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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.

IntroductionIt is estimated that five out of six farms in the world are operating less than two hectares of land, called smallholder farmers, and they are producing over one third of the global food. Cropping system intensification research and interventions at farmers' fields could be one of the ways to improve the prevailing cropping systems. Understanding socio-economic issues are important for the successful implementation of improved or new cropping systems and for increasing farmers' income in the coastal zone of the Ganges delta. A socio-economic evaluation study was carried out to understand how far the suggested cropping options were feasible to smallholder farmers in the coastal zone; quantify the benefits due to the adoption of new cropping systems; how far those options were socio-economically suitable for the targeted smallholder farmers; and to identify the key factors that might be affecting the out-scaling of the evolved options to a larger group of farmers.MethodsBaseline and endline surveys were conducted with 90 farmers before and after the demonstration of various cropping systems at farmers' fields. Techno-economic suitability of new crops and management options were evaluated through accounting benefits of adoption and identifying various constraints in adoption. Behavioral analysis was carried out to identify factors affecting large-scale adoption of the new/improved cropping systems evolved.Results and discussionThe socio-economic survey quantified the increase in cropping intensity higher than the baseline level (123–142%) and reduced the rabi (winter/dry) season fallow area by 30–35%. The study identified farmers' preferred interventions were low-cost drip irrigation and mulching, zero-tillage (ZT) potato with straw mulching, improving soil quality with lime and green manuring, and vegetable-based cropping systems interventions. Although the economics of the evolved cropping systems were favorable, however, availability of freshwater stored in ponds/canals, and income from on and off-farm were the most important factors determining the adoption of new systems on a larger scale.

Soil is a finite natural resource and is indispensable for human civilization because it is the medium for food production for the biosphere. Continued soil degradation is a forerunner of catastrophe for the living world. The protection of healthy soils and the restoration of problem soils are strongly needed in the current agricultural scenario as competition for urbanization and other human needs for land resources limits the scope for the further availability of land for agriculture. Naturally occurring degraded soils, such as acid sulphate soils, can be restored with scientific interventions and advanced management strategies. The Ganges Delta is a densely populated region, where the inhabitants’ major livelihood is agriculture. Soil acidity and salinity restrict crop performance in this coastal region, particularly the acid sulphate soils (ASSs) posing a risk to agriculture. ASSs are developed from land-use changes from mangrove forest to agricultural land in this region. There is no systematic study on these soil types covering Bangladesh and India. This paper unfolds several aspects related to the characteristics, problems, and detailed management strategies of ASSs relevant to the Gangetic Delta region where these soils continue to be used for intensive agriculture to meet the livelihood needs. Crop yields are very poor in the unmanaged ASSs due to a very low soil pH (

Rice is the predominant crop during wet season (July–December) and majority of land remain fallow during dry season (January–June) in the coastal saline region of West Bengal, India. Sustainable cropping system intensification in this salt affected region needs improved package of practices which conserve soil moisture, facilitate early crop establishment, ensures profitability and has positive effect on soil health. To achieve these objectives in a rice-based cropping system, we evaluated seven treatments for potato crop during the dry season viz. T1: ridge sowing (control), T2: Zero tillage (ZT) sowing with 9 t ha−1 paddy straw mulching (PSM), T3: T2 + foliar spray of nutrients, T4: ZT sowing with 12 t ha−1 PSM, T5: T4 + foliar spray of nutrients, T6: ZT sowing with 15 t ha−1 PSM, T7: T6 + foliar spray of nutrients in randomized block design with five replications. This study was conducted during 2016-2019 in the Gosaba island of the Indian Sundarbans. Cost of cultivation of potato reduced by about 27% due to ZT sowing (₹ 81,287 ha−1) compared to ridge sowing (₹ 1,11,260 ha−1). Tuber yield, net return and irrigation water productivity was significantly increased in T5, T6 and T7 over other treatments. There was reduction in soil salinity (ECe reduced from 5 to 3 dS m−1), bulk density (from 1.49 to 1.44 Mg m−3), irrigation water use (less 20 cm), conservation of soil moisture (4–8%), and increase in organic carbon (0.39 to 0.44%) due to ZT sowing with PSM. Rice-ZT potato-green gram cropping system was the most profitable one with highest net return (₹ 1,71,752 ha−1), however, the benefit-cost ratio was highest (2.33) with Rice-ZT potato cropping system.