Effects of Different Organic Fertilizers on Growth and Yield of Robusta Coffee Intercropped with Rubber Trees

Abstract

Growing coffee intercropped with para rubber is a way to increase income for farmers in a time when the price of rubber is falling. Therefore, proper soil and fertilizer management will help main and companion crops grow well. Therefore, this research aimed to study the type of organic fertilizer combined with chemical fertilizer to promote the growth of 3-year-old Robusta coffee grown with 15-year-old rubber trees at Ban Khao Wang Ching, Khok Muang Subdistrict, Khlong Hoi Khong District, Songkhla Province. The experiment was analyzed using a Completely Randomized Design (CRD), divided into 3 treatments with 8 replications (1 plant/replication). Using chemical fertilizer (15-15-15) at a rate of 300 g/plant/year, divided into applications every 4 months, 100 g/plant at a time, applied together with a different type of organic fertilizer, namely bio-sludge pellets, chicken manure pellets, vermicompost at the rate of 8 kg/plant/year, divided and applied every 3 months, 2 kg/plant at a time, and use straw to cover the base during the dry season. The results found that the application of chemical fertilizer 15-15-15 at the rate of 300 g/plant/year combined with chicken manure pellets at the rate of 8 kg/plant/year and covering the below canopy zone with rice straw is the most suitable method for growing Robusta coffee with rubber trees. Because it can make Robusta coffee plants grow well and produce the best fruit size. This study indicates that chicken manure pellets could be a valuable tool for increasing the production of Robusta coffee intercropped with rubber trees, through improved growth and yield.