Standing residue, still attached, is one of the most effective ways to catch snowfall and protect soil from wind erosion. Tilling six inches deep allows the soil to dry to the depth of tillage and could result in soil moisture loss of up to one inch of water total. Shallower tillage, even with a rolling stalk chopper, can result in moisture losses of about one-half inch of water per trip. Jasa said this is contrary to the idea that the soil needs to be opened so the water can soak in. Since soil dries to the depth of tillage, any initial water that comes in just replaces what is lost and doesn't add to the soil moisture reserve.
Tillage breaks up and pulverizes the soil surface, which leads to crusting from raindrop impact.
Thus, Jasa said, tillage thought to open up the soil actually seals the soil, resulting in more runoff. Leaving residue cover also softens the force of falling rain, which reduces erosion and crusting, allowing more rainfall to soak in slowly. NU research has shown that the reduced crusting and improved soil structure with no-till can decrease runoff by more than 80 percent. Residue also serves as a mulch to reduce moisture evaporation and shade the soil. This means soils don't get as hot as bare soils and allow better root development during drought conditions.