Lixiviation of K and Mg out of an alluvial silty laom soil under conditions of increased or restricted water supply
1990
Jadczuk, E. | Zmudzin, J.
When available soil K content was determined in a long-term potassium fertilizer trial carried out in a sour cherry orchard planted on a silty loam alluvial soil, it was found that, after four years, recovery of K (calculated in relation to the amount of this element applied in fertilizer) reached but 24% in case of plots treated once with 800 kg of K2O per ha and 32% on plots where 200 kg of K2O per ha were applied every year. The question arose in that respect--what was the reason for losses of K--fixation or lixiviation? In order to estimate a possible range of lixiviation under different conditions of water supply, in autumn 1985 an additional trial was established on the same soil, in a field close to the main fertilizer trial. The results obtained indicate that in a loamy alluvial soil, rich with clay minerals, the range of K lixiviation is low even at very high K fertilizer doses and at increased water supply to the soil surface. Hence it is concluded that probably not lixiviation but rather fixation has been responsible for a relatively quick decrease of K present in this soil in available forms. On the other hand, heavy K fertilizer doses together with rainfall may promote lixiviation of Mg contained in that kind of soil.
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