Soil Orders Research Articles

Evaluation of Kinetic and Isotherm Models for Adsorption of Boron Under Different Soil Orders in Oil Palm Plantations of India

ABSTRACT Adsorption isotherm and kinetic models are essential in predicting the adsorption mechanisms, which helps in boron (B) recommendation at appropriate doses. This study is formulated with the objective of assessing different kinetic and adsorption models for the adsorption of B in different soil orders (Entisol, Alfisol, Inceptisol and Vertisol) in Oil Palm plantations in India. The B adsorption in soils followed the order: Vertisol > Alfisol > Inceptisol > Entisol. The results revealed that, the Langmuir adsorption model fitted well for alfisol (part1 R2 = 0.9912 & part2 R2 = 0.9678), entisol (R2 = 0.9862) and inceptisol (R2 = 0.9924), while the Freundlich model fitted well for vertisol (R2 = 0.9943). The soils under entisol and inceptisol showed linear isotherms whereas, the vertisol and alfisol had curvilinear isotherms and the split Langmuir isotherm was worked out. High bonding energy at the lower part of split isotherm represented stronger retention of B at lower B concentrations. The B equilibrium was attained in 24 h in alfisol and inceptisol, and 12 h in entisol, whereas in vertisol, the equilibrium was not completed until 72 h. From the correlation coefficients obtained from all models, the pseudo-second-order kinetic model explained the B sorption in a better way followed by elovich and power function kinetic models in different soil types. Desorption of B is higher in entisol in most of the added B concentrations. The study suggests a higher rate of B fertilizer application than the recommended in soils having high B adsorption capacity for optimum crop growth and yield.

Impacts of soil, water source, and agro-climatic conditions on exchangeable sodium in rice-cultivated lowland soils of Sri Lanka

Rice is sensitive to salt stress, commonly caused by high concentrations of sodium (Na) in soils. However, the concentration and spatial variability of exchangeable Na in lowland paddy fields of Sri Lanka are not known. This study examined the interactive effects of the agro-climatic zones (ACZs), soil orders, and water sources on exchangeable Na in lowland paddy fields in Sri Lanka using 8566 soil samples. Exchangeable Na was extracted using 0.01 mol/L CaCl2 solution and detected using inductively coupled plasma-mass spectrophotometry. Exchangeable-Na concentration ranged from 0.05 to 4814 mg kg−1 with a mean concentration of 140.7 mg kg−1, and these values were within the optimal range reported for tropical paddy soils. The distribution of exchangeable Na was right skewed with 44%, 35%, and 9.3% of samples falling into 0–100, 100–200, and 200–300 mg kg−1, respectively. Samples from the Low country Dry zone had the highest (157 mg kg−1) Na concentration while that in the Upcountry Intermediate zone was the lowest (13 mg kg−1) ( p < 0.05). Vertisols recorded the highest (255 mg kg−1) and Ultisols recorded the lowest (81 ± 5.0 mg kg−1) among soil orders. Soils receiving supplementary irrigation in Low country Dry zone had lower Na than that in rainfed systems. Exchangeable-Na concentration was positively correlated with soil pH ( p < 0.05). Even though the concentrations of Na in soil samples were within the optimal range, agronomic decisions based on ACZ, soil order, and water source need to be made to minimize the potential development of saline–sodic soils in the study areas.

Distribution Characteristics of Low-Molecular-Weight Organic Acids in Reclaimed Soil Filled with Fly Ash: A Study.

