Enhanced rubber yield and its stability during the rainy season: insights from five-year yield monitoring in Southwestern China

Introduction To meet the growing challenges for sustainable rubber production and rising market demand, rubber plantations should aim to optimize yield and maintain higher yield stability despite seasonal environmental fluctuations. However, the effects of rainy and dry seasons on rubber yield, yield stability, and soil properties as well as the potential links between them remain poorly understood. Methods We conducted a five-year field experiment to examine the influence of rainy and dry seasons on rubber yield, yield stability, and soil properties. Rubber yield was recorded annually from 2014 to 2018, while soil properties were measured during one seasonal cycle (2017–2018) at the endpoint of the five-year experiment. Linear mixed-effects models were used for statistical analysis. Results Across the five years, rubber yield during the rainy season was 52.3% higher than in the dry season, and the yield stability index was 34.6% higher. Linear mixed-effects models showed that the seasonal effect on yield did not reach statistical significance (p = 0.054), while the effect on stability was marginally significant ( p = 0.049). Soil carbon (C) and nitrogen (N) contents showed no significant changes between seasons ( p > 0.05 for both). No clear correlation was found between rubber yield or yield stability and soil C and N changes. Discussion Our results suggest a numerical trend toward higher rubber yield and stability in the rainy season, which may be partly attributed to elevated precipitation and temperature. Longer-term continuous observations (≥ 10 years) are warranted to validate these findings and to clarify the role of soil chemical processes in driving plantation productivity.