Some notes on the soils and use of fertilizers and pesticides by vegetable farmers in Claveria, Misamis Oriental, Philippines

The gently rolling topography which typifies a large portion of the volcanic landscape in Claveria makes it ideal for intensive large-scale vegetable production. The widely grown vegetables include cabbage, beans, tomato, sweet pepper and eggplant.

The breathtaking volcanic landscape of Claveria, Misamis Oriental

But the strongly weathered soils which range from Oxisols in the lower slopes (about 400 to 600 m above sea level or asl) to Ultisols in the upper slopes (about 600 to 900m asl) are a major constraint to vegetable production in the area. Oxisols (also called Ferralsols) and Ultisols (also called Alisols and Acrisols) are clayey, reddish, acidic and nutrient-poor soils although they generally have good physical properties like good structure and moderate to high porosity. As in other volcanic landscapes, the oldest and most infertile soils (Oxisols) are formed on the older and stable lower slopes.

Dr. Apol & Nelds Gonzaga, Ruby Gabaca, Dr. Steve Harper & myself in front of an Ultisol soil at 920m asl. 

Farmers are apparently aware of the chemical and nutrient limitations inherent in these soils. That is why they apply lime and a variety of chemical and organic fertilizers. Rates of application are, however, not based on soil/plant tissue analysis but on what the farmers perceive as necessary. Thus, the rates appear to be insufficient in the case of lime, but excessive for the chemical fertilizers. This undoubtedly increases the production cost and can lead to more soil and environmental problems like acidification and groundwater pollution, respectively.

Heavy fertilizer application is done starting at planting of vegetables

Pest and diseases are also greatly affecting vegetable production in the Claveria landscape. As a result, farmers practice excessive application of pesticides which poses a serious threat to the health of the farming families, the consumers in urban centers, and the environment in general. The lack of awareness among farmers about the proper application of pesticides can be seen from their improper handling of these hazardous chemicals and from the fact that they just leave the pesticide containers at the farm borders.

It is common for farmers to mix two pesticides with water and spray the cocktail to the vegetables twice a week

The above observations strongly justify the urgent need for research on soil and nutrient management as well as integrated pest management in Claveria.

A comparison of organic and conventional farming

The Council for Agricultural Science and Technology (CAST) in the USA, assembled in 1980 a high-powered Task Force composed of 24 scientists (chaired by S.R. Aldrich) with expertise in agricultural economics, agronomy, animal science, dairy science, entomology, food science, horticulture, soil science, veterinary medicine and others to look into the similarities and differences between organic and conventional farming. The Task Force report, which remains very relevant to the current debate surrounding organic and conventional agriculture, was officially published as CAST Report No. 84 "Organic and Conventional Farming Compared" in October 1980.

Some of the interesting highlights of the report are:

1. Conventional and organic farming have much in common. They differ principally in the use of modern chemical technology. Conventional farmers use commercial inputs (fertilizers, pesticides, animal feed additives) to increase productivity while organic farmers prefer to use natural resources.

2. Both conventional and organic farmers use various mechanical, biological, and other means to control pests. Conventional farmers use synthetic pesticides but organic farmers prefer to avoid them.

3. Conventional farmers extensively use nutritional supplements in animal feeds, hormonally active substances, and drugs. These substances are generally unacceptable to organic farmers.

4. The terms "natural" and "organic" are often used interchangeably in organic farming. But in science, organic refers to carbon compounds. Many such compounds occur in nature and many are synthesized in laboratories and factories. Likewise, many inorganic or nonorganic compounds occur naturally. Hence, natural compounds are not necessarily organic, and organic compounds are not necessarily natural.

5. Urea is a natural organic waste product of human and animal metabolism. It is present in animal and human excreta and is therefore accepted as a natural and nonartificial nitrogen source in organic farming. However, the urea that is synthesized in factories which is chemically identical to the urea produced by human and animal metabolism (used as fertilizer in conventional farming), is not acceptable in organic farming. This is one of the inconsistencies in organic agriculture.

6. The urea produced by animals (present in excreta) or by factories (in commercial fertilizers) is transformed in the soil into ammonium and nitrate ions, the important forms of nitrogen taken up by plants. Both ions are inorganic, not organic. Therefore, in scientific terminology, the organically grown food produced with urea derived from animals is actually "inorganically grown."

7. The "organic foods" produced by organic farming are composed of chemicals. Most foods contain many chemicals, and most of these are organic chemicals, whether the foods are produced by conventional farming or organic farming.