This study aims to assess the contents of different kinds of low-molecular-weight organic acids (LMWOAs) in reclaimed soil filled with fly ash in the Huainan mining area in China using high-performance liquid chromatography (HPLC). Using a mobile phase consisting of 0.1% phosphoric acid and acetonitrile in a volume ratio of 98:2, the detection was performed at a wavelength of 210 nm for 15 min. In addition, a cluster analysis was performed on the detected LMWOAs in the reclaimed soil. The correlations between the LMWOA and nutrient contents in the reclaimed soil were also analyzed. In total, eight and seven LMWOAs were detected in the reclaimed soil and filled fly ash, respectively. In contrast, no LMWOAs were detected in the fresh fly ash from a thermal power plant. The order of total LMWOA contents at different sampling points followed the order of farmland control soil > 1# (Triticum aestivum) > 4# (Phragmites australis) > 5# (Vigna radiata) > 2# (Sorghum bicolor) > 3# (Tamarix ramosissima) > fly ash-filled soil. The farmland control soil and fly ash-filled soil exhibited the highest and lowest LMWOA contents of 648.22 and 85.09 μg·g-1, respectively. The LMWOA contents in the reclaimed soil followed the order of oxalic acid > tartaric acid > malonic acid > lactic acid > acetic acid > citric acid > propionic acid > succinic acid. Indeed, oxalic acids exhibited the highest total amount of 1445.79 μg·g-1 and succinic acids exhibited the lowest total amount of 6.50 μg·g-1. The LMWOA contents in the reclaimed soil decreased with increasing soil depth, showing statistically significant differences between the 0-10 and 10-40 cm soil layers (p < 0.05). According to the obtained clustering results, the detected LMWOAs can be divided into two categories. The first category consisted of oxalic acid, while the second category included the remaining LMWOAs. The soil LMWOA contents of 4# (Phragmites australis) and 5# (Vigna radiata) were significantly different from those at the other sampling points. According to the Pearson correlation analysis results, the occurrence and characteristics of the soil LMWOAs can be controlled by regulating the pH values and available nutrient contents in the soil, thereby improving the eco-environmental conditions of the reclaimed rhizosphere.

Culturable Diversity of Endophytic and Rhizoplane Colonizing Bacteria of Indian Mustard (Brassica juncea (L.) Czern & Coss), Affected by Soil Types and Assessment of Plant Growth Promoting Attributes

Microbial community in the rhizosphere of plant significantly influences growth and development of a plant. As the soil vary in microbial composition due to interaction of soil with plant roots and its exudates, the role of soil in shaping microbial diversity of a crop rhizosphere is least studied. In present study, Mustard (Brassica juncea cv Pusa Mehak) was grown in three different soil viz. Vertisols, Inceptisols and Alfisols, and the bacteria were isolated form root tissues and rhizoplane to study their plant growth promoting (PGP) attributes and diversity using BOX-Polymerase chain reaction (PCR) fingerprinting technique, as influenced by soil types. Form threes soil orders, total 37 isolates were obtained of which, 19 could grow on nitrogen free medium, 6 solubilized P from tricalcium phosphate, 2 isolate solubilized potassium from glauconite and 8 had zinc solubilizing ability with the highest zinc solubilization index of 3.84 by isolate VRB-7. Based on the fingerprint analysis, differences occurred in the endophytic bacteria of same host grown in different soil types suggesting influence of soil types in colonization of microbes in rhizoplane and endorhizosphere. The common organisms obtained from host grown in different soil types indicating host genotype driven assembly of bacteria. Similarity in the isolates on rhizoplane and endorhizosphere indicated endophytic colonization of the isolates capable of firmly adhering to the rhizoplane. The findings of this study will help in formulation of crop specific bioinoculant for specific soil types and edaphic properties.

Spatiotemporal Analysis of Soil Quality Degradation and Emissions in the State of Iowa (USA)

The concept of soil quality (SQ) is defined as the soil's capacity to function, which is commonly assessed at the field scale. Soil quality is composed of inherent (soil suitability) and dynamic (soil health, SH) SQ, which can also be analyzed using geospatial tools as a SQ continuum (SQC). This study proposes an innovative spatiotemporal analysis of SQ degradation and emissions from land developments using the state of Iowa (IA) in the United States of America (USA) as a case study. The SQ degradation was linked to anthropogenic soil (SD) and land degradation (LD) in the state. More than 88% of land in IA experienced anthropogenic LD primarily due to agriculture (93%). All six soil orders were subject to various degrees of anthropogenic LD: Entisols (75%), Inceptisols (94%), Histosols (59%), Alfisols (79%), Mollisols (93%), and Vertisols (98%). Soil and LD have primarily increased between 2001 and 2016. In addition to agricultural LD, there was also SD/LD caused by an increase in developments often through urbanization. All land developments in IA can be linked to damages to SQ, with 8385.9 km2 of developed area, causing midpoint total soil carbon (TSC) losses of 1.7 × 1011 kg of C and an associated midpoint of social cost of carbon dioxide emissions (SC-CO2) of $28.8B (where B = billion = 109, USD). More recently developed land area (398.5 km2) between 2001 and 2016 likely caused the midpoint loss of 8.0 × 109 kg of C and a corresponding midpoint of $1.3B in SC-CO2. New developments are often located near urban areas, for example, near the capital city of Des Moines, and other cities (Sioux City, Dubuque). Results of this study reveal several different kinds of SQ damage from developments: loss of potential for future C sequestration in soils, soil C loss, and “realized” soil C social costs (SC-CO2). The state of IA has very limited potential land (2.0% of the total state area) for nature-based solutions (NBS) to compensate for SD and LD. The results of this study can be used to support pending soil health-related legislation in IA and monitoring towards achieving the Sustainable Development Goals (SDGs) developed by the United Nations (UN) by providing a landscape-level perspective on LD to focus field-level initiatives to reduce soil loss and improve SQ. Future technological innovations will provide higher spatial and temporal remote sensing data that can be fused with field-level direct sensing to track SH and SQ changes.

