5[1]BENGOUGH A G,MACKENZIE C J,ELANGWE H E.Biophysics of the growth responses of pea roots to changes in penetration resistance[J].Plant Soil,1994,167:135-141.
6[2]MATERECHERA S A,DEXTER A R,ALSTON A M.Penetration of very strong soils by seedling roots of different plant species[J].Plant Soil,1991,135:31-41.
7[3]RAWLINS S L,DALTON F N.Psychometric measurements of soil water potential without precise temperature control[J].Soil Sci.Soc.Am.Proc.,1967,31:297-301.
8[4]BENGOUGH A G,YOUNG I M.Root elongation of seedling peas through layered soil of different penetration resistances[J].Plant Soil,1993,149:129-139.
9[5]BENGOUGH A G,MULLINS C E.The resistance experienced by roots growing in a pressurized cell-a reappraisal[J].Plant Soil,1990,123:73-82.
10[6]PASSIOURA J B.Soil structure and plant growth[J].Aust.J.Soil Res.,1991,29:717-728.