Soil Microbial Functions After Forest Fires Affected by the Compost Quality

Abstract

Composts are frequently used to restore various degraded lands especially after fire. We investigated how different organic amendments after frequent wildfires can affect soil microbial functions. We crossed three times since fire (1, 5 and 18 years) with three different compost qualities (i.e. young, intermediate and old). After 5 months, alkaline phosphatase increased by the intermediate compost in early post-fire chronosequence (1 and 5 year after fires). This increase was confirmed 10 months after amendment with the three composts but only for the most recent fire. The net nitrification increased 5 months after amendment under both the young and intermediate composts in the 5 and 18 years of time since fire plots. This increase was confirmed 10 months after amendment with the intermediate and old compost treatments for the 1 and 5 years of time since fire plots. In this case, compost amendment even induced positive nitrification rates for the 5 years of time since fire plots. Moreover, older composts affected catabolic diversity after 5 months, whereas at the same time, we detected an increase in biomass of cultivable bacteria. Urease activity gradually increased with the age of composts after 10 months. β-glucosidase activity increased under the young and intermediate composts and did not change with the older. This study suggests compost addition can result in an artificial acceleration of the nutrient cycles. Thus organic amendments in burned ecosystems should be reasoned according to both the step of the Mediterranean post-fire recovery and the quality of organic amendments.

Impact of Potentially Contaminated River Water on Agricultural Irrigated Soils in an Equatorial Climate

“…Descriptive statistics and Student t-test mean difference analysis of the area of interest and the reference area for organic matter (OM, %), available phosphorus (P, ppm), pH, aluminum (Al, meq/100 g soil), and the exchangeable bases calcium (Ca), magnesium (Mg), potassium (K), and sodium (Na) meq/100 g soil. The use of wastewater can improve the nutritional content of agricultural soils, which is why wastewaters are used in many countries as an alternative to organic manures, generating a decrease in production costs [29,59]. The highest phosphorus contents were found in the area where recent agricultural activities had been conducted, while low phosphorus content existed on land that had not been in agricultural use over the past year (Figure 3).…”

“…Wastewater may contain residues of industrial or domestic origin as well as urban runoff [16,28]. Guénon et al [29] reported that, in untreated wastewater, concentrations of Pb and methylmercury can reach 0.16 ± 0.05 mg/L and 3.8 ± 2.5 ng/L, respectively. Recently, technologies such as biochar have been proposed to phytostabilize contaminants in the soil and could potentially sequester contaminates and convert soils degraded by contamination into productive ecosystems once again [30][31][32].…”

Advances towards an Integrated Assessment of Fire Effects on Soils, Vegetation and Geomorphological Processes

“…The potential use of compost to restore nutrient cycling of fire‐affected areas is studied by Guénon & Gros (, this issue). Microbial activity involved in the main nutrient cycles was evaluated after the addition of composts of different qualities to a chronosequence of fire‐affected Mediterranean areas.…”

Glomalin‐related Soil Protein Response to Heating Temperature: A Laboratory Approach

“…It is widely accepted that studying soil requires an interdisciplinary view and soil should not be understood like a single science (Brevik et al ., ), especially after perturbations like fires. Changes in soil properties after a fire have direct and indirect consequences on water resources (Keesstra et al ., ), vegetation and microorganisms (Guénon et al ., ; Guénon & Gross, ; Wang et al ., ) between others. Many of the soil services, which are essential to humans and environment, are provided by soil biota.…”