Abstract

POTISEK-TALAVERA, María del Carmen et al. Soil applied biosolids and its effect on soil organic matter and nutrient content. Terra Latinoam [online]. 2010, vol.28, n.4, pp.327-333. ISSN 2395-8030.

Population growth and water demand increase volumes of wastewater, which when treated generates high volumes of sewage sludge. The high costs of disposal of sewage sludge biosolids makes their use as an amendment or organic fertilizer an alternative. The objective of the present research was to evaluate the content of organic matter, macro and micronutrients in soil after incorporating biosolids and their distribution in the soil profile. The study was carried out in PVC columns packed with silty clay loam soil. Treatments were rates of biosolids (100 and 200 Mg ha^-1), 100 kg N ha^-1 as ammonium sulfate and a control treatment without fertilizer. Biosolids increased organic matter in the surface layer of the soil. There were no significant trends in the distribution of organic matter in the soil profile; on average in the entire profile, highest values were observed in the treatment with a high rate of biosolids (1.2%), while the lowest value was 1.1% in the control. Biosolids increased nitrate and available phosphorous in the soil up to a depth of 35 cm, and potassium did not significantly increase. Applied biosolids increased the micronutrient content in the entire soil profile; the order of micronutrient concentration in the soil with biosolids was Zn > Fe > Mn > Cu. Biosolids used in agricultural, forest and range soils might be an alternative for their final disposal; furthermore, biosolids might be a choice to deliver nutrients to crops, reducing production costs.

Keywords : soil columns; nitrogen; phosphorous; micronutrients.