The effect of drip irrigation for potatoes on soil nitrogen dynamics

Abstract

The effects of potato drip irrigation on soil nitrogen dynamics and potato yield was studied in small-plot field trials. The trials were evaluated during three experimental times (2016–2018). Four variants of irrigation were determined, i.e. non-irrigated, 60, 65 and 70 ASWC (available soil water capacity). At the same time, two pre-planting fertilisation dates were set at a maximum of 120 kg N/ha a in divided, i.e. 60 kg N/ha before planting and 60 kg N/ha by fertigation during vegetation. Pre-planting crop fertilisation or in-season fertigation did not have any significant effect on the potato yields of most variants. In all studied parameters, the positive, beneficial effect of irrigation was recorded and compared to the non-irrigated control. The mitigation of drought stress in plants during the growing season is the most important advantage of irrigation. In the trials, on average, across all years and cultivars, the yield of the irrigated variant increased by 41% compared to the non-irrigated variant. Maintaining optimal soil moisture has a favourable effect use of applied fertilisers. The highest mineral nitrogen content in the soil was recorded for the variant without irrigation. Considering the increased use of nitrogen fertilisers, the subsurface drip line appeared optimal for creating suitable conditions for nitrogen availability to plants in the root zone.