Tillage intensity and cover crop affect yield, energy efficiency, and sustainability of rainfed finger millet and pigeon pea cropping system in semiarid tropics

Little is known about the sustainability of an intercropping system comprising finger millet ( Eleusine coracana ) and pigeon pea ( Cajanus cajan ). We therefore sowed both cover crops and the above crops over 3 years in a seed mix of 8:2 by weight to assess their effects on soil properties, yield potential, and energy‐use efficiency. Treatments consist of tillage intensity‐conventional, reduced, or no tillage in combination with the cover crop horse gram or lablab bean versus no cover crop. Averaged over 3 years, conventional tillage required energy inputs 12% higher than reduced tillage and 4% higher than those without tillage. The sustainable yield index (89.6%) was highest in conventional tillage with horse gram as the cover crop with a mean of 51.6% and a variation of 42.3%. This combination also improved soil quality, although the energy index was greater under reduced tillage than under no‐tillage or conventional tillage. In the wet year (2019), we had higher soil quality index values (8.45–9.97) than in the dry years (2018) (2.50–3.02). The right combination of a cover crop and the intensity of tillage may confer substantial environmental benefits with only minimal detrimental effects on yield.