RESUMO Os custos de plantios florestais podem ser reduzidos com a renda de culturas consorciadas com as espécies arbóreas. Um experimento foi realizado nos anos 2010 e 2011 para avaliar a viabilidade de dois sistemas agroflorestais envolvendo leguminosas (sabiá e gliricídia) e milho (cultivar AG 1051). Em 2010, as leguminosas foram cultivadas em monocultivo e em consorciação (sistema taungya) com o milho, em blocos ao acaso com cinco repetições. Três fileiras de milho foram plantadas entre duas fileiras das leguminosas (espaçamento 4,0 m x 4,0 m). Em 2011, as leguminosas foram cortadas a 0,5 m do nível do solo, e os ramos jovens e folhas foram incorporados nas áreas cultivadas em consórcio (sistema aléias). A consorciação aumenta a altura da planta (AP) na sabiá, mas não na gliricídia. A gliricídia tem menor AP do que a sabiá. A consorciação reduz o rendimento de espigas verdes, mas não o rendimento de grãos. A consorciação com milho reduz os custos de implantação do reflorestamento, especialmente com a venda de espigas verdes. Em aleias, a consorciação reduz o número e a massa totais de espigas verdes e o rendimento de grãos, mas não influencia o rendimento de espigas verdes comercializáveis. Produzir espigas verdes é mais vantajoso do que produzir grãos. O monocultivo do milho proporciona maior renda do que a consorciação.

ABSTRACT Forest plantation costs can be reduced by the income from annual crops that are intercropped with trees. An experiment was carried out over two years to assess the viability of agroforestry systems including sabiá (Mimosa caesalpiniifolia), gliricidia (Gliricidia sepium) and maize (cultivar AG 1051). In 2010, the legumes were grown both as monocrops and intercropped (taungya system) with maize in randomized blocks with five replications. Three rows of maize were planted between two rows of each legume (at a spacing of 4.0 m x 4.0 m). In 2011, the legumes were cut down, and the young branches and leaves were added to the areas of intercropped cultivation (alley cropping system). Gliricidia had lower plant height than sabiá. Moreover, while not affecting for gliricidia, intercropping increased plant height for sabiá. Intercropping reduced green ear yield but not grain yield and reduced the cost of introducing reforestation. Intercropping using the alley system reduced the total number and mass of green ears, as well as grain yield, but did not influence the yield of marketable green ears. Finally, producing green ears was more profitable than producing grain and maize monocropping provided a higher net income than intercropping.

This study aimed to evaluate the productivity, growth performance and economic feasibility of polyculture of Nile tilapia Oreochromis niloticus and shrimp Litopenaeus vannamei at different stocking densities. Feed was provided based on fish requirements. The experiment was conducted at the Aquaculture facility of the Universidade Federal Rural do Semi-Árido - UFERSA, in a completely randomized design with five treatments and four replicates each. Treatments consisted of a tilapia monoculture with 2 tilapias.m-2; and polyculture with 2 tilapias.m-2 and L. vannamei at four different densities (3, 6, 9 and 12 shrimps.m-2). The initial individual biomass for fish and shrimp were 1.23±0.12 g and 0.133±0.009 g, respectively. Water quality parameters, temperature, dissolved oxygen, pH and transparency were monitored. The experiment lasted 120 days and biomass gain was evaluated every two weeks. Final biomass, survival and feed conversion rates were calculated at the end of the experiment. The economic analysis showed that polyculture systems at stocking densities of nine and twelve shrimps.m-2 resulted in higher gross revenue and operational profits of 120.9% and 97.5% respectively, with mean gross return significantly higher than the monoculture. The O. niloticus and L. vannamei polyculture in oligohaline water was shown to be technically and economically feasible. These two species can be cultured together, without competing for the same resources, because they have different trophic niche, thus increasing productivity and economic returns for the farmers.

Avaliou-se a rentabilidade econômica de três cultivares de alface cultivadas em casa-de-vegetação e campo, com diferentes técnicas de preparo do solo, em Rio Branco, Acre. Foram instalados experimentos em janeiro, junho e novembro de 2006. Adotou-se o delineamento em blocos casualizados, com parcelas subdivididas em faixas com quatro repetições. As faixas corresponderam ao cultivo protegido e em campo aberto. Em cada faixa, três cultivares de alface ('Simpson', 'Marisa' e 'Vera'), constituindo as subparcelas, foram sorteadas nas parcelas, representadas por quatro preparos de solo ("encanteiramento" com cobertura de palha de arroz, polietileno prateado e solo descoberto e plantio direto). O custo total médio (CTMe), no cultivo protegido, foi de R$0,50 maço-1, 26% menor que no campo. Obteve-se receita líquida de R$24.270,67ha-1 ciclo-1, em cultivo protegido, e R$14.124.92ha-1 ciclo-1, em campo. O plantio direto para alface promoveu o menor CTMe e a maior receita líquida em cultivo protegido (R$30.724,64ha-1 ciclo-1) e em campo (R$22.892,71ha-1 ciclo-1) e o maior índice de rentabilidade. Portanto, o plantio direto orgânico de alface no Acre, em ambiente protegido, preferencialmente, e, em campo aberto, proporciona melhor desempenho econômico que os demais tipos de preparo e cobertura do solo.

