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Singh S.K.,Regional Center | Sidhu G.S.,Regional Center | Choudhury S.G.,Regional Center | Pandey C.B.,Indian Central Arid Zone Research Institute | And 2 more authors.
Arid Land Research and Management

Soil organic carbon (SOC) density and soil microbial biomass carbon (SMBC) were studied in 0-30 and 0-100 cm depths in arable and non-arable lands under four soil moisture and temperature regimes (SMTR) [i.e., cryic-ardic (wet period <90 days; mean soil temperature <8°C), udic-mesic (wet period 180-270 days; mean soil temperature 8-15°C), udic-thermic (wet period 180-270 days; mean soil temperature 15-22°C), and ustic-hyperthermic (wet period 90-180 days; mean soil temperature >22°C)] and four soil erosion regimes (slight, moderate, severe, and very severe) in cold arid to subtropical conditions of Western Himalayas, India. The study revealed that SOC density (1.2 ± 0.2 kg m-2) was the lowest in ustic-hyperthermic and highest in udic-mesic (4.2 ± 0.8 kg m-2) and udic-thermic (4.2 ± 0.7 kg m-2) conditions. SOC density in aridic-cryic was higher in arable than in nonarable lands, whereas the trend was reverse in other soil moisture and temperature regimes. Spatial variability of SOC was higher in nonarable than arable lands. Across SMTR and land uses, both SOC density and SMBC were significantly higher on slightly to moderately than severely to very severely eroded surfaces. In 0-30 cm depth, SOC density was highest in Dystrudepts (17.6 kg m-2) and lowest in Hapludalfs (1.9 kg m-2), whereas in 0-100 cm depth, Dystrudepts (32 kg m-2) and Haplustepts (4.2 kg m-2) hold the highest and lowest SOC density, respectively. SMBC moved parallel to SOC density. Study claims that agriculture with good soil and water conservation measures has potential to sequester SOC on the hills. © 2014 Taylor and Francis Group, LLC. Source

Chaturvedi A.,National Bureau of Soil Survey and Land Use Planning ICAR | Kamble R.,Rashtrasant Tukadoji Maharaj Nagpur University | Patil N.G.,National Bureau of Soil Survey and Land Use Planning ICAR | Chaturvedi A.,Rashtrasant Tukadoji Maharaj Nagpur University
Urban Forestry and Urban Greening

There are sporadic reports on urban forests in Indian cities. Nagpur is one of the greenest cities of India with 18 per cent of its area under forests and plantations, 17 per cent under cultivation and 2 per cent under water bodies. The present study showed that natural vegetation of the city is very well diversified with a representation of 59 per cent vegetation including 124 trees species belonging to 38 families as compared with the overall district vegetation statistics. Air quality in the city is relatively better with lower SO2 (6μg/m3), NO2 (18μg/m3) and Respirable Suspended Particulate Matters (RSPM, 53μg/m3) as against National Ambient Air Quality Standards (2009) for cities in India of 80, 80 and 100μg/m3, respectively. It was also noted that the diversity in natural forests which are being protected is greater than the plantations undertaken by the civic authorities and private sector efforts. The study thus demonstrated the positive relationship of the city with diversified vegetation cover for cleaner environment. The analysis is expected to guide formulation of strategies for maintaining green space in the city. © 2012 Elsevier GmbH. Source

Sarkar D.,National Bureau of Soil Survey and Land Use Planning ICAR | Haldar A.,Regional Center Sector 11 | Mandal D.,Pesticide Quality Control Laboratory
Journal of the Indian Society of Soil Science

Forms of soil phosphorus (P) are characterized in relation to soil properties in five pedons belonging to Inceptisols and Alfisols, occurring along a toposequence in Hot Dry Subhumid Agroecological Subregion (AESR 12.3) of West Bengal, falling under Chotanagpur plateau region. The soils are shallow (<0.5 m) to very deep (>I .5 m), sandy clay loam to clayey in texture, moderately acidic to neutral in reaction (pHaq. 5.3 - 6.6), low to high in organic carbon content, low in NaHCO3 extractable P (2.1-3.0 mg kg-1 in the surface horizon), low to medium in NH4OAc-extractable K (32.0-43.0 mg kg-1 in the surface horizon) and fairly high in Fe2O3 content (15.0-18.8%). Based upon overall profile weighted mean (PWM) values maximum amount of P is in the form of reductant soluble P (RS-P) [109.9 mg kg-1] while minimum amount is in the form of saloid P (S-P) [1.9 mg kg-1] contributing 31.2% and 0.5% to the total P content, respectively. Sequential extraction of inorganic soil P fractions reveal that the mean relative abundance follow the order: reductant soluble phosphate (RS-P) > iron phosphate (Fe-P) > occluded-P = calcium phosphate (Ca-P) > aluminium phosphate (AI-P) > saloid phosphate (S-P). The overall relative abundance of the different inorganic P fractions in terms of their average ratios are: S-P (0.1): AI-P (0.8): Fe-P (2.2): Ca-P (1.0): RS-P (6.0): occluded-P (1.0). The PWM - total P content suggest that the soils are fairly rich in P reserve ranging from 279.3 to 533.2 mg kg-1 with an overall mean of 352.3 mg kg-1. Significant positive correlation was observed between S-P with OC (r = 0.504**) and total P (r = 0.653***). Close relationship between total P and S-P (r = 0.653***), Fe-P (r = 0.520**) suggested the existence of equilibrium between the former and the latter. The study reconfirms the poor P availability status of the soils under Chotanagpur plateau region of West Bengal. Soil maturity based upon PWM of total P is in the sequence: P5 (most matured) > P4 > P3 > P2 > P1 (least matured) which did not corroborate the maturity sequence inferred from soil taxonomy viz., P4 (most matured) > P1, P2, P3, P5 (least matured). Maturity sequence derived from weathering index (WI) based upon inorganic soil P fractions viz., P4 (most matured) > P3 > P2 > P5 >, P1 (least matured) is in good agreement with that obtained from soil classification indicating a close relationship between the former and the later. The study emphasized the suitability of inorganic soil P based weathering index (WI) for adjudging soil maturity in terms of pedogenic development of the soils. Source

