Tis the season for cattle producers to reap what they have sown – harvest. Not only in crop fields, but also when weaning the spring calving herd. After that, end of year paperwork and looking at the operation’s bottom line puts things in perspective. A significant variable in our bottom line is winter feed costs, which correlates with the number of days grazed.
Here are some common autumn tasks to optimize grazing days and forage production and ultimately improve the operation’s bottom line.
Utilize corn residue
In Iowa alone, there are over 13 million acres dedicated to corn production. The residue left in the field is a cost effective, abundant feed resource. Even when water and fence challenges exist, taking the time to weigh the costs and benefits may have surprising results. The general guidelines are that mature, gestating cows can maintain condition grazing corn stalks with little to no protein or energy supplementation because they can selectively eat plant parts with higher nutrient quality. Depending on management strategies, cow condition, stage of production and weather, supplementation can be warranted.
The first step when utilizing residue is understanding how much residue is available. Fortunately, corn yield is correlated to residue produced, and can be used to calculate grazing days. Some more recent data from Nebraska have shown higher grain yields have slightly less residue yields proportionally and had slightly less digestible residue compared to low grain yield fields, but to estimate grazing days, the same general principals still apply. To make estimating available forage easier, the University of Nebraska - Lincoln developed the Corn Stalk Grazing Calculator.
Because of weather and microbial activity, the earlier after harvest that cattle can be out on the residue, the better feed value that can be captured. Additionally, the selective grazing behavior of cattle means the highest quality parts, husks and leaves, will be eaten first, and even when it may look like plenty of feed available from a distance, feed quality may be limited. When monitoring forage availability while cattle are actively grazing, the amount of husk in the field is the best indicator of when it is time to move fields or begin supplementation. Stocking density and the rate of residue degradation significantly impact how long cattle can rely on residue as the sole feedstuff.
Prioritize utilization improvement
We often talk about advantages of incorporating rotational grazing during the growing season to allow time for plants to rest and recover, but rotating on dormant, winter forages such as cover crops, crop residue or stockpiled forages also helps gain grazing days and waste less forage. Strip grazing and adjusting stocking densities can take a 30% utilization and improve it to over 50% simply by managing animal movement and behavior. Operations can and will be limited by water, fence and labor. But even small improvements in utilization impact in the number of days we can graze before needing stored feeds.
Soil sample for fertilization plan
Soil sampling crop ground is a common practice, but less practiced in pasture settings. However, if looking to boost forage production, addressing the limiting nutrient in the soil is a good starting point. Fertilizing pasture without knowing the limiting nutrient is possible, but not the most economical.
Ideally, pastures should be sampled every 3-5 years to monitor changes in soil fertility and health. These samples should be collected at a consistent time of year, as there are seasonal fluctuations. Autumn tends to be a good time to sample because the ground is still accessible, and it gives us some time to get samples taken, shipped to a lab, and analyzed before developing a fertilization plan.
When sampling, plan ahead and know what nutrients you will be testing for. Soil pH, organic matter, phosphorus and potassium are arguably the most important measures. Depending on operation goals, other test packages may make sense. While planning, check the core depth needed, sample handling guidelines, and consider mapping what areas you plan to sample.
Additionally, ensure a representative sample is taken. This includes accounting for topography and other factors that would cause variability. Typical recommendations are to take 10 - 15 cores, mixing them in a bucket and taking a subset of the sample to ship to the lab. Do this for each area you plan to submit a sample for.
Fall weed control
Even within well managed grazing plans, weeds pop up and occasionally at levels that warrant herbicide use in either spot or broadcast application. The first rule of effective weed control is to identify the weed species present, then determine the most effective control methods.
For many biennial and perennial weeds, fall is one of the best times for a systemic herbicide treatment since the plants are beginning to move energy reserves from their shoots to their roots and reproductive structures. To be effective, the target weed needs healthy foliage capable of absorbing the herbicide. Also, understand what desirable species might be affected, and carefully read herbicide labels to ensure you use the appropriate product, rate, and are aware of any restrictions.
Utilize annual forages
Annual forages can complement an integrated crop and livestock operation in a plethora of ways. In the fall, think about what annual forages can be planted for late fall or spring grazing, and think about how to best capitalize on the last growth from warm season annuals that were planted earlier in the year. For many regions, we have gone past the ideal date for seeding forages intended for late fall growth. However, there is still opportunity to plant winter hardy cool season annuals to utilize in the spring.
Weather is a big factor in determining if establishment is successful, and there are many areas, even in drought free areas where conditions are dry enough to limit establishment and growth and should be considered. In addition to the feed value forages provide, the ecosystem services for soil and water quality add value. With summer annuals, consider if grazing either standing forage or the forage harvested into swaths make the most sense for the operation.
