Soil toposequence, productivity, and a simple technique to detect petroplinthites using ground-penetrating radar in the Sudan Savanna

Abstract

In the Sudan Savanna of West Africa, Plinthosols with a petroplinthic or pisoplinthic horizon at ≤ 50 cm from the surface comprise the major soils. Because these horizons limit the rooting volume and water and nutrient storage capacities of the soils, they should be a major cause of decreased crop yield in the Sudan Savanna. However, the local distribution of Plinthosols is not precisely known, and the relationships between soil classes, effective soil depth, and crop yield, which are considered to be closely related to each other on the Plinthosol soils, are not fully understood. To clarify these relationships, we first reassessed the soil toposequence on a slope at the Institute of Environment and Agricultural Research Saria station in Burkina Faso using the current World Reference Base soil classification system. We then determined the relationships between soil classes and sorghum yield and between the effective soil depth and yield. We also assessed whether ground penetrating radar could predict the position of a petroplinthic horizon. We found (1) that Pisoplinthic Petric Plinthosols were found at the upper slope, Petric Plinthosols were found at the middle slope, and Ferric Lixisols were found at the lower to toe slope; (2) that sorghum yield was significantly larger at the Ferric Lixisols, then at the Petric Plinthosols, and lower at the Pisoplinthic Petric Plinthosols; (3) that sorghum yield was proportional to the effective soil depth at which upper boundary of petroplinthic horizon was found (n = 26, R 2 = 0.78*** exclusion of waterlogged soil); and (4) that ground penetrating radar could predict the effective soil depth and the position of petroplinthic horizons (n = 4, R 2 = 0.99**), suggesting that we could roughly but easily predict sorghum yield and local distribution of Plinthosols having a petroplinthic horizon using GPR. These results may enable us to take more account of the inherent soil conditions when studying soil and water conservation, fertilization methods, and crop breeding, all of which are crucial if sustainable agricultural methods are to be achieved in the Sudan Savanna.

Site-specific responses of lowland rice to acidulated and calcined phosphate rock fertilizers in the Center-West region of Burkina Faso

“…According to the PCA (Fig 3), biomass and grain yield production were explained well by the soil characteristics (PC1), i.e., fine (silt and clay) particles and basic soil fertility (TC, TN, BS, and CEC). The grain yield at Ramongo was significantly lower than the other sites (Table 3) due to the low soil fertility (Table 1), shallow effective soil depth, and low water-holding capacity of its coarse-textured Plinthosols [27]. The quick disappearance of water due to the low water retention could result in insufficient levels of available water for rice growth throughout the season.…”

“…Along a soil toposequence in the Center-West region of Burkina Faso, there was a positive relationship between sorghum yields and soil types that had deep effective soil depths and were consequently likely to have higher water-holding capacities when compared to soils with shallow effective depths [27]. It is known that a topography influences soil characteristics and water availability.…”

“…It is known that a topography influences soil characteristics and water availability. Moreover, the availability of soil P vary within small distances due to the topography [18,27]. Thus, the interactions between the site-specific conditions and P fertilization effects require further investigation.…”

Effects of plastic mulch and nitrogen fertilizer on the soil microbial community, enzymatic activity and yield performance in a dryland maize cropping system

“…Some early studies noted that plastic film mulch significantly increased the activity of maize rhizosphere dehydrogenase (Shen, Chen, & Li, 2016), and soil enzyme activities under film‐mulched plots were shown to be much higher than those observed under non‐mulched controls (Jin et al, 2009; Saito et al, 2006). Existing evidence also indicates that plastic mulch increases microbial biomass and urease and catalase activities (Ikazaki, Nagumo, Simporé, & Barro, 2018; Zaman, Cameron, Di, & Inubushi, 2002). However, along with crop development, the stimulation of soil microbes can be expected to cause competition for nutrient utilization between soil microorganisms and plants (F.‐M.…”

Effects of intercropping component of conservation agriculture on sorghum yield in the Sudan Savanna

“…The mean annual potential evaporation is between 1700 and 2000 mm according to Ouattara et al (2006). Soil in the experimental field is classified as Ferric Petroplinthic Lixisols (IUSS Working Group WRB 2015), which have a petroplinthic horizon starting from a depth of 73 cm (Ikazaki et al 2018b). As in the other areas of the Sudan Savanna (Matlon 1987;Shehu, Jibrin, and Samndi 2015), topsoil with high sand content (81.3%) and low organic carbon (C) content (4.4 g kg -1 ) is structurally inert.…”