EFFECT OF DIFFERENT RATES OF ORGANIC NITROGEN INPUTS ON PLANT TOTAL NUTRIENT, UPTAKE, AND GROWTH PERFORMANCE OF LEAFY VEGETABLE

Abstract

In organic farming, nitrogen (N) is one of the most crucial factors. Other than the limited source of N for organic fertilizer as the key factor for growth-limiting nutrients in organic farming, the cost of fertilization is also affected by different N application rates in organic farming running. Therefore, in this study, emphasis was given to the effect of different rates of N in organic farming on the plant total nutrient, uptake, and growth performance of leafy vegetables. A study was conducted in a glasshouse at an integrated organic farming research area in the Malaysian Agricultural Research and Development Institute (MARDI) at Serdang, Selangor for two consecutive cycles. The experimental treatments were focused on the different rates of N inputs (12, 24, and 36 kg/ha of N from organic sources) with soil alone as a control. The treatments were applied 14 days after seeding (14-DAS) using green spinach as a test crop. The study result found that a 24-63 kg/ha rate of organic N input had improved N and P uptake in spinach (leafy vegetables), as well as their growth performances. Study findings have shown that the range of application rate of organic N between 24 to 36 kg/ha, promotes nutrient uptake in plants and can be scaled up to farm level to sustain organic system productivity.