不同类型水稻种植下稻田根际土壤活性有机碳含量的差异

研究田间试验条件下水稻收获后不同类型稻田根际土壤溶解性有机碳、微生物生物量碳、易氧化态碳和颗粒态碳含量的差异。结果表明，种植常规稻的根际土壤中上述4种形态有机碳的含量分别为68．36～97．85 mg·kg^－1、292．00～434．24mg·kg^－1、4．32～6．72g·kg^－1、21．55～32．28g·kg^－1；种植杂交稻的根际土壤中其含量分别为80．06～98．28 mg·kg^－1，362．62～521．64 mg·kg^－1，4．71～6．82g·kg^－1，25．59～34．81 g·kg^－1；种植杂交稻的根际土壤中上述4种有机碳含量均显著高于种植常规稻的土壤。种植的水稻类型及品种间土壤溶解性有机碳、微生物生物量碳、易氧化态碳及颗粒态碳含量的差异受水稻品种和环境因素的影响，其机理涉及土壤-作物系统碳的输入与输出，与土壤-作物系统中碳分配和土壤生物碳利用的差异有关，需对此做深入研究。

Labile Organic Carbon Content in Rhizosphere Soils Planted with Different Varieties of Rice

Plot experiments were carried out in the field to determine the variation in the contents of dissolvedorganic carbon （DOC）,microbial biomass carbon （MBC）,readily oxidizable carbon （ROC）and particulate organiccarbon （POC）in the rhizosphere soils on which different varieties of rice were planted.The results showed that theDOC,MBC,ROC and POC contents in the soil when the regular indica rice was planted ranged 6 8.3 6 - 9 7.85mg·kg^-1 ,2 9 2.00-434.24 mg·kg^-1 ,4.3 2 -6.72 g·kg^-1 and 2 1.5 5 -3 2.28 g·kg^-1 ,respectively;and,whenthe hybrid indica rice was planted,they were 80.0 6 -9 8.28 mg·kg^-1 ,3 6 2.6 2 -5 2 1.64 mg·kg^-1 ,4.7 1 -6.82g·kg^-1 and 2 5.5 9 -34.8 1 g·kg^-1 ,respectively.It appeared that,aside from the possible environmental factors,variety of the rice planted on the soil played a critical role on those differences.The underlying mechanism,whichmight relate to the carbon input/output as well as the carbon distribution and bio-carbon utilization of the soil-cropsystem,would be,therefore,of great interest to be studied.