Effects of tillage management on soil CO2 emission and wheat yield under rain-fed conditions

Abstract

Tillage disturbance can affect carbon dynamics in soil and plant production through several mechanisms. There are few integrated studies that have dealt with the effect of tillage management on soil CO2 emission and yield of wheat grain (Triticum aestivum L.) in the Loess Plateau in China. A 3-year (2010–12 and 2013–14) field experiment with two types of tillage was established to investigate CO2 emission, its related soil properties, crop yields and yield-scaled CO2 emissions (CO2 emissions per unit crop production) under rain-fed field conditions. Some land was planted with winter wheat without using tillage (‘no tillage’; NT), whereas some used mouldboard plough tillage (‘conventional tillage’; CT). The results indicate that CO2 was significantly and positively related to total nitrogen (P < 0.01), soil organic matter (P < 0.01), soil enzymes (P < 0.01; urease, invertase, and catalase), soil temperature (P < 0.01) and total pore space (P < 0.05). Multiple linear regression analysis in the NT plot included soil temperature and air filled pore space, explaining 85% (P < 0.05) of the CO2 variability, whereas in the CT plot the multiple linear regression model included soil temperature, urease, bulk density and pH, explaining 80% (P < 0.001) of the CO2 variability. Compared with the CT treatment, NT reduced the 3-year average yield-scaled CO2 emissions by 41% because of a 40% reduction in total CO2 emissions with no reduction in wheat yield. Thus, the results indicate that NT could be used to reduce the contribution of agriculture to CO2 emissions while simultaneously maintaining wheat crop production in this area.