- Agronomic: corn
- Animal Production: watering systems
- Crop Production: fertigation, irrigation
- Education and Training: demonstration, extension, farmer to farmer, on-farm/ranch research
- Energy: energy conservation/efficiency, energy use
- Production Systems: general crop production
- Soil Management: soil quality/health
“Nitrogen contamination in the southern half of Minnesota is so severe that 27 percent of the state’s lakes and rivers could not be used as drinking water, according to a new and unexpectedly blunt assessment of the state’s most prevalent form of water pollution” (StarTribune, June 2013).
“The Environmental Protection Agency estimates that agricultural runoff degrades more than 125,000 miles of rivers and streams across the country. Minnesota is spending millions in state tax dollars in a watershed-by- watershed effort to make major reductions in agricultural pollution by 2025” (StarTribune, April, 2014).
According to the Freshwater Society and MN DNR, current levels of groundwater pumping are unsustainable in some parts of the state of Minnesota. Agricultural irrigation is Minnesota’s second-largest and fastest-growing user of groundwater (Freshwater Society, April 2013).
Addressing the usage of water and the movement of nutrients in surface and ground water have become large issues affecting the sustainability of agriculture in many areas, including large swaths of Minnesota.
Farm economics will likely be tight over the foreseeable years as record production of corn and soybean in Minnesota and near record production nationally have driven prices down below breakeven points for many producers. Controlling costs of energy and fertilizer while maintaining or increasing yield are crucial for financial sustainability.
Mr. Martie intends to compare subsurface drip irrigation (SDI) to conventional center pivot and compare SDI aerogation to un-aerated SDI in corn. Two SDI systems were installed in 2014.
This project involves the comparison of an SDI system to adjoining non-irrigated and center-pivot fields (fields are 9-14 acres). SDI consists of flexible polyethylene tubing with emitters permanently welded to the inside wall of the tubing. The “dripperline” is plowed into the soil, in this case 12″ deep, spaced at 48″ based on soil type and current farming practices.
Water is pumped at low pressure through piping and valves where it is introduced into dripperline. Emitters in the dripperline emit amounts of water directly to the root zone of the plant. And, because the water is delivered underground, there is no loss to evaporation, run-off or wind drift.
The efficiency (around 95%) and uniformity with which water is delivered to the plant not only reduces irrigation water requirements but also conserves energy due to lower pumping requirements when compared to center pivots. 2015 data show sizable savings.
Fertilizer applied directly to the root zone through SDI systems can be precisely controlled, saving on fertilizer and reducing the possible contamination of groundwater and/or surface water (Lamm, F.R. and T.P. Trooien, Irrigation Science, 2003).
However, excess duration of moisture can negatively affect productivity. Well-timed aerogation can address that limitation and possibly lead to yield increases.
The objectives are to improve yields & profitability by primarily exploring SDI and secondarily aerogation practices while utilizing irrigation water more efficiently, improving fertilizer use efficiency (less groundwater impact) and lowering energy inputs compared to center pivot irrigation.
Records of corn yields, water usage, labor, energy and fertilizer inputs and soil salinity will be kept on the adjacent center pivot fields and SDI fields with and without aerogation.
Project objectives from proposal:
- Improve yields & profitability by comparing subsurface drip irrigation (SDI) to conventional center pivot and compare SDI aerogation to un-aerated SDI in corn.
- Utilize irrigation water more efficiently, improve fertilizer use efficiency (less groundwater impact) and lower energy inputs compared to center pivot irrigation, all lessening environmental impact.
- Share results through field days and paper publications.