6.1 The Problems with the Present Cropping System

Man’s tendency in agricultural practices today is normally towards mono-culture. That is, to grow only one or a few kinds of crop species which are profitable. Traditional farmers avoided mono-culture as they realized this was a cause of pest outbreak and very risky. As the introduction of chemical pesticides and fertilizers shows quick action temporarily, farmers are motivated to practice mono-culture. In addition, introduction of HYV seed accelerates the extension of mono-cultural practice in rice growing. Major problems are:

It is easy for an insect or disease pest to destroy only one kind of crop. There was serious pest outbreak at Amra (Hog palm) tree farm in Manikganj in 1990. Almost all the Amra trees in the area were attacked by beetles and the leaves were eaten all up. After eating up the Amra trees, the insects tried to eat the leaves of other trees but they could not. Finally the insects disappeared, leaving the Amra trees damaged and the others untouched. Each insect has a diet habit. In this case, if Proshika had a mono Amra orchard, it would have faced complete damage of the orchard. Fortunately, the orchard was saved because it was a mixed fruit garden. This shows that mono-culture is susceptible to pest attack and creates favourable conditions for the pest to spread.

HYV and hybrid (F1) seeds have been introduced to farmers. Because of these seeds, farmers stop using local varieties which are very important for maintaining diversity and as a genetic resource in future. (Chapter 8.1)

Planting only one crop is very risky. If the crop is damaged by insects, diseases or climate (flood, drought, storm, etc.) this will mean total failure of the farm. Even if production is good the market price of the crop might be down due to over supply in the market. Mono-culture will never contribute to stable economic condition for the farmer due to these factors.

Continuous cropping means the same kinds of crops are planted on the same land every year or seasonal continuous cropping. For example, a farmer planted cabbage last winter and again he/she is planting cabbage this winter on the same land. The problems caused are:

Specific (Micro-) Nutrient Deficiency

Zinc and sulphur deficiency in the paddy in Bangladesh are examples of micro-nutrient deficiency. The main reason for this is continuous cropping which requires consumption of the same nutrients continuously and use of chemical fertilizers which supply only a few nutrients (N.P.K.). In this situation, addition of other kinds of chemical fertilizers containing the deficient nutrients will never solve the problem. It is necessary to introduce crop rotation and supply of organic matter to the soil.

The zone around plant roots is very special and very different from the other parts of the soil in terms of activity of micro-organisms. Usually micro-organisms are very active in the root zone because of root secretion. Each plant root zone creates its own unique conditions for specific micro-organisms. For example, the root zone of the tomato plant is favourable for the propagation of nematode, while the maize (cereal crop) is not. Therefore, if continuous cropping is practiced, favourable conditions are established for certain micro-organisms and specific plant diseases may result.

* ( ) is one month after transplanting
by M. Kobayashi, 1985 (Micro-organisms and Organic Matter)