Effects of conservation tillage on crop yield and soil organic carbon in
Northeast China
Abstract
Northeast China(NEC) is the main grain-producing area in China, but soil
degradation is severe due to the long-term use of conventional
tillage(CT). It is necessary to restore soil fertility, maintain crop
yield, and enhance sustainability using conservation tillage in NEC.
However, the integrated effects of conservation tillage on crop yield
and SOC under different conditions in NEC are still unclear. Using 70
peer-reviewed papers, we assessed the crop yield and SOC sequestration
effect, and their relationship under no-till(NT), ridge tillage(RT), and
subsoiling tillage(ST) in NEC. The results indicated that in areas with
a mean annual temperature (MAT) < 3℃, yield under NT was
significantly lower than CT by 3.7% whereas RT and ST were higher than
CT by 0.8% and 13.1% (P<0.05). RT generally had a similar
effect on yield as NT, but RT did not have a negative impact on yield in
colder regions, indicating that this may be a more suitable conservation
tillage practice in these areas. ST may be used in rotation with other
tillage measures to maintain crop yield if necessary. NT could increase
SOC concentration by 24.1%, 43.9%, and 17.4% under high MAT
(>6℃), low mean annual precipitation (MAP)
(<500mm), and continuous cropping, respectively. The mean SOC
sequestration rate under NT, RT, and ST was 0.953, 0.099, and 0.101 Mg C
ha-1 yr-1, respectively. Overall, the implementation of different
conservation tillage measures in NEC can enhance crop yield as well as
carbon sequestration, indicating its potential to be popularized in NEC.