Land‐Use Effects on Soil Nutrient Cycling and Microbial Community Dynamics in the Everglades Agricultural Area, Florida

Abstract

Soil subsidence has become a critical problem since the onset of drainage of the organic soils in the Everglades Agricultural Area (EAA), which may impair current land uses in the future. The objectives of this study were to characterize soil microbial community-level physiology profiles, extracellular enzymatic activities, microbial biomass, and nutrient pools for four land uses: sugarcane, turfgrass, pasture, and forest. Long-term cultivation and management significantly altered the distribution and cycling of nutrients and microbial community composition and activity in the EAA, especially for sugarcane and turf fields. The least-managed fields under pasture had the lowest microbial biomass and phosphorus (P) levels. Turf and forest had more microbial metabolic diversity than pasture or the most intensively managed sugarcane fields. Land-use changes from sugarcane cropping to turf increased microbial activity and organicmatter decomposition rates, indicating that changes from agricultural to urban land uses may further contribute to soil subsidence.

Distribution of carbon, nitrogen and phosphorus in coastal wetland soil related land use in the Modern Yellow River Delta

“…The soil properties including nutrients distribution and budgets are greatly related with land use749 and the land use changes was much influenced by anthropogenic activities which might cause a shift in the composition of nutrients and chemical processes16505152. Since 1855, about 37% of total area of the YRD has been changed from natural wetland to cropland and paddy field (Fig.…”

Seasonal Changes in Nutrient Availability for Sulfur-Amended Everglades Soils Under Sugarcane

“…The soils are primarily Histosols with high organic matter content, and contain high nitrogen (N) and low P and micronutrient concentrations that require supplemental fertilization (Snyder, 2005;Ye et al, 2009). Upon drainage and land use conversion, high decomposition rates of these drained Histosols resulted in subsidence and a decreased depth to the underlying bedrock.…”

Sulfur Distribution and Transformations in Everglades Agricultural Area Soil as Influenced by Sulfur Amendment

“…Extractable NH 4 -N and NO 3 -N were determined by extraction with 2 M KCl followed by colorimetric analysis (Ye et al, 2009). Total P was measured using the ascorbic acidYmolybdenum blue method after Kjeldahl digestion, and labile inorganic P was measured after Mehlich-3 extraction (Ye et al, 2009). Acetic acid extractable nutrients were measured according to guidelines for muck soils (Sanchez, 1990) by extracting 4 g of soil with 25 mL of 0.5N acetic acid for 1 h, then filtering through Whatman no.…”

“…Total N was measured by Kjeldahl digestion followed by NH 4 þ analysis (Bremner, 1996). Extractable NH 4 -N and NO 3 -N were determined by extraction with 2 M KCl followed by colorimetric analysis (Ye et al, 2009). Total P was measured using the ascorbic acidYmolybdenum blue method after Kjeldahl digestion, and labile inorganic P was measured after Mehlich-3 extraction (Ye et al, 2009).…”

“…Historically, it was a seasonally flooded ecosystem but was converted to agricultural use by drainage in the early 1900s. The soils of the EAA are predominately Histosols, with high organic matter content but low P and micronutrient concentrations that require supplemental fertilization (Snyder, 2005;Ye et al, 2009). Because this area has changed from the wetland to agricultural ecosystem in the 1920s, several nutrient deficiencies became evident, mainly P but also micronutrients, such as Cu.…”