INFLUENCE OF CASSAVA-BASED CROPPING SYSTEM ON PHYSICAL PROPERTIES OF TWO TEXTURALLY DIFFERENTIATED SOILS

Abstract

Cropping systems were originally designed to enhance agro-system productivity, however modern agriculture is increasingly concerned with cropping systems' soil sustainability. Hence, this study investigated the effects of cassava-based cropping systems on physical processes and properties of two texturally differentiated soils for sustainable agricultural practices. Two field studies were conducted in 2018 (first trial) at the Federal University of Technology (FUTA) Teaching and Research Farm (Obanla) and at FUTA Teaching and Research Farm (Obakekere) and in 2020 (second trial) at Apatapiti (FUTA Southgate Extension) and Awule area, Akure, Nigeria. The study consisted of eight (8) cropping systems and an uncultivated plot (Control) which were set up in a Randomized Complete Block Design (RCBD) with three (3) replications. The study was conducted on two soil textural types (Clay Loam (CL) and Sandy Clay Loam (SCL)). Two improved cassava varieties, TME 419 (a non-branching variety) and TMS 0581 (a branching variety) were individually intercropped with cowpea (07K-131-1) and maize (TZB-SR) cultivars. The treatments consist of cassava/maize/cowpea, cassava/maize, and cassava/cowpea intercropping and the corresponding cassava monocropping and uncultivated soil. Soil structural, thermal, and hydraulic properties were determined for each treatment at various stages of the first and second trials. Some soil chemical properties were examined before and after the studies. The results from the study revealed that various cropping systems significantly influenced the soil physical properties. The control plots of the CL soil had the highest percentage decrease in soil structural stability index (SSI) in the first and second trials, with 11.27% and 14.09%, respectively while the cassava intercropped with maize and cowpea plots had the least SSI percentage decrease of 1.68% and 5.31% in the first and second trials, respectively. The control had significantly higher surface temperature. In the first and second trials, soil organic matter content (SOM) was significantly affected by cropping systems (p ≤ 0.001), soil types (p ≤ 0.001) and the interaction effect of soil types and cropping systems (p ≤ 0.05). The control under the SCL soil had the highest decrease in organic matter content (11.57%) in the first trial while in the second trial, the organic matter content decreased by 14.08% and 11.57% in the bare soil of CL and SCL soils, respectively. The cassava intercropped with maize and cowpea cropping systems under the CL soil had the least organic matter loss (p < 0.001) of 1.69% and 3.42% of the initial content in the soil. Also, the cassava intercropped with maize and cowpea cropping system of the SCL recorded the least organic matter loss of 4.20% of the initial content at the end of the experiment. The study concluded that intercropping provided vegetative cover against direct raindrop impacts and ensured better soil thermal management, thereby mitigating nutrients and organic matter loss. Practices that improve soil organic matter such as green manure and compost application, cover cropping, improved fallows etc., should be integrated into a strategy for sustainable agricultural development in the region.