Residual effects of alkalized sewage sludge application on soil quality and sugarcane yield

ABSTRACT

The acidification and loss of nutrients and organic matter in tropical soils are indicators of chemical degradation. In such a scenario, alkalized sewage sludge (SS) for fertilization and reclamation of soils is a promising alternative. Here, we evaluate the impact of SS on soil fertility, sugarcane nutrition and yield in three successive crops. The treatments consisted of five rates of SS (0, 10, 20, 30, and 40 t ha⁻¹) and one treatment with mineral fertilizers. The soil characteristics, plant nutrition, and sugarcane yield were assessed. The results showed that SS increased the pH and the sum of bases, reducing exchangeable aluminum and improving chemical soil conditions. SS also increased soil organic matter (SOM), but SOM decreased over time. Likewise, the N and P contents in the soil were decreased with the successive crops. Sugarcane yield increased following SS rates and reduced with each crop cycle. The yields for plant cane, first ratoon, and second ratoon were 174, 94, and 74 t ha⁻¹ at a rate of 40 t ha⁻¹; these values were 75, 19, and 61% higher, respectively, than the mineral fertilization. SS can aid the reclamation of the chemically degraded soil, contributing to sugarcane nutrition and increased yields.

KEYWORDS:

• Organic fertilizer
• urban waste
• soil acidity
• soil degradation

Disclosure statement

No potential conflict of interest was reported by the author(s).