Chemical and microbiological properties in soil cultivated with sugarcane (Saccharum officinarum)

Abstract

The aim of this study was to evaluate the response of chemical parameters and microbiological processes related to the nitrogen (N) cycling in an area cultivated with sugarcane (SC), as compared to the native forest area (NF), considered as the reference. The pH value, the total C (Ctot), N (Ntot) contents, the P, K, Ca, Mg, Zn, Mn, B and Cu contents, the labile carbon (LC) content, cation exchange capacity (CEC), microbial biomass N (Nmic), potentially mineralizable nitrogen (PMN) and the urease activity (UA) were determined in soil samples taken at depths of 0-10 and 10-20 cm. Most of the chemical properties were higher in the NF soil at both depths, except for Ctot, Ntot and the total K content, which did not present significant differences between the areas at the deeper level. All microbiological processes were higher in the NF soil and showed positive correlations with the total Cu and B contents, demonstrating the importance of these nutrients in the biological N cycling. The higher values obtained for almost all parameters in the NF soil attest to the need for constant monitoring of areas cultivated with sugarcane in order to avoid the adverse effects of soil degradation. The results obtained between the areas, in relation to N cycling processes also demonstrated the suitability of using them as reliable indicators of soil quality.

Keywords

• N cycling
• urease activity
• N immobilization
• mineralizable nitrogen.