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Entisol soil is hard and compact in nature, rendering it high in bulk density, which influences root penetration adversely and thereby poor plant growth. In this experiment, used seven treatments in different combination in normal soil, were used as growth media for the Terminalia arjuna seedling. T3 (60% entisol) found the best as it gave the highest biomass in the species regardless of arbuscular mycorrhizal fungi (AMF) treatment. AMF treatment enhanced the growth and biomass of plants significantly in all the given treatments. AMF colonization observed a maximum in tertiary roots. T1 (100% entisol soil) exhibited the highest degree of AMF colonization in tertiary roots, resulting in the highest mycorrhiza dependency of plants for this soil. The addition of normal soil to entisol soil was found to decrease the bulk density, resulting in increased root diameter, and T3 plants exhibited the highest biomass and AMF compatibility for T. arjuna species. The T. arjuna plant’s growth and biomass responded positively to AMF in all types of treatments. The plant’s growth and biomass were highest in the T3 treatment, which had a bulk density of 1.50 g/cm3. In this study, we combined the entisol with mycorrhizal inoculation of the nursery growing medium to promote plant growth and biomass, improve the plant’s ability to hold water and absorb nutrients, and lower the entisol’s bulk density. The T. arjuna (Roxb) plant responds very favorably to mycorrhiza inoculation in nursery conditions with the entisol growth medium.

Entisol soil is hard and compact in nature, rendering it high in bulk density, which influences root penetration adversely and thereby poor plant growth. In this experiment, used seven treatments in different combination in normal soil, were used as growth media for the Terminalia arjuna seedling. T3 (60% entisol) found the best as it gave the highest biomass in the species regardless of arbuscular mycorrhizal fungi (AMF) treatment. AMF treatment enhanced the growth and biomass of plants significantly in all the given treatments. AMF colonization observed a maximum in tertiary roots. T1 (100% entisol soil) exhibited the highest degree of AMF colonization in tertiary roots, resulting in the highest mycorrhiza dependency of plants for this soil. The addition of normal soil to entisol soil was found to decrease the bulk density, resulting in increased root diameter, and T3 plants exhibited the highest biomass and AMF compatibility for T. arjuna species. The T. arjuna plant's growth and biomass responded positively to AMF in all types of treatments. The plant's growth and biomass were highest in the T3 treatment, which had a bulk density of 1.50 g/cm3. In this study, we combined the entisol with mycorrhizal inoculation of the nursery growing medium to promote plant growth and biomass, improve the plant's ability to hold water and absorb nutrients, and lower the entisol's bulk density. The T. arjuna (Roxb) plant responds very favorably to mycorrhiza inoculation in nursery conditions with the entisol growth medium. [ABSTRACT FROM AUTHOR]

Imidacloprid (IDP) products are applied via soil drenching in the citrus critical root zone (CCRZ) at 0–60 cm soil depth. This study aimed to determine the uptake and leaching of IDP in the CCRZ of a Florida Entisol. The treatments include: (1) a control with no IDP applied, (2) 1.6 g of active ingredient (a.i.) per tree (×2), and (3) 3.2 g a.i. per tree of IDP (×4). The treatments were applied to two trees within each experiment unit, replicated five times, and completely randomized. The IDP concentration in the Entisol was affected by the amount of water received within the sampling intervals. IDP movement in the Entisol was evident for the field trials in Fall 2021 and 2022, irrespective of the treatment. A total of 10 mm of daily irrigation was the major driver of IDP movement in Fall 2021 (September–December 2021), while 11.7 cm of cumulative rainfall plus 10 mm of daily irrigation were the major drivers for IDP in Fall 2022 (November–December 2022). The IDP uptake level by leaves was relatively low probably because of the relatively low temperature and humidity. More applications of IDP did not result in its higher uptake by citrus leaves in the Entisol. Given the persistence of IDP, there is a possibility of leaching, which could potentially contaminate the groundwater, surface water, and non-target organisms. Therefore, it is crucial to carefully manage the use of IDP in citrus production systems to mitigate the unintended environmental impacts.

Phosphorus (P) is a vital macronutrient for continued growth and high fruit production. Glyphosate is the most commonly used herbicide in Florida citrus production for controlling weeds, which can proliferate with Florida's high temperature and precipitation. The focus of the study was to monitor P and orthophosphate bioavailability, uptake, and adsorption in citrus in selected Florida soils. The study was performed under greenhouse conditions using varying amounts of P and glyphosate treatments separately and in tandem to assess the bioavailability, uptake, and adsorption of P in the presence of glyphosate. There were 36 young Valencia citrus trees [Citrus sinensis (L.) Osb] for this experiment. There were nine different treatments with varying P and glyphosate rates and combinations with four replicates of each treatment. The P levels within the soil and the plant organs were measured. Significant differences within the plant tissue (p <.05) were observed that could suggest P was retained within the soil when glyphosate was applied with P. Results showed there was an additive effect when glyphosate and P were applied in tandem, moreover when P is applied with glyphosate, and did not inhibit citrus tree growth. This result could be used to establish effective rates of glyphosate and P when applied together in citrus production systems. [ABSTRACT FROM AUTHOR]

Nickel (Ni) is extremely toxic to plants at high concentrations. Phytoliths have the potential to sequester the heavy metals absorbed by plants and act as a detoxification mechanism for the plant. The authors of the present study aimed to evaluate the effects of Ni on the growth and phytolith yield of grasses in two artificially contaminated soils. Two experiments separated by soil types (Typic Quartzipsamment and Rhodic Hapludox) were conducted in a completely randomized design in a 2 × 4 factorial scheme with three replications. The factors were two species of grass (Urochloa decumbens and Megathyrsus maximus) and three concentrations of Ni (20, 40, and 120 mg kg−1) and control treatment. The grasses were influenced by the increase in Ni rates in the soils. Ni exerted a micronutrient function with the addition of 30 mg kg−1 of Ni in soils, but this concentration caused toxicity in grasses. Such a level is lower than the limits imposed by the Brazilian environmental legislation. Higher Ni availability in Typic Quartzipsamment promoted Ni toxicity, with reduced growth and increased phytolith yield in the shoot, increased Ni in the shoot, and Ni occlusion in phytoliths by grasses, in comparison with Rhodic Hapludox. The yield and Ni capture in phytoliths by grasses in Ni-contaminated soils are related to the genetic and physiological differences between grasses and Ni availability in soils. Ni capture by phytoliths indicates that it may be one of the detoxification mechanisms of Urochloa decumbens to Ni contamination, providing additional tolerance. Megathyrsus maximus may be a future grass for the phytoremediation technique in Ni-contaminated soils. [ABSTRACT FROM AUTHOR]

It is crucial to comprehend how fertilization and cultivation management alter the composition of dissolved organic carbon (DOC) and microbial communities to regulate the biogeochemical cycling of soil nutrients and mitigate adverse impacts on soil–water quality. Based on 15 years of long-term field trials conducted in purple soil on farmland with a slope of 15° in southwestern China, the following five treatments were examined: CK (no fertilizer was applied), T1 (NPK plus organic manure and downslope cultivation), T2 (NPK and downslope cultivation), T3 (1.5-fold NPK and downslope cultivation), and T4 (NPK and contour cultivation). Soil samples were obtained from summer maize at two soil depths (0–10 and 10–20 cm) and from rhizospheric soil, and the changes in the DOC content, UV–visible (UV–Vis) absorptivity, and phospholipid fatty acids (PLFAs) were assessed. Our results revealed a significant change in the DOC content following fertilization, especially in T1, as it was 136.0%, 179.4%, and 132.2% higher, respectively, than that in CK at the 0–10 and 10–20 cm depths and rhizospheric soil. Fertilization decreased the UV–Vis absorptivity variables of DOC (i.e., SUVA254, SUVA260, SUVA400, SUVA465, SUVA665, and C:C ratio) and raised the E4:E6 ratio (fulvic acid to humic acid in DOC), regardless of T2 and T3 at the 10–20 cm depth and in the rhizospheric soil compared with those in CK, respectively. Fertilization significantly increased the total PLFA content and selected microbial groups relative to CK. Among the treatments, T1 significantly increased the total PLFA content by 50.6%, 59.0%, and 46.2%, respectively, relative to CK, at the 0–10 and 10–20 cm depths and in the rhizospheric soil. The microbial community structure in contour cultivation (T4) was significantly greater than in downslope cultivation (T2). Random forest analysis (RFA) revealed that SOC and DOC were likely the primary variables for regulating the total PLFAs in the examined soil. Partial least squares path modeling (PLS-PM) further indicated that the DOC content and the ratio of E4:E6 among DOC compositions had greater effects on the soil microbial community structure in the examined soil. These observations suggested that long-term fertilization and cultivation management are effective approaches to regulating the soil microbial community structure by altering the composition of DOC in sloping farmland. [ABSTRACT FROM AUTHOR]

