Cover cropping in rainfed fruticulture

A significant part of the world’s fruticulture is rainfed managed. Olive, almond and vine are some of the perennial crops whose social and economic importance is huge throughout the Mediterranean basin and which mostly continue to be grown in rainfed conditions. Cover cropping is the most recommended soil management system in fruit growing. However, in rainfed managed orchards, soil tillage continues to dominate, and the use of herbicides is also widely used. In rainfed conditions there is a high risk of competition for water between herbaceous vegetation and trees, which makes difficult the widespread use of cover crops. However, there seem to be new clues to overcoming the problem, consisting of the use of less competitive plants, such as early-maturing self-reseeding annual legumes. These plants are able to protect the soil from erosion, sequester carbon and increase soil organic matter, fix nitrogen and promote the nutritional status of the trees and fruit yield. Their growing cycles finish early in spring which greatly reduces the competition for water.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) and FEDER under Programme PT2020 for financial support to CIMO (UID/AGR/00690/2013).info:eu-repo/semantics/publishedVersio

Large chestnut trees (Castanea sativa) respond poorly to liming and fertilizer application

Establishing a fertilization plan for large trees is particularly difficult due to the high soil volume that the roots exploit and the buffer effect of the perennial woody structure on the concentration of nutrients in the leaves. This work evaluates the response of chestnut, a very large tree, to different fertilizer solutions. The study was conducted in two chestnut orchards planted in acid soils that were subjected to the application of lime plus phosphorus (Lime+P), lime plus a compound NPK fertilizer (Lime+NPK), and an unfertilized control (Control). The effects of the treatments on soil properties, nutritional status and photosynthetic performance of the trees, and nut production, were assessed from field and laboratory analyses. Liming significantly increased soil pH and exchangeable calcium (Ca). Treatments did not significantly influence leaf P and K levels, although leaf N concentrations were significantly higher in the Lime+NPK treatment on two of the three sampling dates. In one of the trials, the average accumulated nut yield was higher in the Lime+NPK (71.7 kg tree−1) treatment compared with the control (59.6 kg tree−1) and the Lime+P (51.7 kg tree−1) treatments, although without significant differences at P < 0.05. Overall, the results show the chestnut tree to be a species tolerant of soil acidity. The results also show that the buffer capacity of the plant in regulating the nutrient concentration in the leaves seems to be higher for P than for N, and therefore, concentrations of N in the leaves require the regular application of the nutrient as a fertilizer.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) and FEDER under Programme PT2020 for financial support to CIMO (UID/AGR/00690/2015) and FEADER (The European Agricultural Fund for Rural Development) through the project CMP122 - PDR2020-101-030981 – EGIS, Estratégias para uma Gestão Integrada do Solo e da Água em Espécies Produtoras de Frutos Secos. We also thank João Paulo Roxo and Carlos Lopes for allowing the experiments to be conducted on their farms.info:eu-repo/semantics/publishedVersio

Efeito da aplicação de extratos de algas e aminoácidos em caldas foliares, isoladamente e como suplemento de fertilização NPK, na composição mineral de folhas e frutos de aveleira

