Effect of Tillage Practices on the Carbon Footprint of Wheat and Maize in the Loess Plateau of China: a Meta Analysis

PurposeTo study the effects of different tillage practices on the yield, greenhouse gas emissions and carbon footprint from wheat (Triticum aestivum L.) and maize (Zea mays L.) fields in the Loess Plateau of China.

MethodWe collected 175 published papers and used meta-analysis to investigate how tillage practices affects yield, greenhouse gas emissions and carbon footprint of wheat and maize fields in the Loess Plateau. Five practices were included: (i) conventional tillage with straw returning (TS), (ii) no-till with straw returning (NTS), (iii) no-till with no straw returning (NT), (iv) subsoiling (SST), and (v) conventional tillage, which was used as a control (CK).

ResultCompared with conventional tillage (CK), TS, NTS, NT and SST increased wheat yield significantly by 10.6%, 9.2%, 6.9% and 11.0% (P<0.05), while increased maize yield significantly by 11.6%, 9.8%, 7.4% and 6.0% (P<0.05), respectively. Compared with conventional tillage, TS and SST significantly increased greenhouse gas emissions of wheat production by 9.2% and 15.8% (P<0.05), while increased greenhouse gas emissions of maize production by 2.4% and 15.5% (P<0.05); compared with conventional tillage, NT and NTS significantly reduced greenhouse gas emissions of wheat production by 11.1% and 7.2% (P<0.05), respectively, and reduced greenhouse gas emissions of maize production by 7.0% and 11.2% (P<0.05). Therefore, compared with conventional tillage, TS, NTS and NT significantly reduced the carbon footprints of wheat production by 1.3%, 15.0% and 17.0% (P<0.05), and significantly reduced the carbon footprints of maize production by 8.4%, 19.1% and 12.2% (P<0.05), while SST significantly increased the carbon footprints of wheat and maize production by 4.3% and 9.0% (P<0.05), respectively. As a result, TS, NTS and NT significantly reduced wheat carbon footprint by 1.3%, 15.0% and 17.0% (P<0.05), respectively, and maize carbon footprint by 8.4%, 19.1% and 12.2% (P<0.05), respectively, while SST significantly increased wheat and maize carbon footprint by 4.3% and 9.0% (P<0.05), respectively.

ConclusionConsidering the above factors, NT and NTS not only increase the yield of wheat and maize, but also reduce the greenhouse gas emissions and carbon footprint produced in the production process. Therefore, NT and NTS can be regarded as the appropriate tillage practices for green production of wheat and maize in the Loess Plateau.