This is Part one of two articles that we will feature on soil health.
Posted on 10/19/17
By Lisa Nowatzki
On October 12, the NDSU Extension Service held the 2017 Cavalier County Soil Health Tour & No-Till Seeding Demonstration in Langdon at the NDSU Research Extension Center. Anitha Chirumamilla, the program MC, and Naeem Kalwar, Soil Health Specialist, welcomed area guests as the tour began.
First on the agenda was a visit to three local area farms owned by Karry Krahn, Jon Iverson, and Edwin Pearson for cover crop demonstrations. According to Kalwar, some of the goals of the farmers are to prevent soil erosion, to add organic matter and nitrogen to the biomass, and to produce hay, and/or areas for livestock grazing.
Soil tests of each area included an EC or soil electrical conductivity test. According to the NDSU Extension service, EC tests determine the levels of soluble salts (salt salinity) in a given sample. Soil pH was also measured. This test measures the acidity and alkalinity of a soil sample.
The SAR or Sodium Absorption Ratio was measured. This test characterizes the soil sodicity, which describes the proportion of sodium to calcium and magnesium in a soil solution.
Another test performed on the soil at the farms included a measure of the soil organic matter or O. M. According to the Extension office, organic matter is a very important part of the composition of a healthy soil.
Finally, the team measured sulfur content, the amount of chloride present and CCE or calcium carbonate equivalent in the soil samples.
All of these tests help to determine soil nutrient content, whether the soil is saline or sodic or a combination of both. Nutrient content plays a very important part in plant health and growth.
At the Krahn site, problems with localized areas of high salinity, low sodicity and excess saturation caused bare sites with little to no growth.
Several goals of the soil tour involves understanding how high salt and high sodium levels affect plants and soils, learning to recognize the visual symptoms, properly sampling the affected areas, knowing what soil tests to ask for, and understanding the results are crucial steps to remediate these areas for profitable crop production.
For Krahn, between 2012 and 2017 soil samples revealed that areas with high salt levels had no alfalfa growth. However, the areas with little alfalfa growth decreased over time.
The final soil analysis revealed that in between the years of 2012 and 2017, with the alfalfa and wheatgrass mix, the amount of salt and sodium in the first foot of soil gradually decreased to zero in 2017. However, the second and third feed had high salt and sodium issues.
The soil consisted of a mixture of 73% of a saline Vallers-Hamerly loam and 23% Easby clay loam. In 2011, (a Fall dormant seeding) and in 2012 a Spring re-seeding of salt tolerant grasses and alfalfa mix were planted. Establishment took three years with the grasses establishing first, which then helped the alfalfa develop.
In 2012 the average production value was .6 bales per acre of mostly kochia. In 2013 the same area yielded 2.5 bales per acre of alfalfa and grass. In 2016, the same area yielded 6.5 bales per acre with 3 cuttings of alfalfa and grass. In 2017, because of the drought, the area only yielded 1 bale per acre with two cuttings.
Soil analysis on the next site, Jon Iverson’s farm, revealed a problem with excess saturation with high salt and sodium levels. Within the spots with no seed germination, salt levels were the same, however, sodium levels were higher.
The soil consisted of a mix of Hamerly and Tonka (47%), Hamerly and Cresbard loam (35%) and Svea and Cresbard loams (18%). In 2016 and 2017, a sensitive cover crop mix (peas, turnips, radishes, and oats) was planted after harvesting spring wheat to use for excess moisture along the road ditches.
Ed Pearson’s farm was next. Soil analysis showed that the sampled area had high salinity and high sodicity with excess saturation. His soil consisted of Cavour and Cresbard loams (87%), Easby clay loam (8%), and Vallers-Hamerly loams saline (6%). Pearson wanted to have something established along the very saline-sodic slough. He planted a salt tolerant/OM Builder mix of sugar beets sweet, clover, oats, turnips and radishes.
Pearson wanted to achieve three goals. First, he wanted to improve the soil health. He also wanted to increase crop productivity, and, finally, he wanted to improve aftermath grazing for his cattle. The 2017 drought delayed germination of his corn crops planted on September first and second. Germination did not occur until September 25-27.
The lower area along the slough had very high salt and sodium levels. The next area, which had a moderate corn crop, also had high salt and sodium issues. Pearson plans to follow-up with buffer grass seeding and soil amendments of gypsum and beet lime in 2018 to reduce lateral movement of water and salts and reduce sodicity.