The effect of different species of cyanobacteria on the rice yield and nitrogen use efficiency under different levels of nitrogen fertilizer on Alluvial West Java

Abstract

Cyanobacteria or blue-green algae play an important role in rice cultivation. Nitrogen-fixing bacteria Cyanobacteria are found in rice fields, some of which can fix N2 up to 30%, produce some phytohormones, vitamins, amino acids, and organic acids increase soil fertility and rice productivity. The study was conducted in Alluvials wetland rice in Jatitujuh, Majalengka Regency, West Java. This research aimed to analyze the influence of cyanobacteria in increasing rice yield and the efficiency of inorganic N fertilizers. The study was arranged in a randomized block design with two factors. The first factor was the cyanobacteria formula, i.e.: (1) without cyanobacteria, (2) Pseudanabaena sp.+Chlorogloea sp., (3) Pseudanabaena sp.+Nostoc sp., (4) Chlorogloea sp.+Nostoc sp. The second factor was the dose of N fertilizer (0%, 50%, 75% and 100%). The highest rice yield obtained by Chlorogloea sp.+Nostoc sp with 100% N, increased by 14.75%. Application of Pseudanabaena sp. + Nostoc sp. was increased rice grain yield and straw biomass by 11.47% and 37.49%, reduced N fertilizer by 25 to 50%, and increased nutrient uptake of N, P, K by 43.73%, 34.80 %, 34.40%. Using cyanobacteria is a promising strategy to increase rice yield and reduce chemical fertilizers.