Mitigation of pyrite oxidation impact in tidal swamp management for agriculture

Abstract

Reclamation of tidal swamps will increase the opportunities of pyrite oxidation which causes severe acidification. Pyrite oxidation occurs due to over drained and pyrite exposed to oxygen. The acidification process is unavoidable; therefore, mitigation efforts needed to minimize adverse impacts. In general, mitigation efforts can be done with 2 approaches, namely preventive approach, an effort to prevent continued acidification, and curative approaches, an effort to rehabilitate degraded land. Land use planning with detailed engineering design is the first step to mitigate the effects of pyrite oxidation. Mitigation efforts for acidified soil can be using water management techniques to leach toxic elements out from the root zone. Many research results revealed that one-way flow system water management was effective to reduce toxic element. High soil acidity and toxic element can also reduce by applying soil ameliorant such as 0.5 to 2.0 t ha−1 of lime. It’s can increase soil pH, plant growth and fertilizer use efficiency. Strong acid soils also cause low nutrient status due to intensive leaching and fixation. Therefore, nutrient supply trough fertilization is needed. Finally, mitigation efforts can also be done by planting acid tolerant rice varieties that resulted from long time rice research in tidal swamps. This paper described some efforts should be done to mitigate pyrite oxidation impacts for agriculture.