Fig. 2
Overall, based on 148 observations, the mean effect value of yield under
conservation tillage is 0.0443, with a 95% confidence interval (CI)
from 0.0249 to 0.0636, indicating that crop yield can be increased by an
average of 4.53% (2.52%-6.57%, P < 0.001) under different
conservation tillage measures in NEC (Fig. 2). However, the large range
in yield effect (-0.4073 to 0.4715), indicates that yield has responded
differently in different studies, and that to apply conservation tillage
practices appropriately it will be necessary to understand those
conditions that effect the magnitude and direction of yield change.