Imidacloprid (IDP) products are applied via soil drenching in the citrus critical root zone (CCRZ) at 0–60 cm soil depth. This study aimed to determine the uptake and leaching of IDP in the CCRZ of a Florida Entisol. The treatments include: (1) a control with no IDP applied, (2) 1.6 g of active ingredient (a.i.) per tree (×2), and (3) 3.2 g a.i. per tree of IDP (×4). The treatments were applied to two trees within each experiment unit, replicated five times, and completely randomized. The IDP concentration in the Entisol was affected by the amount of water received within the sampling intervals. IDP movement in the Entisol was evident for the field trials in Fall 2021 and 2022, irrespective of the treatment. A total of 10 mm of daily irrigation was the major driver of IDP movement in Fall 2021 (September–December 2021), while 11.7 cm of cumulative rainfall plus 10 mm of daily irrigation were the major drivers for IDP in Fall 2022 (November–December 2022). The IDP uptake level by leaves was relatively low probably because of the relatively low temperature and humidity. More applications of IDP did not result in its higher uptake by citrus leaves in the Entisol. Given the persistence of IDP, there is a possibility of leaching, which could potentially contaminate the groundwater, surface water, and non-target organisms. Therefore, it is crucial to carefully manage the use of IDP in citrus production systems to mitigate the unintended environmental impacts. [ABSTRACT FROM AUTHOR]

The unintended loss of glyphosate and P from cropland may pose an environmental risk to downstream water quality and marine ecosystems. Glyphosate and P compete for exchange sites, and since glyphosate is an organophosphate, it reacts similarly to phosphates in soil. The competition for exchange sites between glyphosate and P could lead to an increased risk of loss due to leaching, leading to water quality degradation and harm to aquatic wildlife. The focus of this study was to (i) determine the sorption tendencies of P and orthophosphate in Florida Entisols and (ii) determine the sorption tendencies of glyphosate in Florida Entisols. Adsorption and desorption experiments were performed for both P and glyphosate. The data from the sorption experiments were fitted to linear, Freundlich, and Langmuir models. Orthophosphate-P (ortho-P) was best represented by the linear isotherm. Glyphosate adsorption was best represented by the linear isotherm, and desorption was best represented by both the linear and Freundlich models. Phosphorus and glyphosate sorption and desorption increased with soil depth, likely due to the higher concentrations of Fe and Al with greater depth. These results could improve P and glyphosate application rates when applied in tandem to citrus trees, increasing overall tree health and improving soil quality.

The unintended loss of glyphosate and P from cropland may pose an environmental risk to downstream water quality and marine ecosystems. Glyphosate and P compete for exchange sites, and since glyphosate is an organophosphate, it reacts similarly to phosphates in soil. The competition for exchange sites between glyphosate and P could lead to an increased risk of loss due to leaching, leading to water quality degradation and harm to aquatic wildlife. The focus of this study was to (i) determine the sorption tendencies of P and orthophosphate in Florida Entisols and (ii) determine the sorption tendencies of glyphosate in Florida Entisols. Adsorption and desorption experiments were performed for both P and glyphosate. The data from the sorption experiments were fitted to linear, Freundlich, and Langmuir models. Orthophosphate-P (ortho-P) was best represented by the linear isotherm. Glyphosate adsorption was best represented by the linear isotherm, and desorption was best represented by both the linear and Freundlich models. Phosphorus and glyphosate sorption and desorption increased with soil depth, likely due to the higher concentrations of Fe and Al with greater depth. These results could improve P and glyphosate application rates when applied in tandem to citrus trees, increasing overall tree health and improving soil quality. [ABSTRACT FROM AUTHOR]

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AbstractWater stress significantly impacts the plants’ physiological activity. They are influenced by the stomata and photosynthesis of the plant. The main objectives of the experiments are to determine the stomata and photosynthetic activity changes in the Dalbergia sissoo seedlings under the entisol soil in nursery conditions and the water stress conditions on AMF colonization. The plant growth characteristics and physiological activities in D. sissoo were assessed under three conditions: WW (well watering), FW (fractionated watering), and SW (stopped/no watering), with the results revealing that the FW condition has a higher mycorrhizal dependency of 24.53% than the WW condition, which is 24.37%. AMF root colonization was also higher in D. Sissoo, at 56% and 47% under FW and WW conditions. These findings highlight the significance of AMF, especially when plants are experiencing water stress. When FW was used instead of WW, the photosynthetic rate of D. sissoo and AMF + plants increased by 17.85%. AMF inoculation changed the plant’s physiological activities, resulting in a significantly higher photosynthesis rate and stomatal conductance. However, higher transpiration, intercellular CO2 concentration, and a lower leaf temperature regardless of WW or FW conditions indicate that AM positively affects physiological activities. The findings support the use of AMF in entisol soil to improve plant growth and biomass by alleviating adverse edaphic conditions.

Continuous use of synthetic fertilizer can lead to the accumulation of heavy metals in the soil. The use of organic amendment can reduce the solubility of heavy metals such as Pb and Cd in soil. The experiment was undertaken to determine the decline of soluble Pb and Cd in polluted soils treated with dairy cattle waste-based vermicompost. The study used two soil samples; Inceptisols collected from Air Duku Village and Entisol from Beringin Raya Village, Bengkulu, Indonesia. Entisols and Inceptisols contained 2.0 and 0.4 mg kg-1 soluble Pb and 0.7 and 0.8 mg kg-1soluble Cd, respectively. The samples were pretreated with either 100 ppm Pb or Cd. Vermicompost was applied at the rate of 0, 10, 20, and 30 Mg ha-1 on samples of Inceptisols and Entisol, arranged in Completely Randomized Design (CRD). The mixture was incubated for eight weeks. After the incubation ended, the soil sample was analyzed for soluble Pb and Cd using DTPA extraction before detection using Atomic Absorption Spectroscopy. The study resulted that the soluble Pb and Cd significantly reduced with vermicompost treatment, being the lowest was at the rate of 30 Mg ha-1. Furthermore, the decreased soluble Pb and Cd was more substantial in Inceptisols than Entisols. Soluble Pb in both soils was lower than Cd, suggesting a higher retention affinity of the former. This study summarizes that vermicompost at the rate of 30 Mg ha-1 effectively immobilizes Pb and Cd in contaminated soils.

Entisol has poor physical, chemical, and biological properties that limit the growth and yield of maize. This study aimed to obtain the correct dose of vermicompost to increase the growth and yield of maize on Entisols. The research was arranged using Randomized Block Design, consisted of 7 treatment doses of vermicompost fertilizer (0; 2.5; 5; 7.5; 10; 12.5; and 15 Mg ha-¹ and 4 re;plications. The results showed that the dose of vermicompost significantly affected the growth and yield of maize in coastal entisol soils. The dose of 10 Mg ha-¹ was the best on plant height, leaf number, fresh weight, plant dry weight, shoot fresh weight, fresh root weight, and shoot and root dry weight. Meanwhile, the dose of 12.5 Mg ha-¹ produced the best maize yields for the fresh weight of husked ear per plant, fresh weight of unhusked ear per plant, and dry grain weight per plant, namely, 322.75 g, 286.66 g, and 173.4 g, respectively. The best results of fresh weight of husked ear per plot, fresh weight of unhusked ear per plot, and dry grain weight per plot were achieved by vermicomposting of 15 Mg ha-¹, which were 11.28 kg, 9.72 kg, and 5.94 kg, respectively. [ABSTRACT FROM AUTHOR]

