Understanding Precision Farming and Soil Morphology

The USDA Soil Conservation Service, now Natural Resources Conservation Service, has been charged with creating the country’s soil survey. This survey was designed for broad land use planning. My career was spent mapping soils across the country and that process included identifying soil components within a soil mapping unit. Years were spent digging 30 to 40 holes a day describing soils and developing landscape models for predicting where the soils formed on the landform. The information gathered was then used to create the historical soil survey manuscripts.

Then in 2004, the hard copy manuscripts were entered into USDA NRCS NASIS database and published to the Soil Data Mart (SDM) database. The SDM database contains the soil mapping units, their components, and the component properties for the entire country. Many precision farming web sites and professionals reference the Soil Data Mart soils map, but incorrectly refer to the map unit as a soil type. Using the dominant soil as a soil type is appropriate in broad land use planning, however in precision farming applications, understanding all the soils within the map unit is necessary to correctly identify and understand management zones.

The base image presented below is a SoilWeb soils map displaying a specific field in the lower right hand corner. Inset into this base image are three analyses of that same field, used to identify the various (gross) soil components. The lower right hand corner is the base field soils map presenting two map units: 3401 and 3402. Map unit 3401 is the Longford silt loam, with 1% to 3% slopes. Map unit 3402 is the Longford silt loam, with 3% to 7% slopes. The red X is in map unit 3402 and the focus of this article.


When a polygon is chosen in SoilWeb, the Map Unit Composition is displayed. In this case, map unit 3402 contains seven identified components. The dominant component is the Longford series, however the minor components are listed to identify the expected landform position. The estimated composition percentage is an amalgamation of all the 3402 polygons, not the specific polygon. The SCS soil survey was created using maps varying from scales of 1:15,840 (4 inch to the mile) to 1:24,000 (2.64 inch to the mile). The NRCS has standardized the mapping scales to 1:12,000 and 1:24,000. Precision farming mapping uses much smaller scales of 1:2,400 (26 inches to the mile), or greater.

Although the mapping scales and precision farming scales are significantly dissimilar, information can be gleaned from the soils database to aid in precision farming prescriptions. In a very simple analysis, this field used the Veris Technologies mapper to intensively map the soils using electrical conductivity (EC). EC mapping is a common method of mapping the differences of the soils within the field. Analysis of the Veris mapper data can help predict changes in the soils across the field.

The lower left image is the Veris surface-to-subsoil ratio combined with the five-year crop yield data. The red dots being the lowest values (less variation, highest yields) and the purple dots being the highest values (greatest variation, lowest yields). The soil morphology is homogenous in the red areas and dissimilar in the purple areas. These are clues used to differentiate the various components within the field or within the map unit.

The upper left image is a Veris analysis of only the surface-to-subsoil readings ratio. The red are those with a low EC ratio and green being the high EC ratio. Using the stoplight legend allows for grouping of similar EC points. These various analysis of EC mapping, yield mapping, along with information gleaned from the NRCS soils map database, contains enough information to sufficiently separate the various soil components. The computer analysis provided clues for areas to ground truth the soil type.

The upper right hand image is the gross soil type or soil component map. That map was created to identify field sample sites. Visiting the site to dig holes is needed to understand the soil morphology. This is as important as collecting samples for soil fertility in the upper 6 inches. The soil profile provides clues both in the history of the soil and the answers as to plant productivity.


Understanding the soil morphology is necessary to determine the cause and effects of crop selection and production. The soil morphology explains potential troublesome soil properties. In the soil photos above, the range in the EC readings can be used to identify the natural Longford, the eroded Longford, the higher clay content Crete soil, the toeslope Longford with its higher organic matter and clay content, and the Hobbs soil with its increased organic matter and homogenous silt loam profile.

There are many stories that can be gleaned from understanding the soil morphology. For example, this field has been in no-till for eight years, however the morphological evidence shows the scars still exist from the many decades of tillage. Take the time to use the NRCS soils database to identify the clues used in prescriptive farming.

For more information on analysis of the SSURGO database for precision farming, contact Paul R. Finnell at [email protected] or visit prairiehillssoilsconsulting.com or LinkedIn.


