Browsing by Author "Obi, M.E."
Now showing 1 - 3 of 3
Results Per Page
Sort Options
Item Open Access Agronomic Responses to Four Tillage Variants on a Sandy-loam Ultisol cropped to Sorghum and Soybean in the derived Savanna of Southeastern Nigeria(Department of Agronomy, Nasarawa State University, Keffi., 2014-01-12) Oblaum, S.E.; Amana, Sani Mathew; Obi, M.E.; Wakatsuki, T.The study evaluated the effects of no-till (NT) and conventional tillage (CT) left bare (B) or mulched (M) giving four treatments; NTB, NTM, CTB and CTM) on profile moisture storage, grain yield and carbon storage under sole- and intercropped sorghum and soybean in 2006 and 2007 growing seasons. In the sole sorghum, NTB and CTM enhanced moisture storage over NTM and CTB. The grain yield was lower in CTB than the other treatments. In the sole soybean, NTM and CTM enhanced moisture storage over NTB and CTB, but the differences in grain yield were consistently non-significant. In the intercropped field, moisture storage differed such that CTM > NTB > NTM = CTB. Whereas grain yield of the sorghum component followed suit, that of the soybean component remained uninfluenced. Overall, the differences in sorghum yields among the tillage methods were less pronounced in the first compared to the second year – when rainfall distribution was relatively erratic. The treatment-induced moisture explained over 60 and 72% of the variability in grain yield of the intercropped sorghum in the first and second year, respectively. In this short-term study, the CTB had the least carbon storage potential in the three cropping systems for which differences tended to be sole sorghum ≤ sole soybean ≤ intercrop. The NTB, NTM/NTB and CTM/NTB are recommended for growing sorghum, soybean and their intercrop, respectively.Item Open Access EFFECTS OF COVER MANAGEMENT PRACTICES ON PHYSICAL PROPERTIES IN NSUKKA SANDY LOAM SOIL(Department of Agronomy, Nasarawa State University, Keffi., 2011-06-23) Amana, Sani Mathew; Jayeoba, O.J.; Obi, M.E.Atwo year (2004-2005) field investigationwas carried out on the runoff plots at the University of NigeriaNsukka farm, to monitor the effects of cover management practices on physical properties, in Nkpologu sandy loam soil. The management practices were bare fallow (BF), cocoyam (CY) sorghum (SG), legume (CP) and grass (PM), under no-till practice. There was no change in soil texture due to treatments. The treatments generally increased organic matter content compared with the control. Bulk density was significantly increased in all the treatments with highest value (1.65Mg/m ) in bare fallow and lowest value (1.49 Mg/m ) in grass. There was no significant decrease in porosity and pore size distribution. Mean weight diameter (MWD) of aggregates and saturated hydraulic conductivity (Ksat )were significantly increased.The least values forMWD(1.06mm) and for Ksat (25.80cm/hr) and highest for MWD (2.09mm) and for Ksat (49.20cm/hr) were obtained under bare fallow and grass treatments respectively. The percentage aggregate size above 2.0mm was highest in grass and lowest in bare fallow. Calculations showed significant positive correlation (r = 0.50) between organic matter and MWD. There was significant negative correlation (r = -0.60) between organic matter and bulk density and highly significant positive correlation (r= 0.800) between organic matter and saturated hydraulic conductivity.Item Open Access Effects of cover management practices on Runoff and Erosion in Nsukka sandy loam soil(Department of Agronomy, Nasarawa State University, Keffi., 2010-06-11) Amana, Sani Mathew; Obi, M.E.; Jayeoba, O.J.The effects of cover management and non-tillage on runoff and soil loss were investigated in 2004 and 2005 on runoff plots at the University of Nigeria Nsukka farm on a 5% slope of a sandy loam. Grass, legume, coco yam and sorghum were planted as conservation barriers in order to examine their influence on water and sediment transport. After each erosive storm for the two seasons, runoff and sediment yield were determined. The dense effective barriers (Panicum maximum and Centrosema pubescens) slowed down flow, retained water and prevented sediment yield. The less effective barriers with cocoyam, sorghum and control bare fallow allow flow of water and flow velocity was not reduced enough, resulting in water and soil transport. Cumulative runoff was highest in bare fallow (87mm) and lowest in sorghum (41mm). The highest soil loss of 1.13kg/m2 and relatively low loss of 0.55kg/m2 were obtained in cocoyam and sorghum in 2005. Runoff and soil loss were reduced by 100% under grass and legume. Cocoyam and sorghum reduced runoff by 20% and 53% respectively. Sorghum reduced soil loss by 35%, while there was no difference under the bare fallow and cocoyam. Runoff as percentage of rainfall was highest in bare fallow (60.6%) and lowest in sorghum (2.2%) respectively. Erosion rate calculated was lowest in sorghum (0.2kg/m2/month) highest in cocoyam (0.41kg/m2/month) and in bare fallow the value was 0.3kg/m2/month.