Fertilizer usage and land productivity in intensively cultivated vegetable farming systems in Sri Lanka: an analysis based on a questionnaire survey

• Main Authors: H. A. N. Upekshani, R. S. Dharmakeerthi, P. Weerasinghe, W. S. Dandeniya
• Format: Article
• Language: English
• Published: Postgraduate Institute of Agriculture, University of Peradeniya 2018-12-01
• Series: Tropical Agricultural Research
• Subjects: soil amendments, fertilizer usage, intensive vegetable cultivation, crop productivity
• Online Access: https://tar.sljol.info/articles/8277

Vegetable cultivation in Sri Lanka is an intensive and highly commercialized system. Since, vegetables are heavy nutrient feeders that produce high biomass within a short period, management of fertilizers and amendments are critical for sustainable production. The objective of this study was to assess the fertilizer and amendment usage by intensively vegetable cultivating farmers in Sri Lanka and identify the relationship between farmer practices and their productivity using a questionnaire survey. Study was conducted with randomly selected 100 farmers each from Nuwara Eliya (NE) and Marassana (M) regions. Data were obtained on relative use of inorganic fertilizers, organic amendments and liming materials, with respect to the current recommendations. The vegetable cultivating systems of the two regions were identified as vegetable-potato-vegetable and vegetable-paddy-vegetable for NE and M, respectively. The productivity of crops cultivated in NE was higher than that of M. While about 25% and 67% of farmers in NE and M, respectively, used synthetic fertilizers more than the recommended level, about 66% (NE) to 99% (M) farmers used less than 50% of the recommended organic manure quantities for their vegetable crops. We attributed these differences to other crops included in the rotation, availability and high cost of organic fertilizers, and the value of crops, in addition to the cash subsidy given for synthetic fertilizers. Productivity of fields in M, where moisture stresses are more common, appeared not related to the relative quantity of fertilizer or amendments used. However, the productivity was maximized around 70-90% of recommended level of fertilizers among farmers in NE. We concluded that site-specific fertilizer best management practices need to be introduced to intensively cultivating farmers in Sri Lanka, in order to increase and sustain productivity.