A aveleira (Corylus avellana L.) é uma importante espécie cultivada da família Betulaceae. Cultiva-se maioritariamente nas regiões temperadas do hemisfério norte, perto de grandes massas de água em latitudes médias. A Turquia é o maior produtor mundial, seguida de Itália e Estados Unidos da América. Portugal tem uma produção de avelã relativamente baixa. A otimização da fertilização é um aspeto importante da técnica cultural, uma vez que a disponibilidade de nutrientes influencia diretamente o crescimento das árvores e a produção de fruto. Atendendo a que no presente se procura reduzir o uso de fertilizantes convencionais, devido a alguns impactes negativos no meio ambiente, é importante avaliar estratégias de fertilização complementares, como por exemplo o uso de produtos com ação bioestimulante sobre as plantas. Neste trabalho foram utilizados dois tipos de bioestimulantes, um baseado em extratos de algas marinhas e outro em aminoácidos livres. Os produtos foram aplicados isoladamente e em complemento a adubação ao solo. Assim, foram estabelecidos seis tratamentos [fertilização NPK (NPK), NPK mais extrato de fitoalgas (Fitoalgas Green®) (NPK+FA), FA, NPK mais aminoácidos (Sprint Plus®) (NPK+SP), SP e Testemunha, não fertilizada], organizados num delineamento completamente casualizado com três repetições e três árvores por repetição. O ensaio foi instalado em Travanca, concelho de Macedo de Cavaleiros, em Trás-os-Montes num pomar de aveleiras da cultivar Ennis. Foi avaliado o efeito dos tratamentos no estado nutricional das árvores, a partir de cinco amostragem de folhas efetuadas durante dois anos, na composição mineral dos frutos e nas propriedades do solo. A modalidade testemunha mostrou concentrações de azoto nos tecidos mais baixas que as modalidades que receberam NPK devido ao fornecimento direto do nutriente. O extrato de algas marinhas manteve níveis elevados de azoto nas folhas, talvez por ter estimulado a eficiência de uso do nutriente a partir do solo. Os valores de potássio nas folhas também se revelaram tendencialmente mais elevados nos tratamentos com NPK. As concentrações de azoto e potássio nas folhas decreceram de forma marcada com a estação de crescimento, devido a efeitos de diluição com a expansão da parte aérea e a concentração dos elementos nos frutos. As propriedades do solo também variaram pouco entre tratamentos, embora o pH tenha decrescido nos tratamentos fertilizados com NPK, talvez devido à nitrificação da fração amoniacal do fertilizante.Hazel (Corylus avellana L.) is an important cultivated species of the Betulaceae family. It is mostly cultivated in temperate regions of the northern hemisphere, close to large bodies of water in mid-latitudes. Turkey is the largest producer in the world, followed by Italy and the United States of America. Portugal has a relatively low hazelnut production. Optimizing fertilization is an important aspect of the cropping technique, as the availability of nutrients directly influences tree growth and fruit production. Given that currently there is an international focus on reducing the use of conventional fertilizers, due to some negative impacts on the environment, it is important to evaluate complementary fertilization strategies, such as the use of products with a biostimulant action on plants. In this work two types of plant biostimulants were used, one based on seaweed extracts and the other on free amino acids. The products were applied separately and in addition to soil NPK fertilization. Thus, six treatments were established [NPK fertilization, NPK; NPK plus phytoalgae extract (Fitoalgas Green®), NPK+FA; FA; NPK plus amino acids (Sprint Plus®), NPK+SP; SP; and a non-fertilized Control], arranged in a completely randomized design with three replicates and three trees per replicate. The trial was installed in Travanca, municipality of Macedo de Cavaleiros, in Trás-os-Montes, in an orchard of hazelnut trees of the Ennis cultivar. The effect of the treatments was evaluated based on the nutritional status of the trees (from five sampling of leaves carried out over two years), on the mineral composition of the fruits and on the properties of the soil. The control treatment showed lower tissue nitrogen concentrations than the treatments that received NPK due to the direct supply of the nutrient. The seaweed extract maintained high levels of nitrogen in the leaves, perhaps because it improved the efficiency of using the nutrient from the soil. Potassium values in leaves also tend to be higher in NPK treatments. The concentrations of nitrogen and potassium in the leaves decreased markedly during the growing season, due to dilution effects with the expansion of the canopy and the concentration of elements in the fruits. Soil properties also varied little between treatments, although pH decreased in treatments fertilized with NPK, perhaps due to nitrification of the ammoniacal fraction of the fertilizer

Um olhar sobre a gestão do solo em olival face ao aquecimento global

As previsões para as alterações climáticas para as regiões do território nacional onde a oliveira tem expressão económica traçam um cenário de aumento de temperatura, com vagas de calor mais frequentes, e menor precipitação, em particular no período estival, com riscos de secas mais prolongadas. O que há de novo, então, neste cenário? Significa que o pior do clima mediterrânico, isto é, o que mais restringe atualmente a produtividade primária se está a agravar.Novas práticas em olivais de sequeiro: estratégias de mitigação e adaptação às alterações climáticas (Grupos Operacionais, parceria nº 343, PDR2020-101-032115)info:eu-repo/semantics/publishedVersio

The safe use of compost derived from municipal solid waste depends on its composition and conditions of application

Municipal solid waste compost (MSWC) is a source of organic C and other nutrients, which, when free from potential contaminants, can be used as a soil amendment. This study was carried out over three years in a vineyard with soil pH close to neutral under an experimental design consisting of two treatments (with and without MSWC). Application of MSWC is currently authorized under national legislation to be used in vineyards, orchards and forests at a maximum rate of 10 t ha−1 year−1. In this study, for experimental purposes, a double rate (20 t ha−1 year−1) was used. The accumulated grape yield increased in the amended plot by 28% and the dry biomass of weeds between rows by 119%. The MSWC significantly increased some relevant soil properties such as organic C, pH, cation exchange capacity (CEC) and extractable P, K and B. The concentration of K increased significantly in several tissues, and the concentration of P decreased. However, the concentration of K, P and other essential nutrients in the leaves remained within their sufficiency ranges. Tissue levels of heavy metals (Cr, Cd, Pb and Ni) did not increase with the MSWC application, and the values in the pulp remained below the limits established for foodstuffs. The results from this study indicate that the continuous application of the MSWC does not seem to be sustainable, because of the risk of causing nutritional disorders. Products with similar composition should therefore be used only on more acidic soils and should never exceed the legally established rates.This research was funded by the Foundation for Science and Technology (FCT, Portugal) and FEDER under Programme PT2020 for financial support to CIMO (UIDB/00690/2020). The authors would also like to thank the intermunicipal company ‘Resíduos do Nordeste’ and Dr. Paulo Praça for the free supply of the compost that was used in this study.info:eu-repo/semantics/publishedVersio

