmed statistically significant differences between the experimental treatments. The combination of compost and biopreparations demonstrated the greatest effectiveness in reducing electrical conductivity. These findings indicate the high efficiency of biomeliorants in improving soil conditions and reducing salinity, which is crucial for sustainable agriculture in arid regions. The introduction of biomeliorants helped reduce the content of soluble salts and improve soil structure, ultimately leading to increased crop yields.

The impact of biochar and arbuscular mycorrhizal inoculation on garden egg (Solanum gilo L.) performance

Abstract Garden eggs are an important vegetable, but often yield poorly due to soil fertility depletion. Biochar has gained interest in mitigating nutrient loss, while arbuscular mycorrhizal fungi (AMF) reportedly enhance plant nutrition. However, limited information exists on garden egg responses to biochar application and their interactions with mycorrhizal inoculation. Therefore, the effects of biochar and AMF inoculation on garden egg performance were investigated. In a 3 × 2 factorial field experiment during the 2021 and 2022 cropping seasons, biochar (0, 2.5, and 5 t/ha) and AMF inoculation (−AMF and +AMF) were evaluated in a randomised complete block design with three replicates. Garden egg (NHSg−3) seedlings were transplanted at 60 cm × 60 cm spacing. Data were subjected to ANOVA at p &lt; 0.05. Applying 5 t/ha biochar and AMF inoculation resulted in a significant leaf area increase compared with their respective controls. Fruit yield was significantly higher with 2.5 t/ha biochar than other treatments. The AMF-inoculated plants had significantly higher fruit yield (726.40 kg/ha) than the untreated plants (644.17 kg/ha). Fruit yield for biochar and AMF interactions ranged from 436.50 (− AMF) to 854.53 kg/ha (+AMF inoculation) at 5 t/ha biochar. However, 5 t/ha biochar resulted in significantly higher weed biomass and lower microbial count, while 2.5 t/ha biochar +AMF and −AMF treatments gave 771.63 and 802.08 kg/ha fruit yields, respectively, enhanced microbial counts, and reduced weed biomass. Applying 2.5 t/ha biochar without AMF inoculation was considered adequate for good garden egg performance and improved soil conditions.

Impact of Soil Pore Size Distribution on Crop Growth in Relation to Plant Available Water (PAW) and Soil Organic Carbon (SOC) in Arid/Semi-Arid Regions

Soil structural status in relation to soil pore size distribution, soil water retention, and plant available water (PAW) influence crop plant growth. Also, soil organic carbon content (SOC) usually influence soil structural stability, soil pore size and may affect crop growth, especially in arid/semi-arid regions with low SOC. Our studies focused on soil structure under clay dispersion and conventional and no-tillage systems included cultivation of cover crop in arid/semi-arid region of north-eastern Iran, in 2020 and 2022, respectively. According to our findings, PAW directly depended on soil pore size distribution, the more micropores the more water retention. Consequently, smaller soil pores due to clay dispersion improved water retention in soils and crop growth increased with enhancing PAW. SOC usually is low in arid/semi-arid regions of the world, therefore, addition of soil organic matter by crop residue retention may help in improving soil condition. Based on our results, cover crop residue retention in no-till system increased SOC, and SOC positively influenced soil functions such as soil structural stability, soil pore size (using X-ray images), and root growth. Therefore, soil pore size distribution as influenced by soil structural status could be considered as a principal factor in crop growth in arid/semi-arid region of north-eastern Iran.

Assessment of spatial distribution of lead in soils around an active military shooting range

Abstract In this study, the extent of Pb contamination around an active military shooting range is re-assessed to ascertain current contamination status comparatively to data’s reported 20 years ago. This is because lead bullet disintegration and mobility takes several years and extensively affects levels of soil-Pb contamination. A total of 120 topsoil samples were collected within the impact area (front) and non-impact area (back) for Pb determination. High concentrations of Pb were found at impact berm both front (28940±2996 μg/g) and back (775±128 μg/g). Spatial distribution of contamination reflects the distances from berm. Soil-Pb contamination around non-impact area was notable at back berm through to 100 m distance with significant difference in Pb, Cr, Ni and Zn levels. Concentration of Pb at berm was observed to have increase five-fold over a period of about twenty years from previous study with accumulation factor of about 1000. Principal component analysis PCA indicated 67 % of total metal load of range soil was majorly from impact areas of the berm. The correspondence analysis relay plot shows pollution order of Pb &gt; Ni &gt; Cd &gt; Cr &gt; Zn &gt; Cu. This confirms soil contamination especially around the impact area, i.e. impact berm and firing lines and non-impact area at 0 m, 10 m, 50 m and 100 m. Environmental consequence of high soil-Pb levels within the range especially non-impact areas utilized for farming activities will leave much to desire. Hence, extensive and continuous monitoring is needed. However, remediation through appropriate soil washing technique could reduce Pb levels and improve soil condition regardless of age.

Limited efficacy of a commercial microbial inoculant for improving growth and physiological performance of native plant species.

