AGRI-BRIEFS   AGRONOMIC NEWS ITEMS

From Agronomists of the Potash & Phosphate Institute 655 Engineering Drive, Suite 110 Norcross, Georgia 30092-2837 Phone (770) 447-0335

Winter 2001, No. 2

High profit crop production is the product of matching high yield management with high yield fertilization. A system of best management practices, including the best variety, optimum seeding date and rate, and timely weed control, will fail if the fertilizer program supplies less than the needed amounts of nutrients.

Proper fertilization begins with a realistic yield goal and an understanding of what the crop needs to achieve this goal. Detailed field records of crop yield and protein levels and routine soil testing are a few of the important tools required to develop suitable fertilizer recommendations. Plant tissue testing of poor production areas in fields will add to the knowledge of where specific nutrient limitations are restricting optimum crop production.

Balancing nitrogen with the other major nutrients can often increase the utilization and efficiency of nitrogen. The presence of any deficiency or stress on a crop will limit the ability of plants to obtain the maximum benefit from the other inputs. When extreme stress reduces crop yields below the target level, the efficiency with which inputs are used decreases significantly.

Balancing nitrogen fertilization with adequate phosphorus and potassium is a proven best management practice. With adequate phosphorus, response to nitrogen is improved through better nutrient uptake, hastened maturity, increased nitrogen use efficiency, and greater yields. Improved root growth with adequate phosphorus can also enhance the capture of soil and fertilizer nitrogen, as well as increase winter survival of winter cereals and perennial forages.

Plants with adequate potassium to balance nitrogen are more likely to have high protein content. While potassium is not part of the protein molecule, it is required in large amounts in the formation of protein. A substantial amount of the protein in wheat grain comes from nitrogen stored in the leaves and stems before transport to the kernel. It is potassium that facilitates the conversion, transport and ultimate synthesis of nitrogen into grain protein.

A balanced nutrient supply is the key to profitable crop production. Providing sufficient phosphorus and potassium to balance optimum rates of nitrogen is key to maximizing returns. Establishing healthy plants with balanced nutrition will improve the crops ability to cope with pest and environmental stresses that impact yield and profit potential.