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Cover crops (CC), pruning residues (PR), and olive mill pomace (OP) are common amendments to enhance soil quality in olive groves; however, there is limited information on the dynamics of carbon (C) and nitrogen (N) during their decomposition under varying conditions. In this laboratory decomposition experiment, we assessed the C and N mineralization of CC, PR, and OP at application rates of 2 and 5 mg C g−1 in soils with varying organic C levels, both with and without the addition of NO3−. The results indicated that C and N mineralization patterns varied significantly between amendments, although the predicted remaining C after one year was similar for CC and PR (46.7–48.9%) and slightly lower for OP (40.0%). Soil organic carbon level did not affect remaining amendment-C. The addition of N accelerated the decomposition rate of labile C by 15% but slowed down that of the recalcitrant C another 13%, with no significant effect on remaining C. Conversely, increasing the C dose led to a 13% overall reduction in amendment-C mineralization across all combinations of factors. CC decomposition released between −8 and 31% of the amendment-N by day 130, while PR and OP showed net N immobilization. Therefore, CC residues contribute to both C sequestration and N availability, while PR and OP residues can improve N retention in the olive groves while also contributing to C sequestration. [ABSTRACT FROM AUTHOR]

Carbon farming practices are pivotal for enhancing soil organic carbon (SOC) storage in agricultural systems. This study focuses on evaluating the effects of spontaneous cover crops as a conservation strategy compared to conventional management practices on total, non-protected, and protected SOC fractions, as well as carbon saturation, in olive groves across 13 paired sites (26 sites in total) in Andalucía, Spain. The research evaluates organic carbon concentrations in different soil fractions: non-protected (250–2000 µm), physically protected (53–250 µm), and chemically protected (<53 µm). The results reveal that olive groves managed with temporary spontaneous cover crops (CC) over the last 8–12 years generally exhibit higher SOC concentrations compared to those managed conventionally (BS), with significant differences observed across multiple sites. CC sites exhibited higher carbon stocks, with protected carbon averaging 42.6 Mg C ha−1 compared to 29.7 Mg C ha−1 in BS, and non-protected carbon at 10.3 Mg C ha−1 versus 4.8 Mg C ha−1. A direct relationship was identified between total SOC and both protected and non-protected carbon fractions, indicating that the soil of the studies olive orchards is far from being saturated in protected SOC. Moreover, the soil of the CC olive farms had a lower carbon saturation deficit (45.3%) compared to BS (67.2%). The findings show that maintaining the cover crops in olive orchards significantly contributed to carbon sequestration and reduced carbon saturation deficits by increasing the stocks of protected SOC. [ABSTRACT FROM AUTHOR]

The wood borer Cerambyx welensii Küster is a key contributor to Quercus open woodland (dehesa) decline. Among other factors, olfactory and visual cues could influence host colonisation by this species. In this study, we investigated whether the physiological performance and morphological features of Q. suber trees under summer stress are affected by C. welensii infestation. Additionally, we analysed the relation between morpho-physiological variables and the emission of monoterpenes that potentially mediate host selection by C. welensii. Thirty-six Q. suber trees with known monoterpene emission profiles were selected: 18 trees highly visited by C. welensii, and 18 neighbouring trees not visited or at least not visibly damaged by this wood borer. For each tree, we assessed photosynthesis, stomatal conductance, and transpiration during the early evening, and also the perimeter and crown projection. Trees visited by C. welensii maintained higher photosynthetic activity than non-visited trees (1.5–2.15 times) from 19:35 to 20:45 h. Visited trees had larger perimeters and smaller crown projection area-to-perimeter ratios than non-visited trees. Results suggest that, under stress conditions, the physiological performance of trees infested by C. welensii could have favoured foliar emission of certain monoterpenes influencing intraspecific host selection by this species. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the impact of 21 years of tillage and N fertilization and the conversion from a rainfed to an irrigated cropping system on soil organic C (SOC). The study was carried out in northeastern Spain in a long‐term tillage and N rate field experiment established in 1996 under barley rainfed conditions, which in 2015 was converted into irrigation with corn. Three types of tillage (conventional tillage, CT; reduced tillage, RT; no‐tillage, NT) and three mineral N fertilization rates (0, 60, and 120 kg N ha−1 under barley, and 0, 200, and 400 kg N ha−1 under corn) were compared. Annual C‐inputs as aboveground crop residues and annual SOC sequestration rate (∆SOCrate) (0–40 cm depth) were calculated in three different periods (P1, P2 and P3) under rainfed (‐R) and irrigated (‐I) conditions (P1‐R, from 1996 to 2009; P2‐R, from 2009 to 2015; P3‐I, from 2015 to 2017). At the end of P3‐I, particulate organic C (POC) was measured from the 0–5, 5–10, 10–20, 20–30, and 30–40 cm depths. Averaged over all treatments, ∆SOCrate was 492, 222, and 969 kg C ha−1 yr−1 for P1‐R, P2‐R, and P3‐I, respectively. In P1‐R and P3‐I, C‐input explained 70% of the variability of ∆SOCrate. In P1‐R, ∆SOCrate followed the order NT > RT > CT, while for N rate, order was high > medium > 0. In P3‐I at the highest N rate, ∆SOCrate followed the order NT > RT > CT. In P2‐R, ∆SOCrate did not show differences between tillage and/or N rate treatments. The increase in SOC after conversion from a rainfed to an irrigation system was mainly explained by POC, which was increased by 75% compared to the previous rainfed period. The modification of the cropping system through the introduction of irrigation and adequate crop management practices under no‐tillage and adjusted N fertilizer rates can contribute to the sequestration of large amounts of atmospheric CO2. [ABSTRACT FROM AUTHOR]

