Availability of soil nitrogen and phosphorus under elevated [CO₂] and temperature in the Taihu Lake region, China

Abstract

Abstract Global climate change affects the availability of soil nutrients, thereby influencing crop productivity. This study examined the effects of elevated [CO 2 ] and temperature on the availability of soil N and P in a paddy field in the Taihu Lake region, China. Winter wheat ( Triticum aestivum L.) was planted at two levels of atmospheric [CO 2 ] (375 μmol L –1 ambient; 575 μmol L –1 elevated) and two temperature levels (ambient; ambient + 2°C). The results were as follows: Compared to ambient, the interaction effects of elevated [CO 2 ] and temperature significantly decreased soil NH $ _4^+ $ ‐N contents by 20.3%, 20.6%, and 18.7% in the jointing, heading, and ripening stages ( p < 0.05), respectively, while soil NO 3 – ‐N content had no clear variation trend under different [CO 2 ] and temperature conditions. Elevated [CO 2 ] significantly increased soil available P content by 14.3% in the jointing stage, and elevated temperature significantly decreased soil available P content by 18.8% in the jointing stage. Compared with ambient [CO 2 ], elevated [CO 2 ] significantly increased wheat biomass in jointing and heading stages ( p < 0.05). The positive effect of elevated [CO 2 ] on wheat biomass was more significant at ambient temperature (AT) than at elevated temperature (ET) in the middle and late plant growth stages. These results explained that the availability of soil N and P varied under elevated [CO 2 ] and temperature conditions. The application of N and P should be adjusted to meet the need of wheat plants after the wintering stage.