Desempenho de crotalária cultivada em diferentes épocas de semeadura e de corte

Abstract

Performance of crotalaria cultivated at different sowing and cutting datesAn important alternative to supply the growing demand for organic fertilizers in Brazil is the growth of legumes as green manures as they may add biologically fixed nitrogen and organic matter to the soil. For successful green manuring, it is necessary to identify plant species with characteristics such as high yield of biomass, high capacity to accumulate N, hardness and viability to be used in various management systems. This study investigated sowing and cutting dates more appropriate for biomass mass production and accumulation of N in sunhemp (Crotalaria juncea L.) in the lowlands region of Rio de Janeiro (Baixada Fluminense). Four planting dates, during the Spring-Summer seasons and three cutting dates were tested. With cuttings obtained at 3 or 4 months, the highest values of mass production occurred in mid-Spring, and the lowest values occurred in late-Summer. The highest accumulations of N achieved by crotalaria sowed in mid-Spring were obtained with cuttings at 3 or 4 months. In the late-Spring sowing, plants with cutting at 4 months showed higher accumulation of N than plants with cutting at 2 months. In the summer sowing, there were no significant differences between cutting dates.

Phytomass production and nutrient accumulation by green manure species

“…On the other hand, Cavalcante et al (2012) found no differences among the phytomass productions of sunn hemp, dwarf pigeon pea and jack bean. Leal et al (2012), in the State of Rio de Janeiro, worked with sunn hemp planted in mid-spring, cutting at four months of age and average annual rainfall of 1200 mm, in similar conditions of this study, and found 213.5 kg ha -1 of N and 12,362 kg ha -1 of phytomass (dry matter) accumulated in the aerial part.…”

Produção e aspectos econômicos de milho consorciado com Crotalária juncea L. em diferentes intervalos de semeadura, sob manejo orgânico

“…A adubação verde promove melhorias das características físicas do solo (Chieza et al, 2013), favorece a reciclagem de nutrientes e pode incorporar N ao sistema por meio da fixação biológica de nitrogê-nio (FBN), o que a torna boa alternativa (Castro et al, 2004;Silva et al, 2011;Leal et al, 2012).…”

Growth models for morphological traits of sunn hemp

“…It is an excellent crop for green manure because of its growth characteristics and adaptation to local edaphoclimatic conditions (LEAL et al, 2012). It is known for having high rates of biomass production and nutrient turnover, easy decomposition and efficient biological fixation of atmospheric nitrogen (DOURADO et al, 2001), and the ability to reduce risk of erosion as well as damage caused by nematodes and weeds (DINARDO-MIRANDA;GIL, 2005).…”