Research Article

Surface-Applied Biosolids Enhance Soil Organic Carbon and Nitrogen Stocks but Have Contrasting Effects on Soil Physical Quality

Table 3

Soil bulk density (, Mg m−3) and moisture properties estimated from soil water characteristic curves fitted to power functions () for individual replicate cores () per treatment. Ranges in coefficients of variation () for curve fits and means (se) shown for soil water content (m3 m−3) at permanent wilting point (), field capacity (), and available water capacity (AWC) in 0–5, 5–10, 10–15, and 15–25 cm soils.

Soil depthRateDurationAWC
cmMg ha−1 yr−1YearsMg m−3m3 m−3m3 m−3m3 m−3

0–5001.06 (0.06)50.846–0.9870.099 (0.006)0.223 (0.021)0.124 (0.017)
2081.21 (0.04)40.908–0.9900.121 (0.009)0.327 (0.025)0.207 (0.019)
4080.94 (0.08)40.918–0.9890.126 (0.018)0.391 (0.049)0.265 (0.031)
6081.01 (0.05)20.811–0.9340.281 (0.054)0.907 (0.032)0.625 (0.086)
20200.93 (0.01)40.816–0.9910.129 (0.008)0.353 (0.023)0.224 (0.017)

5–10001.23 (0.03)50.864–0.9880.118 (0.002)0.235 (0.012)0.117 (0.011)
2081.25 (0.01)40.972–0.9940.100 (0.004)0.270 (0.019)0.169 (0.015)
4081.32 (0.02)40.954–0.9760.110 (0.010)0.318 (0.021)0.208 (0.015)
6081.36 (0.05)20.903–0.9730.155 (0.015)0.535 (0.031)0.380 (0.016)
20201.20 (0.01)40.885–0.9950.125 (0.003)0.333 (0.009)0.208 (0.006)

10–15001.30 (0.05)40.904–0.9680.109 (0.007)0.223 (0.025)0.114 (0.018)
2081.36 (0.07)30.970–0.9940.103 (0.006)0.292 (0.009)0.189 (0.009)
4081.32 (0.04)40.963–0.9960.102 (0.010)0.289 (0.018)0.187 (0.012)
6081.32 (0.05)20.960–0.9710.113 (0.005)0.431 (0.011)0.318 (0.016)
20201.29 (0.04)40.971–0.9920.116 (0.004)0.281 (0.019)0.165 (0.016)

15–25001.34 (0.03)50.876–0.9790.107 (0.002)0.229 (0.009)0.121 (0.007)
2081.31 (0.05)40.961–0.9930.103 (0.005)0.295 (0.025)0.192 (0.021)
4081.35 (0.04)40.944–0.9860.100 (0.009)0.314 (0.022)0.214 (0.022)
6081.33 (0.05)20.940–0.9860.107 (0.014)0.506 (0.019)0.399 (0.017)
20201.29 (0.05)40.968–0.9940.113 (0.002)0.278 (0.010)0.166 (0.010)