SSC students get sustainability lesson
WORTHINGTON -- Agriculture students from Southwest Star Concept trudged through muddy fields and knee-high grasses Friday morning during an outdoor classroom experience to learn about sustainable agriculture on Rolf Mahlberg's farm south of Worthington.
The group of students in Molly Neil's agriculture class donned plastic boot covers and stepped between emerging corn and soybean plants in a pair of fields to calculate residue kept in place after years of minimum tillage efforts. The assignment was a follow-up to a classroom session earlier this spring.
Mahlberg -- a former agriculture instructor at Minnesota West Community and Technical College -- and Okabena-Ocheda Watershed District Administrator Dan Livdahl presented a program on sustainable agriculture to them several weeks ago. The pair has led classes in Worthington and Round Lake as well -- all part of the Sustainable Inquiry Research and Education Network (SIREN) project financed by a grant from Sustainable Agriculture and Research Education (SARE).
On Friday, the students stretched residue measurement tapes across the crop rows and counted soybean stubble and decaying corn stalks. The goal was to find at least a 30 percent residue cover still in the field -- considered a sustainable ag practice -- but students discovered much more residue, with counts ranging from 39 percent to 62 percent in both fields.
Mahlberg disk-chiseled his corn field once last fall, and cultivated this spring before soybeans were planted, while last year's soybean field was left untilled last fall and cultivated once this spring before corn was planted. In that field, corn residue from two years ago was still evident.
In the classroom earlier this spring, Mahlberg told students the global population is expected to reach 10.5 billion people by 2050, yet the amount of available land for production agriculture will stay the same. Farmers, he said, need to find ways to get more production from the land without destroying it for future generations.
Leaving residue in the field is a means of erosion control. Without it, raindrops strike exposed soil, break up the particles and lead to soil flowing with the water out of the field and into ditches, streams and eventually lakes.
Mahlberg said erosion control leads to less soil loss and improved productivity.
Following the residue counting exercise in the field, Mahlberg led the students on a tour of his conservation practices.
About 15 years ago, Mahlberg removed all the open tile intakes on his 230-acre parcel and replaced them with environmental intakes. He has also maintained terraces, grassed waterways and, five years ago, built a desilting basin that doubles as a pond for fish and wildlife.
Most recently, Mahlberg planted an area of his farm into prairie grasses and forbs, and also created a perennial deer food plot by planting turnips and clover. He has acres enrolled in both the Conservation Reserve Program (CRP) and Conservation Stewardship Program (CSP) and, while the plots are benefiting the wildlife south of Lake Ocheda, they are also protecting and preserving the soil.
"We want you to be making these choices," Mahlberg told the students.
"Sometimes, the best use for the land is conservation," added Livdahl.