Nutritional Quality Response of Sweet Potato to Different Rates of Organic and Inorganic Fertilizers
Albert Nyarko *
Department of Science, St. Ambrose College of Education, Dormaa-Akwamu, Wamfie, Ghana – Affiliated to the University of Cape Coast, Ghana and Department of Crop and Soil Science, Faculty of Agriculture, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.
Joseph Sarkodie-Addo
Department of Crop and Soil Science, Faculty of Agriculture, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.
Kwadwo Adofo
CSIR–Crops Research Institute, Kumasi-Ashanti, Ghana.
Osborn Addae-Duah
Mampong Technical College of Education, Affiliated to the University of Education, Winneba, Ghana.
Michael Odenkey Quaye
Department of Crop and Soil Science, Faculty of Agriculture, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana and Agricultural Science Education Department, University of Education, Winneba, Ghana.
*Author to whom correspondence should be addressed.
Abstract
The effects of organic manure, inorganic fertilizer (NPK) and the combination of the two on the roots of sweet potato were studied under field condition. Two sweet potato varieties, that is, ‘Apomuden’ and ‘Santom Pona’ were used for the experiment. The result indicated that on the average, NPK 15-15-15 + Cow dung (CD) (4 tons per hectare) (t/ha); NPK 15-15-15 + Poultry manure (PM) (3t/ha); and NPK 7.5-7.5-7.5 + CD (6t/ha) produced significantly highest responses (32.6%, 31.1%, and 30.9%) root dry matter content respectively. NPK 22.5-22.5-22.5 +CD (2t/ha); sole poultry manure (6t/ha), and NPK 15-15-15 + CD (4t/ha) recorded the greatest protein content (6.1% each) individually. Integrated application of organic manure and inorganic fertilizers (NPK, 15-15-15) is recommended for improved sweet potato production.
Keywords: Sweet potato, organic manure, inorganic fertilizers, integrated application, responses