It is crucial to comprehend how fertilization and cultivation management alter the composition of dissolved organic carbon (DOC) and microbial communities to regulate the biogeochemical cycling of soil nutrients and mitigate adverse impacts on soil–water quality. Based on 15 years of long-term field trials conducted in purple soil on farmland with a slope of 15° in southwestern China, the following five treatments were examined: CK (no fertilizer was applied), T1 (NPK plus organic manure and downslope cultivation), T2 (NPK and downslope cultivation), T3 (1.5-fold NPK and downslope cultivation), and T4 (NPK and contour cultivation). Soil samples were obtained from summer maize at two soil depths (0–10 and 10–20 cm) and from rhizospheric soil, and the changes in the DOC content, UV–visible (UV–Vis) absorptivity, and phospholipid fatty acids (PLFAs) were assessed. Our results revealed a significant change in the DOC content following fertilization, especially in T1, as it was 136.0%, 179.4%, and 132.2% higher, respectively, than that in CK at the 0–10 and 10–20 cm depths and rhizospheric soil. Fertilization decreased the UV–Vis absorptivity variables of DOC (i.e., SUVA254, SUVA260, SUVA400, SUVA465, SUVA665, and C:C ratio) and raised the E4:E6 ratio (fulvic acid to humic acid in DOC), regardless of T2 and T3 at the 10–20 cm depth and in the rhizospheric soil compared with those in CK, respectively. Fertilization significantly increased the total PLFA content and selected microbial groups relative to CK. Among the treatments, T1 significantly increased the total PLFA content by 50.6%, 59.0%, and 46.2%, respectively, relative to CK, at the 0–10 and 10–20 cm depths and in the rhizospheric soil. The microbial community structure in contour cultivation (T4) was significantly greater than in downslope cultivation (T2). Random forest analysis (RFA) revealed that SOC and DOC were likely the primary variables for regulating the total PLFAs in the examined soil. Partial least squares path modeling (PLS-PM) further indicated that the DOC content and the ratio of E4:E6 among DOC compositions had greater effects on the soil microbial community structure in the examined soil. These observations suggested that long-term fertilization and cultivation management are effective approaches to regulating the soil microbial community structure by altering the composition of DOC in sloping farmland.

Nickel (Ni) is extremely toxic to plants at high concentrations. Phytoliths have the potential to sequester the heavy metals absorbed by plants and act as a detoxification mechanism for the plant. The authors of the present study aimed to evaluate the effects of Ni on the growth and phytolith yield of grasses in two artificially contaminated soils. Two experiments separated by soil types (Typic Quartzipsamment and Rhodic Hapludox) were conducted in a completely randomized design in a 2 × 4 factorial scheme with three replications. The factors were two species of grass (Urochloa decumbens and Megathyrsus maximus) and three concentrations of Ni (20, 40, and 120 mg kg−1) and control treatment. The grasses were influenced by the increase in Ni rates in the soils. Ni exerted a micronutrient function with the addition of 30 mg kg−1 of Ni in soils, but this concentration caused toxicity in grasses. Such a level is lower than the limits imposed by the Brazilian environmental legislation. Higher Ni availability in Typic Quartzipsamment promoted Ni toxicity, with reduced growth and increased phytolith yield in the shoot, increased Ni in the shoot, and Ni occlusion in phytoliths by grasses, in comparison with Rhodic Hapludox. The yield and Ni capture in phytoliths by grasses in Ni-contaminated soils are related to the genetic and physiological differences between grasses and Ni availability in soils. Ni capture by phytoliths indicates that it may be one of the detoxification mechanisms of Urochloa decumbens to Ni contamination, providing additional tolerance. Megathyrsus maximus may be a future grass for the phytoremediation technique in Ni-contaminated soils.

Nanotechnology can be used to produce slow-release fertilizers. Zeolite and crab shells are materials that can be used as fertilizer encapsulation. This study aimed to compare the effects of nano zeolite and crab shells for encapsulation of nitrogen- potassium fertilizers tested on Entisols and Inceptisols soil on the growth and yield of shallots. The research method used a completely randomized design with three factors. The factors were soil type (Entisol and Inceptisol), coating materials (nano-zeolite and nano-crab shell), and NK fertilizer doses (125:50, 250:100, 375:150, and 500:200). The variables observed include initial soil physical and chemical properties, nanoparticle characterization, growth and yield, and agronomic efficiency. Nanoparticles were characterized using SEM and analyzed using ImageJ. The data collected were tested by ANOVA and Tukey. The ball milling method succeeded in producing 91.41% zeolite and 97.50% nano-sized crab shells. Plant height showed that using crab shells as fertilizer encapsulation with a dose of 125:50 gave better results. The yield of crab shells as encapsulation with a dose of 250:100 in inceptisols was better than that in entisols, but the highest agronomic efficiency (EA) was obtained in zeolite treatment as fertilizer encapsulation with a dose of 125:50.

The residual effects of biochar doses on Entisols after five years of application have not received attention. However, there is an assumption that the positive effects of biochar can last longer in the soil. Therefore, field experiments were carried out in polybags to assess the residual impact of applying biochar doses in the fifth year and the addition of urea fertilizer on the growth of red spinach (Amaranthus tricolor) in Entisol. The growing media used in this study was a medium previously used for five years containing biochar in Entisols. This study used a 2-factor randomized block design consisting of residual doses of biochar (3 levels) and the addition of urea fertilizer (2 levels). There was no interaction between biochar and N fertilizer. Application of biochar at a dose of 500 g/polybag gave a better follow-up effect than 250 g/polybag on the growth of red spinach in the fifth year. Chlorophyll content increased with N fertilization. Applying biochar in the fifth year and N fertilization positively impacted the growth of red spinach in Entisol. Spinach yield increased 30% at the remaining dose of biochar 500 g/polybag and 52% with N fertilization. Within five years, using higher doses of biochar and adding urea will result in better growth of red spinach in Entisol.

The impact of different soil orders and land use systems on the distribution of physico-chemical properties is the most critical matter to address in order to maintain sustainable agricultural production. Hence, the present investigation was carried out to study the variation in the physico-chemical characteristics of soil in diverse land use systems (LUSs), i.e., agriculture, horticulture, and forestry, under major soil orders (entisol, inceptisol, and alfisol) in the Majha region of Punjab. A total of 225 depth-wise (at 0–20 cm, 20–40 cm, 40–60 cm, 60–80 cm and 80–100 cm) soil samples were collected from three land-use systems under different soil orders. The mean values of the physico-chemical properties ranged from 6.80–7.50, 7.64–8.34 and 6.94–7.87 for pH; 0.13–0.42, 0.19–0.54 and 0.19–0.46 dS m−1 for EC; 0.14–0.99, 0.21–0.69 and 0.15–0.72% for OC; 0.75–2.07, 1.07–3.32 and 0.93–2.29% for CaCO3; 7.77–41.84, 10.56–40.23 and 7.24–39.51 kg ha−1 for P; and 98.37–334.68, 94.51–230.18 and 93.01–367.39 kg ha−1 for K under different land uses in soil orders entisols, inceptisols and alfisols, respectively. Soil parameters including pH, CaCO3, and phosphorus (P) distribution differed significantly among soil orders; however, soil EC, organic carbon (OC) and available potassium (K) did not. The inceptisols under the agricultural land use system (ALUS) had the highest soil pH, EC, and CaCO3 values. The highest soil OC content was found in entisols under forest land use systems (FLUS), followed by horticultural land use systems (HLUS). The highest values of soil-available phosphorous (P) were found in FLUS under inceptisols, while the highest amounts of soil-available potassium (K) were found in entisols and alfisols under ALUS and FLUS, respectively. Thus, the distribution of physico-chemical properties under different LUSs in each soil order is highly variable and does not follow any particular trend. In general, soil properties such as OC, P, and K content decreased with an increase in soil depth, while pH and CaCO3 values increased with depth in all land uses and soil orders. There was a positive correlation between soil OC and EC, as well as available P and K in the soils investigated. The available P and K are negatively correlated with soil pH and CaCO3 content in the soil. The principal component analysis (PCA) revealed that soil pH and OC were the most variable soil parameters, which influence the availability of other physico-chemical properties under different soil orders and land use systems. Therefore, it is suggested that the land use systems play an important role in the distribution of physico-chemical properties of soil in different soil orders. The results of the study will help students, researchers, and agricultural management staff in managing different land uses for maintaining soil fertility and productivity in alluvial soils of North-western India. [ABSTRACT FROM AUTHOR]

