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Soil salinity is the major constraint for cropping system intensification in the coastal region of the Ganges Delta. Salts build up on the soil surface, as well as in the crop root zone, due to the capillary rise in underground brackish water, hampering the growth and development of crops and resulting in mortality and low yields. We studied, for three years (2020–2021 to 2022–2023), the effect of conservation agricultural practices (zero tillage planting, crop residue recycling, and crop rotations) on the major soil properties (soil salinity and organic carbon status), crop performance (yield and economics), and water footprint. Conservation agricultural practices significantly reduce soil salinity, build soil organic carbon, reduce water footprint, and increase the profitability of cropping systems compared to tillage-intensive conventional practices. Under conventional agriculture, the sole cropping of rice is more profitable than double and triple cropping systems. [ABSTRACT FROM AUTHOR]

Sundarbans in West Bengal of India by virtue of its strategic location in the Eastern coast on the Bay of Bengal falls in one of the most vulnerable zones of abrupt climate change. Temporal trends of o o weather parameters of Canning Town (22 18'10.8'' N Latitude, 88 39'58.4'' E Longitude, elevation 3.52 m msl) representing Indian Sundarbans were analysed by non-parametric Mann-Kendall test and Sen's slope approaches. Analysis of long term rainfall data (1966-2015) indicated that Canning receives a mean annual rainfall of 1821 mm (±341.8 mm) with a considerable variation (CV = 18.8%). The results revealed that total annual rainfall trend decreased non-significantly at the rate of 0.94 mm yr-1. On an average 84.4 rainy days in a year was recorded in the region, whereas during last ten years (2006-2015), the number of rainy days was reduced to 79.7 days yr-1. There was no significant change in maximum, minimum and mean temperature of the region. Bright sunshine hours declined significantly at an annual rate of 0.055 hr yr-1. Reference crop evapotranspiration (ET0) calculated using FAO Penman-Monteith method revealed that annual ET0 significantly decreased at the rate of 5.98 mm yr-1. There was 2.7 times surplus rainfall than crop evapotranspiration during monsoon months indicating very high scope of water harvesting to tackle water logging during the monsoon season and unavailability of fresh water for irrigation during lean season. [ABSTRACT FROM AUTHOR]

Sorptivity was determined from soils of three different landforms, namely, non-cultivated deltaic (NCD), mud flat (MUD) and depressed low land (DL) under Gosaba Block of coastal West Bengal. The area covers approximately 4 km2 and soil samples were collected during the dry season (Feb. - March) of 2018. A horizontal infiltration study was carried out in the laboratory in plexiglass columns packed with soil for determining the infiltration and sorptivity parameters. Physicochemical parameters like pH2, EC2, saturated moisture content, texture, organic C were determined. The humic components of organic matter, namely, humic acid and fulvic acid, were also separated out to study their effect, if any, on soil sorptivity. Steady state cumulative infiltration was the highest (50-55 mm) in NCD soil and lowest (18-20 mm) in DL soil. The highest sorptivity of 3.1-3.5 mm min-½ was found in NCD soil and lowest in DL soil (1.0-1.1 mm min-1/2). Organic C content of all soils were medium to high (0.50-1.20 %) and EC2 values were also low (< 4 dSm-1) in most of the soils except DL soil which had an EC2 value of 4-5.8 dS m-1. Saturated moisture content was highest in DL soil. The NCD soils contained higher fraction of fulvic acid (0.10-0.12%) which enhanced infiltration, whereas DL soils contained greater fraction of insoluble humic acid (0.27-0.31%) and exhibited less cumulative infiltration. MUD soils showed intermediate values. The relationships between sorptivity and clay, pH, EC, porosity and humic acid were significant (r = -0.90, -0.86, -0.86, -0.87 and -0.90, respectively), exponential and negative. Percentage fulvic acid was positively correlated (r = +0.94**) with sorptivity. [ABSTRACT FROM AUTHOR]