Nutritional Quality Response of Carrot (Daucus carota) to Different Rates of Inorganic Fertilizer and Biochar

Abstract

Nutritional quality of most high valued crops including carrot can be influenced by soil management practices. A field study to evaluate soil management improvement effect on nutritional quality of carrot was carried out in two contrasting cropping seasons of two rainfall regimes ranging from 600 mm to 800 mm in 2016 and 2017 at Mampong in the Forest-Savannah transition zone of Ghana. Three rates of soil amendments using biochar rates of 0, 5 and 10 tons/ha and five rates of inorganic fertilizers (NPK 15:15:15 at 200 kg/ha; P&K 50:50 at 50 kg/ha; P&K 50:100 at 50 kg/ha; Liquid Fertilizer at 1 L: 200 L Water/ha; and the control were applied using 3x5 factorial in RCBD. The combined analysis for the different treatments showed that NPK at 200 kg/ha+10 ton/ha biochar gave the highest protein content while Liquid fertilizer+5 ton/ha biochar gave the highest beta-carotene and total carotenoid contents in carrot root during the minor cropping season of 2016. However, during the major copping season of 2017, a combination of liquid fertilizer +10 ton/ha biochar gave the highest protein content whilst NPK at 200 kg/ha +5 ton/ha biochar gave the highest carotenoid content for the carrot. Nutritional contents such as carbohydrate, beta-carotene and total carotenoids were boosted by soil amendments. This indicates that both biochar and inorganic fertilizers have varying effects on the nutritional qualities of carrot.