Mondini Claudio, Sánchez-Monedero Miguel A, Sinicco Tania, Leita Liviana
CRA-Instituto Sperimentale per la Nutrizione delle Piante, sezione di Gorizia, Via Trieste 23, I-34170 Gorizia, Italy.
J Environ Qual. 2006 Oct 27;35(6):2313-20. doi: 10.2134/jeq2006.0055. Print 2006 Nov-Dec.
Extracted organic C and microbial biomass were evaluated as stability parameters in 3 different ligno-cellulosic waste composts. Organic C was extracted by both water and alkali and further separated in humic-like carbon (HLC) and nonhumic carbon (NHC). Conventional humification parameters, such as humification index and degree of humification were calculated from NHC and HLC. Microbial biomass carbon (B(C)) was determined as an indicator of the degree of biochemical transformation, whereas ninhydrin reactive N (B(NIN)) was measured to obtain the stability parameter B(NIN)/N(TOT) (N(TOT), total N). The water-extracted organic C did not provide reliable information on the transformations underwent by the ligno-cellulosic wastes during composting, since its content remained almost unaltered during the whole process. In contrast, parameters based on the alkali-extracted organic C and microbial biomass clearly reflected organic matter (OM) changes during the process. There was an increase in the net amount of HLC in the alkali extracts throughout composting, especially in the first 7 to 12 wk of the process, as well as a relative enrichment of HLC with respect to NHC. Values of humification index and degree of humification in end products were consistent with an adequate level of compost stability. The stability parameter B(NIN)/N(TOT) showed to be a reliable indicator of stability in ligno-cellulosic wastes. Parameters based on the alkali-extracted C and microbial biomass clearly reflected the transformation of the OM during composting and can be used as stability parameters in ligno-cellulosic waste composts.
在3种不同的木质纤维素废物堆肥中，对提取的有机碳和微生物生物量作为稳定性参数进行了评估。通过水和碱提取有机碳，并进一步分离为类腐殖质碳（HLC）和非腐殖质碳（NHC）。根据NHC和HLC计算常规腐殖化参数，如腐殖化指数和腐殖化程度。测定微生物生物量碳（B(C)）作为生化转化程度的指标，而测定茚三酮反应性氮（B(NIN)）以获得稳定性参数B(NIN)/N(TOT)（N(TOT)，总氮）。水提取的有机碳未能提供关于木质纤维素废物在堆肥过程中所经历转化的可靠信息，因为其含量在整个过程中几乎保持不变。相比之下，基于碱提取的有机碳和微生物生物量的参数清楚地反映了该过程中有机物（OM）的变化。在整个堆肥过程中，碱提取物中HLC的净含量增加，特别是在该过程的前7至12周，并且HLC相对于NHC相对富集。最终产物中的腐殖化指数和腐殖化程度值与堆肥稳定性的适当水平一致。稳定性参数B(NIN)/N(TOT)被证明是木质纤维素废物稳定性的可靠指标。基于碱提取的碳和微生物生物量的参数清楚地反映了堆肥过程中OM的转化，可作为木质纤维素废物堆肥的稳定性参数。