Biochar aided priming of carbon and nutrient availability in three soil orders of India

In recent years biochar (BC) has gained importance for its huge carbon (C) sequestration potential and positive effects on various soil functions. However, there is a paucity of information on the long-term impact of BC on the priming effect and nutrient availability in soil with different properties. This study investigates the effects of BC prepared from rice husk (RBC4, RBC6), sugarcane bagasse (SBC4, SBC6) and mustard stalk (MBC4, MBC6) at 400 and 600 °C on soil C priming and nitrogen (N), phosphorus (P), and potassium (K) availability in an Alfisol, Inceptisol, and Mollisol. BC properties were analyzed, and its decomposition in three soil orders was studied for 290 days in an incubation experiment. Post-incubation, available N, P, and K in soil were estimated. CO2 evolution from BC and soil alone was also studied to determine the direction of priming effect on native soil C. Increasing pyrolysis temperature enhanced pH and EC of most of the BC. The pyrolysis temperature did not show clear trend with respect to priming effect and nutrient availability across feedstock and soil type. MBC6 increased C mineralization in all the soil orders while RBC6 in Alfisol and SBC6 in both Inceptisol and Mollisol demonstrated high negative priming, making them potential amendments for preserving native soil C. Most of the BC showed negative priming of native SOC in long run (290 days) but all these BC enhanced the available N, P, and K in soil. SBC4 enhanced N availability in Alfisol and Inceptisol, RBC4 improved N and P availability in Mollisol and P in Alfisol and MBC6 increased K availability in all the soils. Thus, based on management goals, tailored BC or blending different BC can efficiently improve C sequestration and boost soil fertility.

Perspective: The soil-sphere, save it or lose it

Being first and foremost a plant geneticist specializing in maize, I must admit that when it came to the soil, my most immediate responsibility was to make sure pre-planting amendments were incorporated as recommended. Once those seedlings were up, my focus was almost exclusively on the green plants. But more recently, I taught The Living Soil, a course held at The Woodend Sanctuary and Mansion, owned and operated by the Audubon Naturalist Society of the Central Atlantic States. It was while teaching that I came to see soil more distinctly, as a natural resource with its own taxonomy and individual qualities. It brought back days spent studying soil science and revisiting the relationships among the twelve soil orders as pictured in Dr. Nyle Brady’s textbook [1]. As I considered the time needed to renew these soils and the paucity of highly arable soils globally, I began to see this resource quite differently.

Pengaruh Konsentrasi Beauveria Bassiana Terhadap Intensitas Serangan Serangga Hama Ulat Daun (Plutella xylostella L.), Pertumbuhan Dan Hasil Beberapa Varietas Pakcoy (Brassica rapa L.)

