论文部分内容阅读
关于白浆土的形成,多数学者认为是在干湿交替的水分条件下,土壤表层发生潴育过程的结果。本研究目的在于测定白浆土各土层氧化还原电位的季节变化,以了解干湿交替的水分条件是否会导致铁锰的强烈还原。据1980—1982三年的测试结果表明:(1)在岗地白浆土现阶段所处的地形条件下,因季节性降雨而造成表土层的临时性滞水,并未引起氧化还原电位的大幅度降低。无论是正常雨量年份还是涝年,耕地还是荒地,各土层的Eh_7值均变动在500毫伏左右,最低不低于400毫伏,不足以引起铁锰的强烈还原。(2)低地白浆土,在无排水出路的情况下,土壤常期处于过湿状态,Eh_7值可降至200毫伏以下。具备同样滞水条件的低地草甸土,表土层的Eh值也出现低于200毫伏。(3)室内模拟淹水、水分饱和和正常水分变化(20～30%)三种土壤水分状况的试验结果进一步证明,土壤Eh的降低速度和幅度与其水分状况和有机质数量有很大关系。含有机质较多的表土土柱,在其淹水状况下,Eh值可迅速降低,达到较强的还原状态(—60至150毫伏);在其水份饱和状况下,Eh值可逐渐降至200毫伏左右,达中等还原状态,而在正常持水状况下,Eh值变化不低于300毫伏。含有机质很少的母质,在同样的水分状况下,还原强度较弱。
On the formation of albacore, most scholars believe that the wet and dry alternating water conditions, the surface of the soil occurs as a result of the process of retention. The purpose of this study was to determine the seasonal variations of the redox potential of the soils in Albic soil so as to understand whether the alternate wetting and drying conditions would result in the intense reduction of Fe and Mn. According to the test results of 1980-1982 for three years, it is shown that: (1) Temporary water-holding caused by seasonal precipitation caused by the topography of the Albic soil at the current stage did not cause large redox potential The rate of decrease. Eh_7 values of all soil layers fluctuate about 500 mV and the minimum is no less than 400 mV, which is not enough to cause the intense reduction of iron and manganese, no matter whether it is a year of normal rainfall, a year of flooding, or arable land or wasteland. (2) In the lowland white earth, under the condition of no drainage outlet, the soil is often in a wet state, and the Eh_7 value can be reduced below 200 mV. With the same stagnant water conditions, the Eh values of the topsoil also appear below 200 mV. (3) Indoor simulation of waterlogging, water saturation and normal water change (20 ~ 30%) The results of three soil moisture conditions further prove that the decreasing rate and amplitude of soil Eh are closely related to the water status and the amount of organic matter. Eh values of topsoil with more organic matter may decrease rapidly and reach a strong reduction state (-60 to 150 mV) under the condition of flooding; Eh value may gradually decrease under the condition of water saturation To 200 millivolts or so, reaching a state of moderate reduction, while under normal water conditions, Eh value changes of not less than 300 millivolts. Contains little organic matter in the same water conditions, the reduction of strength is weak.