作 者 ：王莲莲 张树兰 杨学云
期 刊 ：植物营养与肥料学报 2013年 19卷 2期 页码：404-412
Keywords:manural loess soil, long-term fertilizer experiment, soil organic carbon, soil inorganic carbon,
摘 要 ：利用土20年长期肥料定位试验研究了不同土地利用方式和施肥对土壤有机碳和无机碳储量变化的影响。试验包括休闲（Fallow, FL）、 撂荒（Setaside, SL）、 不施肥（CK）、 单施氮（N）、 氮钾（NK）、 磷钾（PK）、 氮磷（NP）、 氮磷钾（NPK）、 氮磷钾配合秸秆还田（SNPK）、 氮磷钾配合低量有机肥（M1NPK）和氮磷钾配合高量有机肥（M2NPK）11个处理。结果表明，CK和 FL 处理等质量耕层土壤有机碳储量仍维持在试验前水平，NP和 SL 处理显著提高了耕层土壤有机碳储量，年均增加分别达到 347 kg/hm2 和518 kg/hm2， 此4个处理等质量耕层土壤无机碳储量均较试验开始前（Initial soil, IniS）显著下降，尤其是NP处理显著低于其它3个处理。与IniS和CK相比，除NK处理外的所有施肥处理均显著地提高了等质量耕层土壤有机碳储量，其大小顺序为 M2NPK>M1NPK>SNPK>NPK≈NP>PK≈N，最大年均增加量为M2NPK 944 kg/hm2，最小为N 127 kg/hm2。施肥处理除PK和M2NPK处理外，其它处理等质量耕层土壤无机碳储量均较试验前明显降低，可能是由于土壤酸化所致。PK和M2NPK处理无机碳储量能够维持不下降，表明土壤无机碳和有机碳在适合条件下可能有某种关系。试验结果还显示，长期试验20年除M1NPK和M2NPK处理外，其它处理耕层土壤容重均明显高于试验开始前，表明等质量土壤碳储量与等深度碳储量相比可以更好地反映土壤碳的变化。
Abstract:The storages of soil organic and inorganic carbon under contrasting land use regimes and fertilization were analyzed on a basis of a 20-year long term experiment in a manural loess soil. There were eleven treatments, fallow (FL), setaside (SL), unamended control (CK), nitrogen (N), nitrogen and potassium (NK), phosphorus and potassium (PK), nitrogen and phosphorus (NP), nitrogen phosphorus and potassium (NPK), wheat/maize straw (S) with NPK (SNPK) and dairy manure (M) with NPK (M1NPK and M2NPK). The results indicated that the storages of soil organic carbon in the soils of the FL and CK, with an equivalent mass to that of top 20 cm soil of CK, remained unchanged relative to the soil prior to the commence of the experiment (Initial soil, IniS), while the storages were significantly improved under the treatments of NP and SL with an annual increase of 347 kg/ha and 518 kg/ha, respectively. The storages of soil inorganic carbon for CK, NP, FL and SL were dropped dramatically compared to initial soil, particularly for NP, on which it is even significantly lower than those of other three treatments. For treatments where nutrient management treatments were applied in conjunction with the cropping regime of winter wheat and summer maize rotation (exclusive of FL and SL treatments), the storages of soil organic carbon in plough layer soils on an equivalent mass basis of all but NK treatments were markedly enhanced compare with those of CK and initial soil in a order of statistic significance as follow: M2NPK > M1NPK > SNPK >NPK ≈ NP > PK ≈ N, of which, the maximum increase was observed on M2NPK with an annual mean value of 944 kg/ha, and a minimum value of 127 kg/ha on N. Whereas considerable decreases of the soil inorganic carbon storage in plough layer soils on an equivalent mass basis were found in all treatments except for PK and M2NPK in comparison to initial soil value, this is probably due to the acidification of the soil as the consequence of either precipitation or fertilization. The fact that the storages of inorganic carbon in PK and M2NPK, in ca. top 20 cm soils on equivalent mass, remained stable relative to their initial soil values might suggest that soil organic carbon may convert to inorganic form under some circumstances. The results also exhibited substantial decline in soil bulk densities in the treatments those receiving no organic manure, this result implied that the soil carbon storage on an equivalent mass basis rather than the equivalent soil depth could be a better indicator of soil carbon changes.
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