Nayak D.C.,Regional Center | Sarkar D.,National Bureau of Soil Survey and Land Use Planning ICAR
Clay Research

Mineralogical studies of sand, silt and clay fractions of four benchmark soils (Ballartop, Chandipur, Narayanpur and Patibunia) occurring on coastal plain, West Bengal were conducted to identify the minerals present in these fractions and also to understand their transformation in this ecosystem. Ballartop, Chandipur and Narayanpur soils were developed on very gently sloping to nearly level plain with poor drainage whereas Patibunia soil was developed on degraded mangrove with imperfectly drainage condition. The soils were dark grayish brown to dark gray in colour except Narayanpur soils which was gray to dark gray throughout the profile with olive brown to dark brown mottles and the texture of the soils varied from silt loam to silty clay. The soils were neutral to moderately saline (pH 6.7 to 8.1) except the soil of Ballartop (pH 4.7- 8.2). The EC value ranged from 0.72 to 8.3 dSm-1 and the clay content varied from 19.8 to 51.9%. The CEC of the soils was low to high and ESP of these soils ranges from 6.1 to 33.5. The mineralogical study revealed that in the heavy sand fraction, the minerals were present in the order: opaque > limonite > biotite > phlogopite > hornblende > pyroxene > goethite > kyanite and the other minerals are in trace. In the light sand fraction, quartz was the dominant mineral (43-89%), followed by muscovite (6-48%), potash feldspar (1-14%) and plagioclase feldspar (1-11%). The minerals in silt fraction followed the order: mica (42-67%) > kaolinite (9-24%) > chlorite (6-16%) > vermiculite (5-15%) smectite (1-10%) > K- plagioclase > feldspar feldspar with minor to trace amount of 10-14Å mixed layer mineral and 8Å smectite/ kaolinite (sm/k). In clay fraction, mica was the dominant mineral followed by kaolinite and varying amount of smectite, chlorite and vermiculite. Significant amount of smectite (26-33%) was present in Narayanpur soils and in some horizons of Chandipur soils. The mineralogy of Ballartop, Chandipur and Patibunia soils was "illitic" and that of Narayanpur soils was "mixed". The higher peak intensity ratio of 001/002 mica reflection of silt and clay fractions indicated the dominance of tri-octahedral mica which have significant amount of reserve potash. Source

Patra P.K.,Japan Agency for Marine - Earth Science and Technology | Canadell J.G.,CSIRO | Houghton R.A.,Woods Hole Oceanographic Institution | Piao S.L.,Peeking University | And 14 more authors.

The source and sinks of carbon dioxide (CO2) and methane (CH4) due to anthropogenic and natural biospheric activities were estimated for the South Asian region (Bangladesh, Bhutan, India, Nepal, Pakistan and Sri Lanka). Flux estimates were based on top-down methods that use inversions of atmospheric data, and bottom-up methods that use field observations, satellite data, and terrestrial ecosystem models. Based on atmospheric CO2 inversions, the net biospheric CO2 flux in South Asia (equivalent to the Net Biome Productivity, NBP) was a sink, estimated at -104 ± 150 Tg C yr−1 during 2007-2008. Based on the bottom-up approach, the net biospheric CO2 flux is estimated to be -191 ± 193 Tg C yr−1 during the period of 2000-2009. This last net flux results from the following flux components: (1) the Net Ecosystem Productivity, NEP (net primary production minus heterotrophic respiration) of -220 ± 186 Tg C yr−1 (2) the annual net carbon flux from land-use change of -14 ± 50 Tg C yr−1, which resulted from a sink of -16 Tg C yr−1 due to the establishment of tree plantations and wood harvest, and a source of 2 Tg C yr−1 due to the expansion of croplands; (3) the riverine export flux from terrestrial ecosystems to the coastal oceans of +42.9 Tg C yr−1; and (4) the net CO2 emission due to biomass burning of +44.1 ± 13.7 Tg C yr−1. Including the emissions from the combustion of fossil fuels of 444 Tg C yr−1 for the 2000s, we estimate a net CO2 land-atmosphere flux of 297 Tg C yr−1. In addition to CO2, a fraction of the sequestered carbon in terrestrial ecosystems is released to the atmosphere as CH4. Based on bottom-up and top-down estimates, and chemistry-transport modeling, we estimate that 37 ± 3.7 Tg C yr−1 were released to atmosphere from South Asia during the 2000s. Taking all CO2 and CH4 fluxes together, our best estimate of the net land-atmosphere CO2-equivalent flux is a net source of 334 Tg C yr−1 for the South Asian region during the 2000s. If CH4 emissions are weighted by radiative forcing of molecular CH4, the total CO2-equivalent flux increases to 1148 Tg C yr−1 suggesting there is great potential of reducing CH4 emissions for stabilizing greenhouse gases concentrations. © Author(s) 2013. Source

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