Pcrtanika 13(1), 79-1\3 (1990) A General Survey of Nitrate-Nitrogen Levels In Well-water under Different Landuses MOHD KAMIL YUSOFF, WA ORAZMIN SULAIMA and ZAI UDIN SHARIF Department of Environmental Sciences Faculty oj Science and Environmental Studies Universiti Pertanian Malaysia 43400 UPM Serdang, Selangor Darul Ehsan, Malaysia. Keywords: N03 --N, land use, well-water. ABSTRAK Satu tinjaun umum mengenai aras N03 -- N dalam air perigi telah dlj'alankan di empat kawasan yang berlainan bent uk gunatanahnya. Empat kawasan yang dipilih ialah kawasan pertanian dengan temakan lembu, kawasan hutan, kawasan bandar dan kawasan pertanian sahaja. Sampel air diambil dari 22 perigi yang terdapat dalam kawasan tersebut dan kandungan N03 - -N dianalisakan. Hasil dari data yang didapati di lapangan dan ujian statistik menunjukkan aras N03 -- Nair perigi dari kawasan gunatanah yang berlainan kecuali kawasan pertanian + temakan, menunjukkan perbezaan yang ketara di mana kawasan pertanian mempunyai aras N03 -- N yang tertinggi diikuti oleh kawasan bandar dan hutan. ABSTRACT A general survey on N03 -- N levels in well-water under different landuses was conducted. Four areas were selected to represent different landuses namely mixedfarming (crop and animal production), forest, urban, and crop production only. Water samples from a total of 22 wells in the selected areas were collected and analysedfor N03-- N. The field and statistical data showed that the differences in N03 -- N levels in well- waterfrom different landuses were significant except for agriculture + animal farming. The highest N03 -- N level was observed in agricultural areas followed by urban and forested areas. INTRODUCTION there are also other contributing factors such as Agriculture is important to the Malaysian rainfall, natural processes (hydrologic, geologic economy. Lately there has been substantial and biological) (Tanji 1979), and industrial developments in the cultivation of rubber, oil and domestic wastes (Tanji 1979; Gray and palm, cocoa, fruits and vegetables. These Jones 1980). developments in agriculture have also resulted in Potable water with high concentrations of increased use of commercial fertilizers, herbicides 0 3 -- N is hazardous to health especially for and insecticides in an effort to obtain higher young infants. The maximum concentration of yields. N03 --N for potable water should not exceed 10 The increase in usage of chemicals in agri­ mg/1. Higher N03-- concentrations can cause cultural activities has raised questions regarding a disease called methaemoglobinemia in infants chemical pollution of groundwater, especially by (Bouwer 1978). plant nutrients, for example, nitrate-nitrogen There is no doubt that the use of chemicals ( 0 3 -- ). Previous studies have indicated that in modern agricultural activities has resulted in most of the 0 3 -- in groundwater is associated increased productivity but there is also the need with the use of fertilizers (Smith et at. 1971 ; to examine its effect on the quality of our water Gentzsch et at. 1974; Lund et at. 1974; Meek resources. In Malaysia, little attention has been et al. 1974; Gray and Jones 1980; Khanif et given to the research aspects of nutrient pollution. at. 1983; Bergstorm 1987). Besides fertilizers, This study seeks to provide basic information in MOHO KAMIL YUSOFF, WAN NORAZMIN SULAIMAN AND ZAINUDIN SHARIF 100 0 N I~~ , \ ----.... I 9 .... _-) \ Pulau I I I Langkalo'i rI ___ I '-_ .... ' r \I '-- WEST MALAYSIA :0. • KUALA LUMPUR Study Area ----'__-- 10 0 30 60 miles '-oj 10 0 ~ 60 90 km Fzg. 1: The location of the study area. order to have a better understanding and aware­ upon forest products such as fruits, bamboo ness of nutrient pollution in groundwater with and rattan for their income, respect to landuse, c. Rembau (A3) is a small town with a popu­ lation of 1500 and an area of 1.5 km2 and Site Information is classified as urban landuse, This area The areas studied include three locations in the contains Government buildings, housing Rembau district of Negeri Sembilan, and one in estates, schools, a hospital, petrol station the Alor Gajah district of Malacca (Figures 1 and and shops, 2). Each area represents a different landuse: d, Chembong (A4) in Rembau has an area of a, Taman Sri Kendong (A1) in Alor Gajah has 1.2 km2 with agriculture as the main land­ 2 an area of 1.2 km , This area was formerly use activity, This area has an Agricultural completely under rubber. Landuses include Training School, a Vocational Agricultural animal farming with pasture land, rubber School, oil palm nurseries and experimental and fruit plantation, and fruits and flower plots for vegetables and fruits, nursenes, b, Kg, Pulau Bintongan (A2) in Rembau is a The soil series in all the selected areas is forested area, The people in this area depend Renggam with granite as parent material. The 80 PERTANIKA VOL. 13 NO. 1,1990 GENERAL SUR\'EY OF NITRATE- ITROGEN LEVELS IN WELL-WATER UNDER DIFFERENT LANDUSES the wells selected for this survey are located In r-,(-"""-- _.