Lands under agricultural systems are important reservoirs in the global carbon cycle and the land management practices used can determine whether these lands are sources or sinks of carbon. Under plough based agriculture, cropped land acts as a significant source of carbon dioxide.
On the other hand, conservation agriculture practices, such as minimum tillage and no-tillage, can have a significant impact on reducing carbon dioxide emissions. Initially the reduced consumption of diesel will lead to reduced emissions as shown in the diagram below.

Carbon dioxide emission reductions possible due to reduction in diesel use in minimum tillage and no-tillage systems for Irish crop production systems
In addition management factors that improve soil organic carbon(SOC) must increase organic matter inputs to the soil and decrease decomposition of soil organic matter(SOM) and oxidation of SOC. Such practices include: reduced tillage intensity, decreased bare or cultivated fallow periods, the use of winter cover crops, increased rotation cropping with the inclusion of legumes, balanced soil fertility, and efficient nutrient management. All these combined measures are just good agricultural practice and are the trade mark of sustainable agricultural systems.