Soil and plant nutrients are vital for optimizing crop yields. Some are free while others require extensive fertilization using the 4R's (Right Rate, Place, Form, and Time). Due to higher fertilizer and application costs, agronomists prioritize the 4R's. For conventional farmers, Nitrogen (N)-Phosphorus (P)-and Potassium (K) seem to be the big three nutrients. These three macronutrients consume most of the fertilizer budget, especially on corn and small grains. Nitrogen (N) is used to make protein, P is used for DNA, RNA, cell walls, and for energy transfer (ATP). Potassium (K) is used like money in the plant, involved in nutrient exchange and balancing electrical charges. Next, secondary nutrients are Calcium (Ca)-Sulfur (S), and Magnesium (Mg). Calcium (Ca) is a major regulator of plant hormones and growth. Calcium carbonate or lime is used to balance pH, just slightly acid. Sulfur (S) is needed with nitrogen to make essential amino acids for protein synthes...

  Scientist are looking for ways to produce a regular source of food on the moon. You can not just plant crops in a greenhouse on the moon and expect them to grow. They need nutrients that recycle and are in the right form. That takes microbes. Understanding what microbes make nutrients plant available may also allow “earth” farmers to use less commercial fertilizer. Farmers are now using biofertilizers (microbes) to enhance plant nutrition. Here’s a summary of important plant microbes used to make plant available nutrients. For nitrogen (N), the rhizobium bacteria convert atmospheric N2 into ammonia (NH3). The rhizobia (R) infect the plant in root nodules and then convert N into useable plant forms. Farmers inoculate soybeans, hay, and cover crops with specific rhizobia strains to generate free N for the plant. Use Bradyrhizobium japonicum for soybeans; R. trifolii for red clover, crimson clover, and white clover; R meliloti for alfalfa; and R. leguminosarum for peas, beans, and t...

  Late season diseases are occurring in corn and soybeans. Tar spot in corn and sclerotia or white mold plus soybean cyst nematodes (SCN) in soybeans. In many cases, it’s too late to prevent the diseases. However, there are some management practices to reduce future incidences of the diseases. For corn tar spot, the symptoms include irregularly shaped black structures on leaves. The black structures are firm, appear mostly smooth on the surface and the spots do not rub off or break open. Tar spot can also produce black spots circled by tan lesions with dark borders. Tar spot overwinters on surface crop residue. The spores are dispersed by the wind and rain droplets splashing the inoculum onto plants. The inoculum likes cool summer conditions with adequate moisture and high humidity. The recent August rains with cooler days and nights is causing good growing conditions. Field with a history of tar spot are most susceptible. The best time to apply a fungicide is at tasseling (VT) up ...

  As crop start to mature, farmers are estimating crop yields. Weather conditions have been variable. Many soil are drier than normal. However, some fields have had almost perfect rains and some way too much. Expect yields to be as variable as the rainfall, even within the same field. The best way to estimate corn yield is to use the yield component method. This method was developed by the University of Illinois. The following procedure comes directly from Dr. Bob Nielson, at Purdue University. The yield component method uses four components. These yield components include number of ears per acre, number of kernel rows per ear, number of kernels per row, and weight per kernel. The first three yield components (ear number, kernel rows, kernels/row) are easily measured in the field. Final weight per kernel obviously cannot be measured until the grain is mature (kernel black layer) and a 15% grain moisture of 15% which is the typical moisture value used to determine a 56-lb market bus...

  A mixed bag is occurring this year. Some farmers have col, dry soil while others are getting too much rain. Variable weather conditions mean there are a variety of nutrient problems. The most common complaint seems to be slow growing soybeans. Soybeans planted into heavy cereal rye combined with cold nights is resulting in slower soybean growth, especially if it is dry (slow nutrient release). As summer progresses, temperatures should warm up the soybeans should catch up. Rye residue conserves moisture and keeps the soil in a more ideal range for optimal plant and microbial growth later in the season when temperature get hotter, high 80’s and 90’s. There are several nutrient issues farmers can scout for this year. On corn and soybeans, Boron (B) and Calcium (Ca) deficiency symptoms are noticeable. On corn, look for parallel lines or just slight zipper effects on the outside of the leaf to identify B deficiency. Boron is needed to get calcium into the plant. After nitrogen and pot...