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В статье представлены результаты полевых экспериментальных исследований влияния глубокого рыхления дна борозды и последующего окучивания посадок картофеля окучивающим рабочим органом на упругой стойке на основные показатели качества органического картофеля. Анализ результатов исследований показал, что применение глубокого рыхления при междурядной обработке повышает качество органического картофеля. В результате установлено, что наибольший положительный эффект достигается при глубине обработки 25-30 см от дна борозды. Доля содержания товарного картофеля при этом увеличилась на 53 %, а содержание некачественного картофеля уменьшилась на 8,2 % по сравнению с обработкой без глубокого рыхления., The article presents the results of field experimental studies of the effect of deep soil loosening of the furrow bottom and subsequent mounding of potato plantings with a special working tool with a spring tine on the main organic potato quality indicators. Analysis of study findings showed that the use of deep loosening in the inter-row cultivation increased organic potato quality. It was found, in particular, that the greatest positive effect was achieved with a loosening depth of 25-30 cm down from the furrow bottom. The share of commercial potato in this case increased by 53%, while the content of poor-quality potato decreased by 8.2% compared to the cultivation without deep soil loosening.

The aim of this study was to assess the short-term effects of tillage practice (reduced tillage – RT; standard tillage – ST) and fertilisation regime (solid cattle manure – SCM; lucerne pellets – LP; grass/clover silage – GCS) on soil quality indicators in an organic potato (Solanum tuberosum L.) production system. Use of RT enhanced the biomass and number of earthworms compared with ST. Concentrations of soil mineral N ((Formula presented.) and (Formula presented.)) showed similar decreasing patterns over time across both tillage systems during the potato production period. However, soil mineral N was overall higher in the 0–15 cm soil layer for RT and in the 15–30 cm layer for ST. Soil bulk density was higher for RT than ST at 1, 4 and 7 weeks after planting, while a linear reverse correlation was found between soil bulk density and tuber yield. Although both soil temperature and soil moisture content were not found to be greatly affected by tillage practice, net soil N mineralisation was estimated to be 65 kg N ha−1 greater under ST than RT for the potato production period. The application of LP and GCS resulted in higher mid- and end-season soil mineral N concentrations and crop N accumulation at harvest compared to SCM. During initial adaptation to reduced tillage practices in organic potato systems, farmers need to carefully weigh potential conflicts between initial yield reductions and soil conservation goals.

The majority of Dutch farmers perceive that mouldboard ploughing prior to potato planting is necessary, despite its negative impacts on inherent soil fertility and soil structure. An innovative agronomic practice in Dutch organic agriculture is the use of cut-and-carry fertilizers with which above-ground biomass of crops with high nitrogen content (e.g. grass/clover) is harvested and transferred to other fields as plant-based fertilizers. The objective of this study was to investigate the interactive effects of two tillage systems (reduced tillage (RT), standard tillage (ST)) and three organic fertilizer amendments (solid cattle manure (SCM), lucerne pellets (LP), grass/clover silage (GCS)) on crop performance and nitrogen utilization of organic potato. Use of RT decreased tuber yield by 13.4 % compared to ST due to lower average tuber size which was related to higher soil bulk density and increased vulnerability to drought stress during tuber bulking. On the other hand, use of RT positively affected nitrogen utilization and tuber quality in terms of specific gravity, dry matter and starch contents. However, the price premium associated with enhanced tuber quality may not offset the observed yield gap between RT and ST. Plant-based fertilizers enhanced nitrogen utilization in terms of apparent nitrogen recovery compared to animal-based. Although use of LP resulted in the highest yield for both tillage systems, its high price may be cost-inhibitive. An integrated approach taking into account N release patterns, environmental conditions, final yields, and production costs is needed in order to optimize resource use efficiency and overall profitability for farmers., Organic Agriculture, 6 (2), ISSN:1879-4238, ISSN:1879-4246

