Abstract: Imperata grassland is recognized as environmental threats causing low land productivity. This has increased the need to assess the effect of grassland conversion to agricultural fields on soil. Undisturbed and disturbed soil samples were collected from Bengkulu Province, Sumatra, Indonesia. We used five different land management practices such as Imperata cylindrica dominated grassland as a reference, cassava field, banana field, legume field and agroforestry. Result shows that 6-year of cassava cultivation decreased 35% of soil water content at field capacity, 23% of water holding capacity, 11% of porosity, 13% of organic C and microbial biomass C, 32% of inorganic N and 10% of mineralizable C. Conversion to banana field only lowered C organic about 6% and soil microbial biomass C up to 8%. Conversion to legume fields and agroforestry significantly increased all the soil properties tested. Agroforestry system has maintained higher soil C and N levels than the other fields. On average, degradation index in cassava field was 11%. The aggradation index has increased from banana field (14%), agroforestry system (37%) and legume field (38%). In conclusion, conversion of Imperata grassland to conservative agricultural land is considered one way to improve soil ecosystem.
I.P. Handayani, P. Prawito and M. Ihsan, 2012. Soil Changes Associated with Imperata cylindrica Grassland Conversion in Indonesia. International Journal of Soil Science, 7: 61-70.