The main objective of this research was to analyse the effect of soil management on soil sealing and on soil water content under contrasting tillage practices and its influence on corn yield. The experimental research was carried out in a field cultivated with irrigated corn differentiated into three zones representing a gradient of soil texture (Z1, Z2, and Z3, i.e., increasingly coarser). Two plots under different soil management practices (conventional intensive tillage, CT, and no‐tillage, NT) were selected in each zone. The susceptibility to sealing of each soil and the steady infiltration rates were evaluated in the laboratory subjecting the soils to rainfall simulation applied at an intensity of 25 mm h−1. In addition, soil porosity under each treatment was quantified. Soil water content (0–90 cm depth) was determined gravimetrically at the beginning and the end of the growing cycle and at the surface (0–5 cm) during three growing seasons and continuously at two depths (5–15 and 50–60 cm) during the last growing cycle. Soil water content was simulated using the SIMPEL model, which was calibrated for the experimental conditions. Corn yield and above‐ground biomass were also analysed. Significant differences in soil sealing among zones, with decreasing soil sealing for coarser textures, and treatments were observed with infiltration rates that were near twice in NT than in CT, being the effect of soil cover significant in the reduction of soil detachment and soil losses. NT showed higher soil water content than CT, especially in the surface layers. Above‐ground biomass production was smaller in CT than in NT, and in the areas with higher sealing susceptibility was 30% to 45% smaller than in other zones, reaching the smallest values in Z1. A similar reduction in corn yield was observed between treatments being smaller in CT than in NT. No‐tillage has been confirmed as an effective technique that benefits soil physical properties as well as crop yields in relation to CT, being its impact greater in soils susceptible to sealing. [ABSTRACT FROM AUTHOR]

This correction stands to correct the original article where a processing error led to the erroneous reference, Lpez-Pantoja et al. 2008. This article is part of the topical collection on Entomological issues during forest diebacks [ABSTRACT FROM AUTHOR]

Key message: Cork oaks highly infested byCerambyx welensiiemit an amount of limonene at dusk, whenC. welensiiadults become active. In contrast, emissions by neighboring cork oaks free ofC. welensiiare dominated by pinene-type compounds. Context: The activity of the woodborer Cerambyx welensii Küster is a key factor in the decline of Quercus suber L. dehesas. Aims: This study aimed to estimate whether trees highly infested by C. welensii exhibited a peculiar emission profile, with known antennally active compounds. Methods: Monoterpenes were sampled in situ in 2006 (day/late evening) and 2008 (early evening) from Q. suber stratified by whether or not trees were highly infested by C. welensii and analyzed by gas chromatography. Results: Limonene, α-pinene, β-pinene, sabinene, and myrcene accounted for over 87.2% of overall monoterpene emissions. Monoterpene composition and emission rates differed between the two groups, both during daytime and early evening, with a high presence of limonene in infested trees and dominance of pinene-type compounds in non-infested trees. Conclusion: This work evidenced differences in foliar monoterpene emissions between Q. suber trees highly infested by C. welensii and non-infested trees, with a high presence of limonene in the former and dominance of pinene-type compounds in non-infested trees. We hypothesize that the detection—especially during the onset of insects daily flight—of certain compounds (e.g., limonene), together with the detection of specific ratios of several monoterpenes (e.g., those of limonene to pinene-type compounds), has a role in the intraspecific host selection by C. welensii. [ABSTRACT FROM AUTHOR]