Leonardites rich in humic and fulvic acids had little effect on tissue elemental composition and dry matter yield in pot-grown olive cuttings

The use of humic substances in agriculture has increased in recent years, and leonardite has been an important raw material in the manufacture of commercial products rich in humic and fulvic acids. Leonardite-based products have been used to improve soil properties and to help plants cope with abiotic and biotic stresses. In this study, the effects of two commercial leonardites and an organic compost, in addition to a control treatment, were assessed for pot-grown olive plants over a period of fourteen months on soil properties, tissue elemental composition and dry matter yield (DMY). Three organic amendments were applied at single and double rates of that set by the manufacturer. The study was arranged in two experiments: one containing the seven treatments mentioned above and the other containing the same treatments supplemented with mineral nitrogen (N), phosphorus (P) and potassium (K) fertilization. Overall, organic compost increased soil organic carbon by ~8% over the control. In the experiment without NPK supplementation, N concentrations in shoots and P in roots were the highest for the compost application (leaf N 12% and root P 32% higher than in the control), while in the experiment with NPK supplementation, no significant differences were observed between treatments. Total DMY was ~10% higher in the set of treatments with NPK in comparison to treatments without NPK. Leonardites did not affect significantly any measured variables in comparison to the control. In this study, a good management of the majority of environmental variables affecting plant growth may have reduced the possibility of obtaining a positive effect on plant nutritional status and growth from the use of commercial leonardites. The leonardites seemed to have caused a slight effect on biological N immobilization. This is not necessarily an advantage or a drawback; it is rather a feature that must be understood to help farmers make better use of these products.This research was funded by the Foundation for Science and Technology (FCT, Portugal) and FEDER under Programme PT2020 for financial support to CIMO (UIDB/00690/2020). The research was integrated in the activities of 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).info:eu-repo/semantics/publishedVersio

Resposta do castanheiro à aplicação de calcário e fertilizantes minerais

A informação de base que suporta as recomendações de fertilização para o castanheiro é ainda pouco consistente. Os castanheiros são árvores de porte elevado que exploram um enorme volume de solo sendo insuficiente a informação que se retira das análises de terras. Por outro lado, o porte elevado das árvores faz com que respondam de forma lenta à aplicação de fertilizantes. Uma outra dificuldade resulta de ser difícil encontrar pomares adequados para conduzir estudos de fertilização devido à sua reduzida área e à elevada heterogeneidade das árvores. Neste trabalho reportam-se resultados de dois ensaios de campo que decorreram em Sobreiro e Tuizelo, no concelho de Vinhais, em que se estabeleceram três tratamentos, designadamente a aplicação de calcário mais fósforo (CalP), calcário mais um fertilizante NPK (CalNPK) e uma modalidade testemunha sem fertilização. Após três colheitas sucessivas, a produção não diferiu significativamente entre tratamentos em qualquer dos ensaios. No ensaio de Tuizelo, contudo, o tratamento CalNPK originou produção média acumulada (71,7 kg/árvore) mais elevada que a modalidade testemunha (59, 7 kg/árvore). A concentração de nutrientes nas folhas e algumas propriedades do solo parecem também mostrar os benefícios da aplicação do fertilizante NPK, talvez devido à presença de azoto, o elemento reconhecido como mais importante na fertilização dos castanheiros em outros estudos realizados na região.Projeto EGIS - Estratégias para uma Gestão Integrada do Solo e da Agua em Espécies Produtoras de Frutos Secos.info:eu-repo/semantics/publishedVersio

Nitrogen fertilization can significantly reduce the incidence of the olive fruit fly

