Reaction of Ferralsol to Acidifying Effect of Nitrogen Fertilisation

• 作者: John Stephen Tenywa Jean Bosco Ngarukiyimana Alice Amoding Katushabe
• 来源期刊: 农业化学和环境(英文)
• 学科: 数学
• 关键词: Urea Hydrolysis AMMONIFICATION Phosphorus Sorption
• 年，卷（期）: 2021,（1）
• 页码范围: 69-79
• 页数: 11页
• 分类号: O17

摘要

<p style="text-align:justify;"> <b><span>Background:</span></b><span> The objective of this study was to determine the short-term effect of urea fertiliser application on soil reactions in a Ferralsol, with particular thrust on P sorption. </span><b><span>Methods:</span></b><span> Two experiments were conducted for this purpose</span><span>:</span><span> </span><span>1</span><span>) a screenhouse pot experiment</span><span>;</span><span> and </span><span>2</span><span>) a laboratory P sorption component. The pot (10 litre capacity plastic pots) experiment was conducted at the Makerere University Agricultural Research, Kabanyolo in Uganda, using a Ferralsol. The study comprised of four urea N (46% N) fertiliser treatments, namely, 0, 40, 80 and 120 kg N·ha</span>^{<span style="vertical-align:super;">-1</span>}<span>, equivalent to 0, 200, 400 and 600 mg N per pot. A completely randomised design was adopted with three replicates. Urea rates were applied in 50% split doses, one at planting and the other at 19 days after seedling emergence (to simulate farmer practice). This was followed by watering to field capacity using distilled water. Soil samples were taken at three daily intervals until day fourteen;thereafter, soil sampling was at an interval of seven days. The second urea split dose was applied at 21 days followed by soil sampling at </span><span>an </span><span>interval of three days till day fourteen. Thereafter, soil was sampled at seven day intervals until the end of experi</span><span>ment. Soil samples were analysed for exchangeable H</span>^{<span style="vertical-align:super;">+</span>}<span>, Al</span>^{<span style="vertical-align:super;">3+</span>}<span>, NH₄<sup style="margin-left:-9px;">+</sup></span><span>and</span><span> NO₃<sup style="margin-left:-9px;">-</sup> </span><span>ions. The reaction trends of the concentrations of these ions and Bray 1 P were used to structure different response curves representing the instantaneous reactions. As for the