<p>The results of previous studies generally show that organic production is more profitable than conventional production. However, as a source of these results, the trials are either of short duration or do not specifically examine the benefits during the transition period, suggesting that previous work may not have captured the full variability of crop net returns. The purpose of this study was to compare the net returns and risks of conventional, transition, and organic cropping systems using long-term crop budgets and stochastic simulations. Conventional crop rotations were represented by a corn / soybean rotation and a corn / soybean / wheat rotation. The organic crop rotation produced corn, soybean and wheat. Historical prices, crop budgets, and FINBIN data are used to develop the long-term crop budgets. The organic crop rotation included a three-year transition period. Ten-year enterprise budgets were created for each crop and rotation so that we could compare the net returns of the transition year of organic crop rotation and the year of organic production. This thesis summarizes the enterprise budget information for each crop in the conventional and organic cropping systems, and summarizes the information used for the simulation analysis. Using @ risk, differences in annual net returns to land between crop rotations were summarized. Results are as follows. First, the transition and organic cropping system was found to have higher net returns to land than the two conventional crop rotations under most of the simulation iterations. Second, the annual net returns during the transition period were relatively low. Third, the highest average annual net return was for organic corn.</p><div><br></div>

Submitted by Katiane Souza (katyane.souza@gmail.com) on 2016-04-05T23:27:02Z No. of bitstreams: 1 arquivototal.pdf: 754987 bytes, checksum: 9c6daa9c670f621928da7b0d4797c1e4 (MD5) / Made available in DSpace on 2016-04-05T23:27:02Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 754987 bytes, checksum: 9c6daa9c670f621928da7b0d4797c1e4 (MD5) Previous issue date: 2006-02-24 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / Green bell pepper (Capsicum annuum L.) is a tropical plant of the Solanaceae family with origin in Latin America. In recent years, organic cropping systems using liquid biofertilizers have had an important impulse in Brazil. The objectives of this study were to evaluate green bell pepper yield, soil fertility changes and plant nutritional status in response to different types of liquid biofertilizers applied to the soil. The experiment was carried out at Macaquinhos Farm, in the municipality of Remígio-PB, in a randomized block design with three replicates. Treatments were distributed on a 2 × 5 factorial arrangement, regarding two types of cattle manure biofertilizer (raw and agrobio) and five doses of biofertilizers based on calcium rates (0; 0,65; 1,30; 1,95 and 2,60 g pit-1). Each plot was composed by 21 pits spaced by 1 × 0,50 m, with two plants. The use of biofertilizers in the doses tested in this study had no significant effect on green bell pepper growth as measured by height and stem diameter. For average fruit mass and average number of fruits per pit, there was a significant response green bell pepper plants to the calcium doses, regardless the type of biofertilizer. A statistical superiority of agrobio biofertilizer over raw biofertilizer was detected for the levels of sulfur, boron, iron and zinc in plant leaf tissues. Regarding soil fertility components, there was no difference between the two biofertilizer types, but pH values and phosphorus and potassium levels increased significantly. / O pimentão (Capsicum annuum L.) é uma planta pertencente a família das solanáceas, de clima tropical e de origem latino americana. Nos últimos anos, sistemas de cultivo orgânico com a utilização de biofertilizantes líquidos tiveram um grande impulso no Brasil. Os objetivos deste estudo foram avaliar a produtividade do pimentão, as mudanças na fertilidade do solo e o estado nutricional das plantas em resposta a diferentes biofertilizantes líquidos aplicados no solo. O experimento foi realizado no Sítio Macaquinhos, localizado no município de Remígio-PB, em delineamento em blocos ao acaso, em triplicata. Os tratamentos foram distribuídos em esquema fatorial 2 × 5, referente a dois tipos de biofertilizantes de esterco bovino (puro e agrobio) e cinco doses definidas a partir de níveis de cálcio (0; 0,65; 1,30; 1,95; 2,60). Cada parcela constou de 21 covas em espaçamento de 1 × 0,50 m, com 2 plantas cada. Nas doses em que foram testados, os biofertilizantes puro e agrobio não afetaram significativamente o crescimento em altura e diâmetro caulinar do pimentão. Quanto ao peso médio e número médio de frutos por cova, houve resposta significativa das plantas de pimentão as doses de cálcio, independentes do tipo de biofertilizante. A superioridade estatística do biofertilizante agrobio sobre o biofertilizante puro foi verificada para os teores foliares de enxofre, boro, ferro e zinco. Os biofertilizantes não diferiram entre si em relação aos componentes da fertilidade do solo, mas elevaram os valores do pH, fósforo e potássio.