-....., ,/ \ .... } N individu~1 house compounds. i I ._.il" } "f ('. MATERIALS AND METHODS I ./ t Water sampies from the selected wells were Spn \ i obtained direct from the tap supplied by the pump I except for the wells in A2 where sampling was '.\ " '-'\ done manually. Each water sample wa poured -, , " into a clean plastic bottle (250 ml capacity) and " Ct'lembct'g ,, "'~._'_.) 0.5 ml of concentrated sulphuric acid was added ,, KG PU.AU BI NTO~ (.... , FWA {A21 "\ to inhibit the bacterial activities. The samples were ~ " Se\efook Mlku j, stored in an ice box and transported back to the REMBAlJ TOWN \ " ., laboratory (80 km away) for analysis on the same ( A3 I Oistr~t ,_._.__ .J of i , '., day. The well waters were sampled six times from , TQt1unq ........ ~ ., i KlIng .... i ... Chengkau October to December 1985. During each visit, a , '­ , L. .... , total of 66 samples were taken with replicates of , Kundor Nerosau 3 samples per well. Sampling was carried out in ,j, I NEGERI SEMSILAN the morning and time taken was about three hours I 1 to cover all areas. i The brucine-sulphate method was used to analyse 0 3 -- N concentrations in water using a .' spectrophotometer (Perkin-Elmer 55E) at 410 nm //Oistrict (US EPA, 1979). /_._ ,.,// of Alor Gojoh " - The data obtdined was analysed statistically , ......... , ..... MAlACCA i , ,~ using the SAS package. The variation over time ,J , KEY ) _ Rood (dates of sampling) represents the sampling varia­ I , .--- ROllway ... __I tion for the testing of differences among landuses , _.- _.- Boundary , ~ study'''" for 0 3 -- N levels. The true experimental error was estimated by averaging the sampling dates Fi~. 2: The location of the (ollr selected ,itn. of each well and landuse, and this procedure takes into account the unequal number of wells water table is greater than 1. 5 m from the ground sampled for each landuse. The experimental surface and the soil texture is maily sandy clay error derived from the variation among wells loam at 10 to 120 cm depth (Malaysian Geological within landuse is the appropriate error to test for Department 1974). the landuse effects. The homogeneity of the error The climate is classified as tropical humid variances in the treatments (landuse) was tested climate with a yearly average rainfall of 2000 before conducting an analysis of variance. mm. The amount of rainfall during the months of October, November and December 1985 were RESULTS AND DISCUSSION 245, 326 and 190 mm respectively. Table 1 shows the mean concentrations of N03-- Among existing wells within the selected in well water in each well under different areas, 22 wells were selected for the purpose of landuses averaged over six sampling dates. this study. The number of wells selected in each Table 2 shows the residual of the homogeneity of area depends on availability and accessibility, and variances analysis. The Chi-Square test for the distribution for AI, A2, A3 and A4 are 7,7, homogeneity of error variances showed that the 5 and 3 wells respectively. All the wells in AI, A3 variance among the four landuses were not and A4 are covered with cement slabs and are homogeneous (Chi-Square = 28.8, probability pump-driven with depths ranging from 10 to 30 < 0.0001). The deletion of the variance from m for AI, and 10 to 20 m for A3 and A4. All of landuse of Agriculture + Animal Farming (AI) the wells in A2 are of the open type and manually gave a Chi-Square of 1.12, which has a probability operated with depths ranging from 5 to 10 m. All of between 0.5 to 0.75. Hence the three other I'ERTA IKA \·OL. 13 O. I, 1990 81 MOHD KAMIL YUSOFF, WAN NORAZMIN SULAIMAN AD ZAI UDIN SHARIF TABLE 1 NO,--N levels (mg/l) in well water averaged over 6 sampling dates. Well No. Landuse 2 3 4 5 6 7 Mean Al 7.11 3.33 2.56 1.06 0.78 1.06 1.95 2.55 A2 0.99 0.23 0.73 0.96 0.29 0.47 0.27 0.56 A3 1.51 0.31 0.40 2.60 2.11 1.38 A4 4.13 2.78 1.84 2.91 landuses (A2, A3 and A4) were grouped together analysis showed that the experimental error has in a combined analysis of variance. a magnitude of3.7l099. The mean square error The results of the combined analysis of (MSE) for the landuse of Agriculture + Animal variance with three landuses (A2, A3 and A4) are Farming (AI) was 29.3327, with 7 degrees of shown in Table 3. In this analysis, the effects of freedom and mean N03--N of 2.25 mg/l.