Drip Irrigation and Nitrogen Management

Brian Velde

The demonstration site has been in a corn soybean rotation with conventional tillage. The field is well drained and has been grid sampled for fertility levels. The field has 13 years of yield data and RTK is used for planting consistency. The demonstration site is currently permitted for 58 acres of irrigation or 9.6 million gallons of water per year to be pumped from the Yellow Medicine River with the MNDNR permit # 2016-0797. A drip irrigation system CAD design has been designed by Maxwell Irrigation. The system will be installed by Nutradrip. The drip irrigation system would consist of 6 different zones approximately 9.5 acres, the zones will provide the ability to apply different rates of water and nitrogen within those zones. Within the zones every 5 feet will be drip tape plowed in 16 inches deep using RTK. This RTK spacing will allow every corn row to have an irrigation/fertigation application done within 15” from the corn roots. The site will have a weather station that will track wind, temp, rain, humidity, solar radiation and GDUs. Two to Four soil probes will be installed to measure soil moisture in different soil types.

Bruce Potter, University of MN Extension and Dr. Jeff Strock, University of MN Department of soil water and climate will help with the experimental design to allow statistical comparisons of 3 management system approaches. The (T0) check will consist of three strategically placed 60 feet wide non-irrigated blocks with 100% pre-plant nitrogen strips running the length of the trial. Treatment 1 (T1) will consist of three, 9.5 acre zone blocks that will have subsurface irrigation and nitrogen application based on in-season crop needs. Treatment 2 (T2) will have three, 9.5 acre zone blocks that will have subsurface irrigation, nitrogen application and additional nutrients, T2 will be our intensive management block. There will be a statistically quantifiable randomized treatment design with three treatments and three replications. In-season tissue samples will be collected from V5 to tassel for nutrient analysis and estimates of photosynthesis/chlorophyll will done by Centrol Crop consulting using a chlorophyll spad meter. Yields will be measured using a yield monitor. Bruce Potter and Dr. Jeff Strock will help with the analysis and interpretation of results. We will use paired comparison to analyze the data. The data that’s not normally distributed, we will use non-parametric analysis. Within the replicated strips we will use sampling points in the different soil types.