We know that different nutrients are required at different times for optimum soybean yields. Current soybean biomass production shows a two-fold increase from the 1930s, and yields show a three-fold increase. With these drastic changes in genetics, it only makes sense that we would also see changes in nutrient uptake. In addition to genetics, there is evidence that environmental factors like temperature, moisture, and soil fertility influence nutrient uptake.
Categories: Agronomy, Agronomy Talk
In corn-after-corn systems, the high amount of residue can immobilize nitrogen and make it unavailable to the following crop. Robust® and Res Plus are products the help to feed microorganisms in the soil. By supporting microbial communities, these products lead, in turn, to increased microbial degradation of corn residue in corn-after-corn systems. Applying these products in the fall may help speed up residue breakdown so the carbon penalty is paid off earlier in the growing season. This would allow for a transition from immobilization to mineralization of residue-bound nitrogen (N).
Nitrogen (N) is a mobile nutrient. When we look at the N cycle, we think of NO3 - is the N form most readily taken up by the plant, followed by NH4 +. Loss of N when applying urea or UAN can occur as ammonia volatilization (lost in gaseous form). In the case of UAN applications, N loss can also occur in the form of NO3 - leaching if a heavy rain follows or denitrification. Two ways to prevent N loss are more accurate timing and more precise placement. If we can supply N to the plant when it needs it, this allows less time for N loss. If we supply N near the base of the plant where it can more easily access the nutrient, this could increase N use efficiency.
When it comes to insecticides in corn and soybeans, it's important to remember that different pests are present at different points in the season. Whether or not an insecticide is warranted can be determined by a few factors. What insects are present? Does this field have a history of a particular insect pest? Are these insects present at a level that will impact your yield and ROI?
Fungicides are used in corn for a number of reasons. First and foremost, they can prevent or mitigate disease. How a fungicide works will depend on its mode of action. In addition to controlling disease, fungicides also work to increase water use efficiency in the plant, photosynthesis, nitrate reductase activity, timing for ear fill, and stress tolerance. One way to increase this stress tolerance is through the mitigation of ethylene production.
Nitrogen (N) is a critical input for a corn crop’s success. It is also one of the more challenging inputs to manage as every year brings a different set of environmental conditions that can change the response to different forms, timing, and placement of N on your farm. Researching N is equally challenging because so many external factors can impact the results. That’s why multi-year and multi-location data are key components to gaining a deeper understanding of N results. Through Beck’s PFR, we will continue to evaluate different timing and placement methods as we strive to help solve the puzzle that is N management.
For many years, research has been conducted on starter fertilizers and placement, either in the row or near the row. The visual observations of the response to a starter often do not necessarily match up with the data at the end of the season. As we continue to learn and develop new products and application technologies, the results seem to be more promising and the responses more consistent. Beck's PFR continues to investigate some of the new application technologies and products that may provide a benefit.
We know that micronutrients such as zinc (Zn), manganese (Mn), and boron (B) are important for the growth and development of a corn plant. These nutrients are especially important at grain fill, as shown below. While timing is key, we also know that plants only require approximately 0.6 lb. of both Zn and B to produce a 220 Bu./A. corn crop, so foliar applications could potentially supply an adequate amount.
Anthracnose is a common fungal disease in most corn production areas of the United States. These symptoms are caused by the fungus Colletotrichum graminicola. This fungus can cause many issues in corn including early- and mid-season leaf blight, top dieback, and stalk rots. In severe cases, these diseases can lead to premature death of infected plants, stalk lodging and reduced harvestability, and loss of grain yield.
Corn grain yield, typically measured in bushels per acre, can be broken down into distinct components that each contribute to the weight of harvested grain. While genetics govern some yield components, much of the harvested yield is directly affected by environmental conditions and management practices. Yield components include number of plants per acre, number of ears per plant, the number of kernels per ear, and the weight of each kernel.
