| Abstrakt: |
Three studies were conducted on irrigated corn at the University of Arkansas System Division of Agriculture's Rice Research and Extension Center near Stuttgart on a DeWitt silt loam soil to evaluate i) no-till, cover crops, and tillage treatments (2017 to 2019); ii) weekly versus sensor-based irrigation timing and iii) urea (46% N) versus urea-ammonium nitrate (UAN, 32% N) with surge irrigation (2018-2019). In addition, a weekly versus sensor-based trial was conducted at the Lon Mann Cotton Research Station near Marianna, Arkansas in 2019. The cover-crop and no-till treatments included no-tillage and a cover crop planted in the fall to a mix of cereal rye, tillage radishes, winter peas, and black oats. The tillage study concluded that there was no significant difference between tillage and no-till, but planting corn no-till into cover crops resulted in a significant yield reduction both years. Another study evaluated the yield and water use differences of a calendar (once a week irrigation) and schedule based on soil moisture sensors. The sensor-based method in the first year used half of the water of the calendar method but resulted in a significant yield reduction (P = 0.02) of 20 bu./ac. However, in 2019, no significant difference in yield was observed at the two locations. Yield and water use differences between these two methods are inconclusive. The objective of the fertigation study was to compare the benefit of surge irrigation to conventional continuous furrow irrigation (control), this comparison was done with urea. Additionally, another treatment was implemented to compare using 32% UAN injected into a surge valve to distribute the fertilizer referred to as fertigation. If fertigation could be shown to be successful, it could provide for an alternative method to apply late-season nitrogen. No differences in yield were found between the urea treatments, but yields were significantly reduced both years for the UAN treatments. Results of the study indicate that yields observed for a field under no-till, with surge irrigation under current Division of Agriculture fertilizer recommendations with urea, and a sensor-based irrigation plan are comparable or better than the conventional weekly irrigated and fertilized tillage system. [ABSTRACT FROM AUTHOR] |
