A comment on inter-field spatial extrapolation of vine (Vitis vinifera L.) water status
Abstract
Aim: Recent work has identified strong intra-field relationships of pre-dawn leaf water potential (ΨPD) between paired sites. This study investigates if these relationships exist at the inter-field level when soil types between fields are constant or different in a vineyard in Southern France.
Method and result: Nine fields were sampled for ΨPD on 6 dates over two growing seasons. When general assumptions of uniformity in climate, growing conditions and soil moisture were able to be met, a linear relationship between the mean ΨPD responses of different fields was observed. The relationship was no longer linear when the soil moisture regime between fields differed.
Conclusion: The results indicate that it should be possible to extrapolate a reference ΨPD value across a production region (syndicate/co-operative) defined on a similar soil type.
Significance and impact of study: These intra-field relationships may minimise the need for ΨPD sampling to define irrigation/crop management in areas planted to similar soil types. The poor fit between fields with differing soil moisture regimes indicates that the original intra-field model may be flawed in larger fields or vineyards with heterogeneous soil moisture conditions.