25 Sep Optimizing Soybean Yield at Harvest
Dan Davidson, Agronomist PhD, CPAg, CCA
Soybean moisture and harvest timing can have a huge impact on crop yield, shatter losses and storability. Field losses, splits and cracked seed coats increase as moisture content decreases.
A 13%-13.5% moisture content is optimal for preventing mechanical damage. Harvesting during high humidity conditions – such as early morning, late evening, or in cloudy conditions – can reduce shatter loss and mechanical damage if the soybeans are below 11% moisture content. Moisture content can also increase several points overnight and decrease several points during a day based on humidity and windy conditions. Always avoid harvesting when beans are driest, such as late afternoons.
As harvest approaches, the most important things to consider are having the combine ready, having logistics outlined, and assuring the soybeans are at the right moisture to capture the most bushels. Soybeans can be 13.5% at noon, 11% at 2:30 pm and 9% by 5 pm on a hot, sunny and windy day. Timely harvest is important to maximize profits. Every farmer who grows soybeans knows this, and there seems to be little they can do about it since weather is the big factor, and their time is at a premium during the harvest push.
Selling soybeans dry means lost bushels. For a field that’s yielding 75 bushels per acre at 13% moisture, harvesting at 8% results in selling 4 fewer bushels. And at $9 per bushel, that is a loss of $36 lost revenue. Of course, during harvest, you could have combine-loads range from 14% down to 8% moisture.
To optimize the number of bushels, consider these harvest tips:
- Begin harvesting at 14% or 15% moisture. Start to harvest when some of the leaves are dry and still attached to the plant.
- Harvest under optimum conditions. Moisture content can increase by several points with overnight dew and can decrease 4 to 6 points with sunny, warm and windy conditions.
- Avoid harvesting when beans are driest, such as on hot and windy afternoons, to maintain moisture and reduce shatter losses. You can switch heads and go to corn for a few hours.
- Be careful harvesting soybeans that dried down and became rewetted by rain and cool, cloudy weather. These pods will easily split and shatter.
- If pods are brown and stems still green, make necessary combine adjustments and operate at slower ground speeds.
- Adjust harvest speed and make combine adjustments to match bean conditions several times a day, as conditions change.
- Lastly, avoid shatter loss. It takes about four average-sized beans per square foot to equal one bushel loss, and shatter losses can exceed several bushels an acre.
If you can store beans on farm and have aeration or ability to dry with a little heat, you can begin harvesting at 14% to 16% moisture and aerate the grain down to 13% to maximize the number of bushels.
Fortalis® is an essential crop input
Your soybean yields can also benefit from Fortalis®, an advanced crop enhancement foliar spray that works by mobilizing calcium already existing within plant tissues, resulting in higher pod retention. When applied as a tank mix, Fortalis® with a fungicide or insecticide contributes to better plant health and higher yield potential. It’s an essential crop input that you need to get the most out of your crop.
Dan Davidson is a PhD agronomist, part-time farmer and soybean expert from Nebraska who consults with soybean checkoff and industry on crop production, marketing, and product development projects.