EFFECTS OF SOIL TEMPERATURE, MOISTURE, AND AIR‐DRYING ON EXTRACTABLE MANGANESE, IRON, COPPER, AND ZINC
EFFECTS OF SOIL TEMPERATURE, MOISTURE, AND AIR‐DRYING ON EXTRACTABLE MANGANESE, IRON, COPPER, AND ZINC
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DOI：
10.1097/00010694-198012000-00008
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发表时间：
1980-12
期刊：
影响因子：
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通讯作者：
L. M. Shuman
中科院分区：
文献类型：
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作者：
L. M. Shuman
用于提取微量元素的土壤样品通常不考虑田间水分含量，并储存在各种条件下。为了研究这些措施对可提取微量元素的影响，我们在不同温度和水分条件下对三种土壤进行了2周的培养。温度分别为10、25和40°C，湿度分别为5、1/3和0巴张力。在风干和潮湿状态下，提取土壤中的二乙烯三胺五乙酸锰、铁、铜和锌。当土壤在0巴湿度下培养时，土壤中可提取的锰、铁和铜随着温度的升高而增加。在干燥机水分水平上，温度对这些元素没有影响。对于提取前风干的样品，温度升高在许多情况下降低了锌的可萃取性。当土壤在0巴湿度下培养时，土壤中可提取的锰的增加幅度较大，铁和铜的增加幅度较小。在两个较干燥的水分水平之间，可提取的锰、铁和铜的变化大多不显著。土壤可浸提态锌随水分水平的增加而减少。在较低的两个培养水分水平下，在提取前风干土壤可增加可提取的锰和铁，但在0-bar水平上，这一模式相反。在几乎所有的情况下，与湿法提取相比，提取前风干的样品可提取的铜和锌增加。不同的温度和湿度会使所研究的所有微量元素的萃取性发生显著变化。气干在低水分下提高浸出率，在高水分下降低浸出率的作用尤为重要。风干前土壤水分状况可能会影响风干对土壤可提取微量元素的影响。
Soil samples for microelement extraction are often taken with little regard to field moisture content and stored under a variety of conditions. In order to study the effects of these practices on extractable microelements, we incubated three soils for 2 weeks at various temperatures and moisture contents. The temperatures were 10, 25, and 40°C, and the moisture levels were 5, 1/3, and 0 bars tension. The soils were extracted for diethylenetriamine pentaacetic acid manganese, iron, copper, and zinc after air-drying, as well as in the moist state. Extractable Mn, Fe, and Cu increased with increased temperatures when the soils were incubated at the 0-bar moisture level. Temperature had no effect on these elements at the dryer moisture levels. Increased temperatures decreased Zn extractability in many cases for samples air-dried prior to extraction. Large increases in extractable Mn and smaller increases in Fe and Cu resulted when soils were incubated at 0-bar moisture. Changes in the extractable Mn, Fe, and Cu between the two drier moisture levels were mostly nonsignificant. Extractable Zn decreased with increasing moisture levels. Air-drying the soils prior to extraction caused increased extractable Mn and Fe, when compared with moist extraction at the lower two incubation moisture levels, but at the 0-bar level this pattern was reversed. Extractable Cu and Zn increased upon air-drying the samples prior to extraction, as compared with moist extraction, in nearly every case. Varying temperature and moisture caused significant changes in the extractability of all the microelements studied. The effect of air-drying increasing extractability at low incubation moisture and decreasing extractability at high moisture is particularly important. The conditions of soil moisture prior to air-drying may influence the effects of air-drying on extractable soil microelements.