Crop results this season were influenced by weather extremes on both ends. Planting season was challenging with record high rainfall in April, May, and June. The four-year drought ended abruptly as parts of the area suffered devastating flooding and crop loss. Conditions improved dramatically during the middle of the growing season in July and August. However, a new drought emerged late in August and continued through harvest. September and October were one of the driest stretches ever recorded for this area. As of Oct. 22, our entire area – as well as most of the U.S. – is covered by a moderate to severe drought according to the U.S. Drought Monitor. The drought area is much more extensive this fall than one year ago. The late season drought started just in time to impact this season’s yields.
The big question now is will the drought stick around for next season? According to Eric Snodgrass, Atmospheric Scientist with Nutrien Ag Solutions, the current weak La Niña weather pattern is expected to influence this winter and early spring, but it’s too early to predict after that. However, Snodgrass studied a composite of years with very dry falls, and there was a clear bias of drought persisting into the following growing season during those years. Ideally, we need to recharge the soil moisture before the ground freezes or early next spring, but we certainly do not want a repeat of this past spring.
Harvest progressed rapidly this fall thanks to low humidity, warm temperatures, wind, and no rain delays. There were delays on the north side of our region and along floodplains where replant acres needed more time to mature and dry. These conditions were dangerous fire hazards in the fields, but on the positive side, dry soil reduced compaction from heavy equipment. Also, the corn was able to dry down in the field which reduced the cost of on-farm or commercial drying.
Crop yields this year were all over the board, but generally corn yields were as good or better than expected and soybean yields were not as good as we thought. The soybeans were damaged by the late-summer drought more than corn. We noticed a huge difference in yields moving from north to south in our territory. The northern side struggled more with heavy spring rains compared to the southern side. Farms in the right location had a chance to achieve record high corn yields and very good soybean yields. While other areas with drainage challenges suffered from one of their worst crops in recent memory.
Below are a few additional observations we noted comparing crop results this year:
*Soil type, soil quality, and drainage – When we consider soil quality, water holding capacity is one of the main components, which starts with texture (sand, silt, and clay). The soil type classification and the Iowa Corn Suitability Rating (CSR2) value provide a very good clue of a soil’s inherent productivity or “soil quality”. The higher value the better, but this year the soil’s ability to drain excess moisture either by natural drainage or extensive drainage tile was critical. Often the highest CSR2 soil can struggle with adequate drainage without ample tile. The top yielding farms this year needed adequate drainage, but at the same time they needed enough water and nutrient holding capacity to sustain the dry late season. That combination is simply not possible on all farms despite our best management techniques.
*Full-season corn – The trend of planting progressively fuller season corn varieties has been ongoing for the past decade or longer, and I predict it will take another step forward after this year. In the past, the northern side of our territory would typically plant 97-to-102 day maturity corn and the south side would plant more 103 to 108 day maturity. It seems our climate is changing because our growing seasons have been getting longer on average in this region. The fuller season corn is winning on yields (on average), so farmers and managers have slowly been moving to later and later maturities. The 110- to-114 day corn is now planted farther and farther north with generally good results. The risk is a cool season where we do not get enough heat or days to finish before the first killing frost. The corn would remain very wet and possibly underdeveloped at harvest. It is a question of risk vs. reward, and this year the full-season corn offered the highest reward.
*Fungicide Application – This was a bad year for corn diseases, especially southern rust and tar spot. Both are cured by spraying fungicide after tassel. The challenge is that we typically do not see much disease pressure at the time when the application needs to happen. The plant diseases usually show up later, depending on the conditions, when it is too late to spray. We notice a smaller yield advantage from fungicides even without disease pressure, but this year there was a big advantage. On soybeans, fungicides were not as big of a factor this year, but most farms were sprayed with an insecticide for aphids, so typically the fungicide and insecticide are sprayed together.
*Early planted corn and soybeans – Farmers push to get both crops planted as early as possible. This year the early planted crops did better than the later planted crops assuming a uniform stand was attained. Planting early gives the crop a longer growing season and higher yields on average. This was particularly true for soybeans. The earlier planted soybeans (where they had a good stand) had a distinct advantage this year. There are, of course, risks with planting early like poor stand from cold soils, and possibly needing to replant.
Looking ahead to next year, the soil moisture reserves are once again very low. Quality Iowa soil can hold around ten inches of water in the top 5 feet. It is unlikely that supply will be replenished before next spring. This year showed us how extreme the pendulum can swing with weather. This fall provided an opportunity to get farms ready for the next heavy rain event by touching up terraces, waterways, or adding tile. There’s a few things we can do to prepare for drought too like reducing tillage, improving soil fertility / health, and selecting drought tolerant seed varieties. As always, we need to be ready for whatever Mother Nature throws at us.
