The effect of nitrogen, phosphorous and potassium (NPK) fertilizer on nutrient uptake and yield of soybean (Glycine max (l.) Merr.)

Abstract

Soya bean is an important oil crop, protein source and a cake after pressing out the oil is widely used as a component of livestock feed. Despite the growth in the livestock sector implying increased demand for feed, production and yields of this crop are still low. Consequently, the livestock sector in Uganda heavily relies on the imported soya bean concentrates from Europe and China. This study was carried out to determine the effect of Nitrogen, Phosphorous and Potassium (NPK) fertilizer on the yield and yield components of soybean Glycine max (L.) Merr. The experiment was carried out at the Department of Environmental Management backyard. Soybean was grown in buckets with a capacity of 5kg of soil. Relatively poor soils were used in order to a response to fertilization. The treatments were T1 - no fertilizer (control), T2 – 0.204g of NPK (17:17:17), T3 – 0.408g of NPK (17:17:17), T4 – 0.612g of NPK (17:17:17), T5 – 0.816g of NPK (17:17:17) and T6 – 1.02g of NPK (17:17:17). The experiment was laid in a Completely Randomized Block Design (CRBD) and each block had 6 treatments and replicated 3 times. Data were periodically collected on the height, number of leaves and number of pods. At maturity the soybean plants were uprooted,sun-dried and the dry weight taken. Data was analyzed using Minitab statistical software and means separated using standard error of difference 5% significant level. The results showed that there was no significant difference in the growth parameters and yield attributes, apart from the height of the soybean plants in the 7th week that portrayed a significant difference.