Assessing the effect of cultural practices on Mississippi corn production: 1. Grain yield

Improved management strategies are needed to increase corn (Zea mays L.) production. This study aimed to determine suitable cultural practices for improved corn production in Mississippi. Two experiments were setup side-by-side (addition/deletion) at Verona and Stoneville, MS, from 2020 to 2022. A randomized complete block design was implemented that included two row configurations (single- and twin-row), two plant populations (32,000 and 40,000 plants acre-1), and six combinations of nutrients with or without a fungicide. Nutrients including nitrogen (N) 210 and 280 lb acre-1, phosphorus (P) 40 lb acre-1, potassium (K) 100 lb acre-1, elemental sulfur (S) 20 lb acre-1, zinc (Zn) 10 lb acre-1, and fungicide at 3.72 oz acre-1 were applied. In the addition trial, nutrients plus fungicide were added incrementally, whereas in the deletion trial these were withheld in a stepwise manner. Among the tested factors, row configuration impacts were the most consistent among all site-years; specifically, twin-rows resulted in higher yield compared to single-row. Additionally, higher plant population under irrigated conditions (Stoneville) resulted in greater yield compared to rainfed conditions (Verona). Higher rate of N and fungicide application affected grain yield positively, but these agronomic benefits were not economically feasible. This study determined that application of different nutrients can enhance the yield to a limited extent, and farmers should consider the economic investment of fertilizer and fungicides. Moreover, producers should balance yield and profit by taking soil testing and fertilizer prices into consideration. Corn is the most consumed cereal, and its demand is increasing. Field experimentations are needed to continuously improve corn yield. We conducted field trials over 3 years at two locations in Mississippi. Corn yield was collected when planted at 32,000 or 40,000 plant population, on twin or single row, with application of several different fertilizers and fungicide. We found that twin-rows always had higher yield compared to single-row. Whenever irrigation was available, yield was higher with 40,000, and without irrigation, yield was higher in 32,000. With fertilizer application, applying higher rates of nitrogen and fungicide application increased grain yield. But when the price of fertilizer and fungicide are considered, the yield increase is not enough to make any profit to the producers. So, we found that even though there are advantages of fertilizer application, farmers should test their soils before deciding what and how much fertilizer they should apply.