Improving Chickpea, Durum Wheat, and Mustard Yield, Crop Health, and Soil Fertility with Potassium Chloride, Phosphorus, and Copper Fertilizer
Date
2025-01-16
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ORCID
Type
Thesis
Degree Level
Masters
Abstract
Potash (KCl; 0-0-60) fertilizer is the most economical and widely used source for K and Cl for crop nutrition. However, the link between potash fertilization and crop yield and disease incidence has not been investigated with chickpea, mustard, and durum wheat crops on the prairies. To address this gap, field experiments near Central Butte, SK were completed in 2022 and 2023 along with controlled environment studies using three soils taken from across the Brown soil zone of Saskatchewan where the crops are commonly grown. For the field study, small plot RCBD experiments were set up in a field with treatments of starter potash banded at 40 kg KCl/ha and a control with no KCl at two slope sites: a dry knoll and a moist depression. In both years of the field study, growing season conditions were drier and hotter than normal and there were no significant responses in crop yield or large reductions in disease resulting from the additional starter potash application. This outcome aligned with the soil test values of high exchangeable potassium and K supply rate found in the soil and the limited moisture available during both growing seasons. In the depressional site, greater crop yield and nutrient removal was observed compared to the upslope knoll site due to the higher inherent soil fertility and additional moisture available. Crop and straw tissue analysis revealed no significant increases in K or Cl concentration from the KCl application. Most of the K and Cl uptake in the above ground biomass was in the straw portion rather than the grain, with about 30% of the above ground K and Cl contained and removed in the grain of chickpea and 10% in the grain of durum and mustard. The controlled environment studies examined the effect of starter KCl, monoammonium phosphate (MAP), and copper sulfate (CuSO4) alone and in combination on early crop growth and root and shoot disease incidence of the chickpea, mustard, and durum wheat crops. Even though there were high extractable concentrations and supply rates of K, P, and Cu levels considered above sufficiency in all three soils used, significant early season growth responses to fertilization were sometimes observed, varying by soil and crop type. Increases in early season biomass were found in the mustard grown in the sandy Chaplin association soil as well as the durum wheat grown in the loamy Sutherland association soil, and chickpeas grown in the Swinton association. In some cases where benefits were observed from fertilization, greatest increases were observed from the additive effect of fertilizers. Generally, the plant tissue P, Cu, and Cl concentrations responded more to fertilization than K, possibly due to inherently large K supplies in the soils. Chickpea biomass in the growth chamber was influenced by the presence of an emerging concern, referred to as the chickpea health issue, and there was no observed treatment effect on the severity of the chickpea health issue or other diseases present. Overall, yield and disease incidence responses of chickpea, mustard, and durum wheat to fertilization with KCl alone appear to be muted under dry conditions often found in the field in southern SK soils, but may be attenuated when phosphorus and copper fertilizers are applied under optimal conditions for growth.
Description
Keywords
Potash, KCl fertilization, Soil fertility, Mustard, Durum wheat, Chickpea, Crop nutrition, Brown soil zone, Monoammonium phosphate, Copper sulfate, Early season growth, Disease incidence, Chickpea health issue, Plant tissue analysis, Nutrient uptake, Landscape effects, Controlled environment study
Citation
Degree
Master of Science (M.Sc.)
Department
Soil Science
Program
Soil Science