Response of potato growth and yield to potassium fertigation with a subsurface drip system

Abstract

Water and fertilizer significantly impact potato (Solanum tuberosum L.) growth and yield, necessitating an efficient field supply system. This study examined the effects of irrigation and fertigation on potato growth and yield using a subsurface drip system consisting of a pipe buried 40 cm underground. The water required for fertigation was 243 mm ha⁻¹. Fertigation treatments with water were applied as topdressing through the subsurface drip system with potassium (K) fertilizer concentrations of I (only applied irrigation), K 20, K 50, and K 70 kg ha⁻¹. Plants fertigated with 50 kg ha⁻¹ (K50) absorbed the most potassium. Absorption did not increase with higher potassium levels; instead, potassium accumulated in the residual soil, linked to the soil's cation exchange capacity. Although potato growth was not significantly different among K treatments, it was highest in the K50 treatment. Yield was also highest with K50 and did not increase with >50 kg ha⁻¹ of potassium. Subsurface drip irrigation had the most substantial impact on yield. While irrigation remained influential during fertigation, its effect diminished as fertigation effectiveness increased up to 50 kg ha⁻¹ of potassium. Irrigation alone increased yield by 32.2% compared with the control, while K50 fertigation increased yield by 56.7%. Overall, this study demonstrates that subsurface drip fertigation with potassium optimizes potato yield, offering a sustainable approach for resource management in agriculture.