O cultivo orgânico de batata inglesa apresenta viabilidade econômica, porém enfrenta problemas em relação à manutenção da sanidade. Este trabalho foi realizado para verificar o efeito da adubação com silício na incidência de insetos-praga e na produtividade da cultura da batata inglesa em sistema orgânico. Foram testados 5 tratamentos com 4 repetições: 1- testemunha; 2- adubação via solo com ácido silícico, na dose correspondente a 0,35t.ha-1; 3- adubação via foliar com solução de ácido silícico a 0,35%; 4- adubação via solo com pó de rocha, na dose correspondente a 2t.ha-1; 5-adubação via foliar com solução de pó de rocha a 2%. Os tratamentos foram aplicados 20 dias após o plantio da batata-semente. Foi monitorada a incidência de insetos-praga por meio da determinação do número pulgões, de lesões foliares provocadas por Diabrotica speciosa (Germar) e de folíolos minados por Liriomyza spp.. Determinaram, ainda, a altura e o diâmetro das plantas e a produtividade. Verificou-se que as plantas adubadas com silício, independentemente da forma de aplicação e da fonte utilizada, apresentaram menor número de injúrias foliares em relação àquelas da testemunha. Contudo, não foi constatado o efeito da adubação com silício no desenvolvimento e produtividade da cultura. The organic cultivation of potato presents economical viability, however it faces problems in relation to the maintenance of sanity. This work was carried out to verify the effect of the silicon fertilization on the incidence of pest insects and in the productivity of potato in an organic system. Five treatments were tested, with four replications: 1- control; 2- fertilization applied via soil with silicic acid, in the dose corresponding to 0.35t.ha-1 3- fertilization applied via leaf with solution of silicic acid at 0.35%; 4- fertilization applied via soil with rock powder, in the dose corresponding to 2t.ha-1; 5- fertilization applied via leaf with rock powder solution at 2%. The treatments were applied 20 days after the plantation of the seed potato. The incidence of pest insects was monitored by means of the determination of the number of foliar lesions caused by Diabrotica speciosa (Germar) and the number of leaves mined by Liriomyza spp. The diameter and the height of the plants and the productivity were determined. Independently of the form of application and the source used, it was verified that the plants fertilized with silicon presented lower number of leaf injuries in relation to the control ones. However, it was not possible to verify the effect of the fertilization with silicon on the development and productivity of the culture.

International audience; Chapters: Seed Legislation in Europe and Crop Genetic Diversity. Postharvest Management of Fruits and Vegetables Storage. Herbicides: History, Classification and Genetic Manipulation of Plants for Herbicide Resistance. Nitrogen-Fixing Plant-Microbe Symbioses. Factors Influencing Farm Profitability. Soil Fertility and Crop Productivity in African Sustainable Agriculture. Drought Stress Tolerant Horse Gram for Sustainable Agriculture. Essential Oils for Pest Control in Agroecology.Organic Potato Farming Adoption in Iran. Crop Plant Hormones and Environmental Stress

