Utilization Azollapinnata as substitution of manure to improve organic rice yield and paddy soil health

Abstract

Organic rice has become the champion program of the Department of Agriculture in several districts in Indonesia, it is related to increasing awareness of consuming healthy foods which free from inorganic contaminants. Organic farming requires organic fertilizer supply in large quantities as a source of nutrition plants. Azollapinnata water fern is alternative organic matter in organic rice fields because of higher nutritional value compared to manure and can be cultivated in situ that reduces transportation costs. This research was conducted in the fields which first planted organic rice. The randomized block design was used, repeated three times with the treatment: cow manure 100% and the combination of Azolla + manure 25%, 50%, and 75% up to 100%. The results showed that Azolla 50% + cow manure 50% could increase plant height and tillers number, but the organic C content, total N, and C/N of soil was not different than the application of 100% cow manure. Although the yield of all treatments showed similarly,it could increase the dry grain rice weight as much as 19.17% compared with the 100% manure treatment. TheAzolla 50% + cow manure 50% treatment could increase the soil organic C content ranging from 1.3% to 1.7% which indicates the restoration of sick soil leads to healthy soil.