Conservation Tillage Management Effects on Soil Carbon and Soil Respiration in a Wheat-Corn Double-cropping System 

Wenxu Dong, Chunsheng Hu, Yuming Zhang, Yisong Cheng, Xiaoxin Li, Yuying Wang and Wei Zhou 

Reduced tillage with returned residues is one of the most effective agricultural strategies for sequestering atmospheric. The North China Plain (NCP) is one of China？？s major agricultural areas, Where rotary tillage has been a dominant practice and no-tillage is also gradually being adopted. Few studies have quantified the effects of different intensities of these main tillage alternatives on soil CO2 emission and C storage compared with more intensive tillage systems (i.e. mouldboard plough) in the NCP, where for decades a corn (Zea mays L.)-wheat (Triticum  estivum L.) rotation has been the principal system.

The study was conducted in 2001-2006 at Luancheng Agroecosystem Experimental Station, Chinese Academy of Sciences. The experimental design included five treatments: mouldboard ploughing without residue (CK), mouldboard ploughing with crushed residue (MC), rotary tillage with crushed residue (RC), no-tillage with crushed residue (NC), and no-tillage with whole residue (NW).The results showed that No-tillage operations with residue can lower the burst of soil CO2 flux as found in intensive tillage, and the CO2 flux under no-till remained low during the entire study. Total C input from aboveground crop residue over all years was highest (13.1 Mg. ha-1) in MC treatment, and the C input in RC, NC and NW was 6, 13 and 18% lower than MC, respectively. Soils under rotary tillage (RC) and no-tillage with crushed residues (NC) had greater

TOC than under mouldboard ploughing with residue or not. We can conclude that there is greater potential to increase C storage with no-tillage in this area by increasing aboveground biomass.