The effect of the combination of urea, manure of cow and Azolla on the growth and N uptake of the black rice of Ominio variety

Abstract

The application of inorganic fertilizers is carried out continuously and it is not balanced with the organic fertilizers causes the soil to harden more easily, unstable pH, the ability of the soil to absorb nutrients, especially Nitrogen is low. A combination of inorganic fertilizers such as manure of cow and Azolla as well as organic fertilizers, urea are used as an alternative to increasing Nitrogen and plant growth. This research has been carried out at Agriculture’s screen house Universitas Sumatera Utara and Socfindo Laboratory. This study was conducted using non-factorial randomized block design with 5 treatments such as U0 (without urea), U1 (urea 250 kg/Ha), U2 (urea 250 kg/Ha with manure of cow 20 ton/Ha, U3 (urea 250 kg/Ha with Azolla 10 ton/Ha), U4 (the combination of urea 250 kg/Ha, manure of cow 20 ton/Ha and Azolla 10 ton/Ha) and 4 replications. The combination of urea, manure of cow and Azolla (U3 treatment) was able to show the best results on plant height, the number of tillers per clump, root dry weight and N-uptake of black rice plants of varieties Ominio. The recommended dosages of urea, manure of cow and Azolla are 250 kg/Ha, 20 ton/Ha and 10 ton/Ha, respectively.