Life cycle assessment, C footprint and carbon balance of virgin olive oils production from traditional and intensive olive groves in southern Spain

Olive oil production shapes the socio-economic and environmental life of many areas of the Mediterranean basin, especially southern Spain, the highest olive oil-producing region worldwide. Olive grove cultivation is tending to intensify from traditional low-density to intensive and high-density cropping systems, which might result in higher environmental impacts. The aim of this study is to estimate the environmental impacts, carbon (C) footprint and carbon balance of producing virgin origin olive oil in Spain from four traditional rainfed, four irrigated, and three intensive olive farms, including the processing phase. Environmental impacts of producing 1 kg of unpacked virgin olive oil at the farm and industrial phases were quantified with the Life Cycle Assessment (LCA) tool and a "cradle-to-gate" approach using data from surveys at these farms and 12 olive oil mills. On average, the farming phase accounted for 76.3% of the EIs. Therefore, to reduce the impact of the virgin olive oils production, most of the efforts should be made especially in the farming phase. Despite the high variability between seasons and between independent replicates of the same farming system, intensive farming had significant higher impacts on most environmental impact categories than traditional rainfed farming, mainly due to the application of nitrogen fertilizer, plant protection products and herbicides. In terms of climate change, the environmental impact of the functional unit is in the ranges of 1.80-2.41, 1.59-2.78 and 2.28-3.26 kg of CO₂ eq. for traditional rainfed, irrigated and intensive, respectively. C footprint was negative and averaged -5.5, -4.3 and -2.7 kg CO₂ eq. Olive groves are efficient atmospheric CO₂ sinks mainly by fixing CO₂ into permanent and non-permanent trees structures. The lower intensification of the traditional rainfed groves contributed more in mitigating the increase of atmospheric CO₂. Finally, the C footprint and C balance are negative, especially in traditional irrigated and intensive farming. The application of organic sources of fertilizer and the implementation of temporary spontaneous cover crops, both technically and economically feasible, are sound strategies to achieve a positive carbon balance and reduce the impacts of olive cultivation.

A Preliminary Study of the Ability of the 4Kscore test, the Prostate Cancer Prevention Trial-Risk Calculator and the European Research Screening Prostate-Risk Calculator for Predicting High-Grade Prostate Cancer

INTRODUCTION

To prevent the overdiagnosis and overtreatment of prostate cancer (PC), therapeutic strategies have been established such as active surveillance and focal therapy, as well as methods for clarifying the diagnosis of high-grade prostate cancer (HGPC) (defined as a Gleason score ≥7), such as multiparametric magnetic resonance imaging and new markers such as the 4Kscore test (4KsT). By means of a pilot study, we aim to test the ability of the 4KsT to identify HGPC in prostate biopsies (Bx) and compare the test with other multivariate prognostic models such as the Prostate Cancer Prevention Trial Risk Calculator 2.0 (PCPTRC 2.0) and the European Research Screening Prostate Cancer Risk Calculator 4 (ERSPC-RC 4).

MATERIAL AND METHODS

Fifty-one patients underwent a prostate Bx according to standard clinical practice, with a minimum of 10 cores. The diagnosis of HGPC was agreed upon by 4 uropathologists. We compared the predictions from the various models by using the Mann-Whitney U test, area under the ROC curve (AUC) (DeLong test), probability density function (PDF), box plots and clinical utility curves.

RESULTS

Forty-three percent of the patients had PC, and 23.5% had HGPC. The medians of probability for the 4KsT, PCPTRC 2.0 and ERSPC-RC 4 were significantly different between the patients with HGPC and those without HGPC (p≤.022) and were more differentiated in the case of 4KsT (51.5% for HGPC [25-75 percentile: 25-80.5%] vs. 16% [P 25-75: 8-26.5%] for non-HGPC; p=.002). All models presented AUCs above 0.7, with no significant differences between any of them and 4KsT (p≥.20). The PDF and box plots showed good discriminative ability, especially in the ERSPC-RC 4 and 4KsT models. The utility curves showed how a cutoff of 9% for 4KsT identified all cases of HGPC and provided a 22% savings in biopsies, which is similar to what occurs with the ERSPC-RC 4 models and a cutoff of 3%.

CONCLUSIONS

The assessed predictive models offer good discriminative ability for HGPCs in Bx. The 4KsT is a good classification model as a whole, followed by ERSPC-RC 4 and PCPTRC 2.0. The clinical utility curves help suggest cutoff points for clinical decisions: 9% for 4KsT and 3% for ERSPC-RC 4. This preliminary study should be interpreted with caution due to its limited sample size.

