02354nam a2200433 a 450000100080000000500110000800800410001910000200006024501140008026000510019430000100024550000180025552013090027365000120158265000100159465000120160465000130161665000120162965000110164165000190165265000150167165000140168665000090170065000120170965000160172165000160173765000160175365000140176965000090178365000090179265000090180165000120181065000100182265300160183265300170184865300110186565300240187665300200190015564361996-09-25       1993    bl uuuu  m   00u1 u    #d1 aSANZONOWICZ, C.  aMagnitude, interaction and amelioration of subsurface acidity constraints to soybean root growth in solution.  aRaleigh: North Carolina State Universityc1993  a197p.  aPh.D. Thesis.  aA vertical split root technique was used to evaluate effects of H+, AI, Ca, Mg and (CI and SO4=) on root development of soybean (Glycine max (L.) Merr.) var. Ransom.; Soybean shoot growth and root length in a compartment filled with topsolil were not affected by treatments imposed to the subsurface solution. At low pH, low Ca, high Ai concentrations and at absence of B and Zn there was reduced length of all root components,increased lateral root density, and reduced distance from the main root apex to the youngest lateral root. Reduced root growth in solution was associated with low pH, low Ca, high AI, absence of B and Zn, otherwise they stimulated root branching in the soil compartment, and this led to a greater number of roots crossing the membrane with time. Lateral roots had greater sensitivity than main roots to low pH, low Ca and high AI.; In the absence of AI, the Ca/H molar activity ratio was the best predictor of main root growth.; There was no response in main root growth to increased Ca supply when Ca/H ratiowas &gt 1000. Aluminum toxicity to roots was modified by pH, Ca, Mg and accompanying anions. In the presence of AI, molar activity ratios of Ca/AI and Ca were the best predictions of main root growth. Ferron reagent was likely overestimated reactive AL and failed ....  aacidity  aroots  asoil pH  asoybeans  asubsoil  aAcidez  aAcidez do Solo  aAdubação  aAlumínio  aBoro  aCálcio  aCrescimento  aGlycine Max  aHidrogênio  aMagnésio  aRaiz  aSoja  aSolo  aSulfato  aZinco  aConstraints  aFertilizacao  aGrowth  aMelhoramento dosolo  aSoil amendmants