Evaluation of saturated hydraulic conductivity from soil properties in an Inceptisol using different land cover and depths

hree soil profiles from Regional Research Station of Bidhan Chandra Krishi Viswavidyalaya, Gayeshpur situated in New Alluvial zone of Nadia district, West Bengal were studied to assess the predictability of the hydraulic conductivity of the soil as influenced by different physical and chemical and properties of cultivated and forest land. The various statistical procedures were employed on the measured laboratory based data for comprehensive agree-ment of dependent hydraulic conductivity of soils as a model function of independent soil variables that is likely to be useful for different land cover systems. Soils are neutral in reaction, silty clay to silty clay loam in nature. Forest soil contained greater organic carbon (OC) (5.9 ± 0.16 g kg-1) compared to cultivated soil (4.4 ± 0.34 g kg-1). Jhau plan-tation recorded the highest value (6.8 g kg-1) of OC due to soil texture and cation exchange capacity (CEC). Soil hydraulic conductivity was greater in soil for cabbage and Sagun tree among the cultivated and forest soil studied with values 2.80 and 1.10 cmh -1. Correlation study showed a positive and negative relation with hydraulic conductiv-ity for sand (r= 0.68; P > 0.05) and clay (r= - 0.71; P > 0.05) respectively. Further, principal component analysis con-cluded that addition of bulk density with clay and sand can predict the hydraulic conductivity for different land uses

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Not AvailableThe influence of total electrolyte concentration (TEC) and sodium adsorption ratio (SAR) of water on ESR-SAR relationships of normal clay loam, saline silty loam and calcareous sodic loam soils was studied in a laboratory experiment. Twelve solutions, encompassing three TEC levels viz., 25, 50, and 100 me L⁻¹ and four SAR levels viz., 5, 10, 20 and 30 mmol1/2 L−1/2 were prepared to equilibrate the soil samples using pure chloride salts of calcium, magnesium and sodium at Ca: Mg = 2: 1. The SAR of equilibrium solution decreased as compared to the equilibrating solution and more so in waters of low salt concentration and low SAR. At all electrolyte concentration, SAR values were not attained to the equilibrium solution because of addition of Ca and Mg from mineral dissolution or supply of Ca and Mg from exchange sites. At higher TEC levels, considerable increase in exchangeable sodium percentage (ESP) was observed when it was correlated for anion exclusion and more so in calcareous sodic loam followed by saline silty loam and normal clay loam soils. Irrespective of TEC, the exchangeable sodium in all the soils increased by 2.1 to 3.8-fold and irrespective of SAR, it increased by about 1.1 to 2.1-fold, respectively. So, there is a positive interaction of TEC and SAR in sodification of soils. A positive interaction of TEC and SAR influenced the ESP build-up and CEC and silt + clay content played a major role in the visual disparity in sodification of these soils. Gapon's selectivity coefficient values were perceptible in the order of calcareous sodic loam > saline silt loam > normal clay loam. This indicates the preference of normal clay loam soils for Ca²⁺ + Mg²⁺ than that of Na⁺ on the exchange complex, whereas loam soil exhibited high affinity for sodium. Regression coefficient of ESR-SAR relationships was maximum for sodic loam followed by saline silty loam and normal clay loam soil. The exchange equilibrium was strongly affected by TEC of the solution phase. Variation in soil pH was gradual with respect to TEC and SAR of equilibrating solution and a sharp change was observed. At a fixed TEC, critical ESP values were observed calcareous sodic loam followed by saline silt loam and normal clay loam. On the other hand, SAReq needed for critical ESP built-up was in the order of calcareous sodic loam > saline silt loam > normal clay loam. This may be because of dissolution of calcium bearing minerals in calcareous sodic loam; and wash out of calcium and magnesium from the exchange sites for saline silt loam soil.Not Availabl

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Not AvailableInceptisols and Vertisols are two dominant soil orders that support major agricultural production in India. These soils often exist in semi-arid and arid regions. Low precipitation and high evaporation demand leads to salt accumulation in these areas. The problem of salt accumulation is further compounded by the presence of saline/alkaline groundwaters. We evaluated the effect of modified Ca/Mg waters on ionic composition, dispersion, and clay flocculation of sodic Inceptisols, saline-sodic Inceptisols, and normal Vertisols from different parts of India. A completely randomized factorial design with three replications of individual soils were sequentially leached with five pore volumes of deionized, saline water of 60 and 120 me L−1 total electrolyte concentration (TEC) at a fixed SAR of 5.0 mmol1/2 L−1/2 and Ca:Mg ratio of 2:1, 1:1 and 1:2. Application of saline waters decreased pH and increased EC of the soil leachates after leaching five pore volumes of three Ca/Mg ratios of 60 and 120 me L−1 solutions in sodic Inceptisols and normal Vertisols. In saline-sodic Inceptisols, application of saline waters decreased both pH and electrical conductivity (EC) of the soil leachates. Preferential Ca2+ holding in soil was only noticed in sodic Inceptisols when leaching process was performed with independent saline waters, but Mg2+ has a tendency to hold in soil upon application of independent saline waters for all soils except sodic Inceptisols. Periodic application of deionized water could increase soil dispersion and decreased flocculation of clay particles. Mg2+ ion had less flocculating vis-à-vis high-dispersion effect on soil clays than the Ca2+ ion.Not Availabl

