7.4 Weeds
Man’s attitude towards so-called weeds is more or less the same as his attitude towards so-called harmful insects. Farmers say weeds are enemies. They always try to clean a field or farming by clearing the weeds so that there are none loft. This is thought of as beautiful. But is it beautiful for nature and rally beautiful for man?
“Weeds are WEEDS only from our human egotistical point of view, because they grow where we do not want them. In nature, however, they play an important and interesting role. They resist conditions which cultivated plants cannot resist, such as drought, acidity of soil, lack of humus, mineral deficiencies, as well a one-sidedness of minerals, etc. They are witness of Man’s failure to master the soil, and they grow abundantly wherever man has missed the train – they only indicate our errors and nature’s corrections. Weeds want to tell a story – they are nature’s means of teaching man, and their story is interesting. If we would only listen to it we could apprehend a great deal of the finer forces through which Nature helps and heals and balances and, sometimes, also has fun with us.”Ehrenfried E. Pfeiffer, Weeds and What they Tell
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7.4.1 The Nature of Weeds
Soil Erosion Checker
The most important role of weeds is to conserve the soil. In heavy rain, we can observe that there is muddy water running away from farm land which is plowed with no or few weeds. On the other hand, we can observe that on land which is weed covered, the water running away is clear with no topsoil erosion.
Weed is Nature’s First Aid
Weed is nature ‘s first aid. When our skin is injured, at first thin skin covers the flesh where the original skin has been broken in order to stop bleeding. When the wound is recovered, the thin skin is removed.
Bare soil is like a wound in nature and weeds are the thin skin of protection – covering the bare soil to stop soil erosion. When other plants and trees come to take their place, the weeds disappear.
As soil becomes fertile, the types of weeds change. In less fertile land, the same weed species appear again and again. The more the farmer weeds out, the more the same weeds appear. In three years applying mulch, with no plowing, at Proshika farm, we have observed that the types of weeds are changing and weeds are becoming less harmful to the crops.
Indicator of Soil Fertility
Each weed has its own characteristics. Some grow in infertile soil and others in relatively fertile soil. From these characteristics, we can get a sense of the farm land’s fertility, Ph, etc. Chan (Imperata Cylindrica) is a very common weed in Bangladesh, growing only where soil is very infertile and hence it is an indicator of infertile soil. There are many other weeds which give us valuable information.
Source of Fertility for Soil
Weeds are good compost materials as well as mulch material. It is completely wrong to throw away weeded plants, because they have consumed nutrients from the soil and produced much carbohydrate through photosynthesis. Both can be returned. By recycling the weeds soil, becomes fertile.
7.4.2 Weeds Management Tips
A basic technique of weed management is to cover the soil so that weeds have no chance to grow. The following are some methods we have tried with good results.
Mulch with Less Tillage
As we saw in section 5.2.1, thick mulch (more than 2 inch) controls 90% of weeds. Living mulch and using a cover crop are also effective weed control. Seem or Velvet bean as a cover crop is a very effective control of Chan which cannot grow in insufficient sunlight.
Green Manure
Green manure reduces weeds. First weeds cannot grow well with the green manure crop because it is fast growing and densely planted. Second, when the green crop is plowed into soil, weeds are also mixed with soil. Third, green manure changes the soil quality which makes the types of weeds change. In these ways, weeds are reduced.
Relay crop
Relay cropping means sowing seeds for the next crop before the standing crop is harvested. Common relay crops in Bangladesh are Aman rice and Khesari (grass pea). The Khesari seeds are broadcast a weed before the Aman harvest. This does not provide enough time for weeds to grow.
Farming among the Weeds
Many different kinds of weeds are growing with the grain and clover in these fields. A local farmer who had expected to see my fields completely overgrown by weeds was surprised to find the barley growing so vigorously among the many other plants. Technical experts have also come here, seen the weeds, seen the watercress and clover growing all around, and have gone away shaking their heads in amazement. Twenty years ago, when I was encouraging the use of permanent ground cover in fruit orchards, there was not a blade of grass to be seen in fields or orchards anywhere in the country.Seeing orchards such as mine, people came to understand that fruit trees could grow quite well among the weeds and grasses. Today orchards covered with grasses are common throughout Japan and those without grass cover have become rare. It is the same with fields of grain. Rice, barley, and rye can be successfully grown while the fields are covered with clover and weeds all year long.
Masanobu Fukuoka, The One Straw Revolution
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