Comparative Effect of Phosphorus Sources for Grain Amaranth Production

Abstract

Phosphorus (P) is expensive to the sub-Saharan African resource-poor farmers; therefore, there is a need for investigation of locally available alternative P sources to enhance farmers' productivity. Optimum P rate was determined during the early and late rains of 1999. Using the optimum P rate, influences of three P sources ogun rock phosphate (ORP), sokoto rock phosphate (SRP), single super phosphate (SSP) and a control were evaluated on amaranth varieties in 2000 at the vegetable research plots of the National Horticultural Research Institute (NIHORT), Ibadan, Nigeria. In 1999, three grain amaranth varieties (NH84/452, NH84/445, and NH84/493) were combined factorially with four P rates: 0, 30, 60, and 90 kgP/ha. Application of P significantly increased plant height, number of branches, leaf dry weight, and grain yield (GY) per plant. Significant increase in GY was in the order NH/493 . NH/445 . NH/452. Optimum P rates across varieties for leaf dry-matter yield was established at 51.8 kgP/ha and for grain yield production was 48.4 kgP/ha. The experiment in the following year, 2000, was a RCB design using the optimum P determined in 1999. Three P sources (ORP, SRP, SSP) and a control were factorially combined with the three amaranth varieties. In the 2000 experiment, grain yield was 21.3, 16.9, 16.0, and 7.8 g/plant, respectively, for SSP, SRP, ORP, and the control. Growth was ranked in the order SSP . ORP . SRP . control. It was concluded for fertilizer recommendation Downloaded by [University of Western Ontario] at 07:52 04 February 2015 purposes that 50 kgP/ha is optimum for grain amaranth production and that amaranth productivity indices could be alternatively improved with indigenous P sources.

Fertilización orgánica-mineral del cultivo de amaranto (Amaranthus hypochondriacus L.)

“…The fertilization formula was 80-20-00 kg ha -1 of N-P-K plus one ton of compost ha -1 with the highest grain yield in both variables (Figure 3 and 4). In relation to the doses of N, these results are similar to those reported by Ojo et al (2007) who mention that under optimal conditions the optimum N doses should be in the range of 60 to 80 kg ha -1 . However, Myers (1998), in an experiment conducted in Missouri, USA, evaluated doses of 0 to 180 kg N ha -1 and found a higher yield at the highest dose.…”

“…Siendo la fórmula de fertilización 80-20-00 kg ha -1 de N-P-K más una tonelada de composta ha -1 con la que se obtuvo el mayor rendimiento de grano, en ambas variables (Figura 3 y 4). En relación a las dosis de N, estos resultados son similares a los reportados por Ojo et al (2007) quienes mencionan que en condiciones de temporal las dosis de N óptimas deberán estar en el rango de entre 60 y 80 kg ha -1 . No obstante, Myers (1998) en un experimento realizado en Missouri, Estados Unidos de América evaluó dosis de 0 a 180 kg N ha -1 y encontró mayor rendimiento con la dosis más alta.…”

Phosphate Fertilization in Amaranth Culture cv. BRS Alegria in Second Harvest in the Cerrado

“…Phosphorus is found at low concentrations in the soil solution, causing limitation of biomass productivity in tropical soils [15]. In the literature, the reported cases where the effect of P doses on amaranth culture [17] and [18] were studied under field conditions. Therefore, the information on residual P, after soybean cultivation, is not sufficient for a correct positioning on its management in the amaranth culture in succession, when aiming at economic yield.…”

“…BRS Alegria seeded in succession to soybean in Goiás, obtained 2,000 kg ha -1 of grain yield with application of 60 and 80 kg ha -1 of P 2 O 5 and K 2 O, respectively. In a study conducted in Malaysia, [17] in Malaysia, they concluded, for the purpose of fertilizer recommendation, that 50 kg of P ha -1 (114.57 kg.ha -1 of P 2 O 5 ) was the most adequate for the production of leaves and grains of amaranth.…”

Effect of compost-biochar mixes and irrigation on the growth and yield of Amaranthus (Amaranthus hybridus) under two growing temperatures

“…Although environmental conditions are known to influence crop growth and global climatic changes are assumed to worsen cropping conditions in sub-Saharan African with dry spells becoming more frequent, only one paper published recently deals with the impact of soil moisture stress on AIVs (Olufolaji and Ojo, 2010). A few others focused on nutrient management (Ojo et al, 2007). It can be concluded that most aspects of the cultivation or cropping systems of AIVs are heavily under emphasized.…”