This research aims to determine the interaction between administering concentrations of B. bassiana and several varieties on attacks by leaf caterpillar insect pests in increasing plant growth, plant fresh weight and quality of pakcoy plants. The experiment was carried out on experimental land in Cibedug Village, Cikole Village, Lembang District, West Bandung Regency with an altitude of 1100 m above sea level (asl) with Andisol soil order and was carried out from August 2023 to September 2023. The experimental design used was an environmental design experiment using a Split Plot Design consisting of 12 treatment combinations repeated 3 times. consists of two treatment factors, namely B. bassiana concentration (K) with the following levels: k0 : 0 g L-1 Solution (control), k1 : 2 g L-1 Solution, k2 : 4 g L-1 Solution and k3 : 6 g L-1 Solution and the second factor are several Pakcoy varieties (V) with the following levels: v1: Nauli F1 variety, v2: Flaminggo variety, v3: Masbro variety, which is repeated three times. The results of the research showed that there was no interaction between the concentration of B. bassiana and several pak choy varieties on all observed parameters. Giving a B.bassiana concentration of 4 g L-1 Solution had the most efficient effect on the intensity of attacks, weight and length of the 3rd instar larvae of P.xylostella. The Nauli F1 variety gave the best results in terms of plant height and number of leaves and the Flaminggo variety gave the best results in terms of fresh weight per plant and fresh weight per plot.

Estimating soil N2O emissions induced by organic and inorganic fertilizer inputs using a Tier-2, regression-based meta-analytic approach for U.S. agricultural lands

Consistent methods are essential for generating country and region-specific estimates of greenhouse gas (GHG) emissions used for reporting and policymaking. The estimates of direct N2O emissions from U.S. agricultural soils have primarily relied on the use of emission factors (EFs, Tier-1) and process-based models (Tier-3). However, Tier-1 estimates are relatively crude while Tier-3 calculations can be costly. This work addressed this gap by developing a Tier-2, regression-based approach by leveraging a meta-database containing 1883 field N2O observations together with environmental and management covariates from 139 studies. Our results estimated higher monthly soil N2O emissions (N2Om, kg N/ha) during the growing season (0.38) than the fallow period (0.15), highlighting the importance of considering measurement periods when utilizing meta-databases for analyzing N2O drivers. Significantly different N2Om were found for tillage practices (conventional > no-till: 0.42 > 0.27), fertilizer type (liquid > solid manure: 0.55 > 0.32), and soil texture (fine > coarse: 0.36 > 0.22). The comparisons of the influence of crop type and rotation, water management, and soil order on N2O emissions are complicated by regional data availability and interactions among different factors. Additionally, the finding that N2O emissions reported based on area (N2Om), N input rate (EF), or yield can alter treatment rankings underscores the need to establish transparent criteria for rewarding or discouraging regionally-based management practices using N2O metrics. Finally, we show how General Linear Models (GLMs) can be used to estimate country and regional Tier-2 N2Om using a suite of covariates. Our GLMs identified tillage, water management, N input type and rate, soil properties, and elevation as the most influential covariates for the conterminous U.S. The limited accuracy of regional-scale GLMs, however, suggests the need to further improve the quality and availability of GHG and covariate data through concerted efforts in data collection.

The Availability of Soil N, P, K, and Mustard Yield after the Application of Liquid Organic Fertilizer from Household Waste in Ultisols

Ultisols are one of the dominant soil orders in Indonesia, accounting for approximately 25% of the total land area. The main problem of this soil is high aluminum (Al) saturation with low pH and plant nutrients. The study was intended to determine the effect of liquid organic fertilizer (LOF) from household waste on the availability of N, P, K, and mustard yield in Ultisols. The research used a complete randomized design (CRD) with six concentrations of liquid organic fertilizer of household waste. The treatments were repeated four times. The treatment included control, 10, 20, 30,40, and 50 ml LOF in a liter of water. The study revealed that the liquid organic fertilizer from household waste increased 1.06 folds of total soil N and 1.04 folds of exchangeable-K compared to the control but did not affect available P. Also, soil pH was comparable among treatments. The greatest concentration of LOF (50 ml per liter of water) exhibited the highest yield of mustard, indicated by the highest fresh and dry shoot weight. In general, the study contributes to the development of eco-frindly agriculture.

