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Population increase and the need to achieve food security; especially in Nigeria, necessitated encroachment into forests and marginal lands for agricultural land uses in the Savanna ecologies. However, tropical soils are inherently fragile and prone to rapid degradation under intensive agriculture; especially when soil cover is removed and the soil tilled conventionally. Also, Savanna Alfisols are low in inherent fertility, organic matter, cation exchange capacity, dominated by low activity clays and sesquioxides. The increasing incidence of soil degradation and nutrient impoverishment of the savanna ecologies resulted in deceasing soil quality, agricultural production and increasing farmer food insecurity that generated interest in the need to evaluate effect of slope and Land use on soil properties, quality and carbon stock on Afaka soils in Nigerian Guinea Savanna. Data generated were analyzed using ANOVA and significant means were determined using Duncan multiple range test (DMRT). Results obtained reveal that cultivation activities and erosion accounted for increased silt (19.10 %) in cultivated areas than forest areas (14.89%), while sand fractions (54.44%) dominate separates in the Forest and the Cultivated land uses. Upper CJAST, 32(4): 1-13, 2019; Article no.CJAST.46375 ) was significantly higher than cultivated land use types (1.21 tCha -1 ). At cultivated slope terrains, middle slopes retained significantly higher SOC (1.37 tCha -1 ) than upper and lower slope terrains. Considering soils for prime quality, soils under forest lower slope terrain ranked best quality (SQ1; prime quality) for sustainable cultivation purposes, followed by cultivated middle slope and forest land use type that ranked SQ2. Cultivated upper slope soils ranked least (SQ6) in quality for use in crop production, while cultivated lower slope and cultivated land use type soils ranked SQ5. However, increasing loss of forests to intensive cultivation activities without adequate soil management practices would portend increase in global warming and climate change in the study area. Original Research Article

Carbon sequestration in soil aggregates and Carbon stock (SOC) under Maize-Legume Cropping system in a Northern Guinea Savanna Alfisol, Nigeria trial was conducted in 2014 and 2015 cropping seasons. The experiment was a randomized complete block design (RCBD), replicated three times and treatments used were: Sole Maize (M), Desmodium (D) and Soybeans (S); Maizesoybeans intercrop (MS), Maize-Desmodium intercrop (MD), Maize Strip cropped with Soybean (MS 2:4) and Maize Strip cropped with Desmodium (MD 2:4). Data obtained were evaluated for Organic carbon, carbon stock, Bulk density and mean weight diameter of aggregates in the soil. Results obtained show that Mono-crop (Sole) Maize treatment gave significantly higher BD than other treatments at 8WAP and 16WAP, suggesting that soils under sole maize were degraded for sustainable crop production. Organic carbon sequestered over 2014 to 2015 was least under MD and highest under MD2:4 treatments and mean carbon stock sequestered in the macro and micro aggregates was highest under MD 2:4 (28.35 t Cha -1 ) and least under MD (8.82 t Cha -1 ). Soil Chidowe et al.; BJAST, 21(1): 1-12, 2017; Article no.BJAST.32538 2 organic carbon (SOC) sequestered in macro aggregates under MS (1.38 gkg -1 ) were significantly higher than the other treatments. Maize/Desmodium 2:4 treatment was inferred to have best improved soil conditions (quality/health) for sustainable crop production, mitigate climate change and global warming by sequestering carbon better than the other treatments. Original Research Article

Northern Guinea Savanna of Nigeria soils are continuously and intensively cultivated, resulting in soil quality degradation, carbon stock depletion, accelerated soil erosion and soil nutrient depletion. Effects of land use change on soil carbon stocks (SOC) are of concern regarding greenhouse gas emissions mitigation and sustainable crop production, because there is a need for food sufficiency while conserving the environment. Also, managing soils under intensive use and restoring degraded soils are top priorities for a sustained agronomic production while conserving soil and water resources. Hence, this study; "Tillage, Desmodium intortum, fertilizer rates for carbon stock, soil quality and grain yield in Northern Guinea Savanna" is aimed at devising possible mitigating measures for soil quality degradation, carbon stock depletion and impoverished crop yields using Zea mays as test crop. The study was a Randomized Complete Block Design (RCBD) in split-split plot arrangement with four replicates. The four main tillage and Desmodium intortum combination treatments were: 1) Maize − without Desmodium + Conventional tillage (MC), 2) Maize + Desmodium live-mulch incorporated and relayed + Conservation tillage (MDIC), 3) Maize + Desmodium in no-tillage system (MDNT), 4) Maize + Desmodium in strip tillage (MDST). The main treatment plots were each divided to accommodate four (4) rates of N (60, 80, 100 and 120 kg•ha −1) as sub plots, while the N rate plots were further divided to accommodate three (3) rates of P (6.6, 13.2, and 26.4 kg•ha −1) as sub-subplots. Findings support that Desmodium intercrops with Maize treatments (MDIC, MDNT, and MDST) resulted in increased organic carbon contents in 2013, with MDNT resulting in significantly higher organic carbon content (7.37 g•kg −1 in 2012 and 8.37 g•kg −1 in 2013) than the other treatments. Also, zero

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