The Role of Charcoal Particle Size in Adsorption and Desorption Capacity of Potassium in Calcareous Soil

This chapter aims to determine effect of particle sizes of charcoal on desorbed of adsorbed potassium using silt clay loam texture soil collected from Abo- Graib research station/ Department of researches and studies/ Horticulture office. Potassium is considered to be one of the main important nutrient for most agriculture and economical crops. In this experiment, ten ml of potassium chloride solutions (0, 5, 10, 20, 60, 100 and 200 mg K L-1) was added to (soil, soil+ charcoal 0.5mm and soil+ charcoal 1mm) treatments. The adsorbed potassium was extracted using 1M- NH4AOc- pH = 7 and the potassium content in leachates was determined. The findings demonstrated that, when combined with soil treatment at various concentrations, charcoal treatments have a stronger potential to desorbate potassium. The desorbed potassium was 395 mg K kg -1 soil for (soil + charcoal diameter- 1 mm) treatment at a concentration of 5 mg K L -1 and 386.5 mg K kg -1 soil for (soil + charcoal diameter- 0.5 mm) treatment and the lowest amount of desorbed potassium 383 mg K kg -1 was in soil for soil treatment and this trend was matched different concentrations of the added potassium. The curves of potassium desorbed showed that the amount of desorbed potassium increased with the addition of charcoal, particularly when the particle sizes increased. The percentage of desorbed potassium was 4.30% in the treatment using soil and charcoal with a diameter of 1 mm (5 mg K L-1) and reduced to 2.19% in the treatment using soil and charcoal with a diameter of 0.5 mm and the lowest percentage of desorbed potassium was 1.30% in (soil) treatment. The study's findings showed that the amount of desorbed potassium correlated adversely with the size of the charcoal particle, which may have an impact on the efficiency of soil fertilization with potassium.