Combination between Acidity Amendments and Sewage Sludge with Phosphorus on Soil Chemical Characteristics and on Development of Castor Bean

Productivity and nutrition of castor bean fertilized with sewage sludge stabilized by different processes

“…This behaviour may have occurred owing to competition between these two elements for the adsorption sites in the soil (Malavolta, 2006). Capuani et al (2015) applied sewage sludge with different combinations of limestone and studied the characteristics of the castor bean and chemical properties of the soil and observed the same inverse relationship between these nutrients. According to these authors, the combinations of Ca and Mg should be taken into account, resulting in a more appropriate balance of these elements in the soil.…”

“…Some studies have reported that the addition of sewage sludge to the soil increases the productivity of the castor bean crop, resulting in high dry matter and seed oil yield (Capuani et al, 2015;Maciel-Torres et al, 2017). Cavalcanti et al (2015) reported that the productivity of castor bean fertilized with sewage sludge and potassium magnesium sulphate was similar to that found with NPK fertilization, indicating the potential of this residue as a substitute for mineral fertilization.…”

“…The K content in the soil may be associated with the presence of muscovite in the source material, which is associated with metargilites/metassiltites belonging to the Serra de Santa Helena geological formation, likely explaining the levels of K ranging from medium to high in the soils of this formation. When assessing the application of sewage sludge in the cultivation of castor bean, Capuani et al (2015) observed an increase in the availability of K in the soil. However, it should be noted that sewage sludge tends to be poor in K owing to the high solubility of this element, which results in it being retained in wastewater during sewage treatment.…”

“…The benefits on the chemical and physical properties of soils are very evident and contribute to considerable increases in crop productivity (Alburquerque et al, 2015;Capuani et al, 2015;Cavalcanti et al, 2015;Áfaz et al, 2017;Maciel-Torres et al, 2017;Eid et al, 2018).…”