Food security is largely challenged by climate warming and continue increasing in global human population. The far-reaching consequences of climate warming combined with the urgent demand to increase food production require climate-resilient land management options to simultaneously increase productivity and promote adaptations to climate change and its mitigation. Conservation agriculture has been widely proposed as a sustainable strategy to maintain food production and simultaneously promote soil health, which encompasses reduced or zero/no tillage, permanent soil cover, and diverse crop rotations. Today, adoption of conservation agriculture across 12.5% of arable land in one-third of countries worldwide because of environmental benefits associated with its implementation. However, crop yields under conservation agriculture are estimated to be 2.5 % less than those of conventional agriculture globally. Further, climate warming generally causes drought, disturbs crop growth cycles and increases plant pathogens, and ultimately leads to crop yields reduction. The contribution of conservation agriculture to support food security and soil health under climate warming remain virtually unknown, which creates uncertainty in climate projections. Long-term warming experiments investigating the influence of conservation agriculture in supporting multiple ecosystem functions under climate warming are lacking.
Soil health both increases crop production and improves resilience to climate warming, thus improvement of soil health is recognized as a fundamental mechanism to mitigate adverse effects from warming and maintain food security. The benefits of conservation to soil health have been reported widely, such as promoting SOC and nitrogen accrual by accelerating microbial turnover and necromass accrual through plant biomass inputs. On the contrary, warming may accelerate microbial decomposition and nitrogen mineralization, and lead to key soil health indicator, such as SOC and nitrogen loss. Soil microbiomes are major contributors to sustainable agriculture because they drive key processes in agroecosystems prerequisite to optimizing soil health and crop productivity. Conservation agriculture generally promotes the diversity, activity and beneficial functions of soil microorganisms, but warming may exert contrary effect. Because of the complex interactive effects of warming and soil management on crop yields and individual soil properties, it’s challenging to predict the effectiveness of conservation agriculture as the climate warms.
To investigate interactive effects of warming and soil management on crop yields, soil health indicators, and microbial biodiversity, we conduct a long-term field experiment including different soil management systems (conservation agriculture versus conventional agriculture) and warming levels (warming versus ambient) on the North China Plain since 2010 (Figure 1). We simultaneously assessed 17 soil health indicators, microbial diversity and crop yields to demonstrate the combined effects of warming and management.
We found that experimental warming raised wheat yield with an increased yield benefit through time under conservation agriculture. A positive warming effect on soil health, which was characterized by soil fungi-mediated linearly increased soil organic carbon and microbial biomass carbon over time, was observed under conservation agriculture. The warming-triggered shifts in microbial biomass carbon and saprogen richness governed 9.3% higher wheat yield under conservation agriculture. Overall, conservation agriculture results in an average 21% increase in soil health and supports similar levels of crop production after long-term warming compared to conventional agriculture.
In summary, this study provides empirical evidence for the potential benefits of conservation agriculture for long-term sustainable food production because improved soil health improves resilience to the effects of climate warming. The combination of conservation agriculture and experimental warming for eight years on the temperate semi-arid climate of the North China Plain stimulated an increase in soil health indicators indicating improved water infiltration and storage (soil aggregate stability), carbon and nutrient cycling, and microbial activity. The improvement in soil health and shifts in soil fungal diversity supported similar crop yields to conventional agriculture (Figure 2). These findings emphasize the potential cumulative benefits of conservation agriculture with time and strengthen the evidence for conservation agriculture as ‘climate-smart’ management tool to adapt to climate warming and ensure good security by improving soil health.
For details, please refer to our paper at:
https://www.nature.com/articles/s41467-024-53169-6