Strip till for field crop production
Besides reducing greenhouse gases, other advantages of increasing or maintaining a high level of soil organic matter include reduced soil erosion, increased resistance to compaction, increased biological activity and enhanced soil fertility. Since tillage results in soil carbon loss, identifying tillage methods that reduce the amount of carbon released into the atmosphere is important.
A comparison study of soil CO2 emissions following fall moldboard plowing, disk ripping and strip tilling conducted in 2005 in Minnesota (Faaborg et al., 2005) determined that strip tillage maintained more soil carbon than moldboard plowing and disk ripping. Disk ripping and strip tillage released 53.2 and 82.6 percent less CO2, respectively, than moldboard plowing (Figure 1). Moldboard plowing disturbed and exposed the greatest amount of soil, allowing carbon previously stored as organic matter or present as CO2 in the soil atmosphere to escape into the atmosphere.
Enhance Crop Residue Management
Residue from previous crops limits evaporation from the soil surface and maintains relatively high humidity levels in undisturbed soils at 90 to 100 percent, which are ideal for seed germination. Even with excellent seed-to-soil contact, approximately 85 percent of the water entering a germinating wheat seed is in the form of water vapor. In dry conditions, reduced-tillage planting systems preserve moisture in the seedbed, enhancing uniform germination and plant establishment.
Crop residue is also a food source for beneficial fungi, bacteria and insects. Managed properly, the beneficial aspects of maintaining high levels of crop residue with conservation tillage systems outweigh the negative aspects.
Strip till leaves most of the previous year’s crop residue on the soil surface, protecting new crop plants from wind damage during establishment and continuing to protect the soil if the crop fails to establish due to drought or flood. Crop residue readily decays and is incorporated into soil by earthworms and other invertebrates when the growing crop canopy covers the space between the rows.
Equipment components and functions
Several strip-tillage equipment manufacturers offer a variety of designs and features. Most equipment manufacturers market machines with similar features, including coulter blades, row cleaners, tillage shanks, berm-building disks and packing wheels or conditioning baskets. Some strip-till equipment designs include paired coulters or a large disk without a tillage shank.