March 20, 2018 • Page 12 shop online at www.missourivalleyshopper.com National Ag Week March 18-24, 2018 SDSU Extension Research Looks at Growing Early Maturing Soybeans SDSU iGrow BROOKINGS, S.D. - One management strategy soybean growers can implement to reduce risk associated with Mother Nature is to grow soybeans with varying maturity ratings. "With this approach, producers are not 'putting all their eggs in the same basket' so to speak," said David Karki, SDSU Extension Agronomy Field Specialist. He further explained that planting soybeans other than recommended maturity group for the region, especially early maturing varieties, allows producers to start harvest earlier in the fall and continue field activities such as establishing cover crops and/or timely winter wheat planting. "Throughout recent growing seasons, growers have commented that early soybeans have performed equally well in terms of yield, if not better, than soybeans with recommended maturity ratings," Karki said. What SDSU Extension Research Has to Say In collaboration with interested growers and the South Dakota Agricultural Experiment Station at SDSU, SDSU Extension established a small plot trial during the 2017 growing season at two locations in Northeast South Dakota. The first location was at the SDSU Northeast Research Station near South Shore. The second was in a Clark County soybean grower's field near the town of Henry. The trial used two early varieties (rated 0.2 and 0.3) and two recommended varieties (rated 0.9 and 1.0) provided by Mycogen Seeds. All varieties were planted at two different dates: 1. May 5, 2017 which was early 2. May 23, 2017 which is when soybeans are typically planted in the area. The test plots were 10-feet-by-40-feet plots with four replications for each planting date. Due to consistent rainfall in the second half of September harvesting was delayed more than normal and was only completed October 3, 2017. The results featured in Table 1 show that yields, even though numerically quite different, were not statistically significant at the Henry location, especially for the early planting date. "This could be due to weed pressure and population loss as a result of heavy rainfall in late June," said Anthony Bly, SDSU Extension Soils Field Specialist. He explained that this site received 9-inches of rain in three days the last week of June, which flooded almost half of the early planted plots. Some early flooded plot yields were not as consistent at harvest compared to the non-flooded plots. Therefore, the yields from flooded plots were not used while running statistics which may have contributed to large Least Significant Difference (Table 1). This resulted in difficulty to statistically distinguish mean yields for the maturity ratings used in the study. At the Northeast Research Station, yields from the earliest maturing soybean variety (i.e. 0.2) were significantly different from the other three soybean varieties for both plating dates. "These results suggest that planting soybean varieties that are earlier than half the maturity point than recommended for the region did not result in equal or higher yields in 2017 growing season," Karki said. This research group plans to continue this study in the 2018 growing season. The study was funded by South Dakota Soybean Research and Promotion Council. Road Salt & Water Quality: Growing Concern in Some Northern States SDSU iGrow BROOKINGS, S.D. - While road salt throughout the winter months is seen by most as a necessity in our part of the country, it can come at a cost, said David Kringen, SDSU Extension Water Resources Field Specialist. "While the salination of South Dakota surface waters is not a water quality concern at this time, awareness of the issue could prevent it from being a concern in the future," Kringen said. He explained that salt corrosion can not only cause damage to our infrastructure (roads and bridges) and vehicles, it can be harmful to our freshwater ecosystems as well. Salination (or salinization), is the process where water-soluble salts accumulate in soils, or a body of water. It is typically measured by an increase in chloride, which is an anion of many salts (i.e. sodium chloride, magnesium chloride). In soils, salination is a concern, Kringen explained, because excess salts hinder the growth of crops by limiting their ability to take up water. "In freshwater ecosystems, increased salinity can significantly reduce both species richness (the number of species found in an ecosystem) and relative abundance (the abundance of a given species relative to the abundances of the other species) of aquatic plants and invertebrates; which in turn, affects the entire food chain," he said. Measuring Salinity Salinity ranges, measured as a concentration (milligrams per liter), are categorized as fresh to highly saline and can be seen in the table. The U.S. Environmental Protection Agency's nationally-recommended criteria for chronic (long-term) chloride toxicity exposure for freshwater aquatic life is 230 milligrams per liter. In South Dakota, surface waters recognize designated as coldwater permanent fish the link between the salination of water life propagation waters are assigned a nubodies with the application of road salts meric standard of 100 milligrams per liter as metropolitan areas continue to develop for a 30-day average and 175 milligrams and grow. per liter for a daily maximum. "Keep in mind, runoff that enters city "Concentrations above these limits storm sewer systems to be channeled means the water body does not support away is discharged untreated and delivthe beneficial use assigned to it," Kringen ered directly to rivers and streams; rivers said. and streams that we use for domestic, For surface waters designated as a commercial and recreational purposes," domestic water supply, the 30-day averhe said. age and daily maximum concentrations are 250 milligrams per liter and 438 milligrams per liter respectively. March 18th - 24th What research shows A recent study conducted in 2017 investigated long-term chloride trends in 371 freshwater For all your Ag & Industrial lakes in North America. "Results indicated that the Supplies density of roads and other All types of Welding, Machine Work, impervious land cover was Custom Fabrication. Also Fabrication & a strong predictor of longInstallation of Grain & Silage Bodies. term salination in Northeast and upper Midwest “In Business Since 1932” lakes where the study was focused," Kringen said. 106 Industrial Ave., Hartington, NE • 402-254-6788 Other studies also Wiechelman RepaiR Courtesy of iGrow. This table shows how salinity ranges, measured as a concentration (milligrams per liter), are categorized as fresh to highly saline. THE MOST TRUSTED NAME IN TARPS The best-designed, best-engineered, best-built tarping systems and electric accessories on the market! Be sure. Buy Shur-Co®. 2309 Shur-Lok St. 605.665.6000 SHURCO.COM