wAbstract
@We assesses the potential of nitrate-nitrogen (NO3-N)
and fluoride (F) contamination in drinking groundwater of an intensively
cultivated district in India as a function of its agricultural
activities. Three hundred and forty two groundwater samples were
collected from different types of wells with varying depths and
analyzed for pH, EC, NO3-N load and F content.
Database on predominant cropping system, fertilizer and pesticide
uses were also recorded for the district. The NO3-N
load in groundwater samples were low ranging from 0.01 to 5.97
mg L-1 with only 6.7 of them contained greater than
3.0 mg L-1. Samples from the habitational areas showed
higher NO3-N content over the agricultural
fields. But all the samples contained NO3-N
below the 10 mg L-1, the threshold limit fixed by WHO
for drinking purpose. The content decreased with increasing depth
of wells (r=-0.297, P
0.01) and increased with increasing rate
of nitrogenous fertilizer application (r=0.931, P
0.01) and was
higher in areas where shallow-rather than deep-rooted crops are
grown. Fluoride content in groundwater was also low (0.02 to 1.19
mg L-1) with only 2.4 of them exceeding 1.0 mg L-1
posing a potential threat of fluorosis in some locality. On average,
its content varied little spatially and along depth of sampling
aquifers indicating homogeneity in lithology of the district.
The content showed a significant positive correlation (r=-0.237,
P
0.01) with the amount of phosphatic fertilizer (single super
phosphate) used for agriculture. Results thus indicated that the
groundwater of the study area is presently safe for drinking purpose
but some anthropogenic activities associated with intensive cultivation
had a positive influence on its loading with NO3-N
and F.
Keywords: Agricultural activities; NO3-N;
F; Groundwater; Contaminationx
1. Introduction
2. Background of the district
@2.1. Geology and hydrogeology
3. Materials and methods
@3.1. Collection of groundwater samples and datasets for other
influencing parameters
@3.2. Methodology
@3.3. Statistical analysis
4. Results
5. Discussion
@5.1. NO3-N content in groundwater
@5.2. F content in groundwater
6. Conclusions
Acknowledgement
References