Source: Brian Banks, Nutra-Flo senior agronomist
The acceptance of no-till and other conservation tillage practices, including strip-till has increased rapidly in recent years. The most recent Census of Agriculture from the USDA reports that 173 million acres, or 62% of tillable acres in the U.S., utilize some form of conservation tillage practice. Strip-till, in particular is gaining more acceptance in parts of the country because it combines the benefits of both no-till and conventional tillage, while also allowing for the application of fertilizer. The application of fertilizer in a subsurface band decreases negative impacts to the environment and increases nutrient use efficiency; which both lead to increased profitability.
Runoff of nutrients from agriculture into rivers and streams is something many private and governmental entities are monitoring more closely than in years past. Recent research by Dr. Fabian Fernandez at the University of Illinois focused on combined aspects of crop yield, fertilization and tillage practices while also thinking of the impact to the environment showing a positive benefit to subsurface banding in strip-till. Dr. Fernandez states, “although subsurface band applications may not increase yield, they could decrease phosphorus levels on the surface which could be an environmental benefit to reduce the potential of phosphorus runoff.”
Dr. Tom Bruulsema of the International Plant Nutrition Institute agrees the right place for phosphorus to be applied is, “in the soil, not on the soil.” Strip-till machines have the ability to provide tillage and place fertilizer in the root zone in the same trip allowing growers to save time and reduce negative impacts on the environment. Dr. Bruulsema goes on to say that “facilitating the availability of the sources and equipment to get P fertilizer into the right place is an important contribution toward better crops – and better water.”
Another benefit of the application of fertilizer in a strip-till systems is the increase in nutrient use efficiency by reducing nutrient immobilization, or “tie-up.” Subsurface banding of fertilizer can help to reduce nutrient tie up because the nutrients do not react with surface residue and they will also come into contact with a smaller soil volume than surface applied broadcast applications. The 4R Nutrient Stewardship initiative promotes “for phosphorous and potassium, nutrient efficiency is enhanced because the subsurface band lessens P and K fixation by limiting contact with the soil. In the concentrated zone there is enough phosphorus, for example, to overwhelm the clay, calcium and aluminum that could otherwise form stable compounds and reduce phosphorus availability to plants.”
Strip-till has many advantages when growers seek to reach maximum yield potential. The advantage of being able to apply nutrients in a subsurface band has the ability to help increase yield, increase nutrient use efficiency and decrease negative impacts to the environment. Having the ability to provide proper tillage and defined fertilizer placement in the root zone in the same trip, strip-till systems are able to produce superior crops while saving time and money.
1Dr. Tom Bruulsema and Dr. Scott Murrell “Nutrient placement in reduced tillage systems” www.cropnutrition.com
2 4R Nutrient Stewardship. www.nutrientstewardship.com