A New Race of Verticillium dahliae Causing Leaf Mottle of Sunflower in Europe

Sunflower (Helianthus annuus L.) plants with symptoms of interveinal chlorosis were observed in the summer of 2013 in one field in Cadiz (Spain) where the performance of 30 hybrids was assessed. Symptoms affected 80% of the hybrids with incidence as high as 90%. Chlorosis and yellowing near the leaf margin were visible at floral initiation, and they progressed from the lower to upper leaves. Mottled leaves were observed near the top of the plants. On severely affected leaves, chlorotic patches enlarged, coalesced, and large areas of the leaves became necrotic and dried. Cross sections of the lower stem showed a brown discoloration of the vascular system. The fungus that was consistently isolated from stem and petiole tissues of sunflower plants was morphologically identified as Verticillium dahliae Kleb. (Vd) (5) and molecularly confirmed by PCR amplification of the 526-bp band (4). The race of the isolates was determined in a greenhouse experiment at 18 to 28°C from February to April 2014. Isolates 1-13 and 2-13 of Vd, obtained from two of the hybrids in 2013, one of them being Transol, were independently inoculated to 1-month-old plants of each of three sunflower genotypes: the susceptible hybrid Transol and the inbred lines HA89 (carrying the V₁ gene for resistance to Vd) (2) and HAR5 (resistant to other diseases but with unknown reaction to Vd). Plants were inoculated by immersing roots in a suspension of 10⁶ conidia per ml for 30 min. Inoculated plants were individually transplanted to 1-liter pots filled with sand/silt. Roots of the control treatments were immersed in water. Six replications (pots) were established for each isolate × genotype combination, according to a complete randomized 3 × 3 factorial design. Five weeks after inoculation, symptoms developed in 100% of the plants in the three sunflower genotypes. Severity of symptoms (SS) in each plant was assessed as percentage of foliar tissue affected. Significantly higher SS occurred on inoculated plants as compared to non-inoculated plants, which did not develop symptoms. Mean disease severity on inoculated plants was 80% (averaged across isolates and genotypes). A significant effect of genotypes was obtained. Mean SS averaged across isolates were 98, 73, and 69% for HAR5, HA89, and Transol, respectively. When stem tissues from the three sunflower genotypes were sampled and incubated on potato dextrose agar at 25°C, the mycelial growth of Vd was confirmed for the inoculated plants but not for the control plants. Isolates of Vd infecting the resistant inbred line HA89 have only been identified in Argentina (1) and the United States (3). To our knowledge, this is the first report of a race overcoming the V₁ gene in HA89 in Europe. This poses a risk to commercial sunflower breeding programs in European countries. References: (1) A. B. Bertero de Romano and A. Vázquez. Page 177 in: Proc. 10th Int. Sunf. Conf., Surfers Paradise, Australia, 1982. (2) G. N. Fick and D. E. Zimmer. Crop Sci. 14:895, 1974. (3) T. Gulya. Helia 30:115, 2007. (4) J. Mercado-Blanco et al. Plant Dis. 87:1487, 2003. (5) W. E. Sackston. Plant Dis. Rep. 41:885, 1957.

Soil mineral N retention and N(2) O emissions following combined application of (15) N-labelled fertiliser and weed residues

RATIONALE

The combination of plant residues with inorganic fertiliser-N provides the potential to increase N-use efficiency in agricultural fruit production systems, such as olive orchards. The development of weeds in the inter-canopy area of olive orchards is encouraged as a novel strategy to reduce soil erosion. However, little is known about soil N retention or N(2) O production following the combined application of inorganic-N with the mulched weed residues.

METHODS

Emissions of (15) N-N(2) O and soil mineral (15) N retention were measured following combined applications of (15) N-labelled fertiliser and a range of olive crop weed residues to a silty loam soil under controlled conditions. These plant residues differed in their C:N ratios, lignin and polyphenol contents.

RESULTS

The magnitude of soil (15) N-NO(3) (-) retention from combining plant residues and fertiliser-N was highly dependent on potential N mineralisation (r = -0.96) and the (lignin + polyphenol)-to-N ratio (r = 0.98) of the residues. Fertiliser-N-derived retention was zero for a legume-based mulch but up to 80% in the treatment containing plant residues with a high (lignin + polyphenol)-to-N ratio. N(2) O emissions increased after the addition of residues, and increased further (up to 128%) following the combined application of inorganic fertiliser and residues. Fertiliser-derived (15) N-N(2) O was <1.4% of the total (14+15) N-N(2) O emission and <0.01% of the applied (15) N-NO(3) (-) . Enhanced N(2) O emissions following the application of residues and the fertiliser-N values were positively correlated with the C:N ratio of the residue. Thus, combining organic- and inorganic-N immobilised a significant proportion of the inorganic N with little increase in N(2) O, especially in low C:N ratio residues.

CONCLUSIONS

The results demonstrate that whilst there is potential for N(2) O emissions to be controlled by combining weed residues and inorganic fertilisers, this is not easy to achieve as the magnitude and direction of interactions vary between different species due to their varying substrate qualities.

Gross and net rates of nitrogen mineralisation in soil amended with composted olive mill pomace

Olive mill pomace is the major waste product in the olive oil industry and composting these by-products for the purpose of recycling nutrients and organic matter is a sound environmental strategy. Yet little is known about the quantity and timing of nitrogen (N) release from composted olive mill pomace. This paper assesses both gross (using the (15)N dilution technique) and net (aerobic incubation) nitrogen (N) mineralisation and N(2)O emissions of soil amended with seven commercially available composts of olive mill pomace (COMP). All are currently produced in Andalusia and differ in the proportions of raw materials co-composted with the pomace. The absence of significant differences in net N or gross mineralisation and nitrification in COMP-amended soil compared with a control, except for COMP combined with poultry manure, highlighted the recalcitrant nature of the COMP-N. Applications of COMP are hence unlikely to supply available N in available forms, at least in the short-term. Furthermore, N(2)O emissions from COMP-amended soil were negligible and, therefore, applications in the field should not result in increased N loss through denitrification.