As wheat and barley harvest progresses, farmers often ask what should they do with wheat straw? Should I keep the straw on the field to build soil organic matter (SOM) or should I sell it? What is the value of the wheat straw and how many nutrients are being lost? Does straw residue hurt the next crop? Straw is a valuable resource in high demand for bedding or mulch and livestock farmers are even using straw to add fiber to their livestock rations. Fewer farmers are growing wheat today and a little barley is being grown. At a minimum, straw sellers should consider the value of nutrients leaving the farm plus the value of the lost organic material plus the harvesting cost. The nutrient value of straw varies but 9-12 pounds of nitrogen (N), 3-4 pounds of phosphorus (P2O5) and 25-45 pounds of potassium (K2O) per ton can be lost on fields that yield 1-2 tons straw per acre. Based on N-P-K values of $.60-$.90-$.40 per pound, the nutrient value per ton varies for N from $5.40-$7.20, fo...

New research show that microbes, especially bacteria and now fungi are the best at pulling moisture from the sky and making it rain. Dust and dirt particles can help it rain, but they are not as efficient as microbes. A recent article in Science Advances shows how the rain cycle works. Most rain starts as atmospheric water vapor and has to freeze into ice crystals before it comes down, turning into rain. Water in the atmosphere does not always freeze at 32OF. In fact, atmospheric water can stay liquid down to -40OF below zero. Temperatures are much lower at cloud level so clouds can stay full of moisture till it gets cold enough and attaches to something to freeze to cause ice crystals and then turn to rain. “Supercooled” water is a liquid cooler than normal freezing water because it has nothing to hold onto. For clouds to make snow, ice, or rain, it needs a “seed”, a tiny particle for the water molecules to grab onto to form an ice crystal before it falls from the sky as rain. Dust, s...

  Corn and soybeans require a steady supply of phosphorus (P) for early seedling vigor, root development, and stalk growth. P is used by plants in the lipid layer of the cell wall, as the backbone to genes (DNA and RNA) and for energy transfer (ATP). While P is an essential element (ranked 8th in the amount needed) it is one of the big 3 nutrients (N-P-K) because it yields more bushels per acre. Recommended corn and soybean soil test are between 20-40 ppm Mehlich. In corn, most rapid P uptake occurs after the V6 stage (six leaf collars). About 80% of absorbed P ends up in the grain. Post-tasseling P availability is critical to maximize yields. In early vegetative planting (Planting to V6), P is essential for root, shoot, and initial ear structure development. Severe P limitations early can permanently reduce yield potential. The most rapid uptake of corn P is V6 (vegetative stage) to R1 (reproductive stage). Demand spikes as biomass multiplies after V6 (4 to 6 weeks after planting)...

In the last few weeks, some areas have received a considerable amount of rain, some would say excess rain. While all microbes live on water films in the soil, too much water changes the microbial community. Excess water also displaces oxygen in the soil which is detrimental to both certain types of microbes and also to plant health. Roots need to be able to absorb oxygen for respiration to break down the root sugars for energy. Oxygen is the fuel to making both fires burn hotter and also for plants and animals to burn oxygen and sugars to produce energy. In flooded soils, the majority of obligate aerobic microbes die within 24-72 hours. As dissolved oxygen is depleted; biological activity drops by 50% within 48 hours. Then facultative and obligate anaerobic organisms take over. Obligate means that either oxygen is totally required (obligate aerobes) or not required (obligate anaerobe). Aerobe mean oxygen loving, anaerobe means absence of oxygen. Facultative microbes may live in either ...