Rice Fertilization Based on Soil Nutrient Status in Tidal Lowland Agriculture in Delta Saleh, South Sumatra, Indonesia

Abstract

The research was to look at the diversity of soil nutrient status that supports soil fertility to formulate fertilization recommendations for rice plants and to relate water status to available nutrient status on land with type C water inundation in two villages (Sri Katon and Damar Wulan), South Sumatera. Soil samples were taken in the two villages and brough to laboratory for determination of pH values (Electrometry), total-N (Kjeldahl), available-P (P-Bray 1), and available-K (Ammonium Acetate 1 N). Water table were measured in the field at the same time with soil sampling. The results showed he nutrient status in the two villages did not have significant differences in N, K contents, and pH. For the P contents, however, there were differences between Sri Katon village which had an average of 29.75 ppm (with high criteria) and Damar Wulan village (P value of 6. 30ppm; very low). Therefore, the average fertilization in Sri Katon village needs small addition of urea fertilizer and P, except in the T1S5 point which needs 779.73 kg ha ^-1 of SP-36. Meanwhile, in Damar Wulan Village, the addition of urea fertilizer (average of 51.63 kg ha^-1) and P (1110.74 kg ha-1 SP-36) are recommended. The K did not require the addition of fertilizer in all observation sites. Groundwater table observations indicated a potential contamination of sulfidic elements as a result of pyrite mineral oxidation when the groundwater table goes lower than the sulfidic layer. This further can cause N, P, K contents decrease.