Soil microbial inoculants are increasingly being explored as means to improve soil conditions to facilitate ecological restoration. In southwestern Western Australia, highly biodiverse Banksia woodland plant communities are increasingly threatened by various factors including climate change, land development and mining. Banksia woodland restoration is necessary to conserve this plant community. The use of microbial inoculation in Banksia woodland restoration has not yet been investigated. Here, we evaluated the efficacy of a commercial microbial inoculant (GOGO Juice, Neutrog Australia Pty Ltd) for improving the performance of 10 ecologically diverse Banksia woodland plant species in a pot experiment. Plants were subjected to one of two watering regimes (well-watered and drought) in combination with microbial inoculation treatments (non-inoculated and inoculated). Plants were maintained under these two watering treatments for 10weeks, at which point plants in all treatments were subjected to a final drought period lasting 8weeks. Plant performance was evaluated by plant biomass and allocation, gas exchange parameters, foliar carbon and nitrogen and stable isotope (δ15N and δ13C) compositions. Plant xylem sap phytohormones were analysed to investigate the effect of microbial inoculation on plant phytohormone profiles and potential relationships with other observed physiological parameters. Across all investigated plant species, inoculation treatments had small effects on plant growth. Further analysis within each species revealed that inoculation treatments did not result in significant biomass gain under well-watered or drought-stressed conditions, and effects on nitrogen nutrition and photosynthesis were variable and minimal. This suggests that the selected commercial microbial inoculant had limited benefits for the tested plant species. Further investigations on the compatibility between the microorganisms (present in the inoculant) and plants, timing of inoculation, viability of the microorganisms and concentration(s) required to achieve effectiveness, under controlled conditions, and field trials are required to test the feasibility and efficacy in actual restoration environments.

The application of biochar improves the nutrient supply efficiency of organic fertilizer, sustains soil quality and promotes sustainable crop production

AbstractRapeseed meal, a nutritious organic fertilizer (OF), contributes to improving soil environment and crop productivity. However, there are also problems, namely slow fertilizer efficiency and low nutrient utilization during the growing season. This 2‐year field trial was conducted to explore the effect of biochar addition on improving the nutrient availability of OF through a comparative study of various biochar application rates under rice‐rapeseed rotation conditions. The findings revealed that, compared to the individual application of chemical fertilizers (CF), OF alone decreased rice yield (2%/2%) and rapeseed yield (6%/10%) in 2019/2020. Compared with OF, combining biochar (15 t ha−1) with OF (OF + B15) significantly increased rice yield (17%/10%) and rapeseed yield (25%/20%) in the first/second year. Additionally, OF + B15 still increased rice yield (14%/7%) and rapeseed yield (12%/13%) for two consecutive years compared to CF. The co‐application of biochar and OF had positive impacts on soil physicochemical properties and enzymes. Compared to OF, OF + B15 elevated soil organic carbon (SOC) by 57%–81%, soil catalase 19%, invertase 14%–20%, urease 17%–19%, and phosphatase 13%–17% during rice season, and similarly increased SOC by 77%–90%, soil catalase 14%–16%, invertase 14%–20%, urease 18%–24%, and phosphatase 16%–17% in rapeseed season. Biochar addition improved soil conditions and enzymatic activities, and the available nutrient supply of OF. Also, the co‐application of biochar and rapeseed meal surpassed the effect of chemical fertilizer alone on the growth and yield of crops. Therefore, biochar coupling with organic fertilizer is an effective fertilization strategy based on resource recycling, which promotes both crop yield and sustainable agriculture.

Distribusi Kadar Air Tanah Dengan Irigasi Curah Pada Budidaya Tanaman Stevia (Stevia rebaudiana B.)

Sprinkler irrigation emulates rainfall patterns to supply plant water, improving soil conditions and ensuring sustained field performance. This study investigated the impact of sprinkler irrigation on Stevia's Coefficient of Uniformity (CU), soil moisture level, and crop coefficient (Kc). The experiment was conducted in Karangploso Village, Malang Regency, 700 m above sea level. Stevia plants were cultivated using sprinkler irrigation, and their water requirements were assessed by analyzing changes in soil moisture after irrigation. The results showed that sprinkler irrigation significantly increased soil moisture content. At a depth of 0-20 cm, soil moisture increased by an average of 0.135 cm3/cm3 (water depth of 27 mm), while at depths of 20-40 cm and 40-60 cm, the increase was 0.121 cm3/cm3 (24 mm) and 0.065 cm3/cm3 (13 mm), respectively, with a total water depth of 64 mm for 0-60 cm soil depth of 70 mm irrigation event. The crop coefficient (Kc) of Stevia varied during its growth stage, starting from 0.55 in the first week and gradually increasing to 0.57 in the 6th week. The total water requirement for Stevia until harvest at 60 days reached 279.8 mm. This finding emphasize the importance of monitoring and adjusting irrigation practices to ensure optimal growth of Stevia. Sprinkler irrigation effectively increased soil moisture content and determined the appropriate water requirement and Kc value for Stevia cultivation.

Application of humic acid supplemented with micronutrient increase rice production

Fertilizer is one of the crucial inputs to maximize nutrients needed by plants, especially rice. However, insufficient ameliorant application may affect the fertilizers' effectiveness. Humic acid is believed as one of the ameliorants to improve soil conditions resulting in higher nutrient availability. The study aimed to evaluate the effect of combining humic acid and micronutrients on growth, production, and nutrient contents in rice. Three treatments were applied, i.e., control (without humic acid), humic acid, and humic acid + micronutrients. The result showed that both humic acid treatments produced the highest number of tillers, humic acid application solely stimulated the highest root length, and humic acid + micronutrients stimulated the highest plant height, and fresh and dry biomass weight. Grain weight was not affected by treatments, but humic acid + micronutrients gave a higher weight of milled grain and number of filled grains. Humic acid application solely resulted in plant biomass and grains having higher N, P, and K contents. Overall, the application of humic acid + micronutrients is recommended to increase rice production.&#x0D; Keywords: ameliorant; fertilizer; nutrient availability; nutrient uptake