Dados do Trabalho

Título

WHAT ARE THE LONG-TERM EFFECTS OF PIG SLURRY APPLICATION ON SOIL AND SUBSOIL ACIDITY?

Resumo

Soil acidification is a natural process that can be influenced by different fertilization strategies. The degree and nature of this influence depend on factors such as the type of nutrient source (mineral or organic), application rates, and duration of adoption. In southern Brazil, pig slurry (PS) is readily available and frequently applied to soil in significant amounts as a nutrient source. Therefore, it is crucial to understand the impact of long-term PS application on soil acidification. The objective of this study was to evaluate the effects of different fertilizer strategies on soil acidity parameters in an Oxisol under no-till cropping in southern Brazil. The treatments included the application of PS at varying rates (0 m³ ha-1 year-1 as control, 25 m³ ha-1 year-1 as PS25, 50 m³ ha-1 year-1 as PS50, 100 m³ ha-1 year-1 as PS100, and 200 m³ ha-1 year-1 as PS200), soluble mineral fertilizer (NPK), and a combination of NPK with PS25 (NPK+PS). The experiment was conducted from 2001 to 2016 using a randomized block design with four replications. The results showed that soil subjected to fertilization for over 15 years exhibited higher acidity levels than the control, particularly when mineral fertilizers were applied. However, acidity parameters in the 0-20 cm soil layer, in cases where no fertilizer or only PS was applied, indicated no need for lime supplementation for crop growth. Notably, PS application at doses exceeding 100 m³ ha-1 year-1 led to the amelioration of subsoil acidity up to a depth of 60 cm. This study highlights the long-term impact of fertilizer strategies on soil acidity parameters and emphasizes the importance of considering soil acidification when selecting specific fertilizers, be it mineral or organic. Organic fertilizers, such as PS, can delay soil acidification compared to mineral fertilization while serving as a nutrient source and soil conditioner simultaneously.

Palavras-chave

Organic fertilizer; Manure; Soil acidity, No-tillage.