Impact of herbicide usage on paddy productivity- A study in the Gampaha district

Abstract

As the Rice being the staple food of Sri Lankans, paddy cultivation is one of the main agricultural activities in Sri Lanka. Therefore, agrochemical usage is increasing despite of the paddy production nearing a plateau. In this context, the aim of this research are to investigate the impact of herbicide usage and awareness level on paddy productivity. Data was collected by surveying 100 farmers adopting a stratified random sampling method. The Yala season data encompassing the period from May to August in 2020 was recorded. The stochastic frontier model was employed to determine the productivity. The Frontier 4.1 software was used to estimate the parameters. To investigate the awareness level of the farmers regarding herbicide usage, an index was developed based on a Likert scale questionnaire. With the result of the awareness index, multiple linear regressions were used to estimate the effect of farmer awareness level on health and environmental implications on paddy output. According to the results of the estimation, herbicide cost did not show any statistical significant impact on paddy productivity. The farming extent is positively significant and the family labor is negatively significant among the other variables. The mean technical efficiency is 76% implying farmers are still away from their technological frontier by 24%. The herbicide cost is significant at 1% level in the cost function. According to the awareness index, all the farmers have a high awareness level. However, according to the multiple regressions results, awareness level has no impact on the paddy yield. These results imply that herbicide usage and the farmer awareness level on health and environmental issues has no impact on paddy productivity in the Gampaha district. As farmers show high level of awareness it can be leveraged to motivate them to adopt sustainable farming practices. This could help to reduce the cost of production and preserve the environment