Sign up for email alerts of new Fluid Journal issues!
Fluid Journal : Spring 2014
14 The Fluid Journal Spring 2014 should also be explored, namely: timing and form of nutrient delivery. Overview Foliar applications of low salt NPK fertilizers were applied to established irrigated alfalfa during the 2012 and 2013 growing seasons. These applications were made when the regrowth was about 6 to 8 inches tall. Sprayers. In 2012, applications were made with a commercial sprayer and made between the 2nd and 3rd cuttings. The NPK fluid applications at this time were 3-18-18. Rates of applications included a total of 0.25 or 5.0 gallons/A for each cutting. Irrigation was stopped to allow fields to dry prior to applications, as well as 24 hours after application to assure adequate drying on the foliage of the alfalfa. Each treatment was laid out with anticipation of harvest and determining yields. Yield results Application of foliar nutrients applied in-season increased yields during the 2012 season for each of the cuttings. These yield improvements were able to deliver an economic improvement for the forage being used. Kent Frisch, Simplot’s farm manager for this area reports that it appears these applications are something that should be pursued, but did recommend the system needs some changing for each of the applications. Therefore, changes were made for the 2013 season to address farmer concerns. Trials of the in-season application were expanded to three pivots. Each pivot covered 120 acres and included treatments of 3-18-18 applied by aircraft, 6-24-6 applied through center pivots, and each compared to the grower standard practice (GSP) where no additional nutrients were applied. Liquid NPK’s were applied when the crop had a regrowth of 6 to 8 inches. Dr. Tindall is Senior Agronomist for the J. R . Simplot Company in Boise, Idaho and is also a member of the FFF Board of Directors and its Fluid Journal Editorial Committee; Dr. Mooso is the Agronomy Manager for Simplot and member of the FFF R&E Committee. Rates included 3, 5, and 5 gallons/A for each of the respective cuttings. Summing up Harvesting. Each pivot was harvested with commercial swathers with each truck weighed with hay samples removed for quality analysis. In total there were about 600 trucks, weighed and sampled, providing a good evaluation of treatment responses. Main objective of our alfalfa study was to produce livestock feed--all green, chopped, and with a target mixture content of 65 percent. Yields. The 2013 trials indicated a very positive response to in-season NPK applications. Yield improvements were positive for both the 3-18-18 and the 6-24-6 . However, applications through the center pivots tended to be higher. Improvements of yields were impressive, with 6-24-6 providing over a 3 ton (65% moisture) improvement over the GSP 20.5 tons compared to 23.3 (Figure 1). Improvements with these types of applications for both years have encouraged our farm managers to incorporate these applications into as many alfalfa fields as possible for the future. “If we can consistently see these types of responses and the materials can improve our alfalfa production benefits-to-costs by at least 2:1, our “Trials Show Positive Response to In-season NPK Applications.” alfalfa production will be seeing more of these applications,” predicts our farm manager, Kent Frisch. Addressing needs The Fluid Fertilizer Foundation (FFF) and J.R . Simplot, as a member company, continue to improve on nutrient management as it applies to fluid fertilizers and new products. The FFF supports a better understanding of how to use the nutrients our members have developed. This study also points to the improvements in Relative Feed Quality, which were also positively influenced and especially the three foliar 3-18-18 applications. This may have been related to the higher concentration of tissue K that resulted from this particular NPK low- salt foliar application. The positive nature of improvements to alfalfa production with in-season applications of NPK fluids is a great example of addressing the current needs of our FFF members and their good customers.