The impact of cropping systems on soil aggregation and associated carbon (C) and nitrogen (N) stabilization in relation to soil's antecedent C level has not been well addressed, which is essential for prioritization of agricultural soils for C and N sequestration. In this background, the present study investigated the influence of maize-wheat (MW) and soybean-wheat (SW) cropping systems and continuous fallow (CF) on soil aggregation and associated C and N storage in four soils of same type and texture (sandy loam textured Typic Ustorthents) but different antecedent C levels: a low-C soil (Soil 1, 5.6 g C kg–1), two medium-C soils (Soil 2, 9.0 g C kg–1 and Soil 3, 9.6 g C kg–1) and a high-C soil (Soil 4, 12.9 g C kg–1). While in low-C soil, MW outperformed the SW in increasing aggregate mean weight diameter (MWD) by 13% and C and N preservation capacities of macroaggregate fractions by 5–52%; in medium-C soils, the opposite occurred where SW showed 4–9% increased MWD and 8–76% increased C and N preservation capacity over MW. Contrarily in high-C soil, the two cropping systems behaved similarly; these decreased the aggregate MWD by 6–10% and the macroaggregate-preserved C and N by 8–39% compared to the CF. Changes in macroaggregate C and N storage were significantly related to bulk soil C and N levels (R2 = 0.65–0.85, p < 0.05). Conclusively, the selection of cropping systems to improve aggregate C and N storage must preconsider the antecedent soil C level; because the magnitude and direction of cropping impacts on C and N storage depend on soil's antecedent C level. For a greater physical stabilization of sequestered C and N, in the Entisols of northwest India, MW and SW may be promoted to low- and medium-C soils, respectively. [ABSTRACT FROM AUTHOR]

The rate of change in the relative amount of active and passive carbon (AC and PC) due to the land management practices (cropping systems combined with tillage) may vary with soil types depending on their level of chemical and/or physical protection from the decomposition but has rarely been directly measured. We have quantified the C storage potentiality of different soil types, namely old alluvial Inceptisol of Malda and recent alluvial Entisol of Coochbehar in West Bengal (subtropical eastern India) under the influence of different cropping systems (rice-maize: RM and rice-wheat: RW) and tillage practices (zero-tillage: ZT and conventional tillage: CT). The key objective was to demonstrate the short-term impact of conservation agriculture (CA) on soil C dynamics over the conventional practice. Research revealed that after short-term CA, total organic carbon (TOC), AC, PC, and total nitrogen (TN) showed significant (p < 0.05) improvement under the RM cropping system over the RW. The highest TOC content under the RM cropping system was recorded in the sites of Malda over the Coochbehar sites. The ZT significantly (p < 0.05) enhanced the TOC in the upper layers (0–5 and 5–10 cm) and the CT showed improvements in the lower depths (10–20 cm). We observed some irregular variations in the interactions of the cropping system and tillage with respect to different sites. However, the ZT performed better in improving C fractions under RM and RW as compared to CT. The TOC and TN stocks were maximum in the lower depth which was evident in both soil types. The TOC linearly regressed on TN accounted for 94.2% variability (R2 = 0.942) of the C accumulation in soil and vice-versa. The PC was in a significant relationship with TN (R2 = 0.943), but AC was moderately regressed (R2 = 0.851). Lower stratification ratio values in Coochbehar soils (sandy loam in texture) indicated higher profile distribution of AC and PC in the soil profile; while in the Inceptisol, accumulation of the C fractions on the soil surface due to heavy texture resulted in the higher stratification values. The novelty of this study is that old alluvial Inceptisol showed a comparatively greater amount of AC and PC storage capability in comparison with the new alluvial Entisol. Conclusively, our study demonstrated that the adoption of conservation agriculture (CA practice/ZT) in cropping systems with higher C biomass input would significantly enhance the AC and PC fractions; however, the amount of storage is highly governed by the soil type and climatic factors. [ABSTRACT FROM AUTHOR]

Continuous use of synthetic fertilizer can lead to the accumulation of heavy metals in the soil. The use of organic amendment can reduce the solubility of heavy metals such as Pb and Cd in soil. The experiment was undertaken to determine the decline of soluble Pb and Cd in polluted soils treated with dairy cattle waste-based vermicompost. The study used two soil samples; Inceptisols collected from Air Duku Village and Entisol from Beringin Raya Village, Bengkulu, Indonesia. Entisols and Inceptisols contained 2.0 and 0.4 mg kg-1 soluble Pb and 0.7 and 0.8 mg kg-1soluble Cd, respectively. The samples were pretreated with either 100 ppm Pb or Cd. Vermicompost was applied at the rate of 0, 10, 20, and 30 Mg ha-1 on samples of Inceptisols and Entisol, arranged in Completely Randomized Design (CRD). The mixture was incubated for eight weeks. After the incubation ended, the soil sample was analyzed for soluble Pb and Cd using DTPA extraction before detection using Atomic Absorption Spectroscopy. The study resulted that the soluble Pb and Cd significantly reduced with vermicompost treatment, being the lowest was at the rate of 30 Mg ha-1. Furthermore, the decreased soluble Pb and Cd was more substantial in Inceptisols than Entisols. Soluble Pb in both soils was lower than Cd, suggesting a higher retention affinity of the former. This study summarizes that vermicompost at the rate of 30 Mg ha-1 effectively immobilizes Pb and Cd in contaminated soils. [ABSTRACT FROM AUTHOR]

Phytoremediation has become a promising technique for cleaning Pb-contaminated soils. Grasses have a phytoextractor potential for extracting metal from soil by transporting it and accumulating it in high concentrations in their shoots, and they have the ability to immobilize and inactivate it via phytoliths. The objective of this work was to evaluate the phytoremediation potential of forage grasses through the production of phytoliths and the occlusion of Pb in the phytoliths cultivated in Pb-contaminated soils. Three greenhouse experiments were conducted in a completely randomized design, separated by soil type (Typical Hapludox, Xanthic Hapludox and Rhodic Hapludox), in a 3 × 4 factorial scheme consisting of three forage grasses (Megathyrsus maximus, Urochloa brizantha and Urochloa decumbens) and four Pb rates (0, 45, 90 and 270 mg kg−1) with four repetitions. The forage grasses were influenced by increases in the Pb concentrations in the soils. The higher Pb availability in Typic Quartzipsamment promoted Pb toxicity, as indicated by the reduced dry weights of the shoots, increased phytolith production in the shoots, increased Pb in the shoots and Pb occlusion in the phytoliths of the forage grasses. The production and Pb capture in the phytoliths in the grasses in the Pb-contaminated soils were related to the genetic and physiological differences in the forage grasses and the Pb availability in the soils. Urochloa brizantha was the most tolerant forage to the excess Pb, with a higher production of phytoliths and higher Pb occlusion in the phytoliths, making it a forage grass that can be used in the future for the phytoremediation of Pb-contaminated soils. [ABSTRACT FROM AUTHOR]

Leaves of Reutealis trisperma (locally known as kemiri Sunan) are potential sources of organic matter and improve soil fertility, especially by increasing soil nutrient availability. This study aimed to analyze the impact of the application of compost using kemiri Sunan leaves as raw material on soil fertility, such as pH, total N and soil organic C. This study used a completely randomized design with six treatments and four replications. The treatments were without compost (control), compost 4 t ha-1, compost 8 t ha-1, compost 12 t ha-1, compost 16 t ha-1 and compost 20 t ha-1. This study used a PVC pipe with a diameter of 14 cm and a height of 60 cm for the composting process and using polybags for the soil incubation process. The leaves were mixed with EM4, molasses, and water in a ratio of 1:1:50; after mixing, all the ingredients were put into a tube, and observations were made. The soil was then mixed with compost according to the treatment dose of compost 0; 4; 8; 12; 16; 20 t ha-1, then added water until it reached field capacity and then put into a polybag and incubated for 30 days. Observations were made at 0, 15, and 30 days after incubation. The results of this study showed that the application of waste compost of kemiri Sunan leaves had a significantly increased soil pH, total N, and organic C. The best application of kemiri Sunan leaf compost was found at a dose of 20 t ha-1 .

