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Corn Response to Manure and Inorganic Fertilizer

Updated: May 12

Collaborating Producer: Lawrence & Lori Andruchiw, Happy Valley

Research Coordinator: Dr. Akim Omokanye

From: Peace Country Beef & Forage Association 2012 Annual Report

Corn grazing for extending the grazing season in the Peace is gradually expanding, with PCBFA playing a major role in creating awareness on its potential and suitability in cow-calf operations. Corn hybrids with lower corn heat unit (CHU) requirements, which are suitable for silage and grazing, are now available from a variety of sources including Pioneer Hybrids, Pickseed/Champion Feeds and BrettYoung. Corn has a high total input cost, which could be slightly below or above $200/acre depending on the fertility status of the site and seeding rate. Corn has a high fertility requirement, but fertilizer costs may be lower if manure is used. At RedStar farms in Fairview, a late fall soil tests in 2010 following corn grazing for 3 out of 4 years on the site showed sufficient amounts of N, K and S for subsequent corn crop. Then, we estimated a savings of at least $30/acre in fertilizer cost for the site. Here, in this report, the effects of manure application and inorganic fertilizer on corn growth, forage yield and feed value will be examined.


Site: The trial took place at Double LA Farms in Happy Valley (RGD Road 75, SW-05-78–07-W6), near Spirit River, Saddle Hills County. A total of 27 acres was seeded to 4 different corn hybrids, but for this trial we used about 3.0 acres of the site. The corn hybrids planted consisted of Pickseed 2501RR, Pickseed 2219RR, Pioneer P7213R, and Pioneer 39F44. We had 2 fertility sources, which were made up of:

1. Commercial fertilizer blend (85 lb actual N/ac + 42.5 lb actual P/ac) - fertilizer rate following soil tests.

2. Manure plus 1 /2 commercial fertilizer blend from 1 above. Here in this report, both 1 and 2 above will respectively be referred to as CF and M+CF.

Prior to any fertility treatments on the site, the site was worked and lightly harrowed. The commercial fertilizer was then broadcast and the manure spread. Then the site was re-harrowed. Following manure tests in a commercial laboratory (EXOVA), the manure application calculation indicated that the manure had 10.02 lb N/ton. We spread a total of 18.8 t/acre with a Hydra-spread (hydraulic push-gate manure spreader).

The corn hybrids were planted on May 20, 2012 in a randomized block design on 27 acres of land at the rate of 30,000 kernels/acre with a 6-row corn planter at 30-inch row spacing and at a seeding depth of 1.5- 2 inches. Weeds were controlled once with Roundup at 0.67 L/ac.

On October 5, 2012, corn hybrid forage yield was determined from three 17.5ft long corn rows per treatment. The corn forage samples were weighed fresh, then we chopped some corn plants with a corn chopper for determination of moisture content and feed value in a laboratory. On the sampling day, the number of cobs per plant, moisture content and cob maturity were determined.