According to NRCS guidelines, the minimum amount of crop residue that must remain on the soil surface for a cropping system after planting to qualify as conservation tillage is:

Conservation tillage is a farming practice designed to improve soil health and reduce erosion by maintaining a certain amount of crop residue on the soil surface. According to the guidelines set by the Natural Resources Conservation Service (NRCS), to qualify as conservation tillage, at least 30% of the soil surface must be covered with crop residue after planting. This level of residue helps protect the soil from erosion, enhances moisture retention, and supports the overall health of the soil ecosystem.

Maintaining a minimum of 30% crop residue allows for improved soil structure and increased organic matter, which can improve nutrient cycling and support beneficial soil organisms. It is an essential practice in sustainable agriculture, helping to promote soil conservation and build resilience against environmental factors.