International Journal of Environment and Climate Change

A two-season field investigation conducted at Raipur, Chhattisgarh, during the 2020–2021 and 2021–2022 rabi seasons examined chickpea (Cicer arietinum L.) and garden cress (Lepidium sativum L.) grown in replacement-series arrangements under three irrigation schedules. A split-plot design with three replications comprised no irrigation, irrigation at 35 days after sowing (DAS), and irrigation at 35 and 70 DAS as main-plot treatments, crossed with sole crops and 1:1, 2:1, 3:1 and 2:2 chickpea–garden cress row arrangements. Reported component seed-yield means were used to derive land equivalent ratios (LER), proportion-adjusted competitive ratios, aggressivity, relative crowding coefficients and actual yield loss indices. Across the two seasons, mean chickpea yield increased from 945.59 kg ha⁻¹ without irrigation to 1,347.15 kg ha⁻¹ with two irrigations. The 3:1 arrangement produced chickpea seed yields of 1,385.83 and 1,142.36 kg ha⁻¹ and garden cress yields of 420.73 and 570.74 kg ha⁻¹, respectively. Its LERs, obtained from treatment-mean yields, were 1.27 and 1.30. In contrast to interpretations based on unadjusted yield predominance, proportion-standardised competitive ratios for chickpea in the 3:1 arrangement were 0.83 and 0.62, indicating greater relative competitiveness of garden cress per unit sown share. The yield and index estimates suggest land-use complementarity, but the analyses of derived indices are descriptive because the replicate-level data required for uncertainty estimation were unavailable. Consequently, agronomic interpretations should be restricted to the seasons and environments studied.