Effects of supplemental irrigation on yield, water use efficiency and nitrogen use efficiency of potato grown in mollic Andosols

Abstract Background Low soil fertility and reduced seasonal rainfall contribute to low potato ( Solanum tuberosum L.) yield in Kenya. Nitrogen (N) deficiency is the major problem facing by smallholder farmers of Kenya due lack fallow. Hence an introduction supplemental irrigation with adequate application this nutrient could increase yield. The objective study was determine effects N-fertilisation on tuber yield, water use efficiency (WUE) nitrogen (NUE). experiment conducted Nakuru County, for two seasons. experimental soils are classified as mollic Andosols. treatments comprised full (FI) rainfed production (RF) four N levels 0 (N0), 60 (N1), 90 (N2) 130 kg N/ha (N3). Results results showed that total marketable NUE were significantly (P < 0.001) affected × while WUE only N-fertilisation. highest 58.28 tonnes/hectare (t/ha), recorded under FI combined N3. Treatment increased approximately 125.58% all compared RF. (236.44 kg/kg N) obtained N3 but not different from N2. produced 14.24 kg/m 3 . Significant correlation between number tubers/plant r = 0.75, P 0.001), 0.95, (r 0.72, 0.001). Conclusion High can be achieved Andosols when deficits growing season eliminated N/ha.