Inoculation of Bacillus sphaericus UPMB-10 to young oil palm and measurement of its uptake of fixed nitrogen using the 15N isotope dilution technique

• Main Authors: Ab. Aziz, Zakry Fitri, Shamsuddin, Zulkifli, Abdul Rahim, Khairuddin, Zakaria, Zin Zawawi, Abdul Rahim, Anuar
• Format: Article
• Language: English
• Published: Japanese Society of Microbial Ecology / The Japanese Society of Soil Microbiology / Taiwan Society of Microbial Ecology / Japanese Society of Plant and Microbe Interactions 2012
• Online Access: http://psasir.upm.edu.my/id/eprint/48588/1/Inoculation%20of%20Bacillus%20sphaericus%20UPMB-10%20to%20young%20oil%20palm%20and%20measurement%20of%20its%20uptake%20of%20fixed%20nitrogen%20using%20the%2015N%20isotope%20dilution%20technique.pdf; http://psasir.upm.edu.my/id/eprint/48588/; https://www.jstage.jst.go.jp/article/jsme2/27/3/27_ME11309/_article
• Institution: Universiti Putra Malaysia

There are increasing applications of diazotrophic rhizobacteria in the sustainable agriculture system. A field experiment on young immature oil palm was conducted to quantify the uptake of N derived from N2 fixation by the diazotroph Bacillus sphaericus strain UPMB-10, using the 15N isotope dilution method. Eight months after 15N application, young immature oil palms that received 67% of standard N fertilizer application together with B. sphaericus inoculation had significantly lower 15N enrichment than uninoculated palms that received similar N fertilizers. The dilution of labeled N served as a marker for the occurrence of biological N2 fixation. The proportion of N uptake that was derived from the atmosphere was estimated as 63% on the whole plant basis. The inoculation process increased the N and dry matter yields of the palm leaflets and rachis significantly. Field planting of young, immature oil palm in soil inoculated with B. sphaericus UPMB-10 might mitigate inorganic fertilizer-N application through supplementation by biological nitrogen fixation. This could be a new and important source of nitrogen biofertilizer in the early phase of oil palm cultivation in the field.