Published online by Cambridge University Press: 25 November 2015
No-till practices have improved crop yields in the semiarid Great Plains. However, a recent assessment of research studies across the globe indicated that crop yields are often reduced by no-till. To understand this contrast, we examined corn yields across time in a no-till cropping system of one producer in central South Dakota to identify factors associated with increased yield. The producer started no-till in 1990; by 2013, corn yield increased 116%. In comparison, corn increased only 32% during this interval with a conventional, tillage-based system in a neighboring county. With no-till, corn yields increased in increments due to changes in management. For example, corn yield increased 52% when crop diversity in the rotation was expanded from 2 to 5 crops. A further 18% gain in yield occurred when dry pea was grown before corn in sequence. Nitrogen (N) requirement for corn is 25% lower in no-till compared with a tillage-based rotation. Furthermore, phosphorus (P) fertilizer input also has been reduced 30% after 20 yr of no-till, even with higher yields. Our case study shows that integrating no-till with crop diversity and soil microbial changes improves corn yield considerably. This integration also reduces need for inputs such as water, N and P.