Agro-industrial waste enriches soil for corn
by Rita T. de la Cruz
There’ s money in waste. This is an old adage but for the farmers living in Northern Mindanao, this statement becomes a turning point in their agricultural activities as researchers from the Northern Mindanao Integrated Agricultural Research Center (NOMIARC) developed the most recent and effective balanced fertilization program that could turn corn soil from infertile to productive.
Corn is one of the most important agricultural products in Northern Mindanao but due to the infertile soil, most corn growers have to resort to chemical fertilizers to provide the nutrient needed throughout the crop’s growing period. These are expensive and destructive to health and the environment. Moreover, soil acidity has become the most serious constraints for corn growers in Northern Mindanao.
Researchers from NOMIARC developed a sustainable corn production strategy for corn growers in the region using a balanced fertilization both from inorganic and organic sources. The main premise is to use different sources of organic fertilizers like agro-industrial wastes. There are two main reasons for this: to solve the waste disposal in the region and to replace expensive chemical fertilizers, thus minimizing their effect both to humans and the environment.
The balance fertilization program for corn used seven agro-industrial waste materials and chicken manure in combination with the inorganic fertilizer and evaluated their effectiveness in the different types of soil in Northern Mindanao. Among the seven agro-industrial wastes used include: coffee sludge, rice hulls, sawdust, corncobs, spent grains, bagasse, and carbide hydrate. A field trial was conducted for three years (2000-2003) in adtuyon clay soil.
Adtuyon clay is the most extensive soil type in Northern Mindanao. In cultivated areas, the layer is slightly heavier. It developed from volcanic lava or mudflows (lahar) composed of mixed boulders but chiefly andesites (fine-grained grayish volcanic rock) and basalt (hard, black volcanic rock). Since the texture of this soil is basically granular in nature, it promotes easy water movement in the soil mass. Nevertheless, this type of soil is considered agriculturally dull and unimportant.
Promise of agro-industrial waste
The effectiveness of the different agro-industrial wastes in the adtuyon soil, was measured using the following parameters: grain yield, economic benefits and soil nutrient supplying capacity both during wet and dry seasons.
Among the industrial wastes tested, the coffee sludge gave the highest significant yield both during wet and dry seasons. The application of the agro-industrial waste showed increasing grain yield of more than 6 tons/ha after three years compared to that of the untreated soil, which is less than 5 tons/ha.
Economically, soils treated with chicken manure and coffee sludge gained higher net income and return of investment compared to those without any treatment or those treated with inorganic fertilizer alone.
As to the nutrient supplying capacity, the soil and its physical properties was improved and gained an increased value when applied with agro-industrial wastes and chicken manure. The application of carbide hydrate along with the chicken manure increased the soil pH and the exchangeable calcium available over time. It also increased the available phosphorus and exchangeable potassium in soil.
Another important benefit of this balanced fertilization program is, it could arrest the continuous depletion of soil due to the constant use of chemical fertilizers.
This three-year project is funded by the Bureau of Agricultural Research of the Department of Agriculture.
Source:”Evaluation of agro-industrial waste materials and chicken manure for balanced fertilization on corn” by Lorena V. Duna, Carmelito R. Lapoot, Juanita B. Salvani, Cora A. Dumayaca, and Lealyn A. Ramos of the Department of Agriculture-Northern Mindanao Integrated Agricultural Research Center