Assessing almond response to irrigation and soil management practices using vegetation indexes time-series and plant water status measurements

Current water scarcity scenario has led to the implementation of sustainable agricultural practices intended to improve water use efficiency. The present work evaluates during three agricultural campaigns (2018-2020) the response of a young almond orchard to two management practices in terms by combining remote sensing indexes (Normalized Difference Vegetation Index, NDVI; and Soil Adjusted Vegetation Indexes, SAVI) and physiological/morphological measurement (stem water potential, Psi(stem); trunk perimeter and canopy diameter). The management practices included (i) sustained deficit irrigation and (ii) soil management. Severe deficit irrigation resulted in lower vegetation indexes (VI) values, Psi(stem )and tree dimensions (13 %, 23 % and 14 % lower, respectively) than those obtained for full irrigation strategy; whereas moderate deficit irrigation did not affect any of the parameters analysed. The presence of vegetation cover in the inter-row resulted in a VIs increase (19-42 %) and in lower tree dimensions (reductions of 7-8 % for trunk perimeter and 0.34-0.37 m for canopy diameter) when compared to bare soil treatment, but did not have any influence on Psi(stem). The present study proves the suitability of remote sensing and physiological measurements for assessing almond response to the different management practices.