EEFECT OF ORGANIC MATERIALS AND ZA (ZWAVELZURE AMMONIAK) FERTILIZER TO GROWTH AND YIELD OF SHALLOT IN ULTISOL SOIL IN WEST SUMATERA, INDONESIA

The research aimed to study the interaction of several organic materials and ZA fertilizer. The research was conducted in August to November 2018 in experimentc al garden of Faculty of Agriculture, Andalas University. Factorial design in Completely Randomized Design was used in this research. The experiment consisted of 2 factors. The first factor was several types of organic material with 3 treatments, 25 ton/ha of chicken manure, 25 ton/ha of cattle manure and 25 ton/ha of husk charcoal. The second factor was dose of ZA fertilizer with 4 treatments, no ZA application, 300 kg/ha, 400 kg/ha dan 500 kg/ha. The data was analysed by F test in 5% and followed by Duncan?s Multiple Range Test (DNMRT) in 5%. The result showed that the best interaction occured in dose 25 ton/ha of husk charcoal and ZA 500 kg/ha. This interaction affected the diameter of tuber, fresh and dry weight of tuber per hectare. 500 kg/ha of ZA affected the best number of tuber and 25 ton/ha of chicken manure affcted the plant high of shallot plant.