Chemical and spectroscopic analysis of organic matter transformations during composting of pig manure

acide fulvique acide humique analytical methods ashes azote carbon carbone carbono cendre ceniza cerdo chemical composition composition chimique compost compostage composting composts engrais organique espectrometria farmyard manure fulvic acids fumier humic acids nitrogen organic fertilizers organic matter porcin spectrometrie spectrometry spectroscopy swine technique analytique temperatura temperature