ISHS Acta Horticulturae 792: V International Symposium on Irrigation of Horticultural Crops
USE OF STEM WATER POTENTIAL MEASUREMENTS TO CORRECT CROP WATER NEEDS ESTIMATIONS IN A ROTATION OF TWO HORTICULTURAL CROPS |
| Authors: | C. Campillo, M.H. Prieto, C. Daza, M.J. Moņino, M.I. Garcia |
| Keywords: | bare soil, mulch, processing tomato, cauliflower, water budget method |
| Abstract:
The water budget method applying the crop evapotranspiration (ETc) calculation using a crop coefficient has been widely employed for irrigation scheduling purposes. However, several factors induce deviations between real and calculated water consumption as such soil type, crop system or ground cover this can produce results different than those expected. However, stem water potential measurements (SWP) can provide good information about water plant status. The aim of this work was to evaluate the use of SWP to verify and modify the FAO 56 estimation of crop water needs for irrigation scheduling purposes in a rotation with two horticultural crops: cauliflower (autumn-winter) and processing tomato (spring-summer). A split-plot design with three replications was used, with two systems of soil maintenance (bare soil and mulch with black plastic) in the main plot and three irrigation doses in the subplot: one according to the ETc estimation including corrections, and two treatments with 25% of over (1.25ETc) and under irrigation (0.75ETc) respectively. No consistent differences between estimated and real ETc were found in the cauliflower crop, because of the rain during the crop cycle in both soil systems. But in the tomato crop the seasonal SWP detected an underestimation of real ETc in the bare soil and a global increase of 8% of the irrigation water was needed to keep the crop at optimal water status (654 to 605 mm). From fruit set to 50% of red fruit, the deviations were around 15% between real and estimated water consumption. No clear differences were observed in mulch treatment (the water decrease was less than 2% of global water supplied). The obtained results support the interest in SWP to adjust the irrigation scheduling to real crop water needs. | |
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