Selected chemical characteristics of soils in potato growing areas of up country intermediate zone (UCIZ) in Sri Lanka

Abstract

Potato (Solanum tuberosum L.), the major tuber crop grown in the Up country of Sri Lanka occupies nearly 6000 ha. Badulla is the main potato-growing district in the UCIZ. This study was conducted to evaluate the important chemical characteristics of the soils in the intensive potato growing areas in Badulla district in relation to nutrient management of potato cultivation. Soil pH, extractable P (OLSEN), exchangeable K and organic matter content was determined for 1 0 0 samples, randomly selected form the soil samples collected under National Soil Testing Programme. The pH value of the soils in majority (64%) of intensive potato cultivation areas lies between 4 and 5. More than 67% of potato lands in Badulla district recorded pH value less than 5. Extractable P levels in 83% of lands are over 30 ppm while, exchangeable K levels are Over 160 ppm, in 69% of the lands. Soil organic matter content of 80% of tested samples recorded between 1 - 3%. These results reveal that the inappropriate application, of fertilizer for potato cultivation in the UCIZ and possibility to cut down phosphorus fertilizer by % from department of agriculture (DOA) recommendation and V2 of potassium fertilizers for several seasons. Accurate fertilizer usage is therefore utmost importance in intensive potato growing areas in Badulla district to gain maximum benefits from the cultivation. Correction of soil pH and addition of organic matter to improve soil health can play an important role in increasing fertilizer use efficiency.