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

Abstract

Pradhan, R., Izaurralde, R. C., Nyborg, M. and Malhi, S. S. 1997. Yield and N uptake of barley on two artificially eroded soils in north-central Alberta. Can. J. Soil Sci. 77: 317-322. 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 KNO 3 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 (KNO 3 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 KNO 3 than with urea. The effectiveness of each N source, however, varied with site. At the 20-cm depth of erosion, KNO 3 was more effective than urea. The trend in fertilizer-use efficiency increased with depth of erosion at Site 1 but decreased at Site 2.

Recovery of 15N-labelled fertilizers applied to barley on two artificially eroded soils in north-central Alberta

“…As the N supplying power of soil decreased with erosion (Izaurralde et al 1993), plants growing on eroded soil derived less N from native soil N than those growing on non-eroded soil (Table 6). This also explains the reason for the reduction in N uptake of barley with deeper cuts, reported in our previous paper (Pradhan et al 1997). …”

“…Therefore, the lack of improvement in the N uptake ability of barley plants on eroded treatments compared to non-eroded treatment in the present experiments can be attributed to decreased root growth. This also explains why the application of N fertilizers to barley on eroded soils, even at a high rate (150 kg N ha -1 ), was not able to restore yield and N uptake to the levels obtained on non-eroded soils observed in our previously reported results in the same experiment (Pradhan et al 1997). For personal use only.…”