The Assessment of Soil Fertility Index for Evaluation of Rice Production in Karanganyar Regency

Rice (Oryza sativa L.) is a very important food crop because the result is used as a staple food for residents in Indonesia. Higher food fulfillment leads to the increase of rice production of the Mojogedang sub-district. Paddy fields that have high soil fertility will produce good rice productivity. Rice fields in Mojogedang Sub-district are managed with organic systems and conventional systems, the management of different fields of rice field certainly affects the level of fertility in the paddy fields so it is necessary to evaluate the soil fertility index. The survey area consists of 10 points with organic and conventional management systems. The parameters taken include chemical and biological properties of soil, including; pH, redox potential, C-organic, CEC, base saturation, P available, available K, N Total, C/N ratio, and total microbial. The data obtained by performed analysis of the main component principal component analysis (PCA) using statistical applications. Then after complete the calculation of The Soil Fertility Index (SFI) at each point and management system. The results of statistical analysis obtained soil Fertility Index on organic management systems have a class of 4 or very high and in conventional management systems have a class of 3 or High. The value of the index obtained is strongly influenced by the K indicator available where the indicator has a noticeable effect on the various management systems. Increased soil fertility index due to the use of manure that can improve plant nutrients and applied for long periods.