Effect of temperature and time on phosphorus adsorption in alluvial soils of the Red River Delta

Abstract

Phosphorus (P) is one of the most important macronutrients to plants, but it is very sensitive to the adsorption by soil solid-state. On the other hand, in the context of the climate change impact, the increase in temperature will accelerate solid-state diffusion and the value of the binding constant of soil solution. As a consequence, in order to enhance P-fertiliser efficiency, it is required to consider the temperature and time of fertiliser application. However, to date studies on effects of time and temperature on P-fertiliser efficiency are lacking in Vietnam. This study is in a series of researches on P dynamic in alluvial soils of the Red River delta, aiming at giving recommendations of P-fertiliser efficiency enhancement in cultivation practices. The study was implemented in three alluvial soil samples of the Red River Delta taken at Hai Phong city, Nam Dinh and Ninh Binh provinces. The study results showed that there was an association between temperature and P adsorption, but the adsorption rate was more observable within 25 and 40^oC. By contrast, in the first stage (from 1^st to 4^th days after fertiliser application) P adsorption doubled and tripled compared with the later stage (from 4^th to 8^th days). In conclusion, temperature and time should be included to enhance P-fertilizer efficiency for alluvial soils in the Red River Delta.