Produção de matéria seca e eficiência nutricional para P, Ca e Mg em leguminosas herbáceas

Abstract

RESUMOAs leguminosas para adubação verde têm sido introduzidas nos sistemas agrícolas para a recuperação de solos desgastados pelo uso intensivo. O objetivo desse trabalho foi avaliar a resposta de leguminosas herbáceas à aplicação de calcário e fósforo sobre a produção de biomassa e eficiência nutricional para o P, Ca e Mg. O experimento foi desenvolvido em casa-de-vegetação do Departamento de Ciência do Solo da Universidade Federal Rural da Amazônia, utilizando-se um Latossolo Amarelo distrófico coletado na profundidade de 0 -20 cm, em Belém, PA. O delineamento experimental usado foi o de blocos ao acaso, com arranjo de tratamentos em um fatorial 3 3 , onde foram comparadas três espécies de leguminosas: mucuna preta (Stizolobium atterrimum), mucuna cochinchinensis (Stilozobium cochinchinensis) e feijão-de-porco (Canavalia ensiformes); três níveis de calagem: de calcário dolomítico (0, 4 e 8 t.ha -1 ) e de fósforo (0, 25 e 45 mg.dm -3 ), com quatro repetições cada um. Mucuna cochinchinensis e o feijão de porco produziram maiores quantidades de biomassa vegetal do que a mucuna preta, sendo que a primeira espécie acumulou maior quantidade de P e a segunda maior quantidade de Ca. Mucuna cochinchinensis apresentou maior eficiência de utilização de P, Ca e Mg na ausência da calagem. Nos solos intemperizados com baixa concentração de P, Ca e Mg, o feijão-de-porco e a mucuna cochinchinensis poderão ter melhor desempenho do que a mucuna preta, visto que apresentaram maior eficiência de translocação e de utilização desses nutrientes, respectivamente. PALAVRAS-CHAVECalagem, adubação fosfatada, absorção de nutrientes, translocação de nutrientes, eficiência de utilização de nutriente. Dry matter production and nutritional efficiency for P, Ca and Mg in herbaceous legumes ABSTRACT The legumes used for green manure have been introduced in agricultural systems for recovering degraded soils by intensive use. The objective of this work was to evaluate the response of herbaceous legumes to liming and P application on dry matter and its nutritional efficiency. The experiment was developed in greenhouse at the Soil Science Department of the Federal University Agricultural of Amazon (Brazil

Grasses and legumes as cover crop in no-tillage system in northeastern Pará Brazil

“…Nitrogen contents and accumulation observed in sunn hemp were similar to those obtained by Amabile et al (1999). For jack bean, similar values were found by Fernandes et al (2007). For sunn hemp, pearl millet and signalgrass Torres et al (2005) related greater N contents to those noted in this study, mainly because of higher soil fertility, higher pH and organic matter contents.…”

“…The P content in jack bean tissues was superior to those obtained in other studies (Fernandes et al 2007;Oliveira et al 2002). Apart from soil factors, weather and climatic variation during the year may influence nutrient uptake by plants.…”

“…The jack bean also showed high dry matter yield (8,696 kg ha -1 ), due to its good adaptation in low fertility soils (Fernandes et al 2007), like those found in Northeastern Pará. As a yield of 6 t ha -1 has been considered the minimum amount of plant residues for appropriate soil Table 2.…”

Concentration of nutrients and chlorophyll index in pigeon pea fertilized with rock phosphate and liming in cerrado oxisol

“…This result, which was also observed by Fernandes et al (2007), in which the plants retained a greater amount of phosphorus in the roots under conditions of low nutrient supply, maintained the root growth at the expense of shoots. According to these authors, one explanation for this result is that the roots, being closer to the supply source, use the limited influence of this nutrient for maintenance and growth.…”

“…According to these authors, one explanation for this result is that the roots, being closer to the supply source, use the limited influence of this nutrient for maintenance and growth. Fernandes et al (2007) studied the velvet bean, Mucuna cochinchinensis and jack bean observed that the phosphorus content in plants increased with increasing doses of phosphorus and lime, with the most significant effect being the interaction between the factors, suggesting that the good performance of these species as accumulators and the later recycling of nutrients depend on a minimum supply of phosphorus and liming.…”