Effects of agro-climatic zones, soil orders, and irrigation types on the exchangeable cadmium in paddy soils

Even though the concentrations of the total cadmium (Cd) in paddy soils from different countries have been reported, the exchangeable-Cd (Ex-Cd) concentrations in these soils are unknown despite its importance in agriculture. This study was conducted with a total of 5460 soil samples collected in Sri Lanka, representing six agro-climatic zones, six soil orders, and three irrigation types. The Ex-Cd concentrations in soil samples were extracted using 0.01 ​M CaCl2 and analyzed using an inductively coupled plasma-mass spectrophotometry. The Ex-Cd concentrations were <0.31–163 ​μg ​kg−1, with mean and median concentrations being 14.1 and 8.98 ​μg ​kg−1, respectively, which was affected by both agro-climatic and soil conditions. Samples from the Wet zone, particularly the Wet zone Low country, had higher Ex-Cd (24.1 ​μg ​kg−1) than those from the Dry zone Low country (11.6 ​μg ​kg−1). Among the soil orders, Histosols (21.3 ​μg ​kg−1) and Inceptisols (19.5 ​μg ​kg−1) had the highest Cd concentration while Vertisols had the lowest (6.3 ​ ​kg−1). The irrigation types only affected Ex-Cd concentrations in Dry zone Low country, but not in other agro-climatic zones. Overall, it is important to consider agro-climatic zones, soil orders, and irrigation types when implementing agronomic strategies to mitigate the risk associated with Cd accumulation in paddy fields.

The potential of N-fixing bacteria consortium inoculation and NPK application in increasing soil N-total, plant N uptake and tomato (Lycopersicum esculentum Mill.) yields in Andisol

Nitrogen is an essential nutrient for growing tomato plants (Lycopersicum esculentum Mill.) on Andisol soil order. However, many farmers tend to use an excessive amount of inorganic fertilizers, which can have adverse effects on both the environment and tomato yield. To combat this problem, an alternative solution is to replace the inorganic fertilizer through inoculation of Azotobacter as an N-fixing bacteria. An experiment was conducted to examine the combined effects of the N-fixing consortium with NPK on total soil N, N uptake, Azotobacter spp. population, growth and the tomato plants yield. The experiment was performed on Andisols, located roughly 1250 m above sea level in West Java Province. The experimental design used was a Randomized Block Design, in three replications, consisting of A (Control), B (N-fixing inoculation), C (N-fixing + ¼ NPK), D (N-fixing + ½ NPK), E (N-fixing + ¾ NPK), F (N-fixing + 1 NPK), and G (1 NPK). The experiment revealed that the Lembang Andisol had an acidic pH, moderate available N, and high P retention. Applying Azotobacter sp. and Azotobacter vinelandii (N-fixing consortium) combined with one dose of NPK increased plant height and the total soil N content. N-fixing inoculation combined with 1/4 NPK, ½ NP, and ¾ NPK increased plant N uptake. The inoculation of N-fixing + ¼ NPK increased fruit weight, the number of fruits, and the yield per hectare of tomatoes. Inoculating Azotobacter sp. and Azotobacter vinelandii in mixed culture can reduce NPK usage by 75%, resulting in higher tomato yield.

Possible Integration of Soil Information into Land Degradation Analysis for the United Nations (UN) Land Degradation Neutrality (LDN) Concept: A Case Study of the Contiguous United States of America (USA)

Soil makes important contributions to the United Nations (UN) Land Degradation Neutrality (LDN) concept and targets; however, currently, soil is not integrated into measurable information (e.g., indicators, metrics) to monitor land degradation (LD) patterns and trends. This study examines the role of soil in LDN in the UN Convention to Combat Desertification (UNCCD), and UN Sustainable Development Goal (SDG 15: Life on Land). This study is specifically focused on the LDN and biodiversity loss as they relate to an indicator 15.3.1 Proportion of land that is degraded over total land area. Tracking of LD status can be improved by using detailed soils databases combined with satellite-derived land cover maps. This study has applied these newly improved methods to quantify and map the anthropogenic LD status and trends in the contiguous United States of America (USA), as well as to identify potential land areas for nature-based solutions (NBS) to compensate for LD. Anthropogenic LD in 2016 in the contiguous USA affected over two million square kilometers, about one-third of the country’s total area, with high variability by state. Between 2001 and 2016, LD in the USA showed an overall increase of 1.5%, with some states exhibiting increases in degraded land while other states had overall improvements to their land. All ten soil orders present in the contiguous USA have been anthropogenically degraded, with Mollisols, Alfisols, and Vertisols having the highest LD levels. Compensating for LD requires a variety of strategies and measures (e.g., NBS), which often require additional land. In 2016, the potential land area for NBS was over two million square kilometers, an area approximately equal to that of degraded land. Some of the states that have high proportions of land available for potential NBS are dominated by soils (Aridisols) typical of deserts and therefore may have less promise for NBS. The variability of LD needs to be evaluated at finer spatial scales for realistic LDN analysis.