Leave a Reply

Data Management Stories
Data ManagementAgriculture Impacts Weather: The Case for Connected Ecosystems
February 15, 2018
It’s fascinating to see how modern technology has helped us increase our agricultural productivity in areas not otherwise suited for Read More
Norris planter
Data ManagementBig Data is a Chicken-or-Egg Scenario on the Farm
February 1, 2018
According to McKinsey, the agricultural sector is the least digitized industry in the U.S., writes Tony Baer on ZDNet.com. Yet, Read More
Business Management2018 Retail Precision Ag Programs: At-A-Glance
February 1, 2018
Deep in the midst off December downtime, we reached out to three retailers well-versed in running a grower-facing precision ag Read More
Data ManagementClimate Corp. Announces CNH Data Sharing Partnership
February 1, 2018
CNH Industrial and The Climate Corporation announced today a new partnership that will extend and develop a portfolio of data Read More
Trending Articles
AsiaCloud-based Irrigation Could Double India’s Crop Yield and Halve Water Use
February 12, 2018
A cloud-based, micro-irrigation system tested on a farm in India has cut water use by up to 80%  and doubled Read More
Tools & Smart EquipmentAutonomous Tractors Could Work in Wetter Conditions than Traditional Tractors
February 8, 2018
March 20th is the first day of spring, making spring much closer than even I expected. On the farm I Read More
AmericasPrecision Farming Companies to Watch in 2018 (OPINION)
January 17, 2018
My friends, as many of you told me repeatedly throughout the last 12 months, 2017 was an interesting year in Read More
Data ManagementPrecision Ag Hardware and Software: A Little Off-Season Maintenance Goes A Long Way
January 11, 2018
All service technicians have heard this line. Most often when spring makes its anticipated return to our lives. It is Read More
Service ProvidersAnez Consulting: Focus On Fertility
January 9, 2018
Central Minnesota features variability aplenty when it comes to soil characteristics and topography, from flat, black expanses rich in organic Read More
Americas5 Best Ag Tech Shows in Brazil
January 8, 2018
Brazil continues to demonstrate its potential in agriculture. Several international companies are investing in our country because we have a Read More
Latest News
Industry NewsUnderstory Patents Solid State Weather Sensor
February 16, 2018
Understory today announced that it received a patent for its mechanical strain-based weather sensor, a key component in its weather Read More
Retailer Grower
Business ManagementAgriculture and Technology: Industry Progress Lies in C…
February 16, 2018
Water is essential for agriculture. While this may seem obvious, nowhere is it more apparent than the Sonoran Desert of Read More
Industry NewsAgtegra Cooperative Pledges $500,000 to SDSU Precision …
February 15, 2018
Agtegra Cooperative, Aberdeen, SD, today in Pierre announced a $500,000 donation to South Dakota State University for the Precision Agriculture Read More
Ag Retailer and Grower WinField United
Business ManagementThe Importance of Teamwork for Successful Precision Ag …
February 15, 2018
Interdependency is defined as the quality or condition of being mutually reliant on each other. I’m not a huge sports Read More
Data ManagementAgriculture Impacts Weather: The Case for Connected Eco…
February 15, 2018
It’s fascinating to see how modern technology has helped us increase our agricultural productivity in areas not otherwise suited for Read More
Adapt-N VRT
Decision Support SoftwareDTN Partners with Adapt-N to Provide Weather and Nitrog…
February 14, 2018
DTN has announced a partnership today at the National Farm Machinery Show with Agronomic Technology Corp (ATC), a Yara International Read More
Corn close up
Imagery/SensingSyngenta Acquires Satellite Imagery Provider FarmShots
February 14, 2018
Syngenta has acquired FarmShots, Inc., a North Carolina-based innovator of high-resolution satellite imagery that detects plant health by analyzing absorbed Read More
Tools & Smart EquipmentMachine Learning: The Secret Sauce of Precision Agricul…
February 13, 2018
With the development of agricultural technologies, crop and plant diseases have been advancing as well, causing degradation of both quality Read More
Farmers Edge Truck
Africa/Middle EastFarmers Edge Aligns with PartnerRE to Streamline Crop I…
February 13, 2018
Today Winnipeg-based FMIS giant Farmers Edge announced a partnership around crop insurance with Zurich-based PartnerRE. Although a bit short on Read More
Robotics Specialty Crops
AmericasHortau, Agrian Announce Strategic Partnership
February 12, 2018
Hortau today announced a strategic partnership with Agrian Inc. to deliver an expansive precision irrigation service for commercial agriculture. “With Read More
AsiaCloud-based Irrigation Could Double India’s Crop Yield …
February 12, 2018
A cloud-based, micro-irrigation system tested on a farm in India has cut water use by up to 80%  and doubled Read More
Forbes Mixing Bowl NYC
EventsInnovative Forum Geared to Let Food, Farming, and Tech …
February 9, 2018
Industry innovators in agriculture, food, and information technology are set to mix it up again at this year’s Forbes Mixing Read More
Tools & Smart EquipmentAutonomous Tractors Could Work in Wetter Conditions tha…
February 8, 2018
March 20th is the first day of spring, making spring much closer than even I expected. On the farm I Read More
corn weather
Industry NewsSciFi in Ag: Stanford Cooling Project Could Drive Energ…
February 7, 2018
(Article Notes: This monthly column takes some crazy sounding ideas and applies them to the field of Ag Tech. The Read More
Industry NewsAgGateway Debuts ADAPT ISO Plugin Version 2.0
February 6, 2018
AgGateway’s ADAPT Framework, which is designed to make it easy for various hardware and software systems that growers use in Read More
Systems ManagementThere’s No Easy Button For Value in Variable-Rate Nutri…
February 6, 2018
Roger Dumond has weathered the ups and downs of precision agriculture programs as much as anybody who’s been riding that Read More
Business ManagementFeel Something is Missing in Precision Agriculture? Ans…
February 5, 2018
I’ve seen a lot of ideas and met a lot of people in the agtech world. There have been great Read More
HomeSST Software to be Acquired by Proagrica
February 5, 2018
UPDATED 2.5.18, 2:10 PM Proagrica has signed an agreement to acquire 100% of SST Software, including Raven’s ownership stake. Based Read More