Crop diversification strategies for enhancing farm income in monoculture rice systems

Abstract:

Rice monoculture dominates more than 9 million hectares in Thailand, yet falling paddy prices have squeezed farm margins to near-zero in many provinces. This research compared four diversification strategies against continuous rice at two locations—Chiang Mai and Nakhon Pathom—over the 2021-2023 cropping cycle. Systems evaluated were rice-maize, rice-pulse (mungbean), rice-vegetable (yard-long bean), and rice-oilseed (sesame). The rice-vegetable rotation delivered the highest system productivity (9.23 t rice-equivalent yield ha^-1) and net return (USD 1,387 ha^-1), roughly double the rice monoculture (USD 687 ha^-1). The benefit-cost ratio reached 2.68 for rice-vegetable versus 1.72 for monoculture. Rice-maize and rice-pulse also outperformed monoculture, though by smaller margins. Soil organic carbon improved under all diversified systems. These findings indicate that even simple two-crop rotations can lift farm profitability without requiring major changes in equipment or expertise.