Select forages using pasture/hayland suitability

Every year, I visit many fields where desired forage species have shown poor seedling vigor or are experiencing reduced stand population after establishment. I also make several visits to determine if established forage stands have degenerated past critical minimum.

Establishing and maintaining desired species are the most important components of any forage production system. By matching forages to the environment they are best suited for, you increase production potential, soil stability and animal performance. Agronomists often use the NRCS-derived pasture and hayland suitability group concept for recommending forage species selection.

Pasture and hayland suitability groups are determined primarily on the root growth characteristics of a given group of individual soil series.

Pasture and hayland suitability groups are listed in the NRCS Field Office Technical Guide.

Criteria used to determine a pasture and hayland suitability group include: restrictive layer (fragipan or depth to bedrock); field slope; drainage class' soil texture (percent sand, silt, clay or course fragments); landscape physiology (terraces, floodplains, etc.); available soil water-holding capacity and soil permeability. These criteria estimate the root growth, water and nutrient extraction, and forage disease susceptibility of a given soil resource.

Since root growth and crop physiology vary among forage species, matching your soil/landscape resource to forage type is a recipe for success. Intuitively, forage producers know this. However, many do not use the pasture and hayland suitability grouping concept when selecting forages.

As an example of pasture and hayland suitability grouping, I'll use the soils from a typical Lawrence County, Mo., beef operation (see accompanying table).

This ranch has eight major soils, ranging across several pasture and hayland suitability groups. Soil productively across the ranch ranges from 20 to 84 (100 is ideal). Only 55 percent of the ranch's land is well suited for alfalfa production. Ladino clover would be a good pasture legume choice in the poor drainage or restricted water percolation areas of the ranch.

By using NRCS pasture and hayland suitability groupings, forage producers can do a better job of managing their soil resource. I'll fine-tune this concept in next month's column.

For additional information, please contact your MFA certified crop adviser or county NRCS office.