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Conservation agriculture (CA) is recognized as a promising crop management strategy for sustainable agricultural intensification. The objective of this study was to evaluate CA cropping systems for rainfed maize as an alternative to the traditional tillage-based cropping systems (CT) in the context of family farms, using a multi-criteria model that represents the point of view of farmers. Farmers considered several aspects for evaluating the cropping systems, thatwere systematized in the model through five criteria (with sub-criteria): (a) costs; (b) yield; (c) labour; (d) human health and environment; and (e) production risks. CA did not differ from CT for the 'costs' criterion but was superior for the 'yield' and 'labour' criteria. In contrast, CT obtained better ratings for the criteria 'human health and environment' and 'production risks'. Considering all criteria, CA was better appraised than CT. However, a new local policy measure that subsidizes the hiring of mechanized tillage services overturns this outcome, indicating the importance of exogenous factors. Overall, the participatory processes in building the model allowed us to better understand the reasons of adoption or non-adoption of CA by small-scale farmers in the tropics.

descentralização de políticas públicas no país permitiu a participação da sociedade civil organizada em diferentes âmbitos de sua formulação, execução e fiscalização. Desde a década de 1990, a universalização desse processo vem se consolidando no meio rural por meio da operacionalização de serviços de assistência técnica e extensão rural realizada por organizações não governamentais. Com a regulamentação da Política Nacional de Assistência Técnica e extensão Rural houve uma ampliação na participação das organizações sociais ligadas aos movimentos sociais de agricultores familiares. O presente texto aborda uma experiência vivenciada por agentes de desenvolvimento em assentamentos de reforma agrária do município de Unai, Minas Gerais.

This paper evaluates the effects of the introduction of no tillage systems (SPD) in rainfed maize grain production, by smallholders, under Cerrado conditions, in the region of Unaí, Minas Gerais State, Brazil. The main constraints faced by farmers to produce are related to soil fertility management, difficulties in assessing tractors for preparing their land, and high levels of weed infestation. SPD was tested jointly with farmers trying to decrease these problems impacts. It showed promising results to stabilize, technically and economically, maize production. SPD solved completely the tractors dependency and contributed to decrease labour requirements for weed control. The production levels attained led to a better valorisation of the most scarce production factors, such as family labour and land. It was also evidenced the need to conduct more studies on the use of cover crops in those production systems. Key-words: Family farming; conservation agriculture; no-tillage. Este artigo analisa o efeito da introdução do uso do sistema plantio direto (SPD) no cultivo de milho grão sequeiro, em condições de Cerrado, por agricultores familiares de Unaí, MG. As principais limitações para a condução das lavouras desses agricultores relacionam-se ao manejo da fertilidade, precariedade de acesso à mecanização para preparo de solo e alta infestação de plantas daninhas. O SPD foi testado junto a esses agricultores, buscando-se limitar os efeitos desses problemas. Ele mostrou-se promissor para viabilizar, técnica e economicamente, a produção de milho dos assentados. O plantio direto eliminou a dependência de maquinário para preparo de solo e reduziu a carga de trabalho para controle de plantas daninhas. As produtividades alcançadas possibilitaram a valorização de fatores escassos, tais como a terra e, sobretudo, a mão-de-obra familiar. Evidenciou-se, também, a necessidade de se conduzir mais estudos sobre o uso de plantas de cobertura nesses sistemas de produção. Palavras-chave: Agricultura familiar; agricultura conservacionista; plantio direto.

In the context of conservation agriculture on small scale farms of the Brazilian Cerrado, we hypothesized that planting a cover crop in relay with a commercial crop improves the efficiency of use of available natural resources, increasing biomass for use as fodder without reducing the grain yield of the main crop. The objective of this study was to measure the performance of two intercropped systems in terms of total above-ground biomass production and maize (Zea mays) grain yield: pigeon pea (Cajanus cajan) and Brachiaria (Brachiaria ruziziensis) sown as cover crops in established maize under a no-tillage management. The cover crops were sown at two different dates and a comparison was made with the three crops sown as a sole crop at the early sowing date. The experiment was conducted during the 2007-2008 and 2008-2009 growing seasons. Maize grain yield was not reduced by the presence of the relay cover crops in comparison with maize as the sole crop, even when the cover crop was sown soon after maize emergence. In contrast, the production of above-ground biomass by the cover crop was significantly lower when grown with maize than it was when grown as a sole crop. In the intercropped systems, when sown early, the cover crop produced higher total biomass than when sown late. Total above-ground biomass production of maize intercropped with a cover crop was much higher than that of any of the crops sown alone: the total biomass (average of the two growing seasons) produced by maize and pigeon pea was more than double that of maize grown alone. The land equivalent ratio (LER) of maize grain yield and biomass production was higher than one whatever the intercropped system used. It was particularly high when maize was intercropped with early sown pigeon pea; grain yield LER and biomass LER reaching, respectively, 1.72 and 1.73 in 2007-2008 and 2.02 and 2.03 in 2008-2009. These high LER values provide evidence for the complementary and the high efficiency of use of available resources by the intercropped plants and thus the advantage of such systems to produce both maize grain and cover crop forage under the conditions of our study.

A descentralização de políticas públicas no país permitiu a participação da sociedade civil organizada em diferentes âmbitos de sua formulação, execução e fiscalização. Desde a década de 1990, a universalização desse processo vem se consolidando no meio rural por meio da operacionalização de serviços de assistência técnica e extensão rural realizada por organizações não governamentais. Com a regulamentação da Política Nacional de Assistência Técnica e Extensão Rural, houve uma ampliação na participação das organizações sociais ligadas aos movimentos sociais de agricultores familiares. Este texto aborda uma experiência vivenciada por agentes de desenvolvimento em assentamentos de reforma agrária do município de Unaí, Minas Gerais. The citizen society participation in formulation, implementation and fiscalization of the public politics was granted to decentralization. The universalization of this process has been reinforcing by way of the technical assistance and rural extension services operates by NGO - Non-governmental organization since the decade 1990. Farms social organization participation has been enlarging after the Rural Extension and Technical Assistance National Politic regulation. This text presents one analyze about the experienced have lived by development agents in agrarian reform settlement in Unaí, Minas Gerais state.

The public policy of agrarian reform in Brazil still gives priority to collective organization of the settlement, of the services and even of the agricultural production. This collective logic is promoted and institutionalized both by the State and the agrarian reform movements. Paradoxically, the settlement is based on the concession of individual land plots to a public formed mostly by former wage-earners, in the context of the promotion of family-based economic enterprises. This paper analyzes the origins and consequences of the interaction between these logics, focusing the case of land reform settlements of the municipality of Unai, in the state of Minas Gerais. There is a tension between the individual interest of “the new land-owner”, the logic of the family and the collective logic dependent on the modalities of public policy. The obligation of familiar or communitarian solidarity is fed by the precariousness of the settlement process and by the unifying ideology and human values. The results in Unai teach us that: a) the budgets and the instruments of public policy for agrarian reform are not adapted or suitable, and may become contradictory and lead to conflicts; b) in spite of such conditions and institutional environment, tools and methods for social construction of partnerships allow for a synergy between individual, familiar and collective logics; c) at the local level, the educational effort is indispensable in order to strengthen the dignity and identity of the settlers, but it will be efficient only on medium or long term.