From: Dryland soil chemical properties and crop yields affected by long-term tillage and cropping sequence
Tillage and cropping sequencea | Soil depth | |||||
---|---|---|---|---|---|---|
0–7.5 cm | 7.5–15 cm | 15–30 cm | 30–60 cm | 60–90 cm | 90–120 cm | |
Olsen-P concentration (mg P kg−1) | ||||||
NTCW | 36.8abAc | 2.8B | 2.3B | 2.0B | 2.3B | 3.3B |
STCW | 40.0aA | 5.5B | 2.0C | 2.0C | 2.0C | 2.0C |
FSTCW | 34.3aA | 3.0B | 2.3B | 2.0B | 2.1B | 3.3B |
FSTW-B/P | 36.6aA | 6.0B | 2.1C | 2.1C | 1.9C | 2.6C |
STW-F | 25.0bA | 4.9B | 3.3BC | 2.0C | 2.2B | 2.6BC |
Contrast | ||||||
NT vs. T | −0.4 | −1.5 | 0.1 | 0.1 | 0.3 | 0.7 |
CW vs. W-F | 15.0*** | 0.63 | −1.3* | 0.1 | −0.2 | −0.6 |
CW vs. W-B/P | −2.4 | −3.6* | 0.1 | −0.1 | 0.2 | 0.7 |
K concentration (mg K kg−1) | ||||||
NTCW | 331aA | 279aB | 157C | 96D | 91D | 105D |
STCW | 331aA | 228B | 179B | 112C | 98C | 96C |
FSTCW | 325abA | 263aB | 150C | 97D | 91D | 100D |
FSTW-B/P | 348aA | 242aB | 149C | 103C | 102C | 115C |
STW-F | 272bA | 186bB | 129C | 93C | 98C | 95C |
Contrast | ||||||
NT vs. T | 3.0 | 6.5 | −7.0 | −8.9 | −3.1 | 6.9 |
CW vs. W-F | 58.1* | 96.6** | 49.6* | 18.4* | 0.1 | 1.0 |
CW vs. W-B/P | −23.9 | 21.5 | 0.4 | −5.3 | −11.5 | −15.6 |
SO4–S concentration (mg SO4–S kg−1) | ||||||
NTCW | 6.8A | 3.5A | 3.0A | 3.0A | 4.3A | 5.0bA |
STCW | 6.3A | 3.5A | 3.0A | 3.3A | 4.8A | 5.8bA |
FSTCW | 6.0B | 3.5B | 3.3B | 4.3B | 10.5AB | 26.5aA |
FSTW-B/P | 12.8B | 11.0B | 11.8B | 12.3AB | 21.0A | 23.9aA |
STW-F | 8.0A | 8.1A | 7.5A | 10.4A | 11.4A | 11.8bA |
Contrast | ||||||
NT vs. T | 0.6 | 0.1 | −0.1 | −0.8 | −3.4 | −11.3* |
CW vs. W-F | −1.8 | −4.6 | −4.5 | −7.1 | −6.6 | −6.0 |
CW vs. W-B/P | −6.8 | −7.5 | −8.5 | −8.0 | −10.5 | 2.6 |