Lessons from across Minnesota
I had the opportunity this winter to tour the state and present over twenty workshops in Minnesota on the topic of phosphorus balance. Topics centered on management options for livestock farmers with inadequate acres of land based on phosphorus rather than nitrogen. I always enjoy meeting and visiting with livestock farmers across the state. I have also had the opportunity to visit with many other farmers and the general public about phosphorus and nitrogen issues. Comments on some issues were similar and reactions to other issues were highly variable. I will attempt to summarize some of the feedback and add some of my observations.
Adding acres to a farm's land base is usually difficult. Whether farmers are looking for land to purchase or lease, it is usually a challenge anywhere in the state. First, the land must be available and hopefully within a reasonable distance. Competition from neighboring livestock and crop farmers for land frequently creates relatively high purchase or rental prices. Purchased land price has commonly been higher than its short term economic return. Land is unique among farm assets since it is more an investment; its principal is not a depreciable expense.
Ability to sell manure for its full value is variable. Many livestock farms are faced with the necessity of selling some manure to meet nutrient management plan requirements. In some areas of Minnesota, livestock farmers are able to sell manure for its lab tested NPK value based on current commercial fertilizer prices plus organic matter and trace mineral factors. In other areas, farmers are barely able to give manure away. There are some locations where dairy farmers are receiving around $200 per acre for injected liquid dairy manure applied in the 10,000 to 12,000 gallons per acre range as long as the dairy farmer assumes the application expenses. I observe three main situations impacting the realization of the value of manure. Many crop farmers who formerly had livestock tend to understand the importance of manure and are willing to pay a fair price for it. When crop consultants understand the significance of manure and encourage their clients to purchase manure, many of their crop farmer clients are willing to pay a fair price for manure. A challenge in high livestock density areas is the high likelihood that nearby farms are unable to take manure because of an abundance of their own manure, thereby reducing manure's value.
Quite a bit of manure/bedding pack does not get incorporated within 12 hours of application; this is due to spreading manure on frozen ground or delayed incorporation after surface applying manure anytime. This represents a substantial economic loss of manure-based nitrogen to the farmer. Also, this presents a potential environmental risk with nitrogen and phosphorus runoff. On the other hand, I understand time pressures on many livestock producers when they rationalize not to take the time to incorporate all their manure within 12 hours of application. This issue comes down to an act of balancing three important resources: time, economics, and environment.
Use of corn starter on high phosphorus testing soils varies. Many livestock producers with soils testing high in phosphorus have abandoned utilizing corn starter and are comfortable that they have not experienced yield or quality losses. Other producers with similar high phosphorus testing soils continue to utilize corn starter for fear of losing yield or quality. University of Minnesota researchers suggest that using starter containing phosphorus on soils testing over 25 ppm Bray 1-P or 20 ppm Olson may not always be necessary, even in cool springs. Farmers with high phosphorus testing soils may consider assessing each field for potential corn starter savings. Grid soil sampling can help identify field areas with high and low levels of soil phosphorus.
Awareness of nitrogen and phosphorus environmental issues varies with both farmers and the general public. Some people are aware that escaped nitrogen and phosphorus presents an environmental risk to our public water. Other people, both farmers and non-farmers, have minimal understanding of the environmental risk of losing these nutrients. Farmers with operations near lakes or rivers frequently have 'discussions' with people living next to the water on where blame rests for elevated nutrient levels in the water.
There are a lot of questions about cover crops. Even though the workshops did not specifically address cover crops, questions often came up on how cover crops would work on conventional dairy farms with a typical alfalfa/corn silage/corn grain rotation. The corn grain/corn silage side of the rotation is where cover crops would be considered an option. One question is, "What do I have to gain or lose by planting a cover crop after corn silage?" We need more research on the potential results of using a cover crop this way.