OsemwotaIkpotok in Osadebamwen, a professor of Soil Science, in Ambrose Ali University ( AAU), Ekpoma – Edo State has said that the country is losing million tons of yams produced annually due to improper application of fertilizer without soil testing and poor storage.
Osadebamwen made the remarks while delivering the University’s 79th inaugural lecture with the theme, ‘Maintaining Soil Fertility for Sustainable Crop Production in Nigeria: The Soil and Crop in Partnership’.
He opined that the improper application of inorganic fertilizer without soil test has resulted to nitrogen and potassium ratios imbalance
He noted that it is not only application of fertilizer that causes the susceptibility to poor storage quality but improper application of type and the ratios of application.
According to him, in Nigeria, yam consumers are complaining bitterly that yam produced with the application of inorganic fertilizers do not stay long in storage before they deteriorate when compared to yam produced without the application of inorganic fertilizers.
“This is especially true for yams produced in the middle belt of Nigeria which is the food basket of the nation. This problem may have arisen because of the imbalance of Nitrogen and Potassium ratio both in soil and the crop,” he said.
“The harvested yams become easily susceptible to microbial attack especially fungal and bacterial attack, indicating potassium inadequacy and or imbalance and excess nitrogen,” he added.
The soil science expert, who said that chemical fertilizers alone cannot sustain crop needs on poorly buffered kaolinitic soils, noted that integrated application of organic and inorganic fertilizers are key to sustainable soil fertility management.
He said an integrated soil fertility management can be achieved through the use of grain legumes, which enhance soil fertility through biological nitrogen fixation and application of chemical fertilizers.
“Nitrogen fixing legumes are the basis for sustainable farming systems that incorporate integrated nutrient management
“Soil fertility can be further improved by incorporating cover crops that add organic matter to the soil. This leads to improving soil structure and promotes a healthy and fertile soil”, he added.
He howeve r , recommended the establishment of organic and organo-mineral fertilizer manufacturing companies in all the states of the federation.
He also called for the establishment of soil testing laboratories in all the states of the federation.
He said the soil testing laboratories would provide services for the assessment of the quality of soils and recommend site and crop specific fertilizers as well as eliminate indiscriminate and blanket application of fertilizers and raise crop productive.
Osadebamwen, also called for the provision of detailed soil map in the country with emphasis on potential agricultural productive areas.
He said the detailed soil map will allow for sustainable intensification of agricultural production and settlement of food security.
He also called for the provision of fertilizer to farmers at highly subsidized rates as well as the training and employment of more extension workers to assist the farmers particularly the illiterate ones in the use of farms inputs such as fertilizers.
