Arranjo Espacial, Densidade E Época De Semeadura No Acúmulo De Matéria Seca E Nutrientes De Três Adubos Verdes

Abstract

A preocupação com o avanço do processo degradativo instalado em grande parte dos solos brasileiros e com a prevenção da degradação de novas ABSTRACT RESUMOáreas tem conduzido à necessidade do uso de práticas de adição de matéria orgânica ao solo (Alcântara et al. 2000). Dentre estas, destaca-se a adubação verde, frequentemente associada à manutenção e/ou melhoria das condições físicas, químicas e biológicas do solo.

Biomass of Crotalaria juncea as a function of plant densities in the semiarid region of Northeastern Brazil

“…The previous discussion is confirmed by the fact that our results were closer to those obtained when the sowing was carried out in the autumn-winter season in southern regions of the country. The period until sunn hemp flowering in our study (49 to 63 d) was similar to the sowings in the month of March in São Paulo (24°35' S, 47°50' W), when days are decreasing in duration (Lima et al, 2010). The SDM obtained by us was smaller than that obtained when the sowing occurred in November in that state (15.6 t ha -1 ), and the time to flowering was 116 d. According to Lima et al (2010), the greater day length in São Paulo between November and January delays flowering and allows greater accumulation of SDM.…”

“…The period until sunn hemp flowering in our study (49 to 63 d) was similar to the sowings in the month of March in São Paulo (24°35' S, 47°50' W), when days are decreasing in duration (Lima et al, 2010). The SDM obtained by us was smaller than that obtained when the sowing occurred in November in that state (15.6 t ha -1 ), and the time to flowering was 116 d. According to Lima et al (2010), the greater day length in São Paulo between November and January delays flowering and allows greater accumulation of SDM. There is no time for further accumulation of SDM under the photoperiod conditions of the Northeast region, where flowering occurs earlier.…”

“…The development of species like this one is influenced by the interaction between photoperiod and temperature, the sowing date and the latitude (Amabile et al, 2000). Sunn hemp is a photoperiod-sensitive species and its flowering is induced by the shortening of day length, resulting in a decrease in biomass production (Lima et al, 2010;Eiras and Coelho, 2012). In Mossoro, the length of the day varies slightly, ranging from 11.8 h in June to 12.4 h in December, which is the photoperiod range in which Santos and Campelo Júnior (2003) observe the shortest time until sunn hemp flowering.…”

“…Mitigation of soil degradation can be achieved by more sustainable management practices, such as crop rotation and cultivation of species for green manuring and soil cover (Lima et al, 2010;Eiras and Coelho, 2012). Green manures, incorporated into soil management or used to cover the soil (Espíndola et al, 2005) protect and enrich the soil with SOM and nutrients and reduce the use of industrialized inputs while mitigating environmental degradation (Mateus and Wütke, 2006).…”

Organic cabbage growth using green manure in pre-cultivation and organic top dressing fertilization

“…The amount of N, K, Ca and Mg accumulated in shoot area of green velvet was higher compared to treatments with maize, which shows the high capacity of this leguminous plant for nutrient cycling (Table 2). Close values, except for Ca, were found by Lima et al (2010) in velvet bean, reporting average values of 196.6; 14.4; 100.7; 41.9 and 13.9 kg ha -1 , for N, P, K, Ca and Mg, respectively. The amount of N, P and Mg accumulated in maize shoots, in population density of 200,000 plants ha -1 was lower than that of the accumulated quantity on density of 100,000 plants ha -1 , due to the lower productivity observed in the highest population density (Table 2).…”