Soil particle-size distribution (PSD) is an important soil feature that is associated with soil erosion, soil fertility, and soil physical and chemical properties. However, very few studies have been carried out to investigate soil degradation using the fractal dimension (D) of the PSD of soils from different land-use types in the calcareous soil of Iran. For this study, 120 soil samples (0–20 cm) were collected from different land-use types in the Fars Province, and various basic soil properties such as soil organic matter (SOM), soil texture fractions, calcium carbonate (CaCO3), pH, and cation-exchange capacity (CEC) were measured. The PSD of the soil samples was determined using the international classification system for soil size fraction, and the D of the PSD was calculated for all soils. The results of this study show that D is significantly correlated with clay content (r = 0.93) followed by sand content (r = −0.54) and CEC (r = 0.51). The mean D values of the forest areas (D = 2.931), with a SOM content of 2.1%, are significantly higher than those of the agricultural land (D = 2.905 and SOM = 1.6%) and pastures (D = 2.910 and SOM = 1.6%), indicating that fine soil particles, particularly clay, have been preserved in forest soils but lost in agricultural and pasture soils. We conclude that agricultural land has experienced significantly higher levels of soil erosion than forest areas. [ABSTRACT FROM AUTHOR]

The transformation of rocks and organic inputs into parent material and soil is a dynamic process controlled by physical, chemical and biological factors. In this process, the parent material, climate, topography, organism and time are known as formation factors. The differences in physiography cause variability in soil properties with the effect of other formation factors. In this study; It is aimed to reveal how the physiographic variability is reflected in the profile morphology and the statistical effects of this reflection on soil properties. Morphological descriptions of four soil profiles (PI, PII, PIII, PIV) were made in the north-south direction to represent the varying physiographic units (shoulder, toeslope, backslope) and some physical and chemical properties of soil samples taken on the basis of the horizon were determined. In addition, the variables in soil properties were evaluated with some statistical parameters. As a result of the study, all profiles were classified as Lithic Xerorthent / Petrocalcic Leptosol. While the profiles on the upper and lower skirts have similar characteristics, it has been determined that the profile in the low plain differs in terms of horizon depth and thickness, soil color, lime content, texture and water characteristics. With this study, it has been revealed that the relationship can be explained more clearly as a result of the evaluation of the change in soil properties with statistical approaches.

Comparison of the carbon (C) stocks among different soil orders allows us to explore the role of various soil characteristics in long‐term C storage and their vulnerabilities. This study quantified and compared the accumulation rates of soil organic carbon (SOC) fractions (in 0–60 cm soil profile) in an Alfisol of Malda (25°27′33.9″N, 88°19′10.2″E) and an Entisol of Cooch Behar (26°09′62.7″N, 89°53′51.7″E) districts of West Bengal, India. We noticed a greater level of SOC (0–60 cm depth) in the Alfisol than the Entisol as the former soils were clayey in nature (fine textured) which provided the maximum stabilization of SOC compared to the Entisol (sandy textured). However, the storage of C fractions showed some peculiar results. The concentration of mineral‐associated carbon (Min‐C) was more or less similar in both the soil orders, but its stock was maximum in the Alfisol. While in the Entisol, permanganate oxidizable carbon (POX‐C) and particulate organic matter carbon (POM‐C) stocks recorded maximum among all the studied depths. A positive relation of SOC fractions and stocks with clay (r2 = >0.500 in the Alfisol; r2 = >0.700 in the Entisol) indicated the importance of finer fractions in profile storage of C. Min‐C contributed to SOC of about 75%–85% followed by POM‐C (3.27%–17.87%) and POX‐C (2.57%–4.22%). Higher stratification of SOC and POX‐C and POM‐C fractions was observed in Entisol; while in Alfisol, stratification of Min‐C was greater. Overall, this research demonstrated that the Alfisol has a greater potential in stabilizing Min‐C than the Entisol with POM‐C and POX‐C and the distribution of these fractions varied as per its stabilization. [ABSTRACT FROM AUTHOR]

El objetivo de este trabajo fue evaluar el efecto de los momentos de secado del cultivo de cobertura (CC) sobre el rendimiento de un maíz tardío, bajo la hipótesis de que a medida que se atrasa la fecha de secado será mayor la captura de carbono, menor la cantidad de agua disponible para el cultivo subsiguiente, mayor la cantidad de nitrógeno (N) inmovilizado en la biomasa (mayor relación C/N del CC). Para ello se estableció un ensayo en parcelas divididas, donde la parcela principal fue la fecha de secado y la secundaria la fertilización nitrogenada 1ra fecha de secado (julio), 2da fecha de secado (agosto) y 3ra fecha de secado (septiembre), a su vez, cada parcela se dividió a la mitad para establecer tratamientos con y sin fertilización nitrogenada en el cultivo de maíz. Se determinó agua total (AT), producción aérea, carbono y nitrógeno de biomasa aérea (C/N), biomasa de raíces, uso consuntivo (UC), eficiencia del uso del agua (EUA) contenido de nitrógeno de nitratos y rendimiento de maíz. Los resultados obtenidos en el tratamiento 1ra fecha de secado fueron: producción de biomasa aérea del CC de 3015 Kg MS.ha-1, producción de biomasa radicular del CC de 1765 Kg.ha-1, UC de 237 mm, EUA de 12,2 Kg.ha-1.mm-1 y rendimiento de maíz de 6566 Kg.ha-1. Para el tratamiento 2da fecha de secado fueron: producción de biomasa aérea del CC de 5060 Kg MS.ha-1, producción de biomasa radicular del CC de 6352 Kg.ha-1, UC de 260 mm, EUA de 20 Kg.ha-1.mm-1 y rendimiento de maíz de 6450 Kg.ha-1. Por último, para el tratamiento 3ra fecha de secado fueron: producción de biomasa aérea del CC de 8252 Kg MS.ha-1, producción de biomasa radicular del CC de 4000 Kg.ha-1, UC de 347 mm, EUA de 24,2 Kg ha-1.mm-1 y rendimiento de maíz de 5931 Kg.ha-1. El momento de secado del CC tuvo influencia sobre el rendimiento de maíz en la Región Semiárida Pampeana, ante un régimen de humedad del tipo ústico, propio de dicha región.

Temporal changes in soil development were assessed on fluvial terraces of the Little River in the upper Coastal Plain of North Carolina. We examined five profiles from each of six surfaces spanning about 100,000 years. Soil-age relationships were evaluated with inter-surface clay mineral comparisons and regression of chemical properties versus previously reported optically-stimulated luminescence ages using the most developed subsoil horizon per profile. Bases to alumina (Bases/Al2O3) ratios have negative correlations with age, whereas dithionite-Fe (FeD) concentrations are positively correlated with time and differentiate floodplain (<200 yr BP) from terrace (≥10 ± 2 ka) soils and T4 pedons (75 ± 10 ka) from younger (T1-T3b, 10 ± 2–55 ± 15 ka) and older (T5b, 94 ± 16 ka) profiles. Entisols develop into Ultisols with exponentially decreasing Bases/Al2O3 ratios, reflecting rapid weatherable mineral depletion and alumina enrichment during argillic horizon development in the first 13–21 kyr of pedogenesis. Increasing FeD represents transformation and illuviation of free Fe inherited from parent sediments. Within ~80–110 kyr, a mixed clay mineral assemblage becomes dominated by kaolinite and gibbsite. Argillic horizons form by illuviation, secondary mineral transformations, and potentially, a bioturbation-translocation mechanism, in which clays distributed within generally sandy deposits are transported to surface horizons by ants and termites and later illuviated to subsoils. T5b profiles have FeD concentrations similar to, and gibbsite abundances greater than, those of pedons on 0.6–1.6 Ma terraces along Coastal Plain rivers that also drain the Appalachian Piedmont. This is likely because the greater permeability and lower weatherable mineral contents of sandy, Coastal Plain-sourced Little River alluvium favor more rapid weathering, gibbsite formation, and Fe translocation than the finer-grained, mineralogically mixed sediments of Piedmont-draining rivers. Therefore, recognizing provenance-related textural and mineralogical distinctions is crucial for evaluating regional chronosequences. [ABSTRACT FROM AUTHOR]

