Introducing Precision Farming
Because our soil varies greatly, and many areas have a low level of organic material, I have always been keenly interested in soil sampling and how fertility relates to yield. I hoped that by investigating and implementing some of these emerging techniques, I could maximize the farm’s productivity.
In 1994 we purchased Micro-Traks Grain-Trak yield monitors and mounted them inside the cab of the combines. It had a 4x4 inch LCD display that reflected yields in bushels per acre in real time, changing constantly as I rolled over the field. To measure the yields, it had a load cell in the clean grain elevator that the grain would impact as the grain flowed past and a speed sensor on a drive shaft to record the distance traveled.
I soon discovered that I needed a way to map the yields, which would allow me to review the data during the slow winter months. I could then make decisions about actions to take in the spring to improve my yields and remediate problem areas. In 1995, I picked up the Micro-Traks Data-Trak unit which would read and write to a 1 megabite PCMCIA card and a 5-channel, L1, C/A-code, Eagle AccuNav Sport handheld GPS unit. I fed the GPS data into the Data-Trak using an accessory cable supplied by Eagle. The Grain-Trak and Data-Trak units then worked with Eagle to keep track of the spatial variations in yield.
The third year, I decided to plunge a little deeper into the technology, hoping to improve my results and eliminate some frustration. In 1996, we added differential corrections.
About this time, we began doing variable-rate fertility work. The farm hired an independent fertilizer dealer, which sampled its soil to determine how closely the farm’s soil variance matched its yield variation. Although the farm had been analyzing its soils for the past 25 years, we usually pulled composite samples from 25 sites on a 125-acre field. Then, we’d place all the samples in one bag and ship it off for analysis. To gain site-specific information the dealer pulled samples from various spots throughout the field on 5-acre grids, thus creating 25 samples per field and mapping the source of each sample using GPS.
After harvesting each field, I would download my geo-referenced yield data to Farm Works, a GIS software package running on the farm’s computer. Then, I could view a color-coded yield map on-screen. I could then tweak that map, change the legend, turn layers off and on, view a transparency to see how the layers interrelate. I can create a yield layer, a moisture layer, a fertility layer a topography layer, or infra-red photo layers. With soils layers, I can create a layer for every element tested, such as nitrogen, phosphorus, potassium, boron, copper, manganese, and more.
Thanks to new technologies, I have been able to produce more with less and hopefully will continue to improve the farm’s profitability while maintaining a balance with nature.
