Strategies for water salinity management in alluvial aquifer in a multilevel crop planning

This article analyses the behaviour of groundwater salinity and its suitability for irrigation purposes and proposes multilevel crop planning to increase agricultural benefits based on water salinity management strategies. The study area is a 12-km-long portion of an alluvial aquifer, where the irrigated perimeter of Sumé is located, in the municipality of Sumé, in the State of Paraíba, Brazil. Three wells were selected, located in the middle portion and at the ends of the aquifer. Based on the physical-chemical data collected, the classification of groundwater for agricultural use was carried out. Then, a multilevel planning model based on water salinity management is proposed, considering the geographic scale of the aquifer, different decision-making levels (lot and of irrigated perimeter), in addition to the involvement of different actors, including organizations and small farmers, at different decision levels. The results indicated that the waters in the initial portion of the aquifer have the highest levels of salinity and that the waters in the final reach have better quality, possibly due to the shorter and longer distances from the sources of contamination, respectively. The possibility of increasing the availability of water in the aquifer and the crop yield was indicated, in addition to other benefits related to the qualification of farmers and the commercialization of products, among others. In this sense, multilevel planning is suggested as a tool that can generate benefits for farmers beyond crop yields, including social and economic aspects. [Display omitted] •Small alluvial aquifers are very sensitive to pollution contamination.•Groundwater electric conductivity are mainly determined by pollution sources.•Family-based agriculture better managed at farm and irrigated perimeter scales.•Multilevel crop planning integrates farmers and institutional actors.