Effect of Strategies for Controlling Spontaneous Plants on the Quality of Soil Organic Matter and Soil Fertility

Abstract

Soil organic matter (SOM) and the chemical attributes of the soil are important indicators of soil quality. The aim of this study was to evaluate the effects of strategies for controlling spontaneous plants on SOM quality and soil fertility in an area of forest under restoration. Three methods for controlling spontaneous plants were established: i) mechanical (MCH), ii) chemical (CHM), and iii) chemical-cultural (CC), and evaluated using a randomized block design. After 13 months, soil samples were collected (0-10 cm) to determine basal respiration over 21 days, total organic carbon (TOC), labile carbon (LC), chemical fractions of the SOM [humine (H), humic acid (HA) and fulvic acid (FA)], and soil fertility. On days 1, 3, and 7, higher values were seen for basal soil respiration, however, no differences were found between the control strategies. There was a small change in SOM quality and soil fertility. MCH showed higher values (up to 11%) for LC, due to the intense silvicultural management. After 13 months of application, each of the strategies for controlling spontaneous vegetation proved to be favorable in relation to SOM quality and soil fertility, especially for LC, due to its relationship with the accumulation or loss of SOM, and immediate response to changes in land use or management.