title: Temporal patterns and source apportionment of nitrate-nitrogen leaching in a paddy field at Kelantan, Malaysia.
abstract: Nitrate-nitrogen leaching from agricultural areas is a major cause for groundwater pollution. Polluted groundwater with high levels of nitrate is hazardous and cause adverse health effects. Human consumption of water with elevated levels of NO3-N has been linked to the infant disorder methemoglobinemia and also to non-Hodgkin's disease lymphoma in adults. This research aims to study the temporal patterns and source apportionment of nitrate-nitrogen leaching in a paddy soil at Ladang Merdeka Ismail Mulong in Kelantan, Malaysia. The complex data matrix (128 x 16) of nitrate-nitrogen parameters was subjected to multivariate analysis mainly Principal Component Analysis (PCA) and Discriminant Analysis (DA). PCA extracted four principal components from this data set which explained 86.4% of the total variance. The most important contributors were soil physical properties confirmed using Alyuda Forecaster software (R2 = 0.98). Discriminant analysis was used to evaluate the temporal variation in soil nitrate-nitrogen on leaching process. Discriminant analysis gave four parameters (hydraulic head, evapotranspiration, rainfall and temperature) contributing more than 98% correct assignments in temporal analysis. DA allowed reduction in dimensionality of the large data set which defines the four operating parameters most efficient and economical to be monitored for temporal variations. This knowledge is important so as to protect the precious groundwater from contamination with nitrate.
authors: Department of Environmental Health, Faculty of Health Sciences, Universiti Teknologi MARA, 41030, Puncak Alam Campus, Selangor, Malaysia.
authors: Hazilia
authors: H
authors: Hussain
authors: Department of Environmental Sciences, Faculty of Environmental Studies, Universiti Putra Malaysia, 43000 Serdang, Selangor, Malaysia.
authors: Mohd Kamil
authors: MK
authors: Yusoff
authors: Department of Environmental Sciences, Faculty of Environmental Studies, Universiti Putra Malaysia, 43000 Serdang, Selangor, Malaysia.
authors: Mohd Firuz
authors: MF
authors: Ramli
authors: Department of Environmental Sciences, Faculty of Environmental Studies, Universiti Putra Malaysia, 43000 Serdang, Selangor, Malaysia.
authors: Puziah
authors: P
authors: Abd Latif
authors: Department of Environmental Sciences, Faculty of Environmental Studies, Universiti Putra Malaysia, 43000 Serdang, Selangor, Malaysia.
authors: Hafizan
authors: H
authors: Juahir
authors: Department of Biological and Agricultural Engineering, Faculty of Engineering, Universiti Putra Malaysia, 43000 Serdang, Selangor, Malaysia.
authors: Mohamed Azwan Mohammed
authors: MA
authors: Zawawi
mesh_terms: D057914:Agricultural Irrigation; D018556:Crops, Agricultural / Q000254:growth & development*; D016002:Discriminant Analysis; D004784:Environmental Monitoring / Q000379:methods; D005308:Fertilizers / Q000032:analysis*; D060587:Groundwater / Q000737:chemistry*; D008296:Malaysia; D015233:Models, Statistical; D015999:Multivariate Analysis; D009566:Nitrates / Q000032:analysis*; D009584:Nitrogen / Q000032:analysis*; D012275:Oryza / Q000254:growth & development*; D018526:Plant Transpiration; D011312:Pressure; D025341:Principal Component Analysis; D011891:Rain; D012621:Seasons; D012984:Software; D012987:Soil / Q000737:chemistry*; D013696:Temperature; D013997:Time Factors; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D005308:Fertilizers; D009566:Nitrates; D012987:Soil; D014874:Water Pollutants, Chemical; D009584:Nitrogen