Table 1. Sampling locations, environmental and biological data.
| Sampling Location | Buinen (B) | Droevendaal (D) | Kollummerwaard (K) | Grebbedijk (G) |
|---|---|---|---|---|
| Soil type | Sandy loam | Sandy loam | Clayey | Clayey |
| Land use | Agricultural | Agricultural | Agricultural | Agricultural |
| Sampling coordinates | 52°55’386"N 006°49’217"S | 51°59’551"N 005º39’608"S | 53°19’507"N 006°16’351"S | 51°57’349"N 005º38’086"S |
| Fertilization scheme/date | KAS (212Kg N/ ha) April and June | NPK (200Kg N/ha) March | KAS (150Kg N/ha) March and April | KAS (156Kg N/ha) March and April |
| pH | 4.40±0.02 | 4.93±0.02 | 7.40±0.05 | 7.20±0.02 |
| N-NO3 - (mg/kg) | 47.51±0.37 | 60.53±1.66 | 24.60±1.72 | 29.93±1.15 |
| N-NH4 + (mg/kg) | 9.23±0.74 | 14.18±1.41 | 8.40±0.75 | 15.13±2.35 |
| OM (%) | 3.96±0.72 | 2.91±0.24 | 4.24±0.14 | 5.47±0.22 |
| Water content (%) | 11.20±0.58 | 11.63±1.62 | 19.30±1.40 | 19.60±1.86 |
| nifH-gene abund (x 105 gdw-1). | 0.72±0.28 | 1.15±0.43 | 17.0±8.13 | 3.10±0.94 |
| Bacterial 16S rRNA gene abund (x 1010 gdw-1). | 1.74±0.21 | 1.68±0.13 | 1.98±0.15 | 1.98±0.13 |
Values of environmental and biological data are average of each soil across the three sampling times (mean ± sd), KAS = calcium, ammonium, nitrate; NPK = nitrate, phosphorus, calcium