By Tony Bailey
Long-term, sustainable, resilient cropping systems should be everyone’s goal. Take time to review this past season’s crop production for potential yield-influencing factors.
The world record yield of 542 bushels per acre for corn was set in 2017 in Virginia. The world record yield for soybeans, 190 bushels per acre, was set in 2016 in Georgia. These numbers are impressive, but if you set these yields as goals, it would be impossible to meet them economically. They do, however, show what’s possible with current genetics and technology.
Plant breeders say the genetic potential of each crop is much higher than current yearly averages. What was your best farm, field or plot average? Maybe 100-plus-bushel soybeans and 300- to 500-plus-bushel corn? However, not all soils are created equal, and each season’s weather isn’t perfect — 2019 weather was far from perfect.
Now’s a great time to assess how much of its genetic yield potential your crop reached, and what might have held it up from its maximum. The view from the combine, along with calibrated yield monitors and yield maps, makes this easier. Take advantage of technology to record weedy or drowned-out spots.
Goals to achieve a long-term, sustainable, resilient cropping system should include reducing soil loss, or even building soil through developing a higher organic matter level with conservation practices. Are you at least below T, the tolerable limit of soil loss, for your soil types? Are movement and deposition of sediment obvious? Are there ephemeral or classic gullies?
Sustainable yields also need soil organic matter. It’s a key component in water infiltration, creating soil structure and nutrient holding capacity. Are your soil-test organic matter levels decreasing, maintaining or increasing?
Improved nutrient use efficiency is key, too. What is the ratio of nutrients applied versus used by the crop? Water use efficiency is crucial. Do raindrops enter the soil or run off?
Here’s a list of common yield-influencing factors your crops may encounter: weather, hybrid and variety selection, planting dates, planting populations, and soil fertility.
More possible factors include soil pH and nutrient availability, including nitrogen, phosphorus, potassium, sulfur and other macro and micronutrients. Others include weed management and populations, and integrated pest management of insects, diseases and nematodes.
Do you pursue the right nutrient rate, timing, placement and form for fertilizer? Do you scout your fields regularly to identify weeds, pests and other challenges?
Also, don’t forget the impact nonfunctioning soils can have on yield. Do soils crust? Is rooting impacted by soil compaction? Both can be caused by sealing and collapsing of soil pores caused by heavy tillage. Crusting and soil compaction can also negatively impact water infiltration and movement through the soil profile at critical times.
It can be challenging to pinpoint a single reason why a location isn’t living up to its capabilities. Identifying the most common factors is the path to developing your plan. Make sure to assess which factors are most problematic on a field-scale or per management zones. Put together a plan to address them. Maintaining and building long-term, sustainable, resilient cropping systems that decrease soil erosion, increase soil organic matter levels, and improve nutrient and water use efficiency should be your goals.
Bailey is the state conservation agronomist with the Natural Resources Conservation Service. He writes on behalf of the Indiana Conservation Partnership.