Yield and N uptake of barley on two artificially eroded soils in north-central Alberta

Abstract

Topsoil depth is an indirect indicator of soil quality and crop productivity. A 2-yr field study was conducted in north-central Alberta with the following objectives: (1) to determine aboveground barley dry matter yield, N uptake, and fertilizer-use efficiency (FUE) in two artificially eroded soils of contrasting properties, and (2) to assess the effectiveness of KNO3 and urea in compensating for lost productivity. Field experiments were conducted on an Orthic Gray Luvisol (Site 1) and on an Eluviated Black Chernozem (Site 2) in 1991 and 1992. The treatments consisted of three depths of topsoil removal (0, 10 and 20 cm) and three N fertilizers (KNO3 and urea at 150 kg N ha−1, and the control). The plots were sown to barley (Hordeum vulgare L.). Yields and N uptake of aboveground barley dry matter decreased with each increment of topsoil removal and were lowest in the 20-cm topsoil removal. Fertilizer N improved yields and N uptake at each depth of erosion. In most of the erosion treatments barley yields and N uptake tended to be greater with KNO3 than with urea. The effectiveness of each N source, however, varied with site. At the 20-cm depth of erosion, KNO3 was more effective than urea. The trend in fertilizer-use efficiency increased with depth of erosion at Site 1 but decreased at Site 2. Key words: Artificial erosion, barley, fertilizer-use efficiency, potassium nitrate, urea