The announcement this past week of a new joint-venture slaughter plant to be built in Sioux City, Iowa is great news for producers in the western corn belt. Producers in this region of the US have continued to add production facilities at a rate that is equal to and possibly faster than anywhere else in the US.

Pig production isn’t the only animal ag industry expanding in the region. Witness the return of feedlots to Northwest Iowa and Southwest Minnesota, the expansion in turkeys and laying hens in the region and the strong growth in dairy along the I-29 corridor in South Dakota.

The reasons for the growth are obvious. A feed grain basis that keeps cost of production at levels that are among the lowest in the world, an agronomic base (corn, soybeans and small grains) that values animal manure as a fertilizer resource and youth seeing opportunities for returning to agriculture via animal ag. Add in the relatively low population density (think urban/rural conflict) and you can see why so many in the region are positive about the future of animal ag.

At the same time, there is rising concern about the concentration of animal ag in the region and the impact on water quality as it relates to land application of the manure. Dr Dan Anderson, extension ag engineer at Iowa State University, has recently looked into this issue. In a report commissioned by the Pork Board (NPB #13-046), Dan matched up animal inventories and crop removal of applied nutrients based on county yield data.

The basic conclusion – 92 of 97 counties with some form of intensive animal ag obtained less than 70% of their nitrogen and phosphorus needs for crop production from animal manures. An even more interesting finding is that crop removal rates (yield) are rising faster than the amounts of manure nutrients being generated by expanding livestock enterprises.

These findings match other data that I’ve pulled together from various sources. In Northern Iowa and Southern Minnesota we often think about the relationship of corn and soybean acreages and pig production as so many pig ‘spaces’ per acre of feed grains grown. A general rule of thumb is that it takes 1 acre of feed grain agriculture per 8 grow-finish pig spaces to utilize the manure as a fertilizer resource. This means a 2400 head grow-finish site requires a land base of approximately 300 acres with the specific acreage requirement detailed in the manure management plan that just about every pork producer/contract grower maintains for their production facilities.

Let’s look at data from the 2012 USDA Census of Ag to match the land base to pig density. The most pig dense county in Minnesota is Martin County (Fairmont). According the 2012 data, there are 1.89 pigs per acre of farmland in the county. The remaining top 5 counties for density per acre of farmland in Minnesota are Blue Earth (1.47), Pipestone (1.10), Waseca (1.05) and Rock (1.04).

In Iowa the top 5 counties for land base versus pig inventory are Washington (3.14), Sioux (2.43), Hardin (2.17), Hamilton (1.98) and Rock (1.96). In Nebraska Platte county has 0.72 pigs per acre of farmland. In South Dakota the densest county for pig production is Hutchinson with 0.25 pigs per acre of farmland.