Planting date adjustment and varietal replacement can effectively adapt to climate warming in China southern rice area

Abstract

CONTEXT

The southern rice cultivation system in China stands out as the most intricate due to its diverse climate and complex terrain, compounded by the interplay between single and double cropping rice. However, the current regionalization of adaptation strategies of rice cropping systems fails to accurately reflect the evolving dynamics brought about by regional variations in rice production and climate warming.

OBJECTIVE

Our aim was to address the challenge of climate change on rice production by evaluating its effects on the rice growth period and potential yield. We also assessed the potential of adjusting planting dates and implementing varietal replacement to mitigate the impacts of climate change on rice production across different maturity stages.

METHODS

Using phenological, climate, and land use data, we employed the validated ORYZA model to analyze the impact of climate change on the growth period and yield of rice in southern China from 1961 to 2020. Subsequently, simulations were carried out for seven scenarios to assess the effects of adjusting planting dates and replacing rice varieties on rice production in the region.

RESULTS AND CONCLUSIONS

Climate change shortened the whole growth period (WGP) by 0.63 ± 0.11 days•10a⁻¹ and decreased potential yield by 239.98 ± 22.76 kg•ha⁻¹•10a⁻¹ over six decades. Changing the planting dates of single and double season rice can lengthen or shorten the growth period of rice, affecting potential yields accordingly. Varietal replacement increased WGP and potential yield by 12.64 days and 2451.07 kg•ha⁻¹ for single rice, but decreased WGP by 13.12 days while increasing yield by 2161.57 kg•ha⁻¹ for double rice. Combined adaptation strategies of planting date and varietal replacement resulted in a 10.7 % increase in WGP and a 19.3 % increase in yield for single rice, and a 7.5 % reduction in WGP but a 9.5 % increase in potential yield for double rice. Our research results show that under changing climatic conditions, adjusting planting dates and implementing varietal replacement can effectively alter the growth period of rice, leading to an increasing trend in potential yield.

SIGNIFICANCE

Variety replacement and sowing date adjustments are two of the most important strategies in crop production management. This study provides the first comprehensive analysis of how both measures impact agricultural production. The findings highlight the significant role of planting date adjustments and variety replacement in adapting to climate warming in southern China, offering critical insights for ensuring food security in the region.