THE NUTRIENTS DISCHARGE CHARATERISTICS IN FROM RICE PADDY ACCORDING TO THE TYPES OF FERTILIZERS IN SOUTH KOREA

摘要

The contribution of nonpoint source (NPS) pollution load to public water body is dramaticallyincreasing in recent years in Korea. Especially, nutrients load from agricultural activities to totalNPS pollutants load shows more than 50% on the Saemangeum watershed because farmlandarea is a dominant landuse (39%) except forestry. Farmers apply more chemical fertilizer thanplant requirement. Application of livestock manure is increasing in rural areas due to increasein meat consumption. This study was carried out to evaluate the effect of nutrients reductionfrom rice paddy in case of introducing best management practices (BMPs) like slow-releasechemical fertilizer (SC), swine compost manure (CM) and swine liquid manure (LM). Thesethree fertilizer were tested by comparing traditional chemical fertilizer practice (CA, CB) onthe Saemangeum watershed in 2013. The surface discharge nutrients load from SC testedpaddy was lower 50%~55% than CA. LM and CM were lower 18%~48% than CB, too. Thisresult shows that SC, CM, and LM are possible to introduce BMPs against traditional chemicalfertilizer practice. But, rice yield of SC was decreased 7.5% than CA. This means that mutualconsent of stakeholder is required to support economic loss of farmer during implementingBMPs. Evaluation based on long term monitoring result is needed in the future.