Effects of simulated erosion and amendments on grain yield and quality of wheat
Field experiments were conducted in 1991 at Josephburg (Black Chernozem soil) and Cooking Lake (Gray Luvisol soil), Alberta, Canada, to determine the influence of depth of erosion (simulated-erosion approach by artificially removing the topsoil) and amendments on grain yield, protein concentration and thousand kernel weight (TKW) of hard-red spring wheat (Triticum aestivum L. cv. Roblin). There were five erosion levels (0, 5, 10, 15 and 20 cm) and four amendments (control, addition of 5 cm of topsoil, addition of fertilizer at 100 kg N/ha and 20 kg P/ha, and cattle manure at 75 Mg/ha on a dry basis). Yield reduction due to topsoil removal was a function of nutrient loss. The applications of fertilizer N and P, and cattle manure improved yield substantially and reduced the impact of yield loss due to erosion. Return of 5 cm of topsoil to the plots made the rate of yield loss an independent function of erosion. At both sites, protein concentration in wheat grain was influenced by the erosion level imposed and the kind of amendment used. The protein concentration at Josephburg decreased from 141 g/kg in the non-eroded treatment to 124 g/kg in the 20-cm erosion treatment. In the same order, the values for the Cooking lake site were 132 and 123 g/kg, respectively. The application of commercial fertilizers at Josephburg resulted in the highest protein concentration (153 g/kg). At both sites, TKW decreased with increasing depth of soil erosion. At Cooking Lake, all amendments produced heavier seeds than the control plots. In conclusion, the productivity of artificially-eroded soil was mostly a function of nutrient removal. The productivity and quality of wheat was partially restored by using either fertilizer or organic amendments.
Soils and Crops Workshop