Glomalina como potencial indicador complementar à bioanálise de solo

Abstract

This research investigated the relationship between easily extractable glomalin (EE-GRSP) and total glomalin (T-GRSP) with the physico-chemical and microbiological characteristics of soil in two agricultural management systems: Pivot (with irrigation) and Dryland (without irrigation), at soil depths of 0 – 10, 10 – 20, and 20 – 30 cm. Glomalin plays a fundamental role in soil aggregation, contributing to organic carbon storage (COS), and is crucial in the dynamics of organic matter and nutrient cycling. Additionally, glomalin can be used to measure and evaluate soil quality, being a glycoprotein sensitive to management and climatic changes, and relatively stable in terms of storage. The results revealed interrelationships among the studied variables, demonstrating that differences in management systems influence the composition and activity of the soil microbial community, especially regarding spore density and the relative abundance of non-cultivable fungal and bacterial communities. In the Pivot system, there was a higher abundance of spores and fungal diversity compared to the Dryland system, possibly due to constant irrigation and the application of swine manure over the years. These results highlight the importance of soil management in determining biological activity, especially in the composition of the fungal community, with possible implications for soil health and agricultural productivity. Furthermore, the correlations between soil physico-chemical and microbiological parameters indicated a positive relationship between the activity of β-glucosidase, acid phosphatase, and arylsulfatase enzymes and the levels of EE-GRSP and T-GRSP (with correlations of r = 0.46, 0.65, 0.52, 0.43, 0.51, and 0.42, respectively), evidencing that glomalin plays an important role in nutrient cycling. These findings highlight the importance of glomalin as a complementary indicator to conventional soil analyses, providing valuable insights for managing soil quality in irrigated and non-irrigated agricultural systems.