No-Till: No-till farming greatly reduces soil disturbance, which in turn reduces soil erosion, builds soil organic matter and helps reduce phosphorus entering waterways.
Soil and crop residue are left undisturbed between harvest and planting, other than nutrient injection.
The advantages of the no-till system include significant improvements in soil health (reduced soil erosion, improved infiltration, etc.) and reduced fuel, reduced equipment requirements and potential increased profitability. The disadvantages of this system include the learning curve associated with the transition to no-till, the length of time (several years) required to observe soil health changes, potentially slower early plant growth and increased seedling diseases in colder and wetter soils.
Strip-Till: Strip-till farming is a modified form of no-till, where tillage is limited to a narrow zone in which next year’s crop will be planted. Soil disturbance is greatly reduced compared to conventional tillage. Strip-till reduces soil erosion, builds soil organic matter and helps reduce phosphorus entering waterways.
Residue-free strips approximately six inches wide are tilled ahead of planting in order to have a warmer and drier zone when row crops are planted. Crop residue is lightly moved to the row middles. Generally, global positioning guidance systems with accuracy to within one inch are used to prepare the strips and later plant in the same zone. A slight mound of soil is typically left after strip tillage in the fall, which can help limit soil erosion. Strips can be prepared in the spring, but producers generally prefer to do so in the fall to reduce spring time constraints and improve seedbed conditions. The practice is well adapted to the colder and wetter soils of north-central Iowa, but also is used throughout the state.
The advantages of strip-till include optimum placement of fertilizers for plant uptake, improved conditions for seed-to-soil contact at planting, reduced seedling disease problems and more rapid early season growth as compared to no-till. Strip-till advantages over conventional tillage include reduced expenses and time requirements, increased soil organic matter and improved soil physical conditions that can improve timeliness of spring field operations. Disadvantages include cost of special equipment, cost of the strip tillage pass, potential for excessive crusting and drying, potential for nitrogen losses and potential soil erosion of the tilled strip.
Additional resources for no-till and strip-till: