Minnesota Agricultural Water Resources Coalition Eligible Activities The program objectives are to implement and evaluate field scale on-farm nutrient management methods to evaluate/demonstrate nutrient efficiency and to minimize nutrients entering ground and surface water. Projects should demonstrate and promote efficient use of agricultural nutrients resulting in economic benefits for production agriculture while providing water quality improvements as a result of implementing such practices.
Basis for this trial began several years ago - Erosion concerns with conventional tillage -Fertilizer placement concerns with reduced tillage systems
- P Tests (P1 test) 15 to 19ppm medium -K Tests (Bray K) 63-91ppm low to medium -Most of the potassium in this field is concentrated in the top two inches of the topsoil profile. Soil samples collected in 2010
Top 2 inches 151ppm Middle 2 inches 83ppm Lower 3 inches 56ppm A stratification test indicated the following potassium soil test levels
High Rate Phosphate60 lbs of P per acre (120 lbs ) Potassium144 lbs of K 2 0 per acre (240 lbs ) Low Rate Phosphate30 lbs of P per acre (60 lbs ) Potassium72 lbs of K 2 0 per acre (120 lbs ) Phosphate and Potassium fertilizer application rates There was a zero phosphate and potassium rate for each tillage treatment in all replications.
- Nitrogen was applied as Anhydrous Ammonia at a rate of 105 lbs per acre Nitrogen application
-Phosphate and potassium were injected in the strip till and vertical tillage systems using a Bourgault fertilizer air cart. The tool bar was raised out of the ground to broadcast fertilizer for the conventional tillage plots. -RTK guidance was used to steer the tractor. Phosphate and potassium application
Conventional tillage was done with a Kent field cultivator. The seed bed was prepared with a single pass which also incorporated the phosphate and potassium.
-Strip tillage was done with a Dalton anhydrous tool bar equipped with coulters and covering disks. -This was the only tillage pass done on the strip till trials.
Vertical tillage, which is a series of coulters on a tool bar, was done following strip tilling.
Starter fertilizer consisted of 5 gallons of 28% N solution and 2 gallons of ATS per acre placed in a surface band 2 inches to the side of the seed. No phosphate was included in the planter applied starter.
The planter used to plant the trial was a Kinze 16-row planter equipped with row cleaners. Steering of the planter tractor was done using RTK guidance to plant directly over the fertilizer band.
-The fertilizer was injected May 5, The planting date was May 16 th. -The base hybrid in the plot is Dekalb and the refuge hybrid is Dekalb The center 8 rows of each plot were harvested for yield determination. -The Dekalb was the harvested hybrid in all three replications.
Field prior to beginning trial. Previous crop was no-till soybeans following corn. All field work was done in the spring of 2011.
Equipment used to inject phosphate, potassium and nitrogen. RTK guidance is steering the tractor.
Field following planting in the strip till area.
Conventional Tillage No P & K Fert Rep Rep Rep Average197 Strip TillNo Fert Rep Rep Rep Average194.2 Strip Tillage followed by Vertical Tillage No Fert Rep Rep Rep Average194.3
Conventional Tillage Low Rate of P & K Rep Rep Rep Average204.2 Strip TillLow Rate Rep Rep Rep Average203.6 Strip Tillage followed by Vertical Tillage Low Rate Rep Rep Rep Average202
Conventional Tillage High Rate of P & K Rep Rep Rep Average203.5 Strip TillHigh Rate Rep Rep Rep Average206.6 Strip Tillage followed by Vertical Tillage High Rate Rep Rep Rep Average207.6
Yield differences across all treatments were small. Even the zero rate of phosphate and potassium produced excellent yields. Conclusion
Lynn Lagerstedt December 5, Tillage, on all treatments, using a shank with a knife and covering disks could have incorporated upper level soil fertility. -Relatively moist conditions in early season could have favored root uptake of nutrients in the top few inches of soil. -This farm has an excellent yield history. Possible reasons