Soil Physical Properties and Root Growth of Pearl Millet as Affected by Ridge Tillage and Farmyard Manure

Abstract

Ridge tillage (RT) and organic manure management are among promising agronomic practices for conserving soil moisture and improving soil physical environment in arid and semiarid rain-fed areas. The studies were conducted during the year 2020 farming season with two soil types from northeastern part of Nigeria to compare the relative efficacy of RT with and without organic manure in improving soil physical properties and root growth of millet under rain-fed semi-arid condition. The effects of the RT treatments in combination with organic manure were compared to the conventional flat-bed treatment (control, FB). The soil types chosen for the study were sandy loam soil located at the University of Maiduguri (Unimaid) and sandy clay loam located at Alakaramti village, respectively. The other land configuration and manure treatments compared were: open-ridge (OR), tied-ridge (TR), flat bed + manure (FBM), open-ridge + manure (ORM), and tied-ridge + manure (TRM) each laid out in randomized complete block design with four replicates. The combination of RT (open or tied) plus organic manure (ORM & TRM) performed better in terms of all measured parameters: bulk density (Bd), porosity (Tp), mean weight diameter (MWD), soil water content (SWC) and root growth as measured with root mass density (RMD) than the bare ridge-tilled (OR & TR) or flat bed with manure (FBM) and without manure (FB) treatments, irrespective of differences in soil type. The improvement in soil condition resulting from combining the practices of RT with organic manure application as reflected by reduced Bd, increased Tp, and higher profile SWC has enhanced millet root growth under the water limited rain-fed farming system of the study area. In regions like northeast Nigeria where low and variable rainfall often limits crop production, the practice of combining RT(open or tied) with organic matter input could be recommended as an optimal agronomic practice for improving drought resilience of crops like millet.