*2.2. Selection of Landscape Patches and Soil Sampling*

We selected 6 distinct urban landscape patches surrounding UF-GCREC and 1 remnant agricultural (Agr) patch for soil sampling and analysis of inorganic N production (Table 1). The non-agricultural patches were turfgrass (TfGr) and potential turfgrass alternatives common for residential landscapes in Florida, which included 1 patch of perennial peanut (PP), a low-growing alternative ground cover; 2 patches with ornamental grasses and shrubs (OMx and OGa); and 2 patches consisting mostly of mulch with little or no other vegetation (MulP and MulC). Table 1 describes the vegetation and other characteristic features of each landscape patch.


**Table 1.** Description of landscape patches.


**Table 1.** *Cont.*

Soil sampling took place on each landscape patch in September 2018. We used a hand auger to take 5 cm-diameter cores from 4 random locations within each patch to a depth of approximately 52 cm. All 4 cores for each patch were then each divided into 3 subsamples by depth (0–15 cm, 15–30 cm, and 30–52 cm) to provide 4 field replicates for each depth per landscape patch. Subsamples of the soils were then air dried and sieved through a standard #10 (2 mm) sieve and analyzed for soil pH, total soil N, and total soil C. Soil pH was measured with a soil:water 1:2 (*w*/*v*) slurry. Total soil N and C were measured on a Thermo Flash 1112 A NC Soil Analyzer in the University of Florida Wetland Biogeochemistry Laboratory. Field moist sieved soils were used to analyze for soil gravimetric water content, percent organic matter, and exchangeable inorganic N. Percent organic matter was determined via the loss on ignition method. Exchangeable inorganic N (NOx and NH4 +) was determined by extracting 10 g soil with 50 mL 2 M KCl for 1 h and analyzing for NO3 − and NH4 <sup>+</sup> via a continuous segmented flow analyzer (AA3, SEAL Inc., Mequon, WI, USA) by EPA methods 353.2 and 350.1, respectively.