Imprint of clay mineralogy, sesquioxides, and crop residue addition for evaluation of soil organic carbon stability and associated microbial activity in dominant soil orders of Indian subcontinent.

The full behaviour of natural clay minerals in soil organic carbon (SOC) stabilization in the presence of oxides and external C inputs is yet unknown. Thus, an incubation experiment was conducted in a sand-clay mixture with different soil clay fractions (SCFs) obtained from Alfisol, Inceptisol, Mollisol, and Vertisol in the presence of wheat residues to compare their C stabilization capacity. The C mineralization rates were higher in 1:1 type dominated SCFs (Alfisol and Inceptisol) compared to 2:1 interstratified mineral dominated SCFs (Vertisol). Wheat residues as C source altered SCFs' abilities to stabilize SOC at only moderate dosages of application (3-12gkg-1). C mineralization and microbial biomass carbon (MBC) fell by 40% and 30%, respectively, as the amount of clay increased from 7.5 to 40%. However, removing sesquioxides from the SCFs boosted C mineralization and MBC by 22% and 16-32%, respectively, which matched with higher enzymatic activities in the sand-clay mixture. The increased C stabilization capacity of Vertisol-SCF may be attributed to its greater specific surface area (SSA) (506m2g-1) and cation exchange capacity (CEC) [meq/100g]. Regression analysis revealed that SSA, CEC, and enzymatic activity explained approximately 86% of total variations in C mineralization. This study highlighted the critical role of 2:1 expanding clay minerals and sesquioxides in greater stabilization of external C input compared to its 1:1 counterpart. It also implied that the role of mineralogy or texture and sesquioxides levels in different soils (Vertisol, Mollisol, Inceptisol, Alfisol) should be prioritized while adding crop residues to reduce C footprint and enhance sequestration.

Distribution of exchangeable cobalt in low-land rice cultivated soils in Sri Lanka as affected by the differences in climate, soil and water source

Cobalt (Co) is considered a beneficial element for plants. However, when soils contain excessive amounts of Co, it could cause phytotoxicity. Despite this, the current status of Co in Sri Lankan rice-cultivated soils is not known. Therefore, this study was conducted to (i) determine the distribution of exchangeable Co concentration, and (ii) examine the interactive effects of climatic zone (CZ), agro-climatic zone (ACZ), soil order, water source, and their interactions in determining exchangeable Co concentration in lowland rice fields in Sri Lanka. A total of 8,292 soil samples representing six ACZs, six soil orders, and three water sources were collected using a stratified random sampling approach. Cobalt was extracted in 0.01 M CaCl2 and measured using Inductively Coupled Plasma Mass Spectrophotometry. Exchangeable Co concentration ranged between 0.03-2,409 μg kg−1 with a mean value of 185.9 μg kg−1. Over 77.5% of the soil samples tested were Co deficient, i.e. &lt;250 μg kg−1. Samples collected from the Intermediate zone, particularly Intermediate zone Mid country, had higher Co concentration than that reported in other ACZs (p&lt;0.05). Among the soil orders, Histosols had higher (232 μg kg−1) and Vertisols had lower (91 μg kg−1) Co concentrations (p&lt;0.05). Moreover, Co concentration was negatively correlated with soil pH (r=−0.3391, p&lt;0.0001) and rice crop productivity (r=−0.1512, p&lt;0.0001). Although exchangeable Co concentration in rice cultivated soils was low, it is important to implement strategies such as proper waste management, treatment of industrial effluents, and the use of safer and more sustainable practices in the chemical and mining industries to minimize further accumulation of Co exceeding the critical limit (i.e. 30 - 40 mg Co kg−1 rice grain), and to ensure the safety of rice production in situations where geological and anthropogenic activities can increase soil exchangeable Co concentration.