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Not AvailableAbstract With rapid urbanization, solid waste management has emerged as a major environmental issue. Solid waste arising from human activities has become one of the major global problems causing extensive pollution and threat to human health. Although, solutions for mitigation of this problem including improved methods of collection, transportation and disposal are in place, but absence of better management and awareness for its productive utilization limits its success. Scientific and eco-friendly technologies for disposing the waste will reduce the quantity of waste to be finally dumped besides generating substantial amount of manure and energy. This article attempts to outline the recent progress made in the better management of municipal solid waste and opportunities in its use in various fields.Not Availabl

Land Degradation Assessment Using 2 Geospatial Techniques

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Not AvailableLand use changes have caused emission of ~ 20% greenhouse gases (GHGs) globally that leads to shrinkage of carbon (C)-storage in the potential areas. Soil carbon pools change rapidly in response to land use change. However, in-depth understanding of C-dynamics is needed with respect to eco-systems variability. Suitable land use systems can help in sequestering C and reduce GHGs' adverse effect. Therefore, seven land uses namely Guava (Psidium guajava), Litchi (Litchi chinensis), Mango (Mangifera indica), Jamun (Syzygium cumini), Eucalyptus (Eucalyptus tereticornis), Prosopis (Prosopis alba) and Rice–wheat cropping system were selected to study their impact on soil properties and distribution of soil organic carbon (SOC) in soil layers in a reclaimed sodic soil (Typic Natrustalf, Alfisols). Soil samples were collected up to a depth of 2 m i.e. 0–0.2, 0.2–0.4, 0.4–0.6, 0.6–0.8, 0.8–1.0, 1.0–1.5 and 1.5–2.0 m. Results showed that soil pH and bulk density increased with depth in all the land uses. Minimum and maximum soil pH was associated with Litchi (6.81) at 0–0.2 m and Eucalyptus (9.52) at 1.5–2.0 m depth, respectively. Eucalyptus recorded minimum and maximum (1.41 and 1.76 Mg m− 3) bulk density at 0–0.2 and 1.5–2.0 m soil depth, respectively. Carbon content in passive pool along with its recalcitrant nature was increased with depth in all the land uses. Depth-wise maximum decreasing tendency of lability index in Jamun plantation (0.44 at 1.0 to 1.5 m and 0.72 at 1.5 to 2.0 m soil depth) reiterated more recalcitrant nature of SOC. However, overall highest SOC storage (133 Mg C ha− 1) as well as maximum passive pool C (76 Mg C ha-1) was maintained in Guava land use.Not Availabl

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Not AvailableA micro-lysimeter (1.0 meter deep and 0.3 m internal diameter) experiment was conducted to study the effect of different quality irrigation water on the soil chemical properties and their influence on growth, yield and other biometric parameters of rice (variety CSR 36). Irrigation water treatments included viz., normal tap water (NTW), dilute saline water (DSW, ECiw 5.0 dS m-1 and SAR 5.0 mmol1/2 L-1/2); concentrated saline water (CSW, ECiw 10.0 dS m-1, SAR 5.0 mmol1/2 L-1/2) , dilute alkali water (DAW, RSC 2.5 me L-1) and concentrated alkali water (CAW, RSC 10.0 me L-1). Three different type of sandy loam soils viz., normal (pH2 7.5 and ECe 1.0 dS m-1), saline (pH2 7.7 and ECe 10.6 dS m-1) and alkali (pH2 9.15 and ECe 2.9 dS m-1) soils were used for this investigation. Saline and alkali water irrigation affected the EC, pH and exchangeable sodium percentage (ESP) of normal, saline and alkali soils. In normal soil, ECe increased 8.5 to 12.5 times in DSW and CSW, respectively as compared to initial experimental soil whereas, it was increased 3.2 to 4.8 times, in the alkali soil. Decrease in ECe was observed in all water treatments except CSW in saline soil as compared to initial experimental soil. Increase in pH of normal and saline soil was more pronounced in case of CAW as compared to alkali soils but decrease in pH was observed in normal, saline and alkali soils on application of DSW and CSW. Significant increase in ESP (exchangeable sodium percentage) was observed in DAW and CAW particularly in alkali soils but it in case of normal and saline soil it was observed in surface samples. ESP decreased in case of DSW and CSW in alkali soil. Cations and anions build up was more pronounced in normal soil followed by alkali and saline soils as compared to exp soil. Rice yield was at par (93%) in DAW as compared to NTW in all soils, whereas, use of CAW reduced grain yield up to 50% for normal and saline soil and in case of alkali soil it is reduced to 15% for alkali soil. Yield was further reduced to 33% in DSW for normal and saline soil and 19% for alkali soil. Yield in CSW was found negligible as total loss of crop was observed in all soils.Not Availabl

