Is crop biomass and soil carbon storage sustainable with long-term application of full plastic film mulching under future climate change?

The ridge-furrow with full plastic film mulching system (PM) is one of the most popular and widely applied field management techniques in dryland areas of China. There is concern for soil carbon storage and crop productivity dynamics under the long-term application of this management, specifically given the background of global climate change. However, the long term effects of this management practice are still poorly understood. More evaluation is required. A process-based biogeochemical model revised through four years of field experiments and a model drive by RCP (Representative Concentration Pathway) projection was applied to explore how soil carbon storage and maize productivity would change under future climate change projections. The field experiment showed that biomass was significantly higher in the PM than cultivation without mulching (CK), and their four-year average biomass values were 4996 +/- 967 and 2850 +/- 817 kg C ha(-1), respectively. Meanwhile, the four-year average soil organic carbon (SOC) storage was 5.93 g C kg(-1) soil, 5.95 g C kg(-1) soil and 5.40 g C kg(-1) soil for (CK) and 5.83 g C kg(-1) soil, 5.78 g C kg(-1) soil and 558 g C kg(-1) soil for PM at depths of 0-10, 10-20 and 20-30 cm, respectively. SOC did not significantly differ between the two treatments within the four years of the experiment. The model simulation with various rainfall and temperature change scenarios indicated that SOC (0-30 cm) and biomass were more affected by climate change in CK compared to PM. During years 2016-2100, SOC and maize biomass constantly increased under PM and CK for the RCP 4.5 and RCP 85 scenarios, and biomass was higher for PM than CK. However, under the highest carbon dioxide emission scenario of RCP 8.5, the improved biomass and SOC in PM decreased when temperature increased by more than 2.85 degrees C after year 2060. The modeling results showed that the PM cultivation system maintained high productivity and increasing trends of SOC under the high and medium greenhouse gas emission scenarios, derived from climate change projections for before the year 2060. The PM is currently an effective way to increase productivity and is a possible measure for dryland agriculture to adapt to near future climate change. (C) 2016 Elsevier Ltd. All rights reserved.