1. Variable Rate Fertilizer Though Center Pivot Irrigation Logan Dean Soils 4213 4/16/12

2. Background information Grow roughly 750 acres of corn, 450 acres of soybeans, 500 acres of wheat annually, and a small patch of alfalfa in Oklahoma. 2200 acres of cotton and peanuts in Texas, with 4 center pivots. Family milked cows from 1948-1997, then switched to a small (150 hd.) cow/calf operation, currently downsized to 25 head.

4. About VRF The need for variable rate fertilizer application is a great step forward in center pivot efficiency. With large tracts of land and obstacles there will be a variance in needs. Variable Rate Seeding has different nutrient requirements

5. About VFR Con’t. Valley Irrigation released a statement February 2 nd,2010 that they will offer variable rate fertilizer using technology from Computronics Holdings Ltd. Computronics Holdings Ltd. worked with the University of Georgia in 1999 to develop the Farmscan VRI control

6. Advantages Apply VRF to different zones One square meter accuracy Shut individual nozzles off (important if you have drainage ditches in the field, or overlapping pivots.)

7. Advantages con’t. Minimizes water use Maximizes water efficiency

8. Disadvantages High initial cost Struggles with applying fertilizer without applying more water Controlling amount of fertilizer to end of pivot Controller programming Mapping and sensing

9. Aerial Images of 3 of our pivots

10. Where we would benefit