Phosphorus release dynamics under phosphate rock and ammonium sulphate in soil amendment

Abstract

Article Info Received : 05.01.2017 Accepted : 07.04.2017 This study was undertaken to assess the release pattern of available phosphorus in a Togo phosphate rock and ammonium sulphate soil amendment. Treatments were prepared through the combinations of soil, phosphate rock (PR) and ammonium sulphate (AS) fertilizer. The treatments were; Control, 12.5g PR, 25g PR, 12.5g PR+1g AS, 12.5g PR+2g AS, 25.0g PR+1g AS and 25.0g PR+2g AS kg -1 soil. Standard laboratory methods were used to assess pH, available phosphorus (P) and total phosphorus (P). Generally, the pH of treatments decreased to the lowest levels between the 4 th and 6 th weeks after amendment. The AS fertilizer treatments had significantly (p≤0.05) lower pH values than those without. Amendments with the 2gAS kg -1 soil had significantly (p≤0.05) lower mean pH values than those with the 1gAS kg -1 soil. The AS fertilizer treatments also had significantly (p ≤ 0.05) higher levels of the available P than those without. The higher the amount of the AS in the amendment, the higher the level of the available P concentration. Increase in the level of AS in the amendment also increased the mean value of the available P released. The peaks of available P released were observed between the 6 th and the 8 th weeks, after the lowest pH values had been attained. Decreased soil pH relatively increased the amount of phosphorus released (y = -12.47x + 111.4; R 2 =0.53). Addition of PR in the treatments increased the total P levels. In conclusion, combined application of AS and PR has the potential to increase soil P availability, which is beneficial to crop farmers.

Effect of Co-applying Different Nitrogen Fertilizers with Bone Char on Enhancing Phosphorus Release in Calcium Carbonate-Rich Soil: an Incubation Study

“…In the present study, the incorporation of bone char with nitrogen fertilizers enhanced phosphorus availability in the calcareous sandy soil because of increasing soil acidity resulting from the addition of nitrogen fertilizers, which in turn leads to increasing the solubility of insoluble phosphate compounds which existed in bone char. Also, several studies found that the co-application of nitrogen fertilizers with insoluble phosphate fertilizers increases phosphorus release in different soils which is attributed to acidifying soil caused by nitrogen fertilizers (Agyarko et al 2017;Apthorp et al 1987;McDowell et al 2002). The availability of phosphorus in the present study tends to increase with increasing incubation period for all treatments.…”

Bio-Organically Acidified Product-Mediated Improvements in Phosphorus Fertilizer Utilization, Uptake and Yielding of Zea mays in Calcareous Soil

“…Comparatively, plant physiological parameters, i.e., chlorophyll content, showed prominent results when SSP, DAP, and RP were applied alone, which might have been because of the failure of these phosphatic fertilizers to facilitate available nutrients, particularly P for plant uptake. Likewise, the soluble P forms (SSP and DAP) were exposed to fixation with soil particles, so that at critical stages, they might not present an adequate quantity of P due to P accumulation either through chemical adsorption or precipitation, which might have decreased the maize yield [60]; similarly the photosynthetic rate, stomatal conductance, and assimilation rate were also increased by acidified manure treatments in combination with DAP. These variable conditions might have increased the organic matter and nutrient contents, soil porosity, water-holding capacity, and, specifically, soil pH reduction, which provided uninterrupted nutrient availability to meet plant nutritional demands, resulting in a better yield quality [61,62].…”

Deciphering the Potential of Bioactivated Rock Phosphate and Di-Ammonium Phosphate on Agronomic Performance, Nutritional Quality and Productivity of Wheat (Triticum aestivum L.)

“…This might be explained as this integrated approach resulted in better soil environment and its physico-chemical properties [77]. These manipulated conditions might have improved organic matter content, soil porosity, water and nutrient holding capacities which assured continuous and uninterrupted nutrient supply to the wheat crop to meet its nutritional requirements resulting in improved wheat yield [78,79]. Comparatively inferior results by sole application of DAP (100% P) might have resulted because of the inability of DAP to supply continuous nutrients, especially P. As P from soluble DAP was vulnerable to its fixation to the soil particles, so at crucial stages it might not supply adequate amount of P due to Pimmobilization either through adsorption and/or chemical precipitation which might have reduced the wheat yield [80,81].…”