Nutritional quality of baby spinach (Spinacia oleracea L.) as affected by nitrogen, phosphorus and potassium fertilisation

Abstract

Baby spinach is a nutritious vegetable rich in phytochemicals and minerals. Cultural practices such as fertilisation have an impact on the nutritional composition of vegetables. Hence, the current study investigated the responses of the chemical composition of baby spinach to nitrogen (N), phosphorus (P) and potassium (K) fertilisation. Three parallel trials for N and P treatments (0, 45, 75, 105 and 120 kg N and P ha⁻¹) and K (0, 60, 85, 100, 125 and 145 kg K ha⁻¹) arranged in a randomised complete block design with four replicates were conducted. Thereafter, a NPK combination trial was also carried out. Nitrogen, P and K increased the concentrations of total phenols, total antioxidants activity, total flavonoids and vitamin C with maximum concentrations observed at 45 kg N ha⁻¹, 45 kg P ha⁻¹ and 85 kg K ha⁻¹. Interactive effects of NPK fertilisers improved the total phenolic content, total antioxidants activity, total flavonoids and vitamin C content at 35 + 35 + 60 kg ha⁻¹ of NPK. Thus, varying fertiliser application significantly influenced the phytochemical properties and nutritional quality of baby spinach.

Keywords:

• baby spinach
• NPK fertilisation
• nutritional quality
• phytochemicals