The Effect of Straw and Purun Tikus (Eleocharis dulcis) Compost to Rice Physiological Traits, Iron Toxicity and Grain Yield on Acid Sulfate Soils

The experiment was aimed to determine the effect straw and Eleocharis dulcis compost on physiological traits and grain yield of rice grown in acid sulfate. The experiment was conducted in 2010 WS in greenhouse of ISARI, Banjarbaru. The soils was sampled from rice fields of acid sulfate soil. The experiment was employed Factorial CRD, in which first factor was three varieties and second factor were six rates straw and E. dulcis compost. Variables observated were physiological traits (root length, stomatal density, transpiration rate, total chlorophyll content, polyphenol oxidase and peroxidase activity), Fe toxicity symptoms and grain yield. The result showed that application of 5.0 t ha-1 straw and 5.0 t ha-1 E. dulcis compost resulted in the best physiological traits of rice plants, decreased Fe toxicity, but led to increase in grain yield. Inpara 1 was more tolerant to iron toxicity, better physiological traits, lower Fe toxicity symptoms, and higher grain yield compared to Inpara 2. On the other hand, IR64 was susceptible to iron toxicity and the lowest observed. Results of the experiment demonstrate that increasing rate of applied E. dulcis compost up to 5 t ha-1 may increase physiologal traits and grain yield and decrease Fe toxicity symptoms.