Investigation of Impact of Phosphate Fertilizer Applied to Paddy Fields on Water Quality of Nearby Reservoirs

Phosphorous (P) is an essential element to plant growth and development necessitating P fertilizer applications for agricultural crops better yields. Paddy, the main food crop of Sri Lankans a intensive where phosphorus nutrition achieved via triple super phosphate applications. Since water circulating system paddy fields are connected other bodies this soluble can contaminate nearby waterbodies. To detect extent leaching from fields, lysimeter experiment was carried out in Low Country Intermediate zone, Lanka four consecutive growing seasons 2015 2016. Paddy under two management practices; control run-off continual conditions were selected study. The farmers practice Department Agriculture recommended application schedules. Lysimeters placed Randomized Complete Block Design with triplicates at upper lower ends gradient each site. Water samples collected below root depth 30 cm, irrigated, run-off, reservoirs analyzed phosphate. highest concentration total leached (0.88 mg/L) did not exceed drinking standard threshold level 2 mg/L Phosphate. quantified Phosphate amount controlled condition 0.49 ± 0.10 kg/ha 0.46 0.04 kg/ha, respectively without statistically significant differences. It represented 2% applied content both sites. This indicates that cultivation does pose threat quality if adhere closely