3Lynch J P,Wojciechowski T.Opportunities and challenges in the subsoil:Pathways to deeper rooted crops[J].Journal of Experimental Botany,2015,66(8):2199-2210.
4David F W,Rober A,Juliette S K.The box plot:A simple visual method to interpret data[J].Academia and Clinic,1989,110(11):916-921.
5Hu H Y,Ning T Y,Li Z J,et al.Coupling effects of urea types and subsoiling on nitrogen-water use and yield of different varieties of maize in northern China[J].Field Crops Research,2013,142(3):85-94.
6Wang Q J,Lu C J,Li H W,et al.The effect of no-tillage with subsoiling on soil properties and maize yield:12-Year experiment on alkaline soils of Northeast China[J].Soil and Tillage Research,2014,137(3):43-49.