How plants function

Root growth and leaf growth are related. Therefore animal grazing affects both the leaves and the root system. Excessive removal of leaves reduces the ability of plants to build and maintain good root systems. Plants need an extensive root system in order to extract what they need to produce an abundance of fodder for animal production.

At the end of dry times, perennial grasses are dry old butts that have no green leaves to promote photosynthesis. Yet they grow with the arrival of rain, so obviously they have a mechanism to start growth after rain. We know that plant growth requires energy, so it is obvious that they must be sourcing energy from somewhere.

To explain this last point, the roots hold reserves of plant carbohydrates (starches/energy) needed to stimulate growth when growing conditions arrive. Some reserves are also held in the crown of perennial grasses. Apart from instigating growth after dormancy, these root reserves are also important for maintaining tissue during drought, when photosynthesis is not occurring.

The most dangerous time for perennial grasses is a run of marginal years when stock eat all the new growth every time there is some rain. This results in root reserves being drawn on regularly with little replacement, and so some plants eventually die. This is what David Freudenberger of CSIRO refers to it as the paradox of average years. Green pick is ongoing so root reserves are at risk.

Plants are the ultimate net workers who supply partners everywhere in order to get what they want done. Plants need food and water the same as humans. Apart from the carbon in the atmosphere being a food source, plants get the other things they need out of the soil. For this reason they have to ensure that their helpers in the soil construct a soil that is full of nutrients, water and air. These helpers either leave the construction site or die if plants do not feed them. Stressed and dying plants lead to unhealthy soil as they do not feed the below ground food chain.

To download a PDF version of Chapter 11: How plants function of "Carbon Grazing - the missing link" (file size 904Kb), click on the highlighted chapter heading.

To purchase a hard copy version of "Carbon Grazing - the missing link" click on the highlighted book title.