Corn is a high yielding, high energy source of forage that can be a great fit for many cattle producers, but how do you ensure your corn crop has the best chance for success?
Whether a corn hybrid is intended for grazing, silage, or grain, the agronomic management of the hybrid during the growing season remains the same, but the hybrid you select will differ depending on the growing environment and end-use goal. Selecting the correct maturity for your intended purpose and region is the first step in silage or grazing corn production. Corn maturity is measured in Corn Heat Units (CHU) which allows you to compare hybrids and determine which hybrids fit in your growing region.
For silage or grazing corn, a hybrid that reaches the dent stage (R5) before a killing frost is ideal — it ensures the proper moisture level in silage piles which minimizes spoilage. It’s recommended to select grazing or silage corn hybrids with 100-200 more CHUs than you would for a grain corn hybrid to reach 65 per cent whole plant moisture for the region.
It’s also important to take the hybrid’s yield potential into consideration by reviewing data across years and locations. That will help you determine how a hybrid will perform under different growing conditions. Other factors to consider on hybrid selection should be standability/stalk strength, dry down rate, and disease/herbicide traits. Reviewing several sources of data when making a hybrid selection can also help you to know all the available information.
Achieving Plant Uniformity
Once you’ve chosen your hybrid, like other crops, corn should be planted into a firm moist seedbed to allow for even germination. Optimal planting depth is one and a half to two inches deep, with a planting date set in early-to-mid-May across Western Canada. Early planting can be risky as cold soil and air temperatures can delay germination. Corn is a warm season crop so cool conditions when planting can cause significant stress on the plants.
Once established, corn can withstand spring frost events with the growing point still below the soil surface up until the V6 stage. Plant stress does occur here but fall frosts typically pose a greater risk to corn yield and standability.
Corn also has an ability to sense plants around it, making plant population especially important. Optimal plant population is anywhere from 28,000 to 34,000 plants per acre. That’s dependent on hybrid selection, environmental factors, and management practices. It’s critical plants in the row emerge at the same time as those that emerge early will sense and react to later emerging plants as weeds, reallocating resources to grow taller and reduce the “weed’s” chance of intercepting sunlight. This ultimately stunts the growth and development of the later-emerging corn plants.
The straight growth habit of corn and its slow canopy closure make it a poor competitor with weeds. A uniform plant population will help minimize weed pressure and make for better staging of herbicide applications. Both BY Brava RR2 and BY Belmont RR2 have Roundup Ready® Corn 2 technology, allowing for flexibility in glyphosate applications to keep the crop free of weeds during the critical early growth phases.
Silage Corn Harvest
It’s best to harvest your corn crop when the plant moisture is between 65 and 70 per cent to ensure proper fermentation and minimize spoilage. Its highest digestible energy for cattle is when the corn is harvested close to maturity. Measuring that can be completed by taking plant samples that are representative of the average crop stage, chopping those finely, then using a moisture tester to determine the percentage of dry matter. The silage corn cutting height should be set for four to six inches to minimize yield reductions.
Grazing corn is best utilized for your herd when the ground is frozen to minimize plant waste. It’s recommended farmers do a whole plant feed analysis to determine which supplements they should provide along with the grazing corn. To maximize utilization, cattle should only be provided access to a few days of feed at a time to ensure they consume the entire plant. Efficient corn grazing utilization is when less than 810 kg/ac of residue remain post-grazing.