土壤是一个不均匀的多相体系,土壤中的很多化学性厦,随位置而异.从微观的角度看,土壤胶体颗粒周围的离子分布的不均匀性,已为大家所熟知;从较为宏观的角度看,由于通气情况不同所造成的团聚体内外部的差异,由于施肥、耕作等措施所造成的土壤性质的局部差异,以及由于植物的吸收和分泌所造成的根际土壤与外部土壤间的差异等,都在植物生长和实际农业措施上,具有重要意义.根据已有的材料和几年来在江西所进行的一些其他的大田测定拮果,我佣深深地感觉到,对于土壤性质的微域变化的研究,应该是问明植物生长的实际土壤环境中的一个重要方面.

For the study of the micro-regional properties of soils,microelectrodes are useful for the measurements of redox potential,pH value and electric conductance.When the buffered solutions were saturated with quinhydrone,the values of theoretical potentials can be obtained by the micro pt electrode with a diameter of 0.5 mm and length of 0.2 mm.If redox potentials of soils are ranged from 80 to 450 mv,2-5 my lower than the ordinary large electrode were found as measured by the microelectrode.For the measurement of pH value of air-dried soils,the difference between the micro quinhydrone electrode and the glass electrode was insignificant.In water-logged soils with a redox potential below 350 mv,however,the exverimental error may be 0.3-0.6 pH unit.