The effects of soil organic matter on the water contents for tillage were investigated by sampling soils with a uniform texture, but a range of soil organic carbon (SOC) from two long-term field experiments at Highfield in Rothamsted Research, UK and Askov Experimental Station, Denmark. The treatments studied in Highfield were Bare fallow (BF), Continuous arable rotation (A), Ley-arable (LA) and Grass (G); and in Askov: unfertilized (UNF), ½ mineral fertilizer (½ NPK), 1 mineral fertilizer (1NPK), and 1½ animal manure (1½AM). Minimally disturbed soil cores (100 cm³) were sampled per plot in both locations from 6 to 10 cm depth to generate water retention data. Soil blocks were also sampled at 6–15 cm depth to determine basic soil properties and to measure soil aggregate strength parameters. The range of soil water contents appropriate for tillage were determined using the water retention and the consistency approaches. SOC content in Highfield was in the order: G > LA = A > BF, and in Askov: 1½ AM > 1NPK = ½NPK > UNF. Results showed that different long-term management of the silt loam Highfield soil, and fertilization of the sandy loam Askov soil affected the mechanical properties of the soils— for Highfield soil, aggregates from the G treatment were stronger in terms of rupture energy when wet (−100 hPa matric potential) than the BF treatment. As the soil dried (−300 and −1000 hPa matric potentials), soil aggregates from the G treatment were relatively weaker and more elastic than the BF soil. Our study showed, for both Highfield and Askov soils, a strong positive linear increase in the range of water contents for tillage with increasing contents of SOC. This suggests that management practices leading to increased SOC can improve soil workability by increasing the range of water contents for tillage. We recommended using the consistency approach over the water retention approach for determining the range of water contents for tillage because it seems to give realistic estimates of the water contents for tillage.

通过对质地均匀的土壤进行采样，研究了土壤有机质对耕作含水量的影响，但是来自英国Rothamsted Research的Highfield和Askov实验站的两次长期野外实验获得了一系列土壤有机碳（SOC） ，丹麦。在Highfield研究的处理方法是：裸休（BF），连续耕作（A），Ley-arable（LA）和Grass（G）；在阿斯科夫（Askov）：未施肥（UNF），1/2矿物肥料（1/2 NPK），1矿物肥料（1NPK）和1½动物肥料（1½AM）。最小扰动的土壤核心（100 cm ³在6至10厘米深度的两个位置的每个样地中对）进行采样，以生成保水数据。还对6至15厘米深度的土壤块进行了采样，以确定基本的土壤性质并测量土壤的聚集体强度参数。使用保水和稠度方法确定适合耕作的土壤水分含量范围。高场中的SOC含量顺序为：G> LA = A> BF，而在Askov中：1½AM> 1NPK =½NPK> UNF。结果表明，对粉壤土高田土壤的不同长期管理以及沙质壤土Askov土壤的施肥影响了土壤的机械性能。对于高田土壤，G处理的集料在湿润时的破裂能方面更强（ -100 hPa的基质电势）。随着土壤干燥（基质势为-300和-1000 hPa），G处理的土壤团聚体比BF土壤更弱，更有弹性。我们的研究表明，对于高地土壤和阿斯科夫土壤，随着SOC含量的增加，耕作水含量范围均呈现出强烈的线性正增长。这表明导致土壤有机碳含量增加的管理措施可以通过增加耕作含水量的范围来改善土壤的可加工性。我们建议使用一致性方法而不是保水方法来确定耕作含水量的范围，因为它似乎可以对耕作含水量做出实际的估计。随着SOC含量的增加，耕作水含量范围呈强烈的线性正增长。这表明，导致土壤有机碳含量增加的管理措施可以通过增加耕作含水量的范围来改善土壤的可加工性。我们建议使用一致性方法而不是保水方法来确定耕作含水量的范围，因为它似乎可以对耕作含水量做出实际的估计。随着SOC含量的增加，耕作水含量范围呈强烈的线性正增长。这表明导致土壤有机碳含量增加的管理措施可以通过增加耕作含水量的范围来改善土壤的可加工性。我们建议使用一致性方法而不是保水方法来确定耕作含水量的范围，因为它似乎可以对耕作含水量做出实际的估算。