Rapid Growth Syndrome (RGS) can result in some unsightly plants, but it is of little concern when it comes to plant health and yield. Symptoms include leaves twisted in the whorl that have a wrinkled appearance, followed by bright yellow new leaves. Affected plants are distributed at random throughout the field.
Non-GMO corn production requires additional management considerations, particularly in areas with strong insect
pressure. With careful planning, scouting, and season-long management, non-GMO corn production can be successful.
European corn borer (ECB) (Ostrinia nubilalis [Hubner]) was introduced to the eastern United States in 1917 and quickly became an economically important pest of the Corn Belt. With the introduction of transgenic Bt (Bacillus thuringiensis) corn in 1996, damage from this pest has been mitigated.
Potassium (K) plays vital roles within corn plants for carbohydrate, nutrient, and water flow. It is instrumental in gas exchange from the plant to the atmosphere as it regulates the opening and closing of the stomata of the leaf; it is also a key component in cell walls which add to stalk strength. Potassium is essential for photosynthesis, maximizing water use efficiency, helping maintain plant health, increasing test weight of grain, and nitrogen use efficiency. A corn plant requires almost as much K as nitrogen (N); however, when looking at soil test values across the Midwest, soil test K values have been falling. This is largely due to increased grain yields removing higher amounts of K from the soil and insufficient K applications.
Tags: corn, Agronomy, Agronomy Talk, soil tests, potassium, corn development, POTASSIUM deficiency
University data has shown that soybean yields can be reduced by up to 35% due to competition with weeds. Problematic weeds such as waterhemp can produce over 800,000 seeds/plant while marestail can produce over 200,000 seeds/plant. Therefore, a handful of escapes can lead to a substantial increase in the seed bank, making future management more difficult and putting weed control at the top of farmers' minds.
Phytophthora root and stem rot is a common soil-borne disease in soybeans that is caused by the watermold, Phytophthora sojae. Phytophthora often occurs in poorly drained soils; it is most economically damaging in low-lying areas and fields that are prone to flooding.
Tags: corn, Agronomy, Agronomy Talk, PHYTOPHTHORA ROOT, PHYTOPHTHORA STEM ROT, corn diseases
Ear and kernel development is a lengthy process for a corn plant. It begins at the V5 growth stage as the plant determines kernel rows around and then continues to V12 where the potential maximum length of the ear is determined. Next comes the pollination stages where the maximum number of kernels is established and then finally, R5 when the maximum kernel size is established.
Any stresses, natural or manmade, during this process, can lead to abnormal ear set. Many of the abnormal ears and their causes are detailed below. Accurate diagnosis of these abnormalities can help prevent future problems in the field.
Tags: corn, Agronomy, Agronomy Talk, CORN STRESS, Ear DEFORMITIES, ear stress, ear formation
In recent years, the Dectes Stem Borer (Dectes texanus texanus) has become a regular pest in soybean fields throughout the lower Midwest.
Tags: soybean, Agronomy, Agronomy Talk, dectes stem borer, soybean pests
Soybean gall midge is a new pest in soybeans, first documented in Nebraska in 2011 and South Dakota in 2015. In 2018, damage was documented in 66 counties in four states (Nebraska, Iowa, South Dakota, and Minnesota) with that number increasing by 19 additional counties so far in 2019 including the northwest corner of Missouri. It was not until the fall of 2018 that the species was identified.
Tags: soybeans, Agronomy, Agronomy Talk, SEED TREATMENT, insecticides, pest, gall midge, pest management
Harvesting downed corn is one of the worst jobs on the farm. Year in and year out, there are many abiotic stresses or plant pathogens that will affect standability and ease of harvesting a corn crop. One of the most prevalent issues causing decreased standability of corn is the presence of crown rot and stalk rots. These diseases take advantage of compromised stalk tissue, and degrading it below the ear causing lodging and stalk breakage. There are, however, ways to improve the process of harvesting downed corn that can make it much smoother.
Tags: harvest, corn, Agronomy, stalk rot, down corn, standability