Considerations When Converting to No-Till
I recently came across an article titled “Myth-busting the no-till yield drag theory” by Amanda Kautz, the state soil health specialist with the NRCS in Indiana. Her article provides some interesting food-for-thought about the conversion of a cropping system to no-till. Pertinent points from the article follow.
• The potential yield drag that may result from switching to no-till could be because of a soil biology imbalance.
• A buildup of old and/or excess residue in a no-till system could indicate a lack of nutrient cycling.
• Switching from a tilled system to no-till requires time to rebuild soil biology to a balanced state.
• A yield drag may result if a cropping system is immediately switched from one that incorporates tillage to one with no tillage. This likely results from improper nutrient cycling or nutrients being tied up in excess residue.
• Certain steps should be taken to prepare soils at a cropping site for no-till, and those steps include 1) using cover crops to provide both habitat and a food source for soil microbes during the off-season, and 2) being certain that the carbon to nitrogen ratio (C:N) of the soil is appropriate for the summer crop to be planted [a high C:N ratio may require that fertilizer management, especially N fertilizer, be changed depending on the summer crop to be grown]. Thus, a nutrient management strategy must be planned to match the crop in a no-till system.
• Prepping a cropping site to ensure that the soil biology at that site will adequately cycle nutrients can greatly reduce the yield drag that may result when a site is converted to no-till.
• Important points to keep in mind are 1) return on investment [ROI] will be affected by the potential for lower costs associated with no-till, and 2) the potential benefits to soil biology that should accrue from no-till are difficult to economically quantify, and will likely be significant only over the long-term.
An article titled “Making the transition to no-till corn/cover crop system” provides points that should be considered when converting to a no-till system.
• A no-till system with cover crops should enhance natural soil fertility and improve soil biology.
• Transitioning to no-till can result in a slight yield drag in the short-term if soil biology is imbalanced.
• Soil fertility management will need to be changed to adapt to not having tillage that is required to incorporate some fertilizers.
• Cover crops and their root systems can replace some of the reasons for tillage, and will also provide a food source for soil microbes in the off-season.
• Cover crop residue and limited soil disturbance with no-till can reduce annual weed pressure in the summer crop.
• Overall costs resulting from adopting no-till should be lower over the long-term.
Points derived from articles titled “Bringing soil health to life: Making the most of no-till” and “Tillage or No-Tillage: High Yields or Soil Health?” follow.
• The present emphasis on soil health is likely a deciding factor in what type and how much tillage producers will use to grow a crop.
• Tillage is a big negative for maintaining soil structure, so it will likely take multiple years of no-till to return it to an optimum and balanced level.
• Soil testing is a first step for starting no-till practices. And that means assessing soil at the intended no-till site for both fertility status and microbial makeup.
• Staying nimble and flexible with cover crop species selection in a no-till cropping system is a must. Select those cover crop species that fit the cropping site that is being converted to no-till. After all, all cover crops do not necessarily accomplish the same purpose.
• Producers converting to no-till can potentially expect an initial yield drag, but changing to no-till is a long-term investment that is intended to achieve more sustainable production over the long term.
• The ultimate goal for a producer who converts to a no-till system of production is to improve the soil at the production site so a better crop can be grown that will make more money for the producer.
• Nutrient loss from tilled land and increased societal attention to soil health have advanced the push for less tillage as a means to improve soil health.
• Many producers use tillage because they believe it is the only way to rid fields of problem weeds that current herbicides will not kill.
• One question that is at the forefront of the till or no-till debate is “do producers believe that improving soil health by not tilling will ultimately improve profit and crop yields?”.
• Vertical tillage and strip tillage are being promoted as an alternative to conventional tillage since it reduces soil disturbance, and can also be used to manage heavy residue accumulation that may occur when some crops are produced in a conservation tillage system. [“Subsoiling” is a form of vertical tillage that works with no-till rather than against it. Click here for research that verifies this].
• “Pure” no-till may not be possible in all situations since some level of tillage may be necessary to smooth the soil surface in rutted fields and to control problem weeds.
• Since conventional tillage destroys soil networks that are left intact by no-till, these networks that support a healthy soil have to be rebuilt each year. With no-till, these soil networks are undisturbed and this contributes to a healthy soil that in the long run will support better and more profitable crop yields.
• One of the biggest drawbacks to the conversion from tillage to no-till is a producer having the patience during the first couple of years to wait for the soil ecosystem to rebuild to the point of supporting a healthier, more productive crop. That is why combining no-till with other conservation practices such as cover crops and crop rotation will shorten the transition period and more quickly show greater profit.
Click Tillage, Cover Crops, Soil Microbes and Soil Biology, and Soil Health to access White Papers about these subjects on this website.
Composed by Larry G. Heatherly, Jan. 2024, larryh91746@gmail.com