3,4-dimethylpyrazole phosphate (DMPP) may negate the expected stimulation of elevated atmospheric CO2 and warming on fertilizer-N loss

Abstract

People have accepted the clear fact that elevated CO₂ (eCO₂) and climate warming are happening, but sustainable agricultural systems are still struggling to adapt. 3,4-dimethyl-1H-pyrazol phosphate (DMPP) is currently recognized as a highly effective strategy for reducing nitrogen (N) loss and related environmental impacts. There is still uncertainty, however, whether DMPP could contribute to building climate-resilient ecosystems in a future climate scenario with co-elevated CO₂ and temperature. Thus, this study evaluated the responses of plant N derived from soil or fertilizer and strawberry growth to the tested climate conditions. Plants were supplied with or without DMPP, grown in controlled climate chambers under ambient CO₂ and temperature (aCT; 400 ppm + 25℃), and co-elevated CO₂ and temperature (eCT; 800 ppm + 27℃). The results showed that DMPP increased plant N accumulation by 9 % and 19 % under aCT and eCT conditions, respectively, compared to N treatment without DMPP. We also found a similar trend in total C content in the plants. Compared with aCT, DMPP demonstrated higher efficiency in improving N use efficiency (NUE, 51 % vs. 36 %) and reducing N loss (21 % vs. 29 %) under eCT, which could ensure higher N demand of plant, making fertilizer-N, rather than soil-N, a primary contributor to the N accumulation increment. Moreover, in terms of combating climate challenge, the combination with DMPP further strengthened the beneficial influence of eCT on the N accumulation and biomass in strawberry but reduced fertilizer-N loss. In summary, DMPP exhibits better performance under eCT, which may alleviate the potential adverse effects of co-elevated CO₂ and temperature on ecosystem by reducing fertilizer-N loss and soil-N mineralization more efficiently, providing a promising approach to optimizing sustainable agricultural management under future climate change.