In spite of many studies focused on the impact of land use changes on soil organic carbon (SOC) and the total nitrogen (TN) and soil organic matter (SOM) budget, less is known about the fate of water-extractable organic matter (WEOM) after the conversion of forestland to conventional farmland. The main aims of this study were: 1) to determine the concentration of water-extractable organic carbon (WEOC) and water-extractable total nitrogen (WETN) in topsoil horizons of forestland soils and cropland soils in the Carpathian Foothills in southern Poland and 2) to determine the quality of WEOM in topsoil horizons of forestland soils and cropland soils. Soil samples from topsoil horizons of forestland soils (Oi and Ah horizons) and cropland soils (Ap horizons) were collected and the concentration of WEOC and WETN was determined. In addition, the quality of WEOM was determined using ultraviolet-visible (UV–vis) spectroscopy and Fourier-transform infrared attenuated total reflectance (FTIR-ATR) spectroscopy. The results of this comparative study clearly indicate that conventional agriculture significantly affects the concentration and quality of WEOM in surface soil horizons of Retisols in the Carpathian Foothills in southern Poland. Surface horizons of arable soils (Ap horizons) are characterized by a significantly lower mean concentration of WEOC and WETN in comparison with surface horizons of forestland soils (Oi and Ah horizons), and reflect changes in the content of bulk SOC and TN due to soil tillage. Mean concentrations of WEOC and WETN in the studied Ap horizons of arable soils are 1.98 mg l⁻¹ and 0.15 mg l⁻¹, respectively while the mean concentrations of WEOC and WETN in the Ah horizons of forestland soils are 15.53 mg l⁻¹ and 0.84 mg l⁻¹, respectively. The studied Oi horizons of forestland soils are characterized by the highest mean concentration of WEOC (44.53 mg l⁻¹) and WETN (6.22 mg l⁻¹). Mean specific UV absorbance values at wavelength of 254 nm (SUVA₂₅₄) was the highest for WEOM from Ap horizons indicating the highest transformation of WEOM in these horizons. Mean FTIR-ATR absorption bands of WEOM obtained from Oi and Ah horizons are much more intensive than the bands of WEOM from Ap horizons, which is related to significantly lower concentration of WEOM in the latter horizons in comparison with Oi and Ah horizons of forestland soils.

尽管许多研究集中在土地利用变化对土壤有机碳（SOC）和总氮（TN）和土壤有机质（SOM）预算的影响上，但对水提取有机质（WEOM）的命运知之甚少），将林地转变为常规农田之后。这项研究的主要目的是：1）确定波兰南部喀尔巴阡山脉丘陵地带森林土壤和农田土壤表层土壤中可水提取的有机碳（WEOC）和可水提取的总氮（WETN）的浓度； 2 ）以确定林地土壤和农田土壤表土层中WEOM的质量。收集林地土壤（Oi和Ah层）和农田土壤（Ap层）的表土层的土壤样品，并确定WEOC和WETN的浓度。此外，WEOM的质量使用紫外可见光谱（UV-vis）和傅立叶变换红外衰减全反射（FTIR-ATR）光谱确定。这项比较研究的结果清楚地表明，常规农业显着影响波兰南部喀尔巴阡山脉丘陵区网纹土壤表层土壤中WEOM的浓度和质量。耕地的地表水平（Ap地层）的特征在于，WEOC和WETN的平均浓度比林地土壤的地表水平（Oi和Ah地层）低得多，并反映了土壤中SOC和TN的含量变化耕作。在研究的耕地平均水平上，WEOC和WETN的平均浓度为1.98 mg l 这项比较研究的结果清楚地表明，常规农业显着影响波兰南部喀尔巴阡山脉丘陵区网纹土壤表层中WEOM的浓度和质量。耕地的地表水平（Ap地层）的特征在于，WEOC和WETN的平均浓度比林地土壤的地表水平（Oi和Ah地层）低得多，并反映了土壤中SOC和TN的含量变化耕作。在研究的耕地平均水平上，WEOC和WETN的平均浓度为1.98 mg l 这项比较研究的结果清楚地表明，常规农业显着影响波兰南部喀尔巴阡山脉丘陵区网纹土壤表层中WEOM的浓度和质量。耕地的地表水平（Ap地层）的特征在于，WEOC和WETN的平均浓度比林地土壤的地表水平（Oi和Ah地层）低得多，并反映了土壤中SOC和TN的含量变化耕作。在研究的耕地平均水平上，WEOC和WETN的平均浓度为1.98 mg l 耕地的地表水平（Ap地层）的特征在于，WEOC和WETN的平均浓度比林地土壤的地表水平（Oi和Ah地层）低得多，并反映了土壤中SOC和TN的含量变化耕作。在研究的耕地平均水平上，WEOC和WETN的平均浓度为1.98 mg l 耕地的地表水平（Ap地层）的特征在于，WEOC和WETN的平均浓度比林地土壤的地表水平（Oi和Ah地层）低得多，并反映了土壤中SOC和TN的含量变化耕作。在研究的耕地平均水平上，WEOC和WETN的平均浓度为1.98 mg l^-1和0.15 mg l ^-1，而林地土壤中Ah层的WEOC和WETN的平均浓度分别为15.53 mg l ^-1和0.84 mg l ^-1。所研究的林地土壤Oi层的特征在于WEOC（44.53 mg l ^-1）和WETN（6.22 mg l ^-1）的最高平均浓度。在254 nm波长处的平均特定UV吸收值（SUVA ₂₅₄）是AP视域中WEOM的最高值，表明WEOM在这些视域中的转换率最高。从Oi和Ah层获得的WEOM的平均FTIR-ATR吸收谱带比从Ap层获得的WEOM的谱带要强得多，这与后林带的WEOM浓度相比，林地土壤的Oi和Ah显着更低。