No-tillage agriculture can sustain productivity and protect the environment. A comprehensive understanding of soil arbuscular mycorrhizal (AM) fungal diversity and soil carbon distribution within aggregate fractions is essential to the evaluation of no-tillage agriculture. The long-term field experiment included two tillage treatments (1) no tillage with straw returned to the soil (NTS), and (2) conventional mouldboard-plowing tillage without straw (CT), and was conducted on the Loess Plateau, north-western China, from October 2009. The soil samples were collected from the surface layer (0–20 cm depth) at the maturation stage of the summer maize (Zea mays L.) for analyzing aggregates separated by the dry-sieving method. The organic carbon content in the bulk soil and different particle size aggregates were measured using the dichromate oxidization method. The species compositions of soil AM fungi were compared by applying high-throughput sequencing of 18S rRNA. The results showed that the NTS had 9.1–12.2% higher percentage of soil macro-aggregates, resulting in 9.8% increase in mean weight diameter and 10.0% increase in bulk soil organic carbon content as compared with CT treatment. In addition, the NTS treatment had significantly higher percentages of Septoglomus and Glomus than the CT treatment. We also found some significant differences in the fungal communities of the soils of the two treatments. There was a strong positive relationship between bulk soil organic carbon and the percentages of Septoglomus and Glomus. Our results suggested that the NTS treatment had a protective effect on AM fungal community structures, which might play a key role in the development of agricultural sustainability in the Loess Plateau of China.

The idea of mitigating anthropogenic CO₂ emissions by increasing soil organic carbon (SOC) is notable. However, the estimation of the net ecosystem carbon balance after conversion from conventional tillage to conservational tillage has been poorly quantified for the Loess Plateau in China. A 2-year field experiment was conducted to estimate the agroecosystem carbon balance of a winter wheat–summer maize rotation system using a full carbon cycle analysis. The results showed that a positive net ecosystem carbon balance value in the cases of rotary tillage with straw incorporation, chisel plow tillage with straw incorporation, and no tillage with straw mulching treatments. Note that a negative value was detected for the conventional moldboard plowing tillage without crop straw treatment. The conversion from conventional tillage to conservational tillage substantially enhanced the carbon sink potential from 0.84 t C ha⁻¹ yr⁻¹ to 2.69 t C ha⁻¹ yr⁻¹ in both years. Our findings suggest that the expansion of conservational tillage could enhance the potential carbon sink of the rain-fed land in China.

Data from a field experiment conducted in China's Loess Plateau (2013–2015) were used to determine the energy balance of winter wheat (Triticum aestivum L.) as affected by tillage and straw treatments. Tillage treatments included chisel plow, no tillage, and mouldboard plow. Crop straw levels included straw returning and straw removed. The energy balance was evaluated by comparing the following parameters: net energy, energy profitability, energy use efficiency, and energy intensity. The yield parameters were significantly influenced by the tillage treatments and revealed that the chisel plow entailed fewer field operations and lower energy requirements with a higher yield than mouldboard plowing tillage. The highest proportion of energy input came from a nitrogen fertiliser, followed by diesel fuel. The total energy input applied per hectare increased with an increase in the tillage intensity, and the lowest energy input was required for the no tillage case with the straw returning treatment, and the highest for the case of mouldboard plow with the straw returning treatment. The lowest average energy intensity was recorded for the no tillage case, followed by the case of chisel plow tillage in both cropping seasons. Moreover, in the case of mouldboard plough tillage, the maximum energy intensity was recorded in both cropping seasons. In the cases of the chisel plow tillage and the no tillage, we observed the maximum energy gain, while in the no tillage case, we observed the maximum energy use efficiency. The net return and the benefit/cost ratio were higher in the case of straw returning than those in the case of no straw treatment. We concluded that no tillage and chisel plow tillage with straw returning could improve the energy use efficiency and the benefit/cost ratio of winter wheat production systems.

N fertiliser could indirectly influence soil respiration through modifying plant production and soil properties. However, there is limited information jointly researching soil respiration and wheat yield at different N levels in the Loess Plateau in China. The aim of this experiment was to study the influence of N levels on soil CO2 emission and wheat yield to N levels in a winter wheat field in northwest China from October 2012 to June 2013, and from October 2013 to June 2014. A static chamber