Experimental investigation of wicking bed irrigation using shallow-rooted crops grown under glasshouse conditions

Abstract

Growing crops in cities is challenging due to many factors including space restrictions, busy lifestyles, cost and availability of water. Wicking beds (WBs) have been identified as a simple, potentially water- and labour-efficient irrigation method compared to hand irrigation. However, limited studies exist to validate claims of the effectiveness of WBs with respect to water use efficiency (WUE) and crop productivity. The effectiveness of WBs to grow shallow-rooted crops was scientifically investigated for the first time in this study using a small-scale glasshouse experiment to identify the gaps in WB research and to reveal benefits or problems with the application. Specifically, the growth of lettuce (Lactuca sativa, var. ‘cos’) and two radishes (Raphanus sativus, var. ‘mars’, and (Raphanus sativus var. ‘white long icicle’) was examined. The performance of WBs was compared with a precise hand irrigation treatment based on WUE, yield, biomass, crop type and the presence or absence of mulch. WUE, yield and biomass were always higher in WBs than the hand-irrigated treatments. Furthermore, the WUE benefits of WBs may depend on the type of crop grown (specifically the root form), soil bed depth, and the presence of mulch.