Soil Chemico-biological Properties Affected by the Interactions of Long-term Non-cultivation Practices and Grazing

More has yet to be indicated on how different human practices including long-term non-cultivation (NC) practices, grazing, and their interactions may determine soil chemico-biological properties, which is the hypothesis of the present research. This research was conducted in a 27,000-ha mountainous area (a unique ecosystem). The grazed (G) and non-grazed (NG) lands were classified according to NC years: <5 (Y1), 5-15 (Y2), 16-30 (Y3), and > 30 (Y4), plus a rangeland as control treatment. Two experimental treatments of G and NG lands with five treatments of land releasing in each grazing treatment with three replicates, with a total of 30 sampling areas, were used. The chemico-biological properties of soil (0-30 cm) and aggregates (0.053-2.0 mm) were determined. Soil organic components were significantly higher in NG than that of G lands. A minimum of 15 years was essential for restoration of soil chemico-biological properties in NC lands. Soil microbial respira- tion (SMR) and qCO2 (15.78-3.92 in NG and 15.93-3.49 mg C-CO2 g(-1) Cmic per day in G lands) significantly decreased in NC lands (Y4) and in the G and NG lands. The NC (especially Y3) treatment also significantly increased particulate organic carbon and microbial organic pools, in just NG areas. The NC treatment significantly increased SMR in the aggregates of 0.25-0.50 and 1-2 mm. If releasing the cultivated lands is properly managed (for example, with suitable grazing or using as rangelands), it is possible to enhance degraded lands in a timely manner of at least 15 years.