In the northeast of Portugal, like in many parts of the world, most soils are acidic, which
may hamper crop productivity. This study presents the findings of a factorial experiment on olive
(Olea europaea L.) involving three factors: (i) soil type [schist (Sch) and granite (Gra)]; (ii) cultivars
[Cobrançosa (Cob) and Arbequina (Arb)]; and (iii) fertilizer treatments [liming (CaCO3) plus magnesium
(Mg) (LMg), phosphorus (P) application (+P), boron (B) application (+B), all fertilizing materials
combined (Con+), and an untreated control (Con-)]. Dry matter yield (DMY) did not show significant
differences between cultivars, but plants grown in schist soil exhibited significantly higher biomass
compared to those in granite soil. Among the treatments, +B and Con+ resulted in the highest DMY
(50.8 and 47.2 g pot−1, respectively), followed by +P (34.3 g pot−1) and Con- (28.6 g pot−1). Treatment
LMg yielded significantly lower values (15.6 g pot−1) than Con-. LMg raised the pH above 7 (7.36),
leading to a severe B deficiency. Although Con+ also raised the pH above 7 (7.48), it ranked among
the most productive treatments for providing B. Therefore, when applying lime to B-poor sandy soils,
moderate rates are advised to avoid inducing a B deficiency. Additionally, it seems prudent to apply
B after lime application.
This research was funded by the Operational Group ‘Novas práticas em olivais de sequeiro:
estratégias de mitigação e adaptação às alterações climáticas’, funded by PT2020 and EAFRD
(European Agricultural Fund for Rural Development). The authors are grateful to the Foundation
for Science and Technology (FCT, Portugal) and FEDER under Programme PT2020 for the financial
support to CIMO (UIDB/00690/2020) and CITAB (UIDB/04033/2020).