In order to evaluate the effect of when we kill the cover crop on the yield of a late corn, under the hypothesis that as the desiccate date is delayed, it will increase the carbon sequestration the amount of nitrogen (N) immobilized in the biomass (lower C/N ratio) and weed suppression and it will reduce the water soil storage for the next crop. Trials established in completely randomized blocks with four repetitions of the following treatments: 1st drying date (july), 2nd drying date (august) and 3rd drying date (september), in turn, each plot was divided in half to establish treatments with and without nitrogen fertilization in the corn crop. Total water (AT), aerial production and carbon and nitrogen; root biomass production, consumptive use (UC), water use efficiency (WUE) and nitrogen availability and yield were determined. The results obtained in the treatment of the 1st drying date were: production of air biomass of the CC of 3015 Kg MS.ha-1, production of root biomass of the CC of 1765 Kg.ha-1, UC of 237 mm, USA of 12.2 Kg.ha-1.mm-1 and corn yield of 6566 Kg.ha-1. For the treatment 2 nd drying date were: production of aerial biomass of the CC of 5060 Kg MS.ha-1, production of root biomass of the CC of 6352 Kg.ha-1, UC of 260 mm, USA of 20 Kg.ha-1.mm-1 and corn yield of 6450 Kg.ha-1. Finally, for the treatment of the 3rd date of drying were: production of aerial biomass of the CC of 8252 Kg MS.ha-1, production of root biomass of the CC of 4000 Kg.ha-1, UC of 347 mm, USA of 24.2 Kg.ha-1.mm-1 and corn yield of 5931 Kg.ha-1. The drying time of the CC have an influence on the yield in the Pampean Semi-Arid Region, given a moisture regime of the Utic type, typical of that region. [ABSTRACT FROM AUTHOR]

The low quality of Entisol is caused by low availability of nitrogen, phosphorus, and potassium as well as low soil pH, so the addition of vermicompost is necessary. The purpose of this study was to determine the effect of vermicompost application on soil quality and to obtain the highest vermicompost dosage on the availability of nutrients such as N, P, K, and the yield of corn. The field experiment used a Randomized Completely Block Design (RCBD) with 7 dosages of vermicompost and three replications. The treatments were V0 = 0; V1 = 5; V2 = 10; V3 = 15; V4 = 20; V5 = 25; V6 = 30 Mg ha-1. Variables observed consisted of 1) initial soil and vermicompost characterization analysis, 2) soil analysis and N, P, and K content in leaves, and yield of corn. The results showed that Entisol was classified as low quality; however, vermicompost quality complied with the requirements of quality organic fertilizer. The experiment also indicated that the highest pH of Entisol (5.31) and K content in corn leaves (2.12%) were obtained at a dose of vermicompost 25 Mg ha-1. Meanwhile, the highest weight of husked corn cobs (415.55 g plant-1) and weight of unhusked corn cob (351.11 g plant-1) were obtained at a vermicompost dose of 15 Mg ha-1.

Entisols are newly formed soil types and are commonly found in Indonesia, with a distribution of ±3 million ha distribution. Entisol Kalidawir has a slightly acidic pH value of 5.8 and contains very low total-nitrogen (N) and available-phosphorus (P) nutrients, calcium (Ca), sodium (Na) and magnesium (Mg) in the exchangeable base are also low and clay loam texture. Low soil nutrients and organic matter can have an impact on plant growth and production Maize is one of the most widely cultivated food crops in Indonesia. The purpose of this study was to analyze various doses of the combination of cow manure and NPK fertilizer on N, P and potassium (K) uptake, growth and production of maize. The results showed that the application of 20 t ha-1 of cow manure and 400 kg ha-1 of NPK fertilizer at observations 27 and 54 days after planting increased growth in height and number of leaves of corn plants and increased nutrient uptake of N, P, and K, respectively. Also reached 1, 0.14, and 0.82 g plant-1 and 5.52, 0.83, and 5.11 g plant-1. In addition, it produces the highest corn production of 10.53 t ha-1.

The rate of change in the relative amount of active and passive carbon (AC and PC) due to the land management practices (cropping systems combined with tillage) may vary with soil types depending on their level of chemical and/or physical protection from the decomposition but has rarely been directly measured. We have quantified the C storage potentiality of different soil types, namely old alluvial Inceptisol of Malda and recent alluvial Entisol of Coochbehar in West Bengal (subtropical eastern India) under the influence of different cropping systems (rice-maize: RM and rice-wheat: RW) and tillage practices (zero-tillage: ZT and conventional tillage: CT). The key objective was to demonstrate the short-term impact of conservation agriculture (CA) on soil C dynamics over the conventional practice. Research revealed that after short-term CA, total organic carbon (TOC), AC, PC, and total nitrogen (TN) showed significant (p < 0.05) improvement under the RM cropping system over the RW. The highest TOC content under the RM cropping system was recorded in the sites of Malda over the Coochbehar sites. The ZT significantly (p < 0.05) enhanced the TOC in the upper layers (0–5 and 5–10 cm) and the CT showed improvements in the lower depths (10–20 cm). We observed some irregular variations in the interactions of the cropping system and tillage with respect to different sites. However, the ZT performed better in improving C fractions under RM and RW as compared to CT. The TOC and TN stocks were maximum in the lower depth which was evident in both soil types. The TOC linearly regressed on TN accounted for 94.2% variability (R2 = 0.942) of the C accumulation in soil and vice-versa. The PC was in a significant relationship with TN (R2 = 0.943), but AC was moderately regressed (R2 = 0.851). Lower stratification ratio values in Coochbehar soils (sandy loam in texture) indicated higher profile distribution of AC and PC in the soil profile; while in the Inceptisol, accumulation of the C fractions on the soil surface due to heavy texture resulted in the higher stratification values. The novelty of this study is that old alluvial Inceptisol showed a comparatively greater amount of AC and PC storage capability in comparison with the new alluvial Entisol. Conclusively, our study demonstrated that the adoption of conservation agriculture (CA practice/ZT) in cropping systems with higher C biomass input would significantly enhance the AC and PC fractions; however, the amount of storage is highly governed by the soil type and climatic factors.

Due to reduced tillage practices, glyphosate is widely used as a herbicide in grain farming systems of Australia. Residual glyphosate when mixed with water bodies can be a health concern. Updated information concerning the fate of glyphosate in soil systems with biochar amendment is lacking. For this experiment, different biochars were weighed and premixed in 2 ml Eppendorf tubes. A solution (Mixture of mercuric chloride and radiolabeled C14 glyphosate) having different concentrations provided by the commonwealth scientific and industrial research organization was used. Tubes having solutions were shaken on end over end shaker for 24 h. Tubes were removed from the shaker and centrifuged for 5 min. at 13000 revolutions per minute. Digested, labeled samples after counting disintegration per minute on Tricarb 4810 were used as sorption data. Results showed significant adsorption of glyphosate in the Entisol soil systems in the presence of char. The results have been published, however, the author wants to communicate in detail the role of liquid scintillation counting as a future research method for radiolabeled herbicides to understand the adsorption behavior of herbicides like glyphosate in different soil systems. [ABSTRACT FROM AUTHOR]

El mango cv. Tommy Atkins es cultivado en el departamento del Tolima, principalmente, lugar donde expresa su mejor comportamiento agronómico y calidad de la fruta. El objetivo fue evaluar el estado nutricional de las plantas y cuantificar la extracción de nutrientes por la fruta de mango Tommy Atkins en función del orden de suelo donde se cultiva. Las concentraciones de cada nutriente variaron entre fases muestreadas y de órgano (hojas, flor y fruto) en función del orden del suelo donde es cultivado (Entisol e Inceptisol). La mayor extracción por cada mil kilogramos cosechado de fruta fue de potasio (K) seguido de nitrógeno (N) en los seis muestreos evaluados independientemente del orden de suelo (K, Entisol, E2=2,39 kg t-1, E3=2,07 kg t-1 y E4=2,00 kg t-1; Inceptisol E2=2,58 kg t-1, E3=2,40 kg t-1 y E4=2,05 kg t-1; N, Entisol, E2=1,56 kg t-1, E3=1,65 kg t-1, E4=1,46 kg t-1 e Inceptisol E2=1,52 kg t-1, E3=1,01 kg t-1 y E4=1,69 kg t-1). La extracción total de nutrientes por el mango cv. Tommy Atkins, por cada mil kilogramos cosechados fue cercana a 4,3 kg de nutrientes en suelos de orden Entisol y 4,5 kg de nutrientes en suelos de orden Inceptisol, siendo el orden de extracción K>N>P>Ca>Mg>S en suelos Entisol y K>N>Ca>P>Mg>S en suelos Inceptisol.

