Editing Soil (section)

=== Plant residue ===
{{Pie chart
|caption = Typical types and percentages of plant residue components
|value1 = 45
|label1 = Cellulose
|value2 = 20
|label2 = Lignin
|value3 = 18
|label3 = Hemicellulose
|value4 = 8
|label4 = Protein
|value5 = 5
|label5 = Sugars and starches
|value6 = 2
|label6 = Fats and waxes
}}

[[Cellulose]] and [[hemicellulose]] undergo fast decomposition by fungi and bacteria, with a half-life of 12–18&nbsp;days in a temperate climate.<ref name=Paul1997>{{cite book|last1=Paul |first1=Eldor A. |last2=Paustian |first2=Keith H. |last3=Elliott |first3=E. T. |last4=Cole |first4=C. Vernon |title=Soil organic matter in temperate agroecosystems: long-term experiments in North America |date=1997 |publisher=[[CRC Press]] |location=Boca Raton, Florida |isbn=978-0-8493-2802-2 |page=80 |url=https://fr.1lib.sk/book/5955591/2c4ede |access-date=4 May 2025 }}</ref> [[Wood-decay fungus|Brown rot fungi]] can decompose the cellulose and hemicellulose, leaving the [[lignin]] and [[Phenols|phenolic compounds]] behind. [[Starch]], which is an [[energy storage]] system for plants, undergoes fast decomposition by bacteria and fungi. Lignin consists of [[polymers]] composed of 500 to 600 units with a highly branched, [[Amorphous solid|amorphous]] structure, linked to cellulose, hemicellulose and [[pectin]] in [[plant cell walls]]. Lignin undergoes very slow decomposition, mainly by [[white rot]] fungi and [[actinomycetes]]; its half-life under temperate conditions is about six months.<ref name=Paul1997/>