Efeito da aplicação de leonardite nas propriedades do solo e na produtividade de alface cultivada em vasos

Mestrado de dupla diplomação com a UTFPR - Universidade Tecnológica Federal do ParanáO solo é um meio de suporte para o crescimento de diversas espécies vegetais, fornecendo nutrientes, minerais e água. Porém alguns solos são deficientes ou apresentam baixa disponibilidade de nutrientes para as plantas, necessitando de complementos com fertilização mineral, orgânica e/ou condicionadores. A leonardite tem sido utilizada como condicionador de solo para melhoramento da sua fertilidade, porém seus efeitos no solo estão ainda pouco estudados. O objetivo desse trabalho foi estudar o efeito de duas leonardites comerciais sobre as propriedades do solo, o estado nutricional das plantas e a produção de biomassa de alface, por comparação com outros substratos orgânicos e uma modalidade testemunha. Os tratamentos utilizados foram: Testemunha sem fertilização (T), Composto C1 (35,7 g/vaso), Composto C2 (71,4 g/vaso), Condicionador leonardite H1 (1,74 g/vaso), Condicionador leonardite H2 (3,57 g/vaso), Condicionador leonardite M1 (0,18 g/vaso), Condicionador leonardite M2 (0,36 g/vaso), T+F (solo+ 5 g de NPK), Composto C1+F (35,7 g + 5 g de adubo composto NPK), Composto C2+F (71,4 g + 5 g de adubo composto NPK), Condicionador H1 (1,74 g + 5 g de adubo composto NPK), Condicionador H2 (3,57 g + 5 g de adubo composto NPK), Condicionador M1 (0,18 g + 5 g de adubo composto NPK), Condicionador M2 (0,36 g + 5 g de adubo composto NPK). O experimento foi organizado de forma completamente casualizada com catorze tratamentos e três repetições. Os ensaios decorreram nas estufas do Instituto Politécnico de Bragança em vasos com cerca de 3 kg de solo peneirado, durante dois ciclos, um no outono outro na primavera. Nas plantas de alface foi avaliada a produção de matéria seca, a concentração de nutrientes nos tecidos e a quantidade de nutrientes recuperados nos tecidos. No solo avaliou-se, no fim do segundo ciclo, o teor de nutrientes, pH, carbono orgânico e complexo de troca. Os dados foram submetidos a análise de variância (ANOVA de 1 fator, unidirecional). Quando se registaram diferenças significativas (P < 0,05), as médias foram separadas pelo método de comparação múltipla de médias Tukey-HSD (α = 0,05). Em geral a maioria dos tratamentos com fertilização mineral alcançaram a maior produção de matéria seca e os maiores teores e recuperação de nutrientes nos tecidos. O tratamento M2+F foi o que acumulou maior quantidade de matéria seca durante o primeiro e segundo ciclos de cultivo da alface. Nos solos, os tratamentos que registaram teores mais elevados de nutrientes foram os compostos C2 e C2+F, sendo a associação com fertilizante mineral a mais vantajosa. Nos nutrientes fósforo, potássio e sódio, os condicionadores apresentaram valores baixos em relação à testemunha e aos compostosSoil is a means of support for the growth of several plant species providing nutrients, minerals and water. However, some soils are deficient or have low availability of nutrients for plants, requiring to be supplemented with mineral and organic fertilizers and/or soil conditioners. Leonardite has been used as a soil conditioner to improve soil fertility, but its effects on the soil are still poorly studied. The aim of this work was to study the effect of two commercial leonardites on soil properties, the nutritional status of plants and the production of lettuce, by comparison with other organic substrates and a non-fertilized control treatment. The treatments used were: Control (T), Compound C1 (35.7 g/pot), Compound C2 (71.4 g/pot), Conditioner leonardite H1 (1.74 g/pot), Conditioner leonardite H2 (3, 57 g/pot), Conditioner leonardite M1 (0.18 g/pot), Conditioner leonardite M2 (0.36 g/pot), T + F (soil + 5 g NPK), Compound C1 + F (35.7 g + 5 g of compound NPK fertilizer), Compound C2 + F (71.4 g + 5 g of compound NPK fertilizer), Conditioner H1 (1.74 g + 5 g of compound NPK fertilizer), Conditioner H2 (3.57 g + 5 g of compound NPK fertilizer), Conditioner M1 (0.18 g + 5 g of compound NPK fertilizer), Conditioner M2 (0.36 g + 5 g of compound NPK fertilizer). The experiment was organized in a completely randomized design with fourteen treatments and three replications. The tests took place in the greenhouses of the Polytechnic Institute of Bragança in pots with about 3 kg of sieved soil, during two growing cycles, one in autumn and one in spring. The following analyzes were carried out on lettuce plants: production of dry matter; concentration and nutrient recovery in plant tissues. In the soil, at the end of the second growing cycle, the nutrient content, pH, organic carbon and exchangeable complex were evaluated. Data were submitted to analysis of variance (one-way ANOVA, unidirectional). When significant differences were found (P <0.05), the means were separated by the Tukey-HSD multiple range test (α = 0.05). In general, most treatments with mineral fertilization reached the higher dry matter yields and nutrient concentration and recovery in plant tissues. The M2 + F treatment produced more dry matter during the first and second lettuce cultivation cycles. In the soils the treatments reaching high nutrient levels were the compounds C2 and C2 + F, being the association with mineral fertilizer the most advantageous. In the soil s, phosphorus, potassium and sodium levels were lower with soil conditioners in comparison to the control and organic compound treatments

Synchronization of germinal vesicle maturity improves efficacy of in&#160;vitro embryo production in Holstein cows

Germinal vesicle oocytes obtained by ovum pick-up (OPU) on a random day are heterogeneous in terms of chromatin maturity, and those with an intermediate degree of chromatin compaction present higher developmental competence. We previously developed a synchronization protocol combining follicle aspiration and FSH treatment capable of increasing the percentage of oocytes with intermediate chromatin compaction (classified as GV2 oocytes; within progressive stages of chromatin compaction ranging from GV0 to GV3) at the time of OPU. In this study, we tested the capacity of a similar protocol to synchronize oocyte chromatin maturity before OPU, as well as to improve the efficacy of in&nbsp;vitro embryo production (IVP) in Holstein cows. In the first experiment, eight non-lactating Holstein cows were subjected to the D5/4FSH, during which all follicles larger than 2&nbsp;mm were aspirated and a progesterone intravaginal device was inserted on a random day (day 0). Subsequently, four IM injections of FSH (Folltropin; 40/40/20/20&nbsp;mg) were administered 12h apart on days 2 and 3, and removal of the progesterone device and OPU were performed on day 5. Of the oocytes recovered by OPU, 83.2% were at the GV2 stage. In a second experiment, eighteen non-lactating Holstein cows (Synchro group) were subjected to the D5/4FSH protocol followed by IVM/IVF, and embryo production was compared with that of other seventeen cows submitted to OPU on a random day followed by IVM/IVF (Control group). Blastocyst rate in relation to total oocytes recovered was higher in the Synchro group (37.9%) compared to the Control group (21%; P&nbsp;&lt;&nbsp;0.05). The percentage of good quality blastocysts morphologically selected for freezing and later transfer in relation to the total number of oocytes recovered tended to be higher in the Synchro group (27.68%) compared to the Control group (14.34%; P&nbsp;=&nbsp;0.1). These data suggest that synchronization protocols increasing the percentage of GV2 oocytes in the population subjected to IVM/IVF can improve the efficacy of embryo in&nbsp;vitro production in cattle