TABLE 1.

Physical and chemical properties of soils from the landscape transect

SoilSand concna (g/100 g)Silt concna (g/100 g)Clay concna (g/100 g)pH (SD)bBray-Pia (mg/kg)K+ concna (cmolc/kg)Mg2+ concna (cmolc/kg)Na+ concna (cmolc/kg)Ca2+ concna (cmolc/kg)CEC concna (cmolc/kg)Total Ca (g/kg)Total Na (g/kg)Mean net N Min (mg N/kg) (SD)cAOA amoA copy no. (106 copies/ g soil) (SD)dAOB amoA copy no. (106 copies/ g soi) (SD)d
Forest2035457.1 (0.1)9.11.14.80.113.635.355.12.999.7 (0.9)6.3 (1.4)1.9 (0.8)
Pasture1535506.7 (0.3)5.50.29.30.318.433.953.13.941.5 (17.6)41.7 (21.2)0.4 (0.3)
Cropped11.258.8306.5 (0.3)86.80.70.70.17.414.212.90.618.4 (8.2)0.9 (0.7)0.8 (0.2)
Fallowed12.55532.56.6 (0.1)103.31.11.20.15.416.925.71.728.7 (12.7)3.9 (2.7)1.0 (0.5)
  • a Particle analysis, total C and N, CEC, and extractable cations were determined by standard methods of the Central Analytical Laboratory. They represent values obtained from a composite sample prepared by mixing individual composite samples from each of three field sites. Bray-Pi is inorganic P extractable in 0.5 M acid (HCl). cmolc is antimoles of charge of the indicated anion adsorbed to soil.

  • b Values in parentheses are standard deviations of data from three field replicates.

  • c Net N Min is the readily mineralizable N and equals NH4+ plus NO3 mineralized at 30°C over 30 days. Values in parentheses indicate standard deviations of analytical replicates (n = 3) of a composite soil sample prepared by mixing individual composite samples from each of three field sites.

  • d Values in parentheses are standard deviations of triplicate Q-PCRs on each of three field replicate soil samples.