Fluks Metana dan Karakteristik Tanah pada Beberapa Macam Sistem Budidaya

Abstract

Methane (CH₄) is an important greenhouse gas that has a high heat trapping capacity thus potentially contribute to the global-warming.  Agriculture is considered among the responsible emission sources of CH₄. Relationship among soil characteristics, soil microbes, and CH₄ flux is very important in understanding the mechanism involved in the mitigation effects of certain agriculture practices. Results of this research showed that rice field produced the highest CH₄ flux (7.4976 ± 0.5299 mg CH₄-C m^-2 h^-1, n=3), while vegetable, sweet potato, yam bean and corn cropping produced lower CH₄ flux (-0.7708 ± 0.6434 to 0.4605 ± 0.5255 mg CH₄-C m^-2 h^-1, n=3). Nitrifier population among cropping systems was 3.13x10³ to 3.17x10⁴  MPN g^-1 soil (dry weight), while denitrifier population was 3.77x10³ to 1.17x10⁵ MPN g^-1 soil (dry weight).  There were no specific dominance proportion of nitrosomonas, nitrobacter, denitrifier and total propagule among cropping systems. The CH₄ flux had highly correlation to soil water content (r = 0.951), soil pH (r = 0.852) and soil Eh (r = -0.982). Denitrifier had significantly correlation to soil pH (r = -0.635) and soil ammonium content (r =  -0.681).

Key words :  CH₄ flux, cropping system, soil characteristic, soil microbes