One of the most important pieces of survival gear to have is rope! Why do I say this? Well, prehistoric man started making ropes at least 1.8 million years ago and look where we are now!
Just recently I have had two direct discussions around the value of fibre in agriculture, but not for rope making I might add. The first was in relation to soil management, the second relating to butter fat in milk.
So what is meant by fibre? Fibre is a class of materials that is made up of continuous filaments.
What are fibres composed of? Natural fibres are those produced by plants, animals and geological processes. Those composed of cellulose and lignin are considered vegetable or plant fibres.
What is lignin? Like many things it depends who you ask and the context in which we are talking. There are in my mind four possible answers linked to the headings, structure, biological function, economic significance and biodegradation.
For “successful” agriculture Lignin has a major part to play and my discussions centred first around biodegradability and secondly around biological function and economic significance.
For a start Lignin is a class of complex organic polymers (many sugars and proteins stuck together.) As such they form key structural materials in the support tissues of most plants. Lignin is particularly important in the formation of cell walls because it lends rigidity to a plant and does not rot easily.
As we approach cereal stem extension and consideration for the use of plant growth regulators this is an area of great importance when one considers the commercial implications for lodging.
Wheat straw contains 35–45% cellulose, 20–30% hemicelluloses, and around 15% lignin however the lignin content can vary between different varieties within an individual plant species, i.e. cereals.
The lignin content of the maize stalk left in the field is somewhere around 15–21% and is in part influenced by the production location.
After a crop of winter field beans the amount of straw left in the field can range from 3 to 6 t/ha. Such residues tend to have a high polysaccharide content (circa 50%) with a lignin fraction of around 13%
So why is it so difficult to get the machinery to “break it up” when in theory it is no more “tough” than other field residues!