Sign up for email alerts of new Fluid Journal issues!
Fluid Journal : Fluid Journal 2005-2007
WINTER 2007 Fluid Journal 21 conventional surface soil samples provide a better indication of Cl availability. A 2-foot sample is frequently recommended. Fine textured soils that have a history of K fertilization with potassium chloride (0-0-60) will likely be high in Cl. Similarly, soils irrigated with high chloride water content will likely show high Cl concentrations. Responses to additional Cl fertilization would not be likely. For those areas of the North American continent where soils are high in K and K fertilization is not practiced, Cl fertilization may be a very profitable management addition for wheat, corn, grain sorghum, and forage grasses. Some indication of responses in sunflowers has been recorded but little research has been conducted on other broad leaf crops, including soybeans. Chloride fertilization Chloride fertilizers include ammonium chloride solution (6% nitrogen (N), 16.5% Cl), potassium chloride solid (45-47% Cl), magnesium chloride solid (75% Cl), and calcium chloride solid (65% Cl). Potassium, magnesium, and calcium chloride can be made available as solutions but with substantially lower Cl concentrations. Limitations of these materials in fluid mixes include potassium nitrate salt out in combination with UAN, and Mg and Ca incompatibility with any traces of P in fluid systems. Because of soil mobility of Cl, application close to the time of plant need is probably a better management choice. This would include: • Topdressing of winter wheat along with N and S • At seeding or preplant applications for spring grains • Spring preplant, at planting (sidebanded starter), or sidedress applications (along with N and S) for corn, grain sorghum, and sunflowers • Winter or early spring topdressing with N and S for cool season grasses • Spring and split applications with N and S for perennial warm season grasses. Remember that with any application involving fluid P, Mg and Ca, chlorides are not compatible. Chloride rates in the 20- to 30-lb/ A range have been adequate under most conditions. Relatively high salt indices of these materials preclude applications in direct seed contact for small grains or row crops. Starter placement (2x2 or 2x0) for row crops or spring grains has worked well. Closer placements on finer-textured soils, relative to the row, may be possible with precision applicators. As far as plant availability goes, all of these Cl sources are effective. Once in the soil, Cl is Cl. University research has confirmed that point. Decisions on selection of a material to sell or use have to be based on availability in the market, compatibility with other fluid nutrients with which the material will be mixed, and, of course, price. Figure 1. Chloride deficiency symptoms in wheat. Dr. Rich Engel, Montana State University.
Fluid Journal 2002-2004
Fluid Journal 2008-2009