EFFECTS OF SOIL SALINITY ON SUSTAINABILITY OF CROP PRODUCTION IN GUSAU LOCAL GOVERNMENT AREA, ZAMFARA STATE, NIGERIA

Abstract

The sustainability of agricultural production on the soils in the Sudano-Sahelian agroecological zone needs current information on the salinity status for appropriate management practices. This paper assessed the effects of soil salinity on the sustainability of crop production in Gusau, Local Government Area, Zamfara State. Soils were sampled from a polygon layer of grid stratification map of Gusau LGA at 0 - 20cm depth, a total of 8 polygon layers with over 50% proportion were selected for the collection of samples. Three soil samples were collected purposively at three different locations to produce eight composite soil samples. Soil parameters that were analyzed include Electrical Conductivity (EC) and Total Dissolved Solids (TDS) which are crucial in determining salinity level. Classification chart was used to classify the soils based on various degree of salinity. The results of the soil samples were interpolated using Inverse Distant Weight (IDW) to create maps of the spatial distribution of salinity level across the study area. Modis 13Q1 NDVI data of the study area from 2000 to 2020 were acquired from LP DAAC. The Area of Interest (AOI) and data attributes were selected. The data was used to show the vegetation responsive changes from salinity, which serves as an indirect method of detecting salinity. The EC values shows non salinity (0 to 2 dS/m), low salinity (2 to 4 dS/m) and mild salinity (4 to 5.7 dS/m). TDS ranged from non-hazard (140 ppm) to high hazard (465 ppm). Non-hazard class ranged (< 150 ppm), low hazard (150 to 250 ppm), medium hazard TDS (250 to 300 ppm) and high hazard (300 to 500 ppm) were found spatially distributed in different parts of the study area. A sustainability map of the study area from the severity of soil salinity which determined different management practices shows three sustainability classes of soils, very sustainable soils, sustainable soils and less sustainable soil. The study concludes that soils in Gusau ranges from moderate salinity towards the North and Central part of the study area and low in the Southern part. By implication, the soils in the North and Central areas can only sustain crops that are not sensitive to salinity. It is recommended that farmers should review their farm management strategies on soils with risk of salinity in order to reduce the rate and implications in the area.