Wheat response and residual soil properties following subsoiling of a sandy loam in eastern Montana
1999
Pikul, J.L. Jr | Aase, J.K.
Shallow tillage pans resulting from the use of the same tillage tools may lead to wheat (Triticum aestivum L.) yield reductions. We hypothesized that occasional deep tillage to fracture shallow tillage pans would improve water utilization and result in increased wheat yield. Our hypothesis was tested by comparing paired crop and soil responses on plots that were subsoiled using a paratill (PT) or not subsoiled (NOPT). Soil was a Dooley sandy loam (US soil taxonomy: fine-loamy, mixed Typic Argiboroll; FAO taxonomy: Kastanozem) derived in glacial till near Culbertson, Montana, USA. Effects of PT or NOPT were compared in a long-term cropping study that included annual wheat using no tillage (NT), annual wheat using fall and spring tillage (FST) and wheat rotated with fallow (FWCT). Plots that were subsoiled (PT) were paratilled once in autumn 1992 to about 0.3 m deep. Cone index of the top 0.3 m of soil 2.5 years after subsoiling was lower on PT (891 kPa) compared with NOPT (981 kPa). Soil bulk density was 1.34 Mg m-3 on PT and 1.36 Mg m-3 on NOPT plots. Final water infiltration rate averaged 15 mm h-1 on PT and 6 mm h-1 on NOPT plots for nine months after subsoiling. Average water content of the top 1.2 m of soil in the spring of the year was 21 mm greater on PT than on NOPT plots. There were no differences due to treatments in wheat yield; average grain yield was 1820 kg ha-1 on annual wheat plots and 2380 kg ha-1 on wheat/fallow plots. Residual effects of subsoiling on soil properties were detected for 2.5 years after subsoiling, but soil changes attributed to subsoiling had no effect on wheat yield.
显示更多 [+] 显示较少 [-]