Characterization and classification of soils of a paddy field in Badeggi, Niger State, Nigeria

This study was conducted with the aim of characterizing and classifying the soils of a paddy field in Badeggi Katcha local Government Area of Niger State. Two pedons were dug representing upper and lower slopes of the field and were designated as Badeggi 1 and 2 (BDG1 and BDG2) respectively. The pedons were described on the field following the FAO guidelines for soil description. Soil samples were collected from each identified natural horizons and taken to the laboratory for analysis. Results revealed that BDG1 had greyish brown (10YR 5/2) at the topmost horizon and light brownish grey (10YR 6/2) at the subsoil, while BDG2 had light brownish grey (10YR 6/2) overlying light grey (10YR 7/2) at subsoil. Sand content ranged from 840 to 860 g/kg in BDG 1 and 690 to 830 g/kg in BDG 2, silt ranged from 50 to 70 g/kg in BDG 1 and 90 to 210 g/kg in BDG 2 and clay ranged from 90 to 100 g/kg in BDG 1 and 80 to 100 g/kg in BDG 2. Soils from the two pedons were moderately to slightly acidic, low in organic carbon and available phosphorus, while total nitrogen was rated low to medium and irregularly distributed down the two profiles, but exchangeable Calcium, Magnesium, Potassium and Sodium were high across the study area. Using the USDA soil taxonomy system, the soils were classified as Plinthic Petraquepts (BDG 1) and Fluvaquentic Endoaquepts (BDG 2) which corresponded to Petric Plinthosols (Abruptic) and Fluvic Cambisols (Eutric) respectively, under World Reference Base for Soil Classification (WRB). The study has revealed that BDG1 is moderately well-drained while BDG2 is imperfectly drained. The soils are moderate to slightly acid with low inherent fertility as evidenced by low organic carbon, total nitrogen and available phosphorous. The soils were classified as Inceptisols at Soil Order level.

Smut fungus (Langdonia walkerae) incidence is lower in two bunchgrass species (Aristida stricta and A. beyrichiana) after fires early in the year.

In frequently burned southeastern USA pine-grassland communities, wiregrass (Aristida stricta and A. beyrichiana) are dominant bunchgrasses whose flowers are infected during flowering by a smut fungus (Langdonia walkerae). We hypothesized that because prescribed fire timing affects wiregrass flowering patterns, it could affect smut incidence (occurrence of smut on plants) and severity of infection in inflorescences and spikelets. Because soil order could influence plant susceptibility, we hypothesized that these patterns would differ between soil orders. We hypothesized differences between species as representative of geographic variation in this ecosystem. We surveyed the incidence and severity of L. walkerae in wiregrass populations (85 populations at 14 sites) that had been prescription burned at different times during the previous year. We used binomial regressions to test whether incidence and severity differed by burn day, soil order, or species, with site as a random effect. Fires that occurred in the winter were associated with significantly lower incidence than fires later in the year (as the months progressed into summer). Plants growing on Spodosol soils were significantly less likely to be infected than those on other soils. More variation in incidence, however, was explained by site, suggesting that site-specific characteristics were important. Smut severity in inflorescences and spikelets was greater overall in populations of A. stricta than in southern populations (A. beyrichiana). Our findings indicate that fire timing and soil order affect L. walkerae incidence in wiregrass plants, but neither appears to be associated with greater severity. Patterns of smut infection are related to site history and geographic variation.

Determination of Cu, Pb, and Zn Contents of Soils Formed on Different Parent Materials (Çanakkale, Türkiye)

This study was carried out to determine the heavy metal (Cu, Pb, and Zn) contents and their differences in soils formed on three different parent materials (basalt, clastic and carbonate rocks and granite) in the Ezine district of Çanakkale province. For this purpose, surface sampling was conducted in soils formed under natural conditions on different geological materials. Heavy metal contents of the soil samples were determined using flame atomic absorption spectrometry using the wet digestion Aqua regia method. Analysis of variance (ANOVA) was used to determine the elemental differences in soil samples. Pearson correlation analysis was applied to reveal the relationship between heavy metals and the physicochemical properties of soils taken from different parent materials. As a result of the evaluation, the mean Cu concentrations in the samples ranged from soils formed on basalt (40.8 ± 3.8 μg/g)&gt; soils formed on clastic and carbonate rocks (24.8 ± 1.5 μg/g)&gt; soils formed on granite (22.5 ± 2. 8 μg/g); mean Pb concentrations followed the order of soils formed on granite (37.50 ± 3.30 μg/g)&gt; soils formed on clastic and carbonate rocks (35.67 ± 2.74 μg/g)&gt; soils formed on basalt (21.6 ± 6.7 μg/g). The mean Zn concentrations of the soil samples were as follows: soils formed on basalt (80.9 ± 8.7 μg/g)&gt; soils formed on clastic and carbonate rocks (44.1 ± 3.7 μg/g)&gt; soils formed on granite (37.0 ± 9.4 μg/g). Pb concentrations of all soil samples were found to be higher than the average of the earth's crust.

