The Abundance of N-Transforming Bacteria in Ungrazing and Grazing Area Under Oil Palm- Cattle Integration Management in South Kalimantan

Abstract

Systematic management of oil palm-cattle integration considers as one of the best alternative solutions to meet the need of increasing local beef and dairy. The change in oil palm plantation management systems can influence the soil microbial community. Microbes mediate many key processes in soils and are essential in driving ecosystem stability and sustainability of oil palm production. The research aimed to investigate the influence of grazing in an oil palm plantation on the bacteria involved in the soil nitrogen cycle. We evaluated the abundance of diazotrophic, nitrifying, and denitrifying bacteria in the grazing and ungrazing area of oil palm plantations. Grazing area subject to 11 and 10 times cattle grazing rotation with the two-month interval between rotation were studied. The enumeration of bacteria was evaluated using the Most Probable Number (MPN) technique. Generally, diazotrophic bacteria, nitrifier, and denitrifier were higher in the grazing area compare to ungrazing area. However, the difference between that two grazing-plantation management is not significant (P>0.05). In summary, our results show that an addition of organic materials from the dung of cattle in the grazing area of oil palm plantation influences the soil microbial community including N-transforming bacteria