The olive fruit fly (Bactrocera oleae Rossi) is one of the most important pests of the olive groves. Its negative impact is manifested by yield reduction, due to the consumption of pulp by larvae and increased fruit drop, and loss of quality of the oil, due to oxidation phenomena. All cropping techniques that reduce the incidence of this pest are able to contribute to increase crop yield and improve olive oil quality and help reducing pesticide use. Nitrogen fertilization can greatly influence the development of the canopy and the productivity of the olive tree, although little is known about the effect of nitrogen fertilization on the incidence of this pest. Two field trials were conducted in rainfed olive groves during the years 2017 and 2018, one of the cultivar Madural and the other of the cv. Cobrançosa. Three (0, 40 and 120 kg N ha-1) and four (0, 20, 40 and 120 kg N ha-1) nitrogen rates were tested respectively in 'Madural' and 'Cobrançosa'. The results showed a very significant reduction in the level of pest incidence as the nitrogen rate increased, with the exception of 'Madural' in 2017, a year in which productivity was low as well as the overall level of pest incidence. In 2018, incidence levels varied between 60.7 and 12.7%, respectively in the N0 and N120 treatments in 'Cobrançosa' and between 70.7 and 46.7% in the treatments N0 and N120 in 'Madural'. The most fertilized treatments showed significantly higher yields in both cultivars in 2018, with the higher fruit load inducing increased water stress, with more wrinkled fruits at the beginning of autumn, and delays in maturation. Probably these were the causes which may justify the lower incidence of the pest in the treatments fertilized with the higher nitrogen rates.projet “BioSave: Promoção do potencial económico e da sustentabilidade dos setores do azeite e da castanha “Concurso nº 02/SAICT/2016”, projeto nº 023721.info:eu-repo/semantics/publishedVersio

The effect of nitrogen fertilization on the incidence of olive fruit fly, olive leaf spot and olive anthracnose in two olive cultivars grown in rainfed conditions

Pests and diseases can cause significant loss of olive yield and/or justify control measures with pesticides which are harmful to the environment. Several agroecological variables, such as fertilization, can favour or limit the incidence of pests and diseases. However, in olive, few studies exist on the subject than can assist in the implementation of more sustainable phytosanitary measures. In this study the effect of nitrogen fertilization (0, 20, 40 and 120 kg N ha−1) on the incidence of olive fruit fly (Bactrocera oleae), olive leaf spot (Spilocaea oleaginea) and olive anthracnose (Colletotrichum gloeosporioides) was evaluated in two olive orchards of the cultivars ‘Cobrançosa’ and ‘Madural’. The study took place in 2017 and 2018 in Lombo, NE Portugal. Nitrogen fertilization significantly increased olive yield and nitrogen concentrations in plant tissues and induced a delay in fruit maturity. The incidence of the olive fruit fly was significantly lower in the more fertilized treatments of both cultivars. However, ‘Madural’ showed itself to be more susceptible than ‘Cobrançosa’ to olive fruit fly. The effect of nitrogen on the reduction of the incidence of the olive fruit fly was attributed to the delay caused in fruit maturation, which might have desynchronized the attractiveness of the fruits for insects to lay their eggs on their flight curve. In contrast, olive leaf spot and olive anthracnose were not influenced by nitrogen fertilization. As a result, nutrient management in olive groves must balance carefully the requirements of economic rationality with environmental preservation, particularly with regard to the harmful relationship between the use of excessive nitrogen rates and several adverse environmental effects.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) and European Agricultural Fund for Rural Development (EAFRD) under the Programme PT2020 for financial support to Centro de Investigação de Montanha, CIMO (UID/AGR/00690/2015) and Project 023721 (02/SAICT/2016) “BioSave: Promoção do potencial económico e da sustentabilidade dos setores do azeite e da castanha”.info:eu-repo/semantics/publishedVersio

Acute Effects of Augmented Reality Exergames versus Cycle Ergometer on Reaction Time, Visual Attention, and Verbal Fluency in Community Older Adults

Background: This study aims to investigate the acute effects of an augmented reality session and a cycle ergometer session compared to no exercise on the reaction times, cognitive flexibility, and verbal fluency of older adults. Methods: Each participant did a familiarization with cognitive tests and the following three sessions: cycle ergometer, no exercise (control group), and augmented reality exergame (Portable Exergame Platform for Elderly) sessions. The participants were randomized in a within-group design into one of six possible combinations. Each moment had a 30 min duration, and after the session, the participants performed a Trail Making Test, a verbal fluency test, and a Deary–Liewald reaction time task. The data were analyzed with a one-way ANOVA with a Bonferroni adjustment. Results: The analysis between the no exercise, cycle ergometer, and augmented reality sessions showed no significant differences in the cognitive measurements. Conclusions: One session of the cycle ergometer exercise or the augmented reality exergames does not acutely improve the reaction times, cognitive flexibility, or verbal fluency in the elderly