Response of upland rice to fertilizer phosphorus and its residual value in an ultisol

Abstract

An effective and economically efficient phosphorus (P) management strategy requires accounting for the residual value of P fertilizer. Despite a great deal of research on soil P much remains unknown about the residual value of fertilizer P to upland rice in the humid tropics of Africa. A field experiment was conducted for six years (1993 -1998) to determine the response of four promising upland rice cultivars to fertilizer P applied at 0, 45, 90, 135, and 180 kg P ha 21 as triple superphosphate (TSP) only once in 1993, and its residual value in 1994, 1995, 1996, and 1998. The experimental site was located on an Ultisol, low in available P, in the humid forest zone of Cote d'Ivoire. Grain yields of the rice cultivars were significantly increased by fertilizer P in 1993, and by the fertilizer P residues in the subsequent years although the magnitude of response decreased rapidly with time since the fertilizer was applied. The levels of Bray 1 extractable P in the soil fell below the critical value in the 1994 season in all treatments except those which received 135 and 180 kg P ha 21 in 1993, and fell below the critical value in all P treatments in the 1995 season. 2457 ORDER REPRINTSA decrease in available P coincided with decreased residual value of P fertilizer and the soil P test (Bray 1 P) appeared to predict well the crop response. Our results show that there was a rapid loss of available P in the Ultisol and it is suggested that annual application of light rates of soluble P is a better option than heavy application at one time.

Direct and residual phosphorus effects on soil test values and their relationships with grain yield and phosphorus uptake of upland rice on an ultisol

“…By 1995, Bray 1 P had fallen below the critical SAHRAWAT AND SIKA 330 ORDER REPRINTS range levels (12 to 15 mg Bray 1 P kg soil 21 ) in the soil (4) and this clearly coincided with the decline in grain yields of the rice cultivars (3). The total amounts of P removed in the biomass of five crops varied from 12.6 to 20.8 kg P ha 21 and the apparent recovery of applied P was low and varied from 4.8 to 11.0% of the applied fertilizer P. The data on P removal by rice crops suggest that a greater of the applied P fertilizer was removed by chemical processes in the soil.…”

“…Phosphorus-efficient upland rice cultivars, adapted to acid soil conditions have been identified and evaluated for their P responsiveness and P efficiency in annual and long-term P experiments (1,2,3). Phosphorus (P) deficiency has been identified as the major constraint to rice production on these soils (1).…”

Long-Term Phosphorus Fertilizer Effects on Phosphorus Uptake, Efficiency, and Recovery by Upland Rice on an Ultisol

“…Such information however can provide useful leads for developing P management strategies. [7] Results showed that there was a rapid loss of available P in the Ultisol [7] because of its fixation by sesqui-oxides. Under these conditions, a combination of P-efficient genotypes and improved P management strategy is more practical for achieving sustainable crop production for crops such as upland rice.…”

Réponses des variétés interspécifiques du riz de plateau aux applications de phosphate en zone de forêt au Nigeria

“…Ce constat est accentue´dans les syste`mes de production intensive du riz (Sahrawat et al 2001) et illustre les limites de l'effet de la fertilisation phosphate´e sur les varie´te´s de riz d'origine asiatique couramment cultive´es sur ces sols . Une telle situation favorise la pratique de l'agriculture itine´rante qui est a`la base de la de´forestation et des de´se´quilibres e´cologiques, phe´nom-e`nes qui menacent la durabilite´de l'agriculture.…”