Use of Azolla [Azolla pinnata] as Green Manure for Rice I. Comperison to Chemical Fertilizer

Abstract

The purposes of this study were to compare rice yield under different methods of azolla growing, with and without additional chemical nitrogen fertilizer. The experiments were conducted in various rice experimental stations during wet season in 1979. The results indicated that the use of azolla green mmanure increased and/or tended to increase the yield of rice as compared to the azolla-free plots. This was true for both methods of azolla growing, prior to and/or after transplanting rice. The results also indicated that one layer of azolla, wheather it was incorporated into the soil or not, increased rice yield equivalent to 30 kg.N/ha, while two layers increased the yield of rice as did 60 kg.N/ha. The later is also true for a layer of azolla used in combination with 30 kg.N/ha.