Agronomic Performance of Rice–Wheat Intercropping in an Upland Area of the Bouaké Region, Central Côte d’Ivoire

Abstract

In the context of climate change, innovative rice-based cropping systems represent a sustainable approach to improving  agricultural productivity. Given the reduction in cultivable land and declining soil fertility, assessing the effects of intercropping under different fertilisation regimes is essential in order to improve yield potential and eco-efficiency in rice–wheat cropping systems in Côte d’Ivoire. Accordingly, the agronomic performance of rice–wheat intercropping and of each crop grown as a monoculture was evaluated using a split-plot experimental design with three replications. Four treatments were tested: an absolute control without input (T2), a Costus–Kaolin–Polifol biofertiliser combination (T1), a combination of conventional fertilisers (NPK and 46% N urea) with Costus–Kaolin biofertilisers (T3), and conventional fertilisers alone, consisting of NPK and 46% N urea (T4). The number of tillers, percentages of insect and bird damage to rice, straw biomass, daily productivity, and grain yield per hectare were measured. The area time equivalent ratio (ATER), grain and straw yields, and harvest index (HI) were also determined. The results showed that the intercropping system significantly increased rice grain yield, with 2.4 t/ha under intercropping  compared with 1.5 t/ha under monoculture. Conversely, wheat achieved its highest grain yield under monoculture, with 1.5 t/ha compared with 0.7 t/ha under intercropping. Treatment T3 was the most effective across the cropping systems. System daily productivity (P = 31 kg/ha/day) and an ATER greater than 1 confirmed the agronomic advantage of rice–wheat intercropping.