In soil science , humus refers to any organic matter that has reached a point of stability , where it will break down no further and might , if conditions do not change , remain essentially as it is for centuries , if not millenniaWhitehead , LOCATION@1 , PERSON@1 , J. , NUMBER@1 .

In the earth sciences , `` humus '' means any organic matter which has reached a point of stability , where it will break down no further and might , if conditions do not change , remain essentially as it is for centuries , or millennia .
