Soil physical and hydraulic properties modification under Arachis cultivation in the derived savanna agroecological zone of southwestern Nigeria
Conservation of soil moisture is one of the major limiting factors to crop production. Improvement of soil physical properties could enhance soil moisture conservation, improve crop productivity and reduce food insecurity in sub Saharan Africa. A field study was carried out to determine the effects of 3 plant densities (33333, 66667 and 83333 plants/ha)on soil properties and water loss through evaporation from soils under 2 cultivars of Arachis hypogaeaL. (SAMNUT 10 and SAMNUT 21) and Arachis pintoi(PINTOI) in Ibadan, south western Nigeria. The experiment was a split plot in randomized complete block design with Arachis varieties as the main plot and plant densitiesas subplot with three replications. Data were collected on daily soil water evaporation, bulk density, saturated hydraulic conductivity, particle size, total porosity and permeability. The Soil was loamy-sand and marked reductions in soil water evaporation were observed in surfaces under Arachis varieties compared to bare soil. Reductions in soil water evaporation were 44.5%, 41.1% and 34.7% under SAMNUT 21, PINTOI and SAMNUT 10 respectively. Significant (p= 0.05) improvement on soil structure and hydraulic conductivity was observed under Arachis varieties. Plant density of 66667 plants/ha showed the best positive effect on the improvement of soil physical structures. The cultivation of SAMNUT 21at 66667 plants/ha and PINTOI at 83333 plants/haalong with other measures of sustainable soil water conservation are recommended.
Key words: Arachis species, Plant densities, Evaporation,Soil hydrological properties, Food insecurity.