Standard Operating Procedure Application of ¹⁵N Isotopic Tracer in Nitrogen and Biofertilizer Study on Kenaf Crop

Kenaf (Hibiscus cannabinus L.) is a short-term summer crop that can produce fiber. In Malaysia, kenaf is one of the potentially bio-energy crops as an industrial plant. One of the factors that determines the success of kenaf cultivation is the management of fertilizers and good nutrients. In determining the efficiency of fertilizer use especially nitrogen fertilizers and biological fertilizers, the most accurate and easy-to-use method is the ¹⁵N isotope application. The ¹⁵N isotope application is the direct measurement of nitrogen dynamics in soil and plant. When conducting an experiment using a ¹⁵N isotizer, the ¹⁵N isotrate utilization rate should be calculated accurately to avoid wastage. For the study of nitrogen fertilizer, the application method of ¹⁵N is continuously used, while for biobalysis, the application of ¹⁵N application is diluted. The experimental design should also be well designed according to the requirements of ¹⁵N isotope application. Experimental designs can be of various sizes, depending on available field fields and experimental sources such as labor, machinery for fertilizer, irrigation, insecticide, pesticides, harvesting and costs. The use of microplots is very important in experiments involving the use of ¹⁵N isotope. It aims to prevent plants on the plot to take nitrogen on the area in the ¹⁵N plot and avoid nitrogen pollution from the yield plot area. Plant sampling needs to be done manually for experimental isotope experiments ¹⁵N. Plants in the ¹⁵N plot need to be harvested at the same time as the yield plot. (author)