Appraisal of salinity and fluoride in a semi-arid region of India using statistical and multivariate techniques

“The original publication is available at www.springerlink.com”. Copyright Springer. DOI: 10.1007/s10653-008-9222-5Various physico-chemical parameters, including fluoride (F−), were analyzed to understand the hydro-geochemistry of an aquifer in a semi-arid region of India. Furthermore, the quality of the shallow and deep aquifer (using tube well and hand pumps) was also investigated for their best ecological use including drinking, domestic, agricultural and other activities. Different multivariate techniques were applied to understand the groundwater chemistry of the aquifer. Findings of the correlation matrix were strengthened by the factor analysis, and this shows that salinity is mainly caused by magnesium salts as compared to calcium salts in the aquifer. The problem of salinization seems mainly compounded by the contamination of the shallow aquifers by the recharging water. High factor loading of total alkalinity and bicarbonates indicates that total alkalinity was mainly due to carbonates and bicarbonates of sodium. The concentration of F− was found more in the deep aquifer than the shallow aquifer. Further, only a few groundwater samples lie below the permissible limit of F−, and this indicates a risk of dental caries in the populace of the study area. The present study indicates that regular monitoring of groundwater is an important step to avoid human health risks and to assess its quality for various ecological purposes.Peer reviewe

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Not AvailablePotato (Solanum tuberosum ssp. tuberosum) cultivars grown under tropical conditions exhibit comparatively poor yields compared to the temperate conditions, hence, there is need for stable cultivars with greater yields. The interactions of four cultivars with ten environments for 2 years under All India Coordinated Research Project (Potato) across the country for 2 harvesting stage (75 and 90 DAP) revealed that the cultivars were significantly different among themselves for Total Yield (TY) and Marketable Yield (MY) harvested at 75 and 90 DAP at seven and eight environments, respectively. The pooled analysis showed a significant difference for cultivar and environmental main effects for all traits, indicating the existence of cultivars genetic variability justified from the heterogeneity of environments. The significant effect of G×E interaction for TY and MY at 90 DAP, and a non significance for the same traits at 75 DAP clearly indicated that the prevailing environments during early crop stage were uniform as compared to its later harvesting stage. Partitioning of G×E interaction into linear and non linear components were highly significant for all traits, strongly suggesting the real differences in cultivars for regression over environmental means and the response of cultivars to environment was controlled genetically. The cultivar K. Pukhraj was proven as early bulking and stable cultivar for TY and MY at 75 DAP and predictable in nature, as against K. Khyati which was stable cultivar for TY and MY at 90 DAP across growing environments. Hence, K. Khyati, which recorded the highest TY (27.45 t ha-1) and MY (25.24 t ha-1) for harvesting at 75 DAP, and TY (31.28 t ha-1) and MY (28.19 t ha-1) at 90 DAP, can be recommended for tropical conditions.ICAR, New Delh

Post-monsoon air quality degradation across Northern India: assessing the impact of policy-related shifts in timing and amount of crop residue burnt

The past decade has seen episodes of increasingly severe air pollution across much of the highly populated Indo-Gangetic Plain (IGP), particularly during the post-monsoon season when crop residue burning (CRB) is most prevalent. Recent studies have suggested that a major, possibly dominant contributor to this air quality decline is that northwest (NW) Indian rice residue burning has shifted later into the post-monsoon season, as an unintended consequence of a 2009 groundwater preservation policy that delayed the sowing of irrigated rice paddy. Here we combine air quality modelling of fine particulate matter (PM2.5) over IGP cities, with meteorology, fire and smoke emissions data to directly test this hypothesis. Our analysis of satellite-derived agricultural fires shows that an approximate 10 d shift in the timing of NW India post-monsoon residue burning occurred since the introduction of the 2009 groundwater preservation policy. For the air quality crisis of 2016, we found that NW Indian CRB timing shifts made a small contribution to worsening air quality (3% over Delhi) during the post-monsoon season. However, if the same agricultural fires were further delayed, air quality in the CRB source region (i.e. Ludhiana) and for Delhi could have deteriorated by 30% and 4.4%, respectively. Simulations for other years highlight strong inter-annual variabilities in the impact of these timing shifts, with the magnitude and even direction of PM2.5 concentration changes strongly dependent on specific meteorological conditions. Overall we find post-monsoon IGP air quality to be far more sensitive to meteorology and the amount of residue burned in the fields of NW India than to the timing shifts in residue burning. Our study calls for immediate actions to provide farmers affordable and sustainable alternatives to residue burning to hasten its effective prohibition, which is paramount to reducing the intensity of post-monsoon IGP air pollution episodes