Abstract:
Agriculture in Sri Lanka's Central Highlands, particularly in the Nuwara Eliya
Divisional Secretariat Division, plays a vital role in vegetable production but is
increasingly threatened by environmental degradation due to excessive chemical
fertilizer use. This study investigates the environmental impacts of chemical
fertilizers and evaluates the feasibility of organic alternatives as sustainable inputs,
drawing on agroecological sustainability and innovation adoption frameworks. A
quantitative survey of 100 randomly selected vegetable farmers was conducted using
structured questionnaires, and data were analysed with descriptive statistics and
multiple regression models in SPSS. The results indicated that chemical fertilizers
dominate use Urea (100%), MOP (91%), and TSP (64%) while organic fertilizer
adoption remains minimal due to labour intensity, limited availability, insufficient
knowledge, and yield concerns. Despite this, most farmers recognize environmental
consequences such as water pollution (81%), biodiversity loss (77%), and soil
degradation (43%). Regression analyses reveal significant relationships between
fertllizer practices and environmental outcomes: the organic fertihzer impact model
(p: 0.003) explained 31.8% of variance, with farmers' awareness and attitudes (p :
0.002) and cultivation of potatoes (p : 0.007) and tomatoes (p : 0.001) as key
predictors; the chemical fertllizer impact model (p : 0.023) accounted for 27.7o/o of
varTance, with fertilizer type (p : 0.009) and application frequency (p : 0.020)
significantly influencing outcomes. The organic fertilizer adoption model was highly
significant (p:0.001), explaining4I.2% of variance, showing that frequent organic
fertllizer use increases adoption intention (p : 0.005) while reliance on chemical
inputs reduces it (p : 0.008). Although farmers are increasingly aware of the
environmental risks of chemical fertlhzers, adoption of organic alternatives is
constrained by labour, availability, technical knowledge, and institutional support.
The findings emphasize the need for strengthened extension services, improved
supply chains, targeted subsidies, and policy interventions promoting integrated
nutrient management to enhance sustainable and environmentally responsible
vegetable production in the highlands.
