Balanced soil fertility is an absolute must for high-yielding corn production. Yields are often limited by low soil pH and nutrient deficiencies. Corn is a demanding crop, requiring as much K as it does nitrogen (N) – in some cases more than 200 lbs K2O/ac. High-yielding corn can also take up more than 30 lbs/ac of S and Mg. These "secondary" nutrients are certainly not secondary in importance to corn. Deficiency of S and Mg can limit the potential of the crop.
High corn yields require high amounts of applied K, particularly during early stand development and before pollination. At these times, absorption rates can reach 10 pounds per acre per day. Second only to nitrogen (N) in plant requirements, K is a key component of both drought tolerance and photosynthesis. In fact, photosynthesis rates in K-stressed corn leaves may be reduced by up to 95%. As the primary nutrient behind developing root systems, K also is crucial for timely development of crop quality. K deficiencies often result in weak stalks and lodging.
A balance of Mg is vital to the well being of all organisms. In plants, the first observable signs of Mg starvation is a decrease in the rate of photosynthesis. As rates of photosynthesis decline, so do growth quality and yield. Mg influences many complex nutrient relations. Mg promotes phosphorus (P) absorption, but high K rates can inhibit plant uptake of Mg. K-Mag® provides a readily available soluble source of Mg, and supplies K and Mg in the proper balance.
Corn needs S to completely fill the ear, develop a healthy root system and prevent lodging. S is a key element in proteins, and it is vital to vitamin synthesis in plants – an important determinant of crop quality. S deficiencies are increasing worldwide, largely due to the reduction in S emissions brought about by the Clean Air Act of 1990. S deficiencies can have significant effect on yield. Some experts estimate that for each day S is deficient past the first 21 days after emergence, a loss of 1-2 bu/A, and even total crop failure, can occur. K-Mag® can help remedy S shortages by providing S in the sulfate form.