Flooded fields and wet soil conditions in the fall 2018 meant some soybean fields were not, or are not going to be harvested. Also, some fields occasionally experienced significant shattering or a hailstorm in the fall where soybean seed is knocked from the plants and thus not harvested. When the grain is not harvested, nitrogen (N), phosphorus (P), and potassium (K) nutrients returned to the soil in the soybean grain can be accounted for when planning nutrient applications for the next crop. Other nutrients will also be returned, but most are not a fertilization need in Iowa soils.
Integrated Crop Management News
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With the short timeframe for fieldwork this spring prior to planting, early weed management may fall to the bottom of the priority list for many. For those who have persistent issues with winter annuals (field pennycress, horseweed/marestail) in no-till, an early burndown treatment may be worth the extra effort this spring. Winter annuals resume growth soon after the arrival of warm temperatures, so as soon as fields are fit the weeds will be susceptible to spray.
What happens when anhydrous ammonia is injected into soil?
It was a late harvest in fall 2018. Soils were wet and frozen when it was time to apply anhydrous ammonia. Those situations resulted in much less than normal anhydrous ammonia application last fall. Therefore, considerable anhydrous ammonia needs to be applied this spring. There is only so much capacity to switch from one nitrogen (N) fertilizer product to another. In Iowa, historically the two largest N fertilizers are anhydrous ammonia (largest) and urea-ammonium nitrate (UAN) solution, with granulated urea a distant third.
On-farm trials are an easy way for farmers to learn how practices, products and equipment will work in their cropping systems. The concept of on-farm trials has been around for decades, with farmers placing rows or strips of different practices within their fields for comparison. On-farm trials are easier to conduct now with assistance from formalized on-farm trial programs and the use of GPS and precision technologies.
The above-average snowfall and potential for significant rain events this spring could present challenges during the upcoming planting season. These conditions, on top of excessive soil moisture last fall that may have led to compaction and soil damage during and following harvest, have farmers concerned about completing spring tillage, fertilizer and planting operations in a timely manner.
Producers wanting to add to or improve the forage species in their existing pastures should typically consider using either the frost seeding method in February and early March, or interseeding later in the spring months. This has been an unusual end to the winter, so as soon as the snow melts, frost seeding can begin.
The amount of snow we received and potential spring rain events can be challenging to an early start to the growing season. Approaching field operations for N applications, tillage, weed control, etc. need to be weighed against potential soil compaction and successful seed germination. Two of the greatest concerns during spring is excess soil moisture and cold soil temperature and their impacts on seed germination, especially in areas with poorly drained soils as in northern and central Iowa.
The two bu/acre Iowa corn yield reduction (from the previous 2018 report) shown in the February 9 crop report demonstrated the impact of late-season wet weather. Corn quality and potential food safety issues are also determined late in the growing season. According to data recently completed by the Iowa Department of Agriculture and Land Stewardship (IDALS), levels of the mycotoxins deoxynivalenol (also known as vomitoxin) and zearalenone are elevated in this year’s Iowa corn crop. Vomitoxin primarily affects digestion in swine, while zearalenone has negative effects on repro
It is not easy for insects to survive Iowa winters. Some literally can’t - they freeze to death (corn earworm, black cutworm) or migrate to warmer climates (potato leafhopper). Insects are unlike mammals and birds because they must generate their own heat (called ectotherms). Insects die when they are exposed to temperatures below the melting point of their body fluids, termed the lower lethal temperature.