Plant Health Initiative

Precision Agriculture

Photo above from 1933, same fields below in 1990. Historical photos can document how fields once farmed separately have been consolidated into larger fields, which may contain abrupt changes in soil characteristics. Photo credit: William Casady and Harlan Palm, University of Missouri

Rather than manage whole fields as a single unit, farmers who practice precision farming identify and manage specific areas within fields. Site-specific decisions may be made about soil sampling, fertilization, crop protection, tillage, variety selection or other inputs. The advantages of site-specific management are lower costs and fewer inputs, reduced environmental impacts, and better machinery decisions.

Large fields often include areas of abrupt change in soil characteristics or productivity. The techniques of precision farming can give farmers more precise knowledge of fertility gradients in a field, and a better understanding of yield variability.

 

Tool of precision farming

The tools of precision farming include remote sensing, GPS, and the use of historical photos to create field maps of soil physical and chemical characteristics that affect plant growth. For example, the measurement and mapping of electrical conductivity (EC) of the soil profile provides an indication of the depth of soil layers, soil texture, organic matter content, water content, cation exchange capacity, and salinity levels.

Yield maps can be created which quantify variations within a field. Over time, they become a road map for scouting, analysis, and treatment of underperforming areas.

 

Resources

Precision Agriculture: An Introduction.

Precision Agriculture: Remote Sensing and Ground Truthing
University of Missouri

Use of Historican Aerial Photos to Help Understand Within- Field Variability (NCSRP -pdf format). Historical aerial photos can inform you how field size, shape, and content have changed over the years.

Developing Topographical Maps with DGPS and Their Uses
(NCSRP - pdf format)

Measurements and Uses of Soil Electrical Conductivity
(NCSRP -pdf format)

Basics of Cleaning Yield Monitor Data
(NCSRP - pdf format)

Site-Specific Management Center - Purdue University

University of Minnesota Precision Agriculture Center