Sustainable management of olive rainfed orchards by the introduction of leguminous cover crops

The olive sector has a crucial economic, social, cultural and ecological relevance in the Mediterranean region, where tillage and herbicides application are still generalized practices. However, these practices oppose the recommendations of UE Common Agricultural Policy and thus, management methods that decrease requirement for agricultural chemicals are needed to reduce adverse environmental impacts. Moreover, they can play an important role in atmospheric C01 emission and fixation. We propose green manure legumes to reduce erosion, soil compaction and nih·ate pollution, to improve biodiversity, soil carbon sink and fertility, to save fossil fuels and to increase yield and the safety and nutritional value of food products. The 3-yearfield study carried out in Northeast Portugal revealed that self-reseeding annual legumes is a promising strategy since increase the summer soil water content, the vegetative growth and the physiological tree pe1jormance, that was reflected in a 38% higher cumulative yield then tillage techniques.PTDC-AGR-AAM/098326/200

Green manure legumes affect seasonal soil and leaf CO2 exchange rates in an olive rainfed orchard

Management methods that decrease requirement for agricultural chemicals are needed to reduce adverse environmental impacts. Moreover, they can play an important role in atmospheric C02 emission and fixation. We propose green manure legumes to reduce erosion, soil compaction and nitrate pollution, to improve biodiversity, soil carbon sink and fertility, to save fossil fuels and to increase yield and the nutritional value of food products. The research was carried out near Mirandela, Northeast Portugal, on a 15- year commercial olive orchard (Olea europaea L. cv. Cobrançosa), grown under rainfed conditions

Leguminous cover crops improve the profitability and the sustainability of rainfed olive (Olea europaea L.) orchards: from soil biology to physiology of yield determination

The olive sector has a crucial economic, social, cultural and ecological relevance in the Mediterranean region, where tillage and herbicides application still are generalized practices. However, these techniques oppose to the recommendations of UE policy. Thus, other methods are needed to reduce adverse environmental impacts and to improve biodiversity, soil carbon sink and fertility, to save fossil fuels and to increase yield and the safety and nutritional value of food products. Meanwhile, since Mediterranean basin is particularly vulnerable to climate change, including lower precipitation in summer, olive tree will experiment some hard changes, mainly under rainfed conditions. Therefore, we propose an adequate management of cover crops to shift tillage and herbicides, in order to minimize runoff and evaporation water losses, conserve soil moisture storage and promote the infiltration of water in soil. The experiment was carried out during 4 years on a commercial orchard (cv. Cobrançosa) in Northeast Portugal. The treatments laid out were: (1) ordinary tillage techniques (OT) used by local growers (two tillage trips per year); (2) cover crop with self-reseeding annual legume species (AL); (3) natural vegetation fertilized (NVF) with 60 kg N hm2 (as in OT); (4) natural vegetation (NV) left unfertilized. The results revealed that AL treatment is the best option, reaching 37, 53 and 95% higher cumulative yield than NVF, OT and NV, respectively, in a closely association with greater physiological performance during the summer, mainly evidenced by lower oxidative damage and by favourable changes in water status and net photosynthetic rate, due to lower stomatal and mesophyll limitations. Moreover, the AL covered soil presented considerable microbial diversity and enzymatic activities, which may contribute to promote and conserve soil quality and health, as well the stability of ecosystems. Thus, leguminous cover crops improve the profitability and the sustainability of rainfed olive orchards.info:eu-repo/semantics/publishedVersio

Benefícios da aplicação de azoto, potássio e boro na fisiologia da oliveira em condições de sequeiro

O azoto, o potássio e o boro são nutrientes que frequentemente condicionam a fisiologia da oliveira (Olea europaea L.). O azoto apresenta um papel primordial por ser constituinte de vários compostos orgânicos, em especial proteínas, ácidos nucleicos, hormonas e clorofila. O boro influencia directamente a produção por proporcionar maior desenvolvimento radicular, maximizando o aproveitamento da água e dos fertilizantes, bem como por estar directamente envolvido na formação da parede celular, contribuindo para aumento da resistência geral da planta. Relativamente ao potássio, para além do efeito directo na produção, existem evidências que as árvores bem nutridas com este elemento toleram melhor a seca. Neste trabalho apresentam-se resultados de um ensaio de campo com duas modalidades de azoto, duas modalidades de potássio e duas modalidades de boto, conduzidos em olival de sequeiro de Verdeal Transmontana em Mirandela, desde o início de 2004

Mobilização tradicional versus utilização de herbicidas sistémicos em olival de sequeiro: efeitos fisiológicos e anatómicos

