Table 2. Residual ratios of MaPs in Wutong Village, Gansu Province (S1) and Shihezi City, Xinjiang Province (S2).
| Study site | Sampling site | Mulching pattern | Input per application (kg·haˉ¹) | Mulching duration | Total input (kg·ha-1) |
Collected MaPs (kg·ha-1, average) |
Residual ratio (%) |
|---|---|---|---|---|---|---|---|
| S1 | S1-1 | Continuously FF | 150 | 2012–2017 | 900 | 105 | 11.7 ± 2.23a |
| S1-2 | Continuously FF | 2010–2017 | 1,200 | 97.4 | 8.12 ± 1.83a | ||
| S1-3 | Continuously FF | 2012–2017 | 900 | 108 | 12.0 ± 1.47a | ||
| S1-4 | Intermittently FF | Mid-1980s–2017 | 1,050 | 56.1 | 5.34 ± 3.56b | ||
| S1-5 | Intermittently FF | Mid-1980s–2017 | 1,050 | 57.1 | 5.44 ± 1.56b | ||
| S1-6 | Intermittently FF | Mid-1980s–2017 | 1,050 | 53.7 | 5.11 ± 1.19b | ||
| S2 | S2-1 | Continuously FCDI | 60 | 2012–2017 | 360 | 43.5 | 12.1 ± 6.76ab |
| S2-2 | 2011–2017 | 420 | 88.9 | 21.2 ± 7.64a | |||
| S2-3 | 2010–2017 | 480 | 80.6 | 16.8 ± 3.87ab | |||
| S2-4 | 2003–2017 | 900 | 148 | 16.5 ± 5.62ab | |||
| S2-5 | 2000–2017 | 1,080 | 81.1 | 7.51 ± 0.36b |
Note:
Total input was calculated using equation 3 and residual ratio was calculated using equation 4. Lowercase letters (a, b, c and d) indicate significant differences between different selected fields within each selected study region (p < 0.05, n = 3). Removal rate estimated based on farmers’ information.