Application of Dolomite as Soil Conditioner to pH and Exchangeable Al in Inceptisol

Soil fertility is the state of the soil where water, water and nutrients are in a state that is quite balanced and can be obtained according to the needs of plants, including the physical, chemical and biological needs of the soil. Lack of soil fertility will affect plant growth and productivity so that it is less than optimal. Therefore, it is very necessary to increase soil fertility through soil improvement, one of which is dolomite. Inceptisols are soil orders that have not developed further with the characteristics of a thick solum between 1.5-10 meters above the parent material, reacts acidly with a pH of 4.5-6.5, if it undergoes further development the pH increases to less than 5.0, and base saturation is from low to low. currently. The texture of this whole solum is generally clayey, while the structure is crumbly and the consistency is loose. In general, the fertility and chemical properties of Inceptisols are relatively low, but efforts can still be made to improve with appropriate handling and technology, pH in Inceptisol soils is one of the obstacles in efforts to increase soil productivity. The application of dolomite on acidic agricultural soils is to reduce or eliminate the adverse effects of acid soils, which generally contain high enough quantities of exchangeable aluminum ions so that they can poison plants. This test was carried out at the Experimental Field of the Chemical Laboratory of Soil Fertility and Plant Nutrition, Department of Soil Science and Land Resources, Faculty of Agriculture, Universitas Padjadjaran, Jatinangor, Sumedang Regency, West Java, which is located at an altitude of 794 m above sea level. The experiment used a randomized block design (RAK). In accordance with the objectives of the experiment, five dolomite test treatments were set with five replications. Dolomite affects the process of increasing pH and decreasing exchangeable Al. Giving the test dose of dolomite equivalent to 1.5 doses of dolomite was able to increase pH and decrease Al-exchable.

Health and Characteristics of Australian Apple Growing Soils

Despite being the highest value fruit crop in Australia, little is known about the types and condition or “health” of Australia’s apple growing soils. This study is unique in being the first to report the condition and characteristics of Australia’s apple growing soils; it provides essential baseline data for future monitoring of soil health in apple production systems, as well as soil physical and chemical data required for the development of perennial soil-tree-climate models. Soil chemical and physical properties were measured at 34 orchards, across five states. Soils were assessed for water retention, hydraulic conductivity, bulk density, macroporosity, organic carbon, CEC, ESP, pH, and EC. Despite high to very high levels of organic carbon, most topsoils were moderately to poorly structured. Around one-third to half of all sites showed evidence of poor aeration or impeded drainage, whilst 10 of the 34 sites were prone to nutrient leaching. Plant available soil water (PAWC) varied greatly between sites from 31 mm to 170 mm from 0 to 60 cm depth and between sites within the same soil order. Whilst topsoils had high to very high levels of organic carbon (average: 2.46%), they were otherwise poorly structured, with higher than expected bulk density (average: 1.32 g/cm3) and lower than expected air capacity (average: 9.97%) and macroporosity (average: 1.75%). Subsoils were also found to have little soil water availability (average: 15.39 mm/100 mm), low air capacity (average: 5.28%), and low CEC (average: 8.12 cmol (+) kg−1). Notably, 10 of the 34 sites had less than 6 cmol (+) kg−1 CEC throughout the entire soil profile, indicating potential risk of nutrient leaching. This study indicates that apple growing soils require careful management to improve topsoil structure, and to maintain or increase soil carbon, as well as use of soil moisture sensors to schedule irrigation. In addition, some sites also require improved subsoil drainage and care to ensure fertigation and irrigation do not result in leaching of nutrients beneath the root zone.