In a study in China (Hetao Irrigation District of Inner Mongolia) straw was incorporated in the soil at different depths. Four options were evaluated: No straw, straw at 20 cm depth, straw at 40 cm depth and straw at 60 cm depth. The straw incorporated at 40 cm depth showed the lowest soil salinity at the end of the season, and the highest crop yield. A plastic surface mulch was applied on all treatments.
- results are soil type dependent (silty loam)
- results are crop dependent (sunflower; majority of roots in top 45 cm. Tap root up to 1.5 m)
- results are groundwater depth dependent (1.2 to 2.6 m)
- results are irrigation scheduling dependent (one time pre-plant irrigation of 1800 mm)