一种评估土壤团聚体稳定性的搅拌破碎能量法

Using Mechanic Stirring Method to Assess the Stability Energy of Soil Aggregate

土壤团聚体稳定性是评价土壤质量高低的重要指标,开展团聚体稳定性定量评估对于土壤质量评价具有重要意义。国内外对于土壤团聚体稳定性的定量研究很少,当前尚无成熟的团聚体稳定性量化理论与技术。鉴于此,该文提出了一种评估土壤团聚体稳定性的搅拌破碎能量法。通过实时监测土水溶液搅拌过程中的搅拌机电功率和溶液温度,由能量转化守恒定律计算出土壤搅拌破碎能量,从而确定土壤团聚体的稳定性。通过纯水和完全破碎土样与团聚土样的对比试验,验证了方法的可行性,即同等试验条件下,系统损耗相同,而且团聚土样和完全破碎土样或者纯水的搅拌功率差为搅拌破碎功率。在此基础上通过红壤、黑土和塿土3种对照土样的测试,并与Yoder湿筛法作对比,验证方法的实用性。测量结果表明,红壤稳定性最好,其搅拌破碎能量最大,为48.59 J/g-1,而塿土和黑土则分别为28.67和25.59 J/g-1,表现出相近的弱稳定性。Yoder湿筛法测定的平均质量直径分别为红壤0.69 mm,塿土0.35 mm,黑土0.41 mm,其稳定性评估结果与搅拌破碎能量法一致,证明了方法的实用性。

It is of great importance to quantify the stability of soil aggregate, as an important indicator for soil quality assessment. However, there were no standard theories and techniques to quantify the index. Here a mechanic stirring method to quantify the stability energy of soil aggregate is introduced, where a stirred-dispersive energy was recorded from the real-time change of the motor power and temperature of soil water system. Additionally, companied pure-water test, as well as dispersed and undispersed soil were conducted, and validated the innovating method. Moreover, various types of soils from different Chinese provinces were collected, that is Red earths from Jiangxi Province, Black soils from Jilin Province, and Lou soil from Yangling, Shaanxi Province, for the test of aggregate stability with Yoder wet-sieving method. The stirred dispersive energies of Red earths, Black soils, and Lou soil were 48.59, 25.59, and 28.67 J/g-1, indicating a highest stability of Red earths, followed by Black soils and Lou soil (similar). An evident-validating was found using wet sieving, with a corresponding Mean Weight Diameters (MWD) of 0.69, 0.41, and 0.35 mm, respectively. To sum up, our results showed the accuracy and practicability of the stirred dispersive energy method.