Crescimento de mudas de pinhão-manso em resposta a adubação com superfosfato simples e pó-de-rocha

Abstract

Resumo -Pesquisas feitas com pó-de-rocha têm mostrado a potencialidade de alguns desses resíduos em promover o enriquecimento mineral de solos; prática definida como rochagem do solo. Ela visa aumentar a fertilidade do solo, proporcionar uma boa produtividade e maior sustentabilidade agrícola. O presente trabalho teve por objetivo avaliar o crescimento de mudas de pinhão-manso (Jatropha curcas L.) em resposta a adubação do substrato com superfosfato simples e pó-de-rocha. O experimento foi instalado e conduzido no período de setembro a novembro de 2007, em casa de vegetação do Instituto de Ciências Agrárias/UFMG. Os tratamentos, em esquema fatorial 2 x 5, no delineamento em blocos casualizados, com 3 repetições, corresponderam a 2 doses de pó-de-rocha (0 e 20 kg m -3 de substrato) e 5 doses de superfosfato simples (1,25; 2,5; 5,0; 7,5 e 10,0 kg m -3 de substrato). Foram avaliados: altura da planta, diâmetro do caule, relação altura da planta/diâmetro do caule, número de folhas por planta, área foliar, matéria fresca e seca da raiz e da parte aérea, matéria fresca e seca total, relação matéria seca da parte aérea/matéria seca da raiz e índice de qualidade de Dickson -IQD. Os resultados mostram que não houve interação significativa entre as doses de fósforo e a de pó-de-rocha aplicadas e as variáveis estudadas. A aplicação de superfosfato simples foi significativa para altura da planta, diâmetro do caule, área foliar, matéria fresca da raiz, da parte aérea e total, respondendo positivamente até a dose máxima de fósforo aplicada. Palavras-chave -Jatropha curca. Rochagem. Produção de mudas.Abstract -Research into rock-flour have shown the potential of some of these residues in promoting the mineral enrichment of soils; a practice defined as stonemeal soil. Such practice aims to increase soil fertility and provide good productivity and greater agricultural sustainability. The present study had as objective to evaluate the growth of jatropha seedlings (Jatropha curcas L.) in response to fertilization of the substrate with single superphosphate and rock-flour. The experiment was setup and conducted from September to November, 2007, in a greenhouse at the Institute of Agricultural Sciences/UFMG. The treatments, in a 2 x 5 factorial design of randomized blocks, with three replications, corresponded to two doses of rock-flour (0 and 20 kg m-3 of substrate) and 5 doses of single superphosphate (1.25, 2.5, 5.0, 7.5 and 10.0 kg m-3 of substrate). Plant height, stem diameter, plant height/stem diameter ratio, number of leaves per plant, leaf area, fresh and dry matter of root and shoot, total fresh and dry matter, shoot/root dry-matter ratio, dry matter content and the Dickson quality index-IQD, were all evaluated. The results show no significant interaction between the levels of phosphorus and rock-flour applied and the variables studied. The application of single superphosphate was significant for plant height, stem diameter, leaf area, root, shoot and total fresh matter, with a positive response up to the maximum applied p...

Efficiency of the On-Farm Mycorrhizal Inoculant and Phonolite Rock on Growth and Nutrition of Schinus terebinthifolius and Eucalyptus saligna

“…Experiments in our study were conducted for 120 days, a period that may have been too short to analyze the effectiveness of phonolite application. Phonolite, characterized as an alkaline rock (Sichel et al, 2012), releases nutrients to plants in the medium to long term, even when this application occurs with small size particles (Prates et al, 2012). Furthermore, the phonolite used here had 9 % Na, compared to 6 % K. The presence of Na in the substrate represents an abiotic stress to plants, affecting uptake, transport, and use of some nutrients essential to plant growth (Cruz et al, 2006).…”

Nutritional status of jatropha under cattle manure and natural phosphate in rainfed conditions

“…Despite the expansion of studies on jatropha, fertilization recommendations under conditions of low water availability are still scarce. Among the sources of organic matter used in its fertilization, there is cattle manure (Sousa et al, 2012;Brito et al, 2013), which increases crop growth and yield (Balota et al, 2012;Prates et al, 2012), in isolation or associated with phosphate fertilization under irrigated conditions .…”

“…For production of seedlings, Prates et al (2012) observed that natural phosphate does not influence quality of seedlings in the first three months of plant growth. However, it has been observed that jatropha shows considerable response to phosphate fertilization.…”

“…However, these studies do not mention the use of natural phosphates. Most studies on phosphate fertilization have been conducted using seedlings (Prates et al, 2012) or in combination with salinity and in pot conditions (Souza et al, 2012 …”

Adubação fosfatada no desenvolvimento de Hemerocallis fulva L.

“…Já Prates et al (2012) constataram que a matéria fresca da raiz, matéria fresca da parte aérea e matéria fresca total do pinhão-manso aumentaram linearmente até a dose de 10 kg m -3 do substrato, ambos os experimentos utilizando como fonte o superfosfato simples. Para as mudas, a elevada concentração de P induz a formação de um sistema radicular mais longo e com raízes mais finas, que seriam eficientes na absorção de outros nutrientes (KNAPIK, 2005), porém, as doses ótimas variam de acordo com a espécie.…”