It may look lifeless, but it plays a major role in our day to day to lives.Soil is a vital aspect of the environment just as plants and animals are of great use so is it. It affects in a great way the distribution of plants and animal species on the earth as well as harboring some such as earthworms, bacteria and fungi which are important primary agents during nutrient cycling and help plants by improving nutrient intake in turn supporting the growth of above-ground plants.
It also controls the flow of water and chemical substances between the atmosphere and the earth as and it also acts as a reservoir for gases such as oxygen and carbon-dioxide in the atmosphere.
The best appreciated function of the soil is, being able to support the growth of agricultural and horticultural crops. Soil is the backbone of agriculture. Farmers have worked with their soils over many centuries to produce increasing amounts of food to keep pace with the needs of a burgeoning world population. The soil’s natural cycles go a long way in ensuring that the soil can provide an adequate physical, chemical and biological medium of crop growth. However, a problem like soil erosion threatening crop productivity is still a menace to most farmers.
Brought about by deforestation and overgrazing, it is one of the world’s most chronic environmental problems that is costing the agricultural sector. The soil it carries off now totals to 20 billion tons a year, and this loss is not only severely degrading the environment, it is also eroding the economic viability of various countries. Despite enormous efforts taken standard soil conservation measures have been immensely unsuccessful.
The Vetiver system which involves the use of Vetiver grass (Chrysopogon zizanoides) is an important cheap, sustainable and fully effective method of reducing erosion and increasing crop yields.
It is a perennial bunchgrass of the family Poaceae and native to India where it is commonly known as khus. It has previously been used in countries like Venezuela and Australia for soil and water conservation.
When applied correctly the plant is effective on slopes whereby a well established Vetiver grass hedge slows down rainfall runoff, spreading it evenly and trapping runoff sediments thus creating natural terraces.
The plant has strong fibrous roots system that penetrates and bind the soil to a depth of 2-4 meters thus reducing water flow velocity that can lodge crops and run off’s erosive power. The roots also trap fertile alluvial soil on site which maintains the fertility of a flood plain in the case of farming in a flood plain region. The deep, penetrating, massive fibrous roots also increase water infiltration in low rainfall regions.
It does not compete with other farm crops as it is sterile; it flowers but produces no seed. It remains where it is planted and does not become a weed. It’s stiff and erect stems can withstand relatively deep water flow for a period of two months making it suitable for rehabilitating flood plain regions. The plant however grows in all types of soil and is highly tolerant to all toxic levels in the soil as well as fire and frost.
So how is it grown if it produces no seeds?
Vetiver can be propagated from plant parts such as Tillers or shoots, crown and the roots. Mature tillers are split from Vetiver mother plants, that yields bare root slips for immediate planting or propagating in polythene bags in a nursery.
Clumps from the nursery are trimmed leaving leaves of about 15 cm long and 8 cm of root depth. The Clumps are separated into slips with three tillers each which are then planted 10-15 cm apart. Weeding on young vetiver should be carried out after 3 months of germination. The top is cut back to 30-35 cm to promote tillering. The grass grows faster and produces more tillers if fertilizer is applied.
Healthy soils are critical for global food production, but we are not paying enough attention to this important silent ally.- Jose Graziano da Silva, FAO Director-General
So go forth and protect and your soil the natural way!
This article was written by Claire Nasike an Environment Enthusiast and a Bachelor of Technology in Environmental Resource Management student at Technical University of Kenya. She is 2015’s winner of the Wangari Maathai Scholarship Fund Award, becoming the third winner of the annual environmental innovations award. You can catch her on her blog https://conservationatheart.wordpress.com/ doing what she does best!