Nas condições climáticas da Terra Quente Transmontana, em que as maiores necessidades hídricas do olival coincidem com o período do ano em que praticamente não chove, o controlo das infestantes do olival é extremamente importante para garantir uma boa gestão dos recursos hídricos e, consequentemente, do desenvolvimento e produtividade das oliveiras. A mobilização do solo constitui uma prática muito frequente e tradicional para manter o olival livre de infestantes. Recentemente, os herbicidas sistémicos têm sido usados como prática cultura] alternativa à mobilização do solo. Ambos os sistemas devem ser equacionados em termos ambientais, económicos e da própria biologia da cultura. Neste trabalho pretendeu-se comparar o comportamento fisiológico das oliveiras no período estival de 2008. O ensaio decorreu num olival (cv. Cobrançosa) em plena produção (20 anos de idade, 240 árvores hat), localizado próximo de Mirandela (41° 31 ‘N; 7° 12W). As modalidades em ensaio foram: mobilização tradicional, com duas lavouras na Primavera, e uma aplicação de glifosato no início da Primavera desde 2001. Resultados preliminares revelaram maior desenvolvimento vegetativo e produtividade das árvores da modalidade glifosato. Ao nível das trocas gasosas foliares, nestas plantas registaram-se maiores valores de fotossíntese e condutância estomática. Estes valores estiveram associados a maiores teores em clorofila total, razão clorofila/carotenóides, eficiência quântica aparente, capacidade máxima metabólica e fluorescência variável. Em contrapartida, os teores em açúcares solúveis foram mais reduzidos, provavelmente devido à maior actividade das sinks vegetativas e reprodutivas. Ao nível das relações hídricas não se registaram diferenças significativas na eficiência intrínseca do uso de água, nem no conteúdo relativo de água. O mesmo se observou na estrutura anatómica e tamanho das folhas. ‘ Em conclusão, este estudo demonstrou que o sistema de não mobilização e recurso ao uso mínimo de herbicidas sistémicos assegura um melhor comportamento fisiológico das oliveiras, com consequências positivas na respectiva produtividade

Cover cropping effects on olive physiology in rainfed orchards

Olive orchards are often cultivated under rainfed conditions, although the irrigated areas are currently increasing. In Trás-os-Montes region, only 5% of the total area harvested is irrigated, and this picture will not change in the near future, due to natural limitation on water resources. Therefore, despite the importance of some high-density and super-high-density orchards that have been planted in the South of Portugal, it is still crucial for the olive sector, and in particular for many inland regions, that the rainfed orchards are managed in a profitable and environmentally sustainable way

Impacto de sistemas de gestão do solo na fisiologia do olival de sequeiro

A oliveira (Olea europaea L.) é uma espécie bem adaptada às condições da região Mediterrânica. Contudo, longos períodos de seca e elevadas temperaturas estivais prejudicam a fisiologia e a produtividade dos olivais de sequeiro. Uma das soluções para minorar este problema passa pela otimização do uso da água através da gestão cuidadosa da superfície do solo. Nesse sentido desenvolveram-se duas experiências em olivais de sequeiro na região de Trás-os-Montes.PTDC/AGR-AAM/098326/200

Biomarkers of oxidative stress in olive rainfed orchards under different cover crops

In Northeast Por1ugal, as in •other regions of the Mediterranean Basin, most of the olive orchards are cultivated in hilly areas under rainfed conditions and this picture will not significantly change in the near future due to natural Iimitation on water resources. We propose cover crops to Iimit soil erosion, improve soil quality and fertility, reduce the use of herbicides and other chemicals and develop the nutritional value of food products

Oxidative stress and antioxidant responses in olive tree subjected to cover crops under rainfed conditions

Since Mediterranean basin is particularly vulnerable to present and future climate variability and climate change, olive tree will experiment some hard changes in its environment. Under adverse conditions, imbalances in metabolic processes may lead to increased accumulation of ROS, forming a potential threat of oxidative damage to cells. We propose green manure legumes to shift tillage, in order to improve soil water relationships during the drought period. The research was carried out in northeast Portugal under rainfed conditions. The treatments laid out were: ordinary tillage techniques and a mixture of eleven annual (AL) pasture self-reseeding legumes. The results obtained in summer 2011 revealed that olive in AL plot had higher concentrations of chlorophylls, carotenoids and total thiols, as well stomatal conductance, net photosynthesis, qP, FvN/FmN, quantum yield of PSII, ETR and APX activity. Conversely, olive trees subjected to tillage had higher qN and GST activity. No significant differences were reported in electrolyte leakage, CAT activity and in TBARS and total phenols concentration. Thus, legume species may be a promising strategy contributing to the sustainable management of olive orchards