Preliminary Findings on Comparative Study of Nitrogen Content In Groundwater of Agricultural Area Versus Non-Agricultural Areas In L. Gan Maldives

Abstract

Nitrate contamination of groundwater is prevalent in areas with high agricultural activities. L. Gan is one of the islands in Maldives with a high level of farming. This study aims to determine the impact of agricultural activities on the ground waters of laamu atoll Gan. The objective of the study is to compare the amount of nitrate compounds in agricultural areas and non-agricultural areas by obtaining five water samples from wells of agricultural farm and another 5 water samples from non-agricultural, that is, household wells. One sample is collected from an isolated region to compare the water quality with agricultural farms and household wells. The nitrogen compounds that are being measured are nitrate, nitrite and ammonia using spectrophotometric analysis. The mean concentration of nitrate in agricultural and non-agricultural areas are 1.18 and 1.125 mg/L, respectively, with a mean difference of 0.055 mg/L, which is 4.8% higher nitrate concentration in agricultural areas than in non-agricultural areas.  The nitrate concentration of the water sample obtained from an isolated area is 4.6 mg/L.  For mean Nitrite concentration agricultural area has 0.056 mg/L, and the nonagricultural area has 0.0094 mg/L. the mean difference is 0.0464 mg/L of nitrite, which is 83 % higher nitrite concentration in agricultural areas than in non-agricultural areas. The water sample from the isolated area has a nitrite concentration of 0.033 mg/L. The ammonia concentration for agricultural non-agricultural is 0.526 and 0.26, respectively. The mean difference is 0.246 mg/L and which is 46% higher ammonia content in agricultural areas than in non-agricultural areas. The ammonia content in the isolated region water sample is 0.4 mg/L. This study indicates high nitrogen compounds in agricultural areas compared to non-agricultural areas. Over time the nitrate contamination may increase to a level that my pose health and environmental threats. Hence it is important to regulate the type and amount of fertilizer being used to prevent groundwater contamination