Table 8: Measured changes in selected chemical properties in topsoil (0–25 cm) for the last decade.

Cropping system/yearCA1CA2OACMOM1OM2

Ignition loss (g 100 g−1)

1999 6.83 6.88 7.05 7.30 6.98 7.13
2009 6.13 6.70 6.30 6.78 6.50 6.63
Change (2009–1999)−0.70−0.18−0.75−0.53−0.48−0.50
value1 0.054n.s. 0.608n.s. 0.204n.s. 0.152n.s. 0.265n.s. 0.088n.s.

P-AL (mg 100 g−1)

1996 5.38 4.00 4.25 4.00 3.75 3.88
2009 7.10 8.23 3.13 6.00 3.00 3.65
Change (2009–1996) 1.73 4.23−1.13 2.00−0.75−0.23
value 0.029 0.015 0.036 0.001 0.102n.s. 0.409n.s.

K-AL (mg 100 g−1)

1996 6.75 6.75 6.13 7.13 6.13 6.00
2009 6.7312.0 6.35 9.63 6.30 5.55
Change (2009–1996)−0.03 5.28 0.23 2.50 0.18−0.45
value 0.942n.s. 0.043 0.362n.s. 0.022 0.188n.s. 0.517n.s.

K-HNO3 (mg 100 g−1)

1996 31.1 28.3 30.9 28.6 29.1 26.0
2009 47.8 58.5 39.3 55.5 39.0 35.3
Change (2009−1996) 16.6 30.3 8.38 26.9 9.88 9.25
value 0.012 0.007 0.010 0.003 0.001 0.037

1Level of significance for the pairwise -test of differences. Nonsignificance at the 5% level is denotedn.s.