Phytoremediation has become a promising technique for cleaning Pb-contaminated soils. Grasses have a phytoextractor potential for extracting metal from soil by transporting it and accumulating it in high concentrations in their shoots, and they have the ability to immobilize and inactivate it via phytoliths. The objective of this work was to evaluate the phytoremediation potential of forage grasses through the production of phytoliths and the occlusion of Pb in the phytoliths cultivated in Pb-contaminated soils. Three greenhouse experiments were conducted in a completely randomized design, separated by soil type (Typical Hapludox, Xanthic Hapludox and Rhodic Hapludox), in a 3 × 4 factorial scheme consisting of three forage grasses (Megathyrsus maximus, Urochloa brizantha and Urochloa decumbens) and four Pb rates (0, 45, 90 and 270 mg kg−1) with four repetitions. The forage grasses were influenced by increases in the Pb concentrations in the soils. The higher Pb availability in Typic Quartzipsamment promoted Pb toxicity, as indicated by the reduced dry weights of the shoots, increased phytolith production in the shoots, increased Pb in the shoots and Pb occlusion in the phytoliths of the forage grasses. The production and Pb capture in the phytoliths in the grasses in the Pb-contaminated soils were related to the genetic and physiological differences in the forage grasses and the Pb availability in the soils. Urochloa brizantha was the most tolerant forage to the excess Pb, with a higher production of phytoliths and higher Pb occlusion in the phytoliths, making it a forage grass that can be used in the future for the phytoremediation of Pb-contaminated soils.

Soil particle-size distribution (PSD) is an important soil feature that is associated with soil erosion, soil fertility, and soil physical and chemical properties. However, very few studies have been carried out to investigate soil degradation using the fractal dimension (D) of the PSD of soils from different land-use types in the calcareous soil of Iran. For this study, 120 soil samples (0–20 cm) were collected from different land-use types in the Fars Province, and various basic soil properties such as soil organic matter (SOM), soil texture fractions, calcium carbonate (CaCO3), pH, and cation-exchange capacity (CEC) were measured. The PSD of the soil samples was determined using the international classification system for soil size fraction, and the D of the PSD was calculated for all soils. The results of this study show that D is significantly correlated with clay content (r = 0.93) followed by sand content (r = −0.54) and CEC (r = 0.51). The mean D values of the forest areas (D = 2.931), with a SOM content of 2.1%, are significantly higher than those of the agricultural land (D = 2.905 and SOM = 1.6%) and pastures (D = 2.910 and SOM = 1.6%), indicating that fine soil particles, particularly clay, have been preserved in forest soils but lost in agricultural and pasture soils. We conclude that agricultural land has experienced significantly higher levels of soil erosion than forest areas.

The transformation of rocks and organic inputs into parent material and soil is a dynamic process controlled by physical, chemical and biological factors. In this process, the parent material, climate, topography, organism and time are known as formation factors. The differences in physiography cause variability in soil properties with the effect of other formation factors. In this study; It is aimed to reveal how the physiographic variability is reflected in the profile morphology and the statistical effects of this reflection on soil properties. Morphological descriptions of four soil profiles (PI, PII, PIII, PIV) were made in the north-south direction to represent the varying physiographic units (shoulder, toeslope, backslope) and some physical and chemical properties of soil samples taken on the basis of the horizon were determined. In addition, the variables in soil properties were evaluated with some statistical parameters. As a result of the study, all profiles were classified as Lithic Xerorthent / Petrocalcic Leptosol. While the profiles on the upper and lower skirts have similar characteristics, it has been determined that the profile in the low plain differs in terms of horizon depth and thickness, soil color, lime content, texture and water characteristics. With this study, it has been revealed that the relationship can be explained more clearly as a result of the evaluation of the change in soil properties with statistical approaches. [ABSTRACT FROM AUTHOR]

Mango cv. Tommy Atkins is mainly grown in the department of Tolima, a place where it expresses its best agronomic behavior and quality of the fruit. The objective was to evaluate the nutritional status of the plants and quantify the extraction of nutrients by plants of Tommy Atkins mango fruit based on the soil order where is grown. The concentrations of each nutrient varied between samples and organ phases (leaves, flower, and fruit) depending on the order of the soil where it is cultivated (Entisol and Inceptisol). The highest extraction per one thousand kg of harvested fruit was potassium (K) followed by nitrogen (N) in the three phases independently evaluated of the soil order (K, Entisol, E2 = 2.39 kg t-1, E3 = 2, 07 kg t-1 and E4 = 2.00 kg t-1; Inceptisol E2 = 2. 58 kg t-1, E3 = 2.40 kg t-1 and E4 = 2.05 kg t-1; N, Entisol, E2 = 1.56 kg t-1, E3 = 1.65 kg t-1, E4 = 1.46 kg t-1 and Inceptisol E2 = 1.52 kg t-1, E3 = 1.01 kg t-1 and E4 = 1.69 kg t-1). The total extraction of nutrients by mango cv. Tommy Atkins, for one thousand kg of harvested fruit was close to 4.3 kg of nutrients in soils of the Entisol order and 4.5 kg of nutrients in soils of the Inceptisol order. The extraction order was K> N> P> Ca> Mg> S. [ABSTRACT FROM AUTHOR]

In this study, the morphological, mineralogical, physical and chemical properties of three soil profiles, having different pedological development on the same parent material, were determined and relationships between their physical properties and mineralogical properties were investigated. According to this study’s results, three soil profiles were classified as Vertik Ustorthent, Typic Haplustept and Vertic Calciustept. The results of mineralogical analysis showed that montmorillonite in the 2: 1 type expanding smectite group is the dominant clay mineral and there is a small amount of kaolinite and nontronite clay minerals. Liquid limit and plastic limit of genetic horizons of soils were determined between 48-63% and 25-37%, respectively. The highest liquid limit and plastic limit values in surface horizon were found in Vertik Ustorthent whereas, the lowest values were determined for Vertic Calciustept. According to USCS (Unified Soil Classification System) classification, all soils were classified as high plasticity, inorganic clay (CH) and as moderate plasticity, inorganic clay (CL). In addition, mineralogical test results, values obtained as a result of index properties, and swelling evaluations obtained with the extension of soil properties has been found to be compatible. Besides, pedalogical development (cambic horizon) cannot be said to have much effect on the mineralogical and physical properties of soils.

Entisol of Wajak Malang has low base saturation and organic matter and slightly acid. The result of the analysis also showed that soil has nutrient P with high criteria; however, N, K, Ca, Mg, Na contents are low to very low criteria. Application of humic acid at the first planting can leave residual nutrients and can still be used in the second planting. Besides urea-humic, goat manure can also be because it can improve soil properties, organic matter and nutrients contents. The purpose of this study was to explore the effect of the application of urea-humic residue with goat manure on the availability of phosphorus, potassium and the growth of okra on an Entisol of Wajak Malang. The combination of treatments consisted of: U1 (soil residue urea-humic 100% + goat manure), UH1 (soil residue of urea-humic 75% + goat manure), UH2 (soil residue of urea-humic 100% + goat manure), UH3 (soil residue of urea-humic 125% + goat manure), UH4 (soil residue if urea-humic 150% + goat manure). The five treatments were arranged in a completely randomized design with three replicates. The results showed that urea-humic residue with application goat manure had no significant effect on available P, exchangeable K in the soil, plants height and leaf number of okra on 4, 6 and 8 weeks after planting.

