【摘要】 秸秆是优质的有机资源，研究含钙添加剂种类及添加量对不同秸秆腐解产物可溶性有机物（DOM）组成性质差异，可为秸秆高效腐熟利用提供理论依据和技术参考。以花生秸秆和水稻秸秆为供试物料，通过添加不同含钙添加剂草酸钙（CaC₂O₄）和氢氧化钙[Ca（OH）₂]及不同添加量（4%、 8%）,进行秸秆腐解试验。测定腐解产物养分含量，并利用三维荧光光谱（3DEEM）技术和平行因子方法（PARAFAC）探究秸秆腐解产物DOM的化学组成变化特征。结果表明：（1）总体上，草酸钙处理的秸秆腐解物总碳含量显著大于氢氧化钙处理；高量添加剂处理的秸秆腐解产物总碳含量小于低量处理；花生秸秆腐解产物的总氮、总磷和总钾高于水稻秸秆腐解产物。（2）通过3DEEM-PARAFAC方法分析腐解产物DOM组成，共识别出类胡敏酸（C1）、类胡敏酸（C2）和类色氨酸（C3）三种荧光组分；不同添加剂类型、添加量和不同秸秆类型对腐解产物DOM荧光组分的影响较为复杂，没有明显规律，但是总体上氢氧化钙处理的秸秆腐解产物DOM的C1和C2组分比例大于草酸钙处理，而草酸钙处理的秸秆腐解产物DOM的C3组分比例显著高于氢氧化钙处理；秸秆腐解产物DOM中组分C1、 C2与组分C3呈显著负相关；组分C2含量与总碳含量呈显著负相关。（3）氢氧化钙处理的秸秆腐解产物DOM的腐殖化指数（HIX）明显高于草酸钙处理，而草酸钙处理的秸秆腐解产物DOM生物源指数（BIX）明显高于氢氧化钙处理；高量草酸钙处理秸秆腐解产物DOM主要来自于微生物的转化，而其他处理DOM来自于微生物转化和陆生植物；不同添加量处理下秸秆腐解产物DOM的荧光指数没有明显变化规律；花生秸秆腐解产物DOM的HIX、 BIX和荧光指数（McKnight index）均高于水稻秸秆；秸秆腐解产物DOM中McKnight和HIX呈显著负相关，和BIX间呈极显著正相关，而秸秆腐解产物DOM中BIX和总碳含量呈显著正相关。上述结果表明，氢氧化钙可以促进秸秆腐解以及腐解产物的腐殖化，其中高量氢氧化钙处理的花生秸秆效果较好。更多还原

【Abstract】 Straw is a high-quality organic resource. Clarifying the differences in the composition and properties of dissolved organic matter（DOM） of different straw decomposition products treated by calcium-containing additives can provide a theoretical basis and technical reference for the efficient utilization of organic materials.Straw decomposition experiments were carried out using peanut straw and rice straw as test materials by adding different calcium additives（CaC₂O₄, Ca（OH）₂） with different amounts（4%, 8%）. The nutrient contents of decomposition products were determined.At the same time, changes in the DOM chemical composition in straw decomposition products were analyzed using three-dimensional fluorescence spectroscopy（3DEEM） and the parallel factor method（PARAFAC）. The results showed that:（1） The total carbon content of straw decomposition products was significantly greater in the calcium oxalate treatment than in the calcium hydroxide treatment.The total carbon content of straw decomposition products was less in the high-amount additive treatment than in the low-amount treatment. The total nitrogen, phosphorus and potassium levels of peanut straw decomposition products were higher than those of rice straw decomposition products.（2）The DOM composition of decomposing products was analyzed by the 3DEEM-PARAFAC method. Three fluorescent components, such as humic acid（C1）, humic acid（C2）, and tryptophan（C3）, were identified. The effect of different additive types, addition amounts, and straw types on fluorescence fractions was complex and had no clear pattern.In general, the proportion of C1 and C2 fractions in DOM from the calcium hydroxide treatment was greater than those from the calcium oxalate treatment, while the proportion of C3 fractions in DOM from the calcium oxalate treatment was significantly higher than that from the calcium hydroxide treatment.Fractions C1 and C2 were significantly negatively correlated with fractions C3. The C2 content of DOM was significantly negatively correlated with total carbon content.（3） The HIX value of the DOM in straw decomposition products treated with calcium hydroxide was significantly higher than that treated with calcium oxalate. The BIX value of DOM treated with calcium oxalate was significantly higher than that treated with calcium hydroxide. DOM of straw decomposition products treated with high amounts of calcium hydroxide was mainly from the transformation of microorganisms, while DOM ofother treatments came from the transformation of microorganisms and terrestrial plants.The fluorescence index of straw decomposition products did not change significantly under different addition treatments. HIX, BIX, and McKnight’s index of DOMin peanut straw decomposition products were higher than in rice straw. There was a significant negative correlation between McKnight and HIX and an extremely significant positive correlation with BIX. Meanwhile, the contents of BIX and TC were significantly positively correlated. The above results showed that calcium hydroxide can promote straw decomposition and humification. A higher amount of calcium hydroxide was more effective in peanut straw decomposition.更多还原