Unexpectedly, this article shows that intensive agriculture has improved soil organic carbon. As a major carbon pool on earth, soil organic carbon may act either as a sink or a source of atmospheric CO₂, a greenhouse gas. Previous reports show that continuous cropping decreases the concentration of soil organic carbon. Here the authors observed a 38% increase of soil organic carbon over 25 years of intensive rice-wheat cultivation. The findings disclose also positive effects on plant nutrients.

Figure: Temporal trends in weighted average of soil organic carbon (SOC) during the 25-year period, viz. 1981/82 to 2005/06 in soils of Indian Punjab. Points indicate measurements and the line represents the best fit to the linear regression: SOC = 2.89 + 0.038x, R2 = 0.728.