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Fluid Journal : Fall 2017
16 The Fluid Journal Fall 2017 acidity and associated aluminum toxicity may be to plant a tolerant crop or wheat variety but also integrate an effective liming program in regular farming practices (see also Kurt Schroeder and Mike Pumphrey 2013). Liming benefits include: • Increased soil pH and reduction of available toxic cations: Mn++, Al+++, Fe+++ • Increase in exchangeable Ca++ and Mg++ • Binding of heavy metals • Improved soil structure • Improved nutrient availability • Decrease of susceptibility of moisture stress • Higher soil biological activity • More effective herbicide action Our goal. Soil surface liming using highly reactive lime sources such as fluid and palletized micronized limes at sufficient rates to overcome soil acidity are the most effective method. However, the recommended rates as identified through standard soil analytical laboratories are not economical in inland Northwest farming systems where the return on investment (adding additional cost) can be negative (especially in the current grain market of 2017), The greatest effectiveness, affordability and acceptance, we believe, will be found in alternative lime application methods. This includes precision placement of micronized fluid lime with the seed in the soil in direct seed, no- till operations, concentrated actions in soil microenvironments to neutralize the acidity produced by annual fertilizer applications and overcoming acid soils stratification (Figure 5). It is our intent to introduce and establish such farming techniques to incorporate lime every year as a preventive measure and as a strategic system to gradually overcome acidity while improving soil health and crop yields in the dry land regions. Sampling of specific soil strata may identify where acidity problems and lime needs are concentrated (0 to 3 inch, 3 to 6 inch and 6 to 12 inch). Soil pH below 5.5 (particularly in the seed zone) impacts all of the associated limiting factors as well as aluminum toxicity. Examining the plant for short stubby and twisted roots further verifies aluminum toxicity. The toxicity of Figure 1. Major dryland farming areas of the United States and Canada. Source: Dregne and Willis, 1983. exchangeable aluminum varies greatly between soil types, organic matter content cationic exchange capacity and other factors. Plant tissue Al concentration greater than 200 ppm likely indicates a problem. Soil concentrations over 60 ppm clearly indicate Al toxicity. The study. The goal for the study of precision application of NuCal fluid lime was: • Determine if chosen equipment setup