It was evaluated the economical profitability of three lettuce cultivars cultivated in greenhouse and field with different tillage soil, in Rio Branco, Acre, Brazil. The experiments were installed in January, June and November 2006. The experimental design was randomized blocks in split-plot arrangement in strips, with four replications. The strips corresponded to cultivation in greenhouse and field. In each strip, three lettuce cultivars (Simpson, Marisa and Vera), constituted the split-plot and were raffled in the plot represented by four tillage soil (conventional tillage with mulching peel rice, silvered polyethylene ,non- mulched soil and non-tillage soil). The mean total cost (MTC) in greenhouse was of R$0.50 bundle-1, 26% smaller than in field. The liquid revenue of R$24,270.67ha-1 cycle-1, was obtained in greenhouse and R$14,124.92ha-1 cyicle-1 in field. The non-tillage soil promoted smallest MTC and largest liquid revenue in greenhouse (R$30,724.64ha-1 cycle-1) and in field (R$22,892.71ha-1 ciclo-1) and the largest rentability index. Therefore, the organic no-tillage of lettuce in Acre in greenhouse preference and in field it provides better economical rentability than the other types of tillage and mulching of the soil.

O presente trabalho tem como objetivo estimar o custo de produção e indicadores econômicos, relativos à produção e comercialização de frutos de 20 progênies de pinheiras, nas cinco primeiras safras, visando a identificar a safra a partir da qual a exploração da pinheira é lucrativa e as progênies mais promissoras, do ponto de vista econômico. Os dados de rendimentos de frutos em que se baseou o presente trabalho, foram obtidos no período de 2001 a 2005, em um experimento de avaliação de 20 progênies de meias-irmãs de pinheira, com irrigação por aspersão. As progênies foram avaliadas no delineamento de blocos aleatorizados, com cinco repetições e parcelas de quatro plantas. A exploração das progênies de pinheiras somente mostrou-se lucrativa a partir do quarto ano. Antes disso, somente as progênies A3 e A4, no segundo ano, e P3 e P11, no terceiro ano, geraram lucros satisfatórios. Nas pressuposições impostas na metodologia, com respeito ao período de análise temporal e aos preços tomados para julho de 2007, os mais importantes indicadores da lucratividade (lucro operacional, índice de rentabilidade e preço de equilíbrio) indicaram que a progênie A4 é a recomendada, embora outras progênies (FJ1 e FJ2) também tenham-se destacado. Nem sempre as progênies que apresentaram maior rendimento médio de frutos, nas cinco safras, são também as mais recomendáveis economicamente.

The aim of this study was to estimate the production cost and economic indicators associated with the production and sales of fruits from 20 custard apple progenies during the initial five harvests, in order to identify the harvest season from which custard apple exploitation becomes profitable, as well as the most promising progenies from an economic point of view. The fruit yield data upon which the present work was based were obtained during the period from 2001 to 2005, in an experiment that evaluated 20 custard apple half-sibling progenies, under sprinkler irrigation. The progenies were evaluated in a random block design with five replicates and plots consisting of four plants each. The exploitation of custard apple progenies only showed to be a profitable agribusiness after the fourth year. Before that, only A3 and A4 progenies in the second year, and P3 and P11 in the third year provided profitable incomes. Considering the methodological assumptions imposed concerning the time period analysis and the prices as of July 2007, the most important profitability indicators (operating profit, return index and equilibrium price) evidenced that the A4 progeny is the most recommended, although other progenies are also highlighted, such as FJ1 and FJ2. As already discussed, the progenies showing the highest average yields of five harvests are not always the most economically recommendable ones.

O objetivo deste trabalho foi avaliar a rentabilidade econômica do maracujazeiro-amarelo plantado em covas e em plantio direto sob manejo orgânico no Acre. Avaliaram-se cinco tipos de preparo do solo: T1 plantio direto com cova do tamanho do torrão (0,19 m x 0,063 m), com adubação em cobertura; T2 - cova de 0,30 x 0,30 x 0,30 m, com adubação de plantio na cova; T3 - Idem T2, com adubação em cobertura; T4 - cova de 0,50 x 0,50 x 0,50 m, com adubação de plantio na cova, e T5 - Idem T4, com adubação em cobertura. Os custos econômicos e operacionais médios foram maiores para os sistemas com plantio em covas de 0,50 m, por apresentarem elevado custo total de produção e menor produtividade. A receita líquida foi maior nos sistemas de preparo com covas de 0,30 m, com adubação na cova (R$10.234,19/ha) e em cobertura (R$11.501,44/ha) e no plantio direto (R$8.925,08/ha). Em todos os tratamentos, a situação econômica foi de lucro supernormal, assim a tendência é de mais agricultores entrarem na atividade.

The objective of this research was to evaluate the economical profitability of the yellow passion fruit tree planted in hole and no-tillage under organic cultivation in the state of Acre, Brazil. It was evaluated five types of preparation of the soil: T1- No tillage with a hole of the size of a clod (0.19 m x 0.063 m) with covering; T2- hole of 0.30 m x 0.30 m x 0.30 m with fertilization in the hole of planting; T3- similar to T2 but with fertilization of coverage; T4- hole of 0.50 m x 0.50 m x 0.50 m with fertilization in the hole of planting; and T5- similar to T4 but with fertilization of coverage. The economical and operational costs medium were larger for the no-tillage and the planting systems in holes of 0.50 m, they present an elevated total cost of production and smaller yield. The liquid revenue was larger in the planting systems with holes of 0.30 m with fertilization in the hole (R$10,234.19/ha) and of coverage (R$11,501.44/ha) and in the no-tillage system (R$8,925.08/ha). In all of the treatments, the economical situation was of supernormal profit, so the tendency is of more farmers to enter in the market.