Made available in DSpace on 2014-08-20T14:33:15Z (GMT). No. of bitstreams: 1 Tese_Lirio_Jose_Reichert.pdf: 7240461 bytes, checksum: 8c185c73c1232c1a6276739e8b176d6e (MD5) Previous issue date: 2012-03-02 The farm production systems, in general, have a certain degree of complexity because it involves a set of variables that the farmer can not always control, and requires a decision-making. The farmer does it considering his rationality based on his objectives, perception, intuition, and information. Even with all these precautions, it s not always easy to make those decisions, and so they often need some support or some tool to assist them, even more when the production systems involve practices and/or organic production processes or with technological innovation. In these cases, the farmer needs to involve a number of internal and external elements to the rural property, interact with nature and know how to use it for the benefit of the production unit. A number of studies have been conducted to improve organic production processes, emphasizing its importance and its social, environmental and economic benefits, and the opportunities it brings. Potato organic production has evolved, but, being a system still in consolidation, it faces bottlenecks in production and in marketing, which should be studied deeper. Following this idea, the study aimed to construct models that aggregate different systems evaluation criteria of organic potato developed by family farmers from southern Rio Grande do Sul state. The study had the participation of a group that has been in the research project Rede de Referência (GRR) of Embrapa Clima Temperado, and another group out of the network (GFRR), associated with Cooperativas Sul Ecológica, Arpa-Sul and Coopar. To evaluate the organic potato system, the study used the decision aid multicriteria tool, which allows the inclusion of the subjective view of the actors involved in the decision-making context through formation of a mental frame of reference (QRM), composed of their personal beliefs, assumptions, values and preferences, through modeling criteria construction in a participatory manner. The study showed, in general, that the models constructed (1-GRR and 2-GFRR) do not differ much from the production practices adopted in each group. Nevertheless, the differences occurred in the levels of impact of actions, and in the establishment of different weights between the models, so the final result in order of preference of evaluation criteria was different. For GRR the criterion potato size was the most important, whereas for GFRR was the criterion production risks. When evaluated with four other organic potato production systems (A, B, C, and D), the two models performances were very close. In model 1 the scores were 72.6; 70.2; 4.1, and 10.9, and in model 2, 71.7; 71.3; 2.7, and 5.0, respectively. In the assessment of each group, the farmers agreed with the results obtained in the models, proving their validity and robustness against the models constructed. Os sistemas de produção agrícola, de uma forma geral, se caracterizam por certo grau de complexidade, porque envolvem um conjunto de variáveis que nem sempre são controláveis pelo agricultor e que exigem a tomada de decisão, que o faz considerando sua racionalidade, baseado em seus objetivos, percepção, intuição e informação. Mesmo com todas estas precauções, nem sempre são decisões fáceis de serem tomadas e que, muitas vezes, necessitam de algum apoio ou alguma ferramenta que lhes auxilie, ainda mais quando os sistemas de produção envolvem práticas e/ou processos de produção orgânica ou com alguma inovação tecnológica. Nesses casos, o agricultor necessita envolver uma série de elementos internos e externos à propriedade, interagir com a natureza e saber usá-la em benefício da unidade de produção. Estudos vêm sendo realizados para aperfeiçoar os processos de produção orgânica, enfatizando sua importância e seus benefícios sociais, ambientais, econômicos e as oportunidades que ela traz. A produção orgânica de batatas tem evoluído, porém, por ser um sistema ainda em consolidação, enfrenta pontos de estrangulamento na produção e na comercialização, que devem ser estudados com maior profundidade. Neste sentido, o estudo teve por objetivo construir modelos que agreguem os diferentes critérios de avaliação de sistemas de batata orgânica, desenvolvido por agricultores familiares da região Sul do Rio Grande do Sul. Contou com um grupo que vem atuando no projeto de pesquisa Rede de Referência (GRR) da Embrapa Clima Temperado e outro fora da rede (GFRR), associados às Cooperativas Sul Ecológica, Arpa-Sul e Coopar. Para avaliar os sistemas de produção de batata orgânica o estudo utilizou a ferramenta Multicritério de Apoio à Decisão (MCDA), que permite a inserção da visão subjetiva dos atores envolvidos no contexto decisório por intermédio da formação de um quadro de referência mental (QRM), composto por suas crenças pessoais, hipóteses, valores e preferências, através da construção da modelagem criterial de uma forma participativa. O estudo mostrou de uma maneira geral, que os modelos construídos (1-GRR e 2-GFRR), não se diferenciam muito em relação às práticas de produção adotadas em cada um dos grupos. No entanto, as diferenças ocorreram nos níveis de impacto das ações e no estabelecimento de pesos diferentes entre os modelos, de modo que o resultado final, na ordem de preferência dos critérios de avaliação, foi diferente. Para o GRR o critério tamanho da batata foi o mais importante, enquanto que para o GFRR foi o critério riscos de produção. Os dois modelos quando avaliados com outros quatro sistemas de produção de batata orgânica (A,B,C e D), tiveram desempenho muito próximos na avaliação global. No modelo 1, as pontuações foram de 72,6; 70,2; 4,1 e 10,9 e no modelo 2, 71,7; 71,3; 2,7 e 5,0 respectivamente. Na avaliação em cada um dos grupos, os agricultores concordaram com os resultados obtidos nos modelos, comprovando sua validade e robustez frente aos modelos construídos.