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Not AvailableInformation on soil properties and organic carbon distribution in reclaimed sodic soils under different horticultural fruit trees as well as how organic carbon stock varies depth-wise under these land uses is very limited. Therefore, four horticultural land uses namely, guava (Psidium guajava), litchi (Litchi chinensis), mango (Mangifera indica), and jamun (Syzygium cumini) were selected to study their effect on soil properties and distribution of soil organic carbon (SOC) onto different pools of their oxidizability in a reclaimed sodic soil. Soil samples were collected up to a depth of 60 cm i.e. 0-20, 20-40 and 40-60 cm from the above land uses. Results showed that soil pHw (soil: water ratio: 1:2) and bulk density (BD) increased with depth in all the land uses. Minimum and maximum pHw was associated with litchi (6.81) at 0-20 cm and jamun (7.73) at 40-60 cm depth of soil, respectively. Guava recorded minimum BD (1.45 Mg m-3) at 0-20 cm soil depth whereas, a maximum BD of 1.66 Mg m-3 was associated with litchi plantation at lower soil depths. Among the land uses, highest clay content (19.2%) at 0-20 cm was observed under litchi plantation followed by mango (17.3%), jamun (14.4%) and guava (13.9%). Litchi (1.49%) and mango (1.4%) recorded highest CaCO3 content at 0-20 cm soil depth. The amount of oxidizable organic C (OC) varied among the land uses, on an average, its amount was highest with guava (25.9 Mg C ha-1) followed by jamun (25.1 Mg C ha-1) = litchi (25.0 Mg C ha-1) > mango (16.5 Mg C ha-1) in surface soil. Total organic carbon (TOC) stock at surface soil in descending order was guava (28.8 Mg C ha-1) > jamun (27.3 Mg C ha-1) > litchi (25.7 Mg C ha-1) > mango (19.2 Mg C ha-1). In all the land uses, with depth increment passive pool carbon content was increased due to more physical, chemical and biochemical stabilization of organic carbon in lower depths of soil. Soils under guava plantation recorded highest SOC storage (61.0 Mg C ha-1) as well as maximum passive pool C (25.3 Mg C ha-1) up to 60 cm soil depth. Therefore, guava plants can be recommended in reclaimed sodic soils or otherwise barren degraded salt affected land for income generation to the farmers as well as environmental benefit to the mankind.Not Availabl

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Not AvailableSoil salinization is the third important chemical soil degradation. It develops because of relative preponderance of soluble and sparingly soluble salts of sodium, calcium, magnesium and potassium. Excess salts and nadequate soil-water movement and specific ions toxicities in these soils consequently impede ecosystem functions and limits crop performance. Rehabilitation of salt-affected soil (SAS) occupies a major focus in the current policies of the government in order to achieve land degradation neutrality and land restoration. These are relevant for Sustainable Development Goals (particularly SDG 15-Life and Land) of United Nations.Not Availabl

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Not AvailableThe aggregates are considered to be indicators of soil health. Soil rich in organic carbon and physical properties have higher water stable aggregates. In present investigation the distribution of water stable aggregates and their indices were compared in waterlogged sodic soil with non-waterlogged soil profiles. Average maximum total water stable aggregates (45.16%) were recorded in 0-15 cm soil depth and they decreased with increased soil depth. In 0-15 cm soil depth, macro aggregates increased from 9.9% in soil with pH 8.5 to 20.3% in soil with pH 9.5 in waterlogged condition and the same decreased to 2.84% on the same soil in non waterlogged condition. However, in soil with pH 8.5 in waterlogged condition, macro aggregates increased to 9.9 and 11.4% in 0-15 cm and 15-30 cm soil depths, respectively. In soil with pH 9.5, however, in waterlogged condition macro aggregates decreased with increasing soil depth.Not Availabl