Microbiological attributes, organic carbon, and soil hydrothermal regime under Copernicia prunifera waste application

Authors

• A C Rodrigues ¹
• C R Do Nascimento ²
• L B S De Miranda ¹
• A R L De Miranda ³
• R S Sousa * ⁴
• L A P L Nunes ⁵

1. Federal University of Piaui, Teresina, Piaui, Brazil
2. Technical College of Teresina, Teresina, Piaui, Brazil
3. Federal Institute of Maranhão, Caxias, Maranhão, Brazil
4. Department of Agricultural Engineering and Soil Sci-ence, Federal University of Piaui, Teresina, PI, 64049-550, Brazil
5. Department of Agricultural Engineering and Soil Science, Federal University of Piaui, Teresina, Brazil

Abstract

Purpose This study aimed to verify the effects of the application of carnauba waste on the biological attributes, organic carbon content, and hydrothermal regime of soil.
Method The experiment was performed in randomized blocks with six treatments and four replicates. The treatments were as follows: (1) NPK (recommended dose of synthetic fertilizers: 100:180:86 kg ha^-1 NPK); (2) surface application of 10 t ha^-1 carnauba waste; (3) incorporation of 10 t ha^-1 carnauba waste; (4) surface application of 10 t ha^-1 carnauba waste + NPK; (5) incorporation of 10 t ha^-1 carnauba waste + NPK; and (6) bare and unfertilized soil (control).
Results Treatments that received carnauba waste showed higher amounts of organic carbon, carbon accumulation, microbial biomass, and CO₂ in the surface layer of the soil, from 0.0 to 0.10 m, compared to control treatments. Although there was no difference in the respiration rates between the treatments, the metabolic quotient tended to decrease in the treatments that received carnauba waste. Treatment with carnauba waste resulted in a decreased soil bulk density in the surface layer. Soil covered with carnauba waste maintained higher soil moisture and lower temperatures. Multivariate analysis showed that applying carnauba waste with NPK to the soil surface significantly affected soil quality attributes.
Conclusion The use of carnauba residue combined with fertilizer can improve the microbiological attributes of the soil, increase the organic carbon content in the soil, and reduce thermal amplitude, which can help maintain higher levels of moisture in the soil.

Highlights

• The application of carnauba palm waste to soil can improve various soil attributes, such as organic carbon content and microbial biomass in the top layer of the soil.
• Using carnauba palm waste with NPK fertilizer on the surface layer of the soil has significant effects on soil quality attributes.
• Carnauba palm waste improves soil quality by decreasing soil bulk density and maintaining higher soil moisture while lowering temperature.

Keywords

• Soil temperature and moisture
• Agro-industrial waste
• Carnauba palm
• Organic fertilization

Main Subjects

• Organic waste