The Residual Effect of P and Lime on the Performance of Four Tropical Grasses in a High P‐fixing Oxisol¹

Abstract

Pastures sown after several years cropping may take advantage of the residual lime and P fertilizers applied earlier. A field experiment was conducted to (i) compare the potential of different grasses to use previously applied P fertilizer at two levels of applied lime and (ii) evaluate the capacity of two soil tests to predict P availability to grasses. Four grasses [Andropogon gayanusvar. bisquamulatus (Hochst) Hack] cv. Planaltina; Panicum maximumcv. Makueni; P. maximumvar. trichoglume cv. Green panic and Setaria ancepscv. Kazungula were sown on an old experimental site where P fertilizers and lime have been applied over a period of 6 years for total rates of 0, 44, 87, 131, and 175 kg ha−1of P and 4 Mg ha−1of lime. Despite the well‐known P‐fixing capacity of the soil (clayey, kaolinitic, isohyperthermic, Typic Haplustox), grasses responded markedly to residual P and lime. Andropogon and to some extent Setaria performed better than the other grasses in both, limed and unlimed plots, at low levels of applied P. Makueni performed well only on limed plots at high levels of applied P (175 kg ha−1). Available soil P and dry matter yield correlated well but the range of P availability was too small for prediction purposes. It was concluded that despite high P‐fixing capacity a large portion of residual P remained available to grasses. Soil test procedures should be improved to better reflect the P availability to grasses.

Liming and fertilization to restore degraded Brachiaria decumbens pastures grown on an entisol

“…Positive response of Brachiaria brizantha pasture was observed for lime rates until 2.0 Mg ha -1 , as well increases of the effectiveness of phosphate fertilization (Paulino et al, 1994). Similar findings were obtained by Couto et al (1985).…”

“…Effects of liming and fertilization of degraded pastures for restoration seem to be more evident when they are monitored for many years (Couto et al, 1985;Macedo, 1985;Sanzonowicz et al, 1987;Carvalho et al, 1992;Paulino et al, 1994). Macedo (1985) observed an increase from 14 to 38% in forage yield over a five year period, for Festuca pasture mixed with legumes, althrough liming was not effective in the first year.…”

Fontes, doses e modos de aplicação de fósforo na recuperação de pastagem com brachiaria

“…Resultados semelhantes foram obtidos por Couto et al (1985), em que semearam Andropogon gayanus Kunth. com o objetivo de avaliar fosfato natural de Araxá, termofosfato magnesiano e superfosfato triplo aplicados em Latossolo Vermelho Escuro, argiloso, de cerrado, e verificaram que a maior produção de MS foi com a dose de 105 kg ha -1 de P 2 O 5 na forma de superfosfato triplo, não diferindo estatisticamente do termofosfato magnesiano.…”

Levantamento Florístico de Mata Ciliar em Áreas de Extração de Argila no Município de São Roque do Canaã-Es1

“…A dinâmica da água do solo atua reconhecidamente na definição das características edáficas e vegetacionais da faixa ciliar. O mosaico vegetacional observado nessas formações reflete uma heterogeneidade ambiental resultante das distintas condições ecológicas existentes nas áreas, definidas por variações edáficas, topográficas, de encharcamento do solo, das formações vegetais do entorno, das características hidrológicas da bacia e do curso d'água, entre outros fatores (EITEN, 1963;1992;COUTO et al, 1985;SCHIAVINI E ARAÚJO, 1989;RATTER et al, 1997;PIVELLO et al, 1998;RIBEIRO E WALTER, 1998;ARAÚJO et al,1999).…”