Plant tissue testing, as done by most labs, is not as informative as water-soluble soil tests. Tissue tests only test the soluble contents of the cells.
Foliar feeding is a complex subject, but in general it allows you to supply small amounts of deficient elements to plants (through their leaves, primarily) at the time they need them. Fertilizers applied to the soil before planting may not be available to the plants when they need them most—during peak growth and pod fill. […]
Of course, the way to grow healthy plants is to have fertile soil with good structure. As we have mentioned earlier, this means well aerated, loose soil with high levels of humus and beneficial soil organisms, and high, balanced levels of nutrients (high calcium is essential for disease resistance, for example). Some of the beneficial […]
If a plant is not getting the proper amounts of nutrient elements, it may develop certain symptoms, abnormal colors or growth deformities.
In selecting which variety you wish to plant, assuming you are growing field soybeans, you need to consider several things. First, buy the best quality seed you can find. Certified tested seed is usually worth the cost.
Manures are an excellent source of nitrogen.