Initial Observations from Stepwise Input Additions and Deletions for Corn in the Mississippi Delta.

Various factors influence corn production across the Mississippi Delta and across the Southeast and many have been evaluated continually for decades. While grain yields have increased from below 50 bu/acre in the late 1970's to over 185 bu/acre in the last two years, producers are continually looking for ways to bump yields even higher. Variables include but are not limited to cultivar, row spacing or row configuration, seeding rate, fertility inputs, fungicides, insecticides and various other possibility. However, the greatest influence may be the environment over which a producer has little control. In 2018, studies were initiated to at look at combinations of inputs using additions or deletions. The inputs chosen are row configuration (single-row [SR] vs twin-row [TR]) and seeding rate (32,000 vs 38,000) as a 2x2 factorial arrangement (whole plot) in a split plot design with the subplots consisting of N rate, phosphorus (P) and potassium (K), sulfur (S), zinc (Zn) and fungicide. Two studies were included which systematically adds inputs while the other systematically removes at the higher levels. The high system includes, 280 lb N/acre, 40 lb P/acre, 20 lb S/acre, 10 lb Zn/acre, plus a fungicide. The two studies consisted of 24 treatments in each study with four replications. The center two rows of each 4-row plot was harvested for yield with a sample collected in order to determine harvest moisture, bushel test weight and Seed Index (100-seed weight). At the time of submission, data is still being analyzed and will be summarized in the very near future. Twin-row production systems have on occasion produced higher yields when the seeding rate has been increased. Additional fertilizer should only be applied as determined by soil test in order to deliver an economic return.