水保所知识产出(1956---)知识库

The objective ofthisstudy was to calculate the carbon footprint (CF) ofstraw and plastic filmmulchingpractices
inorderto identifytheoptimum field management for low-carbon agriculture. A four-yearfield experiment was
conducted to determine the effects of different mulching measurements on greenhouse gas (GHG) emissions,
grain yield, and CF of a winter wheat-summer maize cropping system in the Loess Plateau of China. Mulching
treatments were no mulching (NM), straw mulching (SM), half plastic film mulching (HPM); full plastic film
mulching (FPM), and ridge-furrow planting with film mulching over ridges (RPM). Plastic film mulching de-
creased N 2 O emissions compared with NM. However, SM significantly increased direct N 2 O emissions by 59.2%
and indirect N 2 O emissions by 16.2%. Average annual total GHG emissions calculated by life cycle assessment
were5199–7631kgCO 2 -eqha −1 yr −1 .Nitrogen(N)fertilizerwasthelargestcontributortototalGHG emissions,
accounting for >41%. For plastic film mulching treatments, the second greatest contributor was plastic film, ac-
counting for 21.1–35.7% of total GHG emissions. In contrast, the second greatest contributor was direct and indi-
rectN 2 OandCH 4 emissionsunderNM(17.2%)andSM(21.6%).Emissionsfromdieselconsumptionwasthethird
largest component of total GHG emissions. All mulching treatments showed significantly greater annual grain
yield than the NM treatment. The CF of summer maize yield was higher than that of winter wheat. SM showed
the lowest CF (0.38 kg CO 2 -eq kg −1 ), and plastic film mulching increased CFs compared with NM. These results
suggest that SM should be the priority mulching practice used to increase yield and to reduce the CF of winter
wheat-summer maize production in the Loess Plateau, China. Optimizing N fertilizer application rates should
be one of the key production strategies employed to mitigate agricultural GHG emissions.