Tree-crop interaction in Oryza sativa-based riverine agroforestry systems of Chhattisgarh, Central India: implications for climate-smart farming and food security

Abstract

Riverine agroforestry is a dynamic farming system along riverbanks that contributes to climate-resilient agriculture; however, trees often exert strong negative interactions with crops through light interception due to their dense, persistent canopies. This study quantified the effects of bund trees (i.e., Acacia nilotica, Butea monosperma, Mangifera indica, Terminalia arjuna, and Terminalia tomentosa) on paddy (Oryza sativa L.) yield in the Lilagar River bank of Chhattisgarh, Central India. More specifically, the effects of tree diameter and stem density of the most dominant tree species, such as T. arjuna, were assessed. The assessment was made using 1 m2 quadrats established at different distances (i.e., 2, 8, 15, and 25 m) from bund tree bases. A total of 480 trees and 3,840 sample plots were assessed using a nested, stratified, and systematic sampling design. Tree species, diameter, density, and distance significantly affected rice yield (p < 0.01). Mean annual grain yield increased from 3.64 t ha⁻1 at 2 m to 5.52 t ha⁻1 at 25 m distance, indicating a 34% reduction in rice yield near tree bases. Further, a greater yield reduction (42.5%) was observed under larger-diameter trees compared with smaller ones. High tree density (40–60 trees ha⁻1) reduced yield by 66.5% near tree bases, whereas lower densities substantially minimised yield losses. In conclusion, selecting trees with smaller canopies, maintaining low stem densities (20 trees ha⁻1), and regular pruning and/or removing larger trees are recommended to optimise rice yield and food security in the region.