@article{article_306535, title={Phosphorus release dynamics under phosphate rock and ammonium sulphate in soil amendment}, journal={Eurasian Journal of Soil Science}, volume={6}, pages={312–318}, year={2017}, DOI={10.18393/ejss.306535}, author={Agyarko, Kofi and Frimpong, Kwame Agyei and Abunyewa, Akwasi Adutwum}, keywords={Phosphate rock,ammonium sulphate,soil amendment,pH,available phosphorus,total phosphorus}, abstract={<p> <span lang="en-gb" style="font-size:10pt;line-height:115%;font-family:Cambria, serif;" xml:lang="en-gb">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 <sup>-1 </sup> 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 <sup>th </sup> and 6 <sup>th </sup>
weeks after amendment. The AS fertilizer treatments had significantly (p≤0.05)
lower pH values than those without. Amendments with the 2gAS kg <sup>-1 </sup>
soil had significantly (p≤0.05) lower mean pH values than those with the 1gAS
kg <sup>-1 </sup> 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 <sup>th </sup> and the 8 <sup>th </sup> weeks, after the
lowest pH values had been attained. Decreased soil pH relatively increased the
amount of phosphorus released ( </span> <span lang="en-gb" style="font-size:10pt;line-height:115%;font-family:Cambria, serif;" xml:lang="en-gb">y = -12.47x + 111.4; </span> <span lang="en-gb" style="font-size:10pt;line-height:115%;font-family:Cambria, serif;" xml:lang="en-gb">R <sup>2 </sup>=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. </span> <br /> </p>}, number={4}, publisher={Türkiye Toprak Bilimi Derneği}