Characterization of Salinity and Sodicity Levels in Groundwater and Their Impact on the Yield of Banana (Musa Indicata) in District Lasbela

Abstract

The study on characterization of different levels of salinity and sodicity was carried in district Lasbela during 2012-2013.The study area is situated between 24°-54 and 26°-37 north latitude and 64°-02 and 67°-28 east longitude. Lasbela’s geography and landscape is diverse and interesting. A total no 32 groundwater samples were collected from the study area. Water was characterized in accordance to the diagram for the classification of irrigation waters based on EC and SAR values. 94 % of the sites were falling in the high salinity class of C3 where as only 6% of the sites were falling in the C4 class. On the other hand, nearly 81% of the sites have SAR values below 10, which fall in the low category of sodicity S1. Hence only 19% of the sites have medium SAR. The percentage of the salts of the same site is higher when compared to its sodicity. The combined EC_w-SAR classification of groundwater of 81% of the samples are in C3-S1 class followed by the respective classes of C4-S1 and C4-S2 at 13% and 6% of the groundwater analysed. Such water is classified as highly and very highly saline for irrigation. The average yield of banana in the whole area was 7447 kg/ha/year. EC_w has no impact on yield of crops in the region. However a weak but general increase in salinity shows a bit increasing trend in yield while a minute increase in salinity shows a decreasing trend. Also SAR has no noimpact on yield of crops in the region. This might be because of use of such water that was entirely feasible particularly on light (sandy) soils. The present groundwater may be considerably better under many conditions that might be usable which be able to be successfully be applied to produce good yields of salt tolerant crops.

Keywords: Lasbela, Groundwater Quality, Salinity, Sodicity, Yield, Banana, USDA