Impact of Soil Seed Bank Dynamics on Weedy Rice Distribution and Farmer Involvement in Management: Case Study in Marata District, Sri Lanka

Abstract

Weedy rice (Oryza sativa f. spontanea) reduces rice yield qualitatively and quantitatively. This case study was carried out to assess the impact of weedy rice seed soil bank dynamics to the temporal density variation in consecutive two years and to assess the farmers’ involvement on the management of weedy rice in the area. For soil seed bank dynamics, soil samples were collected from 12”x12” 3” space with ten random samples per each location while number of weedy rice plants in 1m2 quadrate was counted in five different places per each location with at least 5m distance between populations in following two consecutive seasons. Our results revealed significantly wide range of variability of weedy rice seed persistency (153.9 - 42.2) in soil seed bank showing their high adaptability and direct correlation to temporal density in rice ecosystems. The 77% of weedy rice infested paddy lands were direct seeded and collective approaches were used by farmers to control weedy rice in the area. The best preventive measure identified was practice of high-quality paddy seeds. The understanding of the soil seed bank dynamics, diversity, density and distribution is vital to implement successful and efficient management practices.