Stages in the adoption of a wetting front detector

Abstract

The adoption of a new irrigation scheduling tool by irrigators in South Africa was evaluated while it was still in prototype form. A wetting front detector (WFD) is a funnel-shaped device, buried in the crop root zone, which provides a mechanical or electronic signal to the irrigator when a wetting front moves past it. There was a survey of 54 irrigators or their advisors, who participated voluntarily by evaluating the tool under their own conditions. The survey showed that all participants perceived the device as simple and intuitive, and based on their own experience, 82% believed it conferred a relative advantage over what they were doing. The successful deployment of WFDs was highly dependent on matching the placement depths to the irrigation method and strategy. This required the irrigators to combine their own experiential learning with the response from the WFDs. The WFD showed promise as an irrigation scheduling aid, but requires the meeting of scientific and local knowledge, or a participatory research and extension approach, to reach its full potential. Copyright RÉ SUMÉNous avons évalué l'adoption d'un nouvel outil de pilotage de l'irrigation par les producteurs en Afrique de Sud alors qu'il était encore au stade de prototype. Le Détecteur de Front d'Humectation (wetting front detector, ou WFD) est un dispositif en forme d'entonnoir, enterré dans la zone de croissance des racines, qui fournit un signal mécanique ou électronique quand un front d'humectation l'atteint. 54 producteurs ou leurs conseillers ont été inclus dans l'étude. Ils ont tous participé volontairement en évaluant l'outil sous leurs propres conditions. L'enquête montre que tous les participants ont considéré le dispositif comme simple et intuitif; 82% pensent qu'il apporte un bénéfice par rapport à leur pratique antérieure. La réussite dans le déploiement du Détecteur de Front d'Humectation (WFD) dépend fortement de la bonne adaptation de la profondeur de placement à la stratégie d'irrigation. Cela exige de la part des irrigants de confronter les connaissances tirées de leur propre expérience avec les résultats provenant du WFD. Nos concluons que le WFD est prometteur en tant qu'aide au pilotage de l'irrigation, mais requiert la conjonction des savoirs scientifique et local ainsi qu'une approche participative de recherche et vulgarisation pour réaliser tout son potentiel.

The role of soil water monitoring tools and agricultural innovation platforms in improving food security and income of farmers in smallholder irrigation schemes in Tanzania

“…Wetting front detectors (WFDs) and Chameleon soil moisture sensors and readers were used in the project. The WFD is a funnel-shaped device which is buried in the soil (Stirzaker et al, 2010;Stirzaker, 2003). As water infiltrates the soil a wetting front is formed, which is the boundary between wet soil above and dry soil below.…”

The use of the wetting front detector as an irrigation‐scheduling tool for pepper production in the Upper East Region of Ghana: Evidence from field experiment and farmers' perceptions

“…The result indicated that the majority of farmers (60%) cited that the WFD as an irrigation‐scheduling tool had a relative advantage over their traditional practices. A study in South Africa showed similar results, in that more than 80% of the respondents felt that WFD had a relative advantage (Stirzaker et al, 2010). However, one‐third of respondents and 50% of non‐lead farmers were unsure about the relative advantage of the WFD.…”

“…Detectors are usually placed in pairs, about one‐third and two‐thirds down the active root zone. When the soil is irrigated, the funnel ‘captures’ some water from the wetting front as it goes past (Stirzaker, 2003; Stirzaker et al, 2010). As the soil moisture exceeds field capacity, water will gravitationally drain, passing through a filter and into a reservoir.…”

“…From the perspective of a smallholder farmer, attributes such as ability, technical knowledge and compatibility with farmers' current practices and management of risk are crucial factors for the adoption of water management technology such as WFDs (Stirzaker et al, 2010). Hence, this study was also initiated to understand farmers' perception of the WFD irrigation‐scheduling tool for dry‐season vegetable production using a questionnaire survey in the Upper East Region of Ghana.…”

Sustainable irrigation and nitrogen management of fertigated vegetable crops

“…Sensors measure soil matric potential (SMP) or volumetric soil water content (VSWC). A useful and simple sensor, the "Full Stop sensor" can be used to determine when sufficient irrigation has been applied by indicating the arrival of the wetting front at a given depth (Charlesworth, 2005;Stirzaker et al, 2009).…”