Effect of Different Nutrient Management Systems on Yield and Yield Components of Rice Crop (<em>Oryza sativa</em> L.) in the Dry Zone of Sri Lanka

Abstract

Purpose: Integrated and organic nutrient management has recently become the focus in Sri Lanka for seeking better perspectives on food quality and environmentally friendly production. This study was conducted to understand the magnitude of yield and yield components under selective nutrient management systems in major cropping seasons within the transitional period of a conventional rice-based cropping system. Research Method: Rice yield components and yield were measured with different nutrient management systems; conventional, integrated, and organic from Yala 2019 to Maha 2020/21. An ANOVA was carried out using the Repeated Measures MIXED model to determine the effect of nutrient management systems on yield and yield components for four continuous cropping seasons. Findings: Total tillers per hill and productive tillers per hill significantly varied with conventional, integrated, and organic systems in descending order. The number of filled spikelets per panicle (43) was significantly increased, and the number of hollow spikelets per panicle (8) and thousand-grain weight (21.5g) were significantly decreased with an organic system in the Yala 2019 season only. Although the biological and expected grain yields of the Yala 2019 season were significantly higher with the conventional and integrated systems, these did not change significantly with the organic system in the last two seasons. Research Limitations: Yield parameters fluctuated due to weather changes in different seasons; thus specific impacts of different nutrient managements have been masked to a certain degree. Originality/ Value: The attempt to convert conventional crop production systems in Sri Lanka to organic can be effectively achieved using the integrated use of nutrients and crop rotations.