A fin de evaluar el efecto que tiene la fertilización nitrogenada en centeno utilizado como cultivo de cobertura (CC), bajo la hipótesis de que la producción de biomasa aérea es condicionada por la disponibilidad de nitrógeno en el suelo, resultando significativa la influencia de éste sobre la Eficiencia en el Uso del Agua (EUA), se establecieron ensayos en bloques completamente aleatorizados con cuatro repeticiones de los siguientes tratamientos: barbecho (B) sin CC, CC sin fertilizar (T) y fertilizado con 40 (40N), 80 (80N) y 120 kg N.ha-1 (120N). Se determinó humedad de suelo, nitratos (N-NO3-) en suelo (0 - 60 cm) y biomasa aérea, con el objetivo de evaluar la incidencia de distintas dosis de fertilización sobre la producción de materia seca (MS) y la EUA del centeno utilizado como CC, y establecer la productividad del cultivo sucesor de maíz sobre el T y sobre los tratamientos fertilizados. Los resultados obtenidos en el tratamiento 120N fueron: producción de MS del CC de 6447 kg.ha-1, EUA de 23 kg MS.ha-1.mm-1, y rendimiento de maíz de 12170 kg.ha-1. Mientras que para el tratamiento T la producción de MS fue 3815 kg.ha-1, la EUA fue 13 kg MS.ha-1 mm-1, y el rendimiento de maíz de 9475 kg.ha-1, mostrando diferencias estadísticamente significativas entre ambos tratamientos. La fertilización de los CC parece ser una alternativa viable para la Región Semiárida Pampeana ya que ha mostrado resultados positivos en la producción de biomasa y en la EUA. La productividad del cultivo de maíz sería mayor sobre los CC fertilizados comparado con los CC sin fertilizar. La descomposición de los residuos de CC podría ser la responsable de la mayor producción, donde la relación C/N juega un papel importante en la dinámica de degradación y en la sincronía de la oferta de nitrógeno respecto a la demanda del maíz. Director: Quiroga, Alberto Raúl - Co Director: Fernández, Romina

Entisol is a type of soil at the initial development stage and has a texture dominated by sand fraction. This causes a decrease in soil quality and can reduce crop production. This compost of leguminase plants can play a role in improving soil chemical properties. The purpose of this research was to determine the effect of Crotalaria juncea L. compost application on the availability of secondary macro nutrients Ca, Mg, and S, and uptake of Ca, Mg, and S by sweet corn plant in Entisol, Wajak. Treatments tested were C0 (Urea 100%), C1 (Compost Crotalaria juncea L. 100% + Urea 75%), C2 (Compost Crotalaria juncea L. 100% + Urea 75%), C3 (Compost Crotalaria juncea L. 100%), C4 (Compost Crotalaria juncea L. 200%). The five treatments were arranged in a completely randomized design with three replications. The results showed that the application of Crotalaria juncea L. compost (20 t ha-1) significantly increased the availability of Ca, Mg and S on 12 weeks by 41.6%, 96.71% and 133.78%, respectively. The application of Crotalaria juncea L. compost (20 t ha-1) did not significantly increase uptake of Ca, Mg and S.

Pinestraw harvesting is an important industry in the southeastern United States. There is a need to understand how fertilization can be used efficiently to sustain or increase long-term pinestraw yields and avoid adverse environmental consequences. The effects of fertilization on needlefall nutrient concentrations, pinestraw yields, and nutrient removals on soils with contrasting soil nutrient sorption potential (Entisol vs. Ultisol) were compared using two midrotation slash pine plantations in North Florida. Diammonium phosphate was applied at 0, 144, 430, or 718 kg ha–1 in the spring of 2009 and 2010. Pinestraw was harvested annually in 2009–12. Needlefall mass, pinestraw yields, total Kjeldahl nitrogen concentrations in needlefall and pinestraw, and total Kjeldahl nitrogen, P, K, Ca, and Mg removals increased with fertilization. Diammonium phosphate at 718 kg ha–1 year–1 increased pinestraw yield over the control by 37 and 35 percent 2 years after the second fertilization, and by 11 percent (from 21.5 to 23.8 Mg ha–1) and 12 percent (from 25.0 to 28.1 Mg ha–1) over the 4-year control totals, at Entisol and Ultisol sites, respectively. Differences between sites were larger than fertilization response for most variables. Yields, nutrient concentrations, and removals were higher at the more fertile Ultisol than Entisol and, at both sites, higher than most reported in the literature. [ABSTRACT FROM AUTHOR]

The entry of Cd, Pb and Ni into the environment is a cause of concern due to potential toxicity of these metals to plants, animals, and humans. The present study evaluated the availability of Cd, Pb, and Ni to plants through soils. We examined three soil types (Typic Quartzipsamment (TQ), Xantic Hapludox (XH) and Rhodic Hapludox (RH)) with addition four rates of heavy metals: Cd (0, 2, 4 and 12 mg), Pb (0, 45, 90 and 270 mg) and Ni (0, 20, 40, 120 mg) per kg soil with reference to the corresponding rates defined in soil investigation values of the Brazilian environmental legislation. The availability of Cd, Pb and Ni was higher in the TQ than in XH and RH, and the roots and shoots of corn plants grown in TQ yielded the highest concentrations of toxic metals. Soil extraction with diethylene-triaminepentaacetic acid (DTPA) effectively assessed the bioavailability of Cd and Pb, while soil extractions with Mehlich-1 and aqua regia effectivety evaluated the bioavailability of Ni. The levels at which Cd, Pb, and Ni became toxic for plants were determined via extractioned by Mehlich-1, DTPA, Mehlich-3, and aqua regia. Plant growth was shown to influence heavy metal toxicity, with higher growth rates lowering the toxic effect of the metal. Cd, Ni, and Pb exhibited higher availiability in soils with low clay concentrations and were more easily absorbed by plants in those soils. [ABSTRACT FROM AUTHOR]

Florida sandy soils, particularly, Entisols are low in boron (B) and occasionally have B deficiency for citrus. A study was set-up at Citrus Research and Education Center, Lake Alfred, Florida, on a Candler fine sand to determine the availability and uptake of B in a high-density citrus planting of Huanglongbing (HLB)-affected trees. Boron was applied at 1.12 kg ha−1 in three splits, at University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) recommended rate (1×), and at 2× the recommended rate using foliar and soil application methods. Soil samples were taken from soil surface to 60 cm depth in 15-cm increments within the irrigated and non-irrigated zones. Soil and leaf samples were analyzed for B using Mehlich III extraction method and acid digestion, respectively. Results showed the leaf B concentration for soil applied rate 1× was significantly higher (P < 0.001) than that of foliar applied either at single or double rate but both were in the optimum range recommended by UF/IFAS. The sorption study revealed that there was no sorption (KD < 0.2 L kg−1) but KD at 0–15-cm depth was 3× greater than that at 15–60 cm depths. The concentration of B in the leaf tissue remained in the recommended optimum critical range. Sorption coefficients showed negligible B sorption which means most applied B would be prone to leaching under heavy rains or saturated soil conditions on Florida sandy soils thus requiring judicious management for optimizing tree performance and sustaining environmental quality. [ABSTRACT FROM AUTHOR]

Purpose: Imidacloprid is a widely used seed dressing insecticide in Brazil. However, the effects of this pesticide on non-target organisms such as soil fauna still present some knowledge gaps in tropical soils. This study aimed to assess the toxicity and risk of imidacloprid to earthworms Eisenia andrei and collembolans Folsomia candida in three contrasting Brazilian tropical soils. Materials and methods: Acute and chronic toxicity assays were performed in the laboratory with both species in a tropical artificial soil (TAS) and in two natural soils (Oxisol and Entisol), at room temperature of 25 °C. The ecological risk was calculated for each species and soil by using the toxicity exposure ratio (TER) and hazard quotient (HQ) approaches. Results and discussion: Acute toxicity for collembolans and earthworms was higher in Entisol (LC50 = 4.68 and 0.55 mg kg−1, respectively) when compared with TAS (LC50 = 10.8 and 9.18 mg kg−1, respectively) and Oxisol (LC50collembolans = 25.1 mg kg−1). Chronic toxicity for collembolans was similar in TAS and Oxisol (EC50 TAS = 0.80 mg kg−1; EC50 OXISOL = 0.83 mg kg−1), whereas higher toxicity was observed in Entisol (EC50 = 0.09 mg kg−1). In chronic assays with earthworms, imidacloprid was also more toxic in Entisol (EC50 = 0.21 mg kg−1) when compared to TAS (EC50 = 1.89 mg kg−1). TER and HQ values indicated a significant risk of exposure of the species to imidacloprid in all soils tested, and the risk in Entisol was at least six times higher than in Oxisol or TAS. Conclusions: The toxicity and risk of imidacloprid varied significantly between tropical soils, being the species exposure to this pesticide particularly hazardous in very sandy natural soils such as Entisol. [ABSTRACT FROM AUTHOR]