Impact of continuous monocropping versus rotational systems on soil-borne disease pressure and yield

Abstract

A wheat farmer in central Anatolia who has grown the same crop for five consecutive years will typically harvest 18-24% less grain than a neighbour who rotates. This research quantified soil-borne disease severity, soil microbial health, and grain yield under three cropping regimes continuous wheat monoculture, two-year wheat-chickpea rotation, and three-year wheat-chickpea-safflower rotation over five years (2018-2023) at Ankara University’s dryland research station. By year 5, Fusarium crown rot severity in monoculture reached 42.8% compared with 18.3% under three-year rotation. Soil microbial biomass carbon was 43% lower in monoculture plots. The three-year rotation restored 79% of baseline soil health indicators and yielded 4.62 t/ha versus 3.74 t/ha in monoculture. Rotation length matters: the two-year cycle improved outcomes over monoculture but was inferior to the three-year system on all measured parameters.