钾肥在砖红壤中的淋失特征初步模拟研究

通过室内大型土柱模拟研究钾肥在砖红壤中的淋失特征,结果表明:K 在砖红壤中运移速度较快,灌水30mm即3d后既可从20cm处淋出;60cm处渗漏液中K 浓度在39d后随着时间的推移逐渐下降,淋失浓度与施肥量表现出正相关;45d后120cm处渗漏液中K 浓度才随着施肥量的增加而上升,推测其运移速度为2 7cm/d。K 在120cm处的累计淋失量与施肥量成正相关,其淋失率为3 28%。应用方程lnYt=a blnt可拟合不同钾肥施用量下砖红壤中120cm处K 的累计淋失量随时间的变化关系。

Preliminary Stimulated Study on Leaching of Potassium in Latosol

The objective of this study was to estimate the losses of potassium in the laboratory by large leaching soil columns containing disturbed soils. Results are as follows: Potassium moves quickly in the latosol. There are K~ which deriving from potassium fertilizer in the leachate at 20 cm depth after irrigating30 mm water;Concentration of K~ in the leachate at 60 cm depth are descending with the time growing and positively related to the fertilizer quantity applied after 39 days; Concentration of K~ in the leachate at 120 cm depth ascends with the fertilizer quantity applied after 45 days, and the movement velocity of potassium in the test is about 2.7 cm/d. Accumulation leaching amount of at 120 cm depth are positively related with the fertilizer quantity applied and their leaching ratio is 3.28%. Using equation lnY_t=a blnt can describe the relation between the accumulation leaching amount of K~ with time at 120 cm depth with different potassium fertilizer quantity applied.