Zero tillage impacts in India's rice–wheat systems: A review

To date, the most widely adopted resource conserving technology in the Indo-Gangetic Plains (IGP) of South Asia has been zero-tillage (ZT) wheat after rice, particularly in India. The paper reviews and synthesizes the experience with ZT in the Indian IGP. ZT wheat is particularly appropriate for rice–wheat systems in the IGP by alleviating system constraints by allowing earlier wheat planting, helping control the weed Phalaris minor, reducing production costs and saving water. ZT wheat after rice generates substantial benefits at the farm level (US$97 ha⁻¹) through the combination of a ‘yield effect’ (a 5–7% yield increase, particularly due to more timely planting of wheat) and a ‘cost savings effect’ (US$52 ha⁻¹, particularly tillage savings). These benefits explain the widespread interest of farmers and the rapidity of the diffusion across the Indian IGP, further aided by the wide applicability of this mechanical innovation.