Corn cobs potential organic fertilizer – study

DAVAO CITY – Corn cobs, when soaked in water for several weeks to release potassium, is showing promise that these could be used as fertilizer, increasing harvest yield and saving money at the same time.

Dr. Apolonio M. Ocampo, of the Institute of Plant Breeding in the University of the Philippines-Los Baños, said they started the study October last year and expected to be finished next year.

Speaking before the ongoing 8th Philippine National Corn Congress at the Waterfront Insular Hotel here, Ocampo said the potassium from corn cobs soaked in water was tested as fertilizer for open pollinated variety of corn that potentially yields six to seven tons per hectare, and hybrid variety that can yield up to 11 tons per hectare.

At least 1,000 farmers from different regions are participating in the congress, and some 16 exhibitors from seeds and other agricultural companies are displaying their products and conducting demonstrations.

Ocampo said that in the first harvest of the experimental corn farm, both varieties yielded similar quantities to that of the same corn varieties applied with inorganic potassium.

But he noticed that after the first harvest, there is still enough amount of potassium left in the soil for the next planting seasons.

He cited that 20 tons of corn cobs, when soaked in water, release an equivalent of 200 kilograms of potassium, or one percent of the total amount of corn cobs.

Noting that a hectare of corn needs only 60 kg of potassium, Ocampo said they have to perform the experiment within four harvest seasons to determine the extent of potassium left in the soil.

“The farmers can really save a lot instead of using inorganic potassium,” he said, adding that a farmer could spend about P1,400 for 60 kg of inorganic potassium.

Ocampo said that based on experiments, the ideal ratio for soaking is 25 liters of water for every kilogram of corn cobs.

The concentration of potassium is highest after four or five weeks of soaking, but then drops when soaked longer than that, he continued.

Ocampo said that he is still studying as to the ideal percentage of solution to be used for spraying.

He cited that in the experiment, 100 milliliter of water with five percent solution of potassium from soaked corn cobs is sprayed to every corn plant in a week, and this is repeated six times.

This method, he said, would be costly for farmers as they have to hire more workers to spray the fertilizer, adding that if the percentage of solution will be increased, less spraying would be required.

Ocampo said the fertilizer from corn cobs could possibly increase a farmer’s production from 500 kilograms to 1 ton every harvest.

A software called Nutrient Expert for Hybrid Maize used in site specific nutrient management for yellow corn has been disseminated to corn farmers since 2010, Ocampo said.

He said this software can compute encoded values of specific characteristics of the soil and history of production, among others, to determine if a certain corn farm requires either pure inorganic or bio-nitrogen for corn or organic matter for fertilization.

Ocampo noted that this tool cannot be applied with varieties that yield below three tons such as the white corn variety.

He said all varieties have potential yields, but in reality, these are not being achieved by farmers unless the perfect conditions are also achieved in terms of climate, nutrients, and pest control.

Ocampo said he participated in providing trainings on the use of such software to farmers in all 16 regions through the Department of Agriculture regional offices. (Lorie Ann A. Cascaro / MindaNews)