Methods of estimating bulk density of soils of varying texture
MBONU, O.A., OPARA, C. C. and IKPE, F.N. (2007). Methods of estimating bulk density of soils of varying texture. Acta Agronomica Nigeriana. Vol. 7(2):103 – 107.
Abstract:
An experiment was carried out at three locations of varying texture, in Port Harcourt (4°51N, 7001E), to determine the most reliable of three methods of bulk density determination. The methods included the core, excavation and clod methods, and the determination was for two depths (0-15 and 15-30cm). The results showed that bulk density values determined by the different methods for particular texture varied significantly (p=0.05); with the excavation method giving the highest values of 2.890, 2.755 and 2.805 gcm-3 for sandy, clay and loamy soils, respectively, and the core method gave lower values of 1.615. 1.496 and 1.410 gcm3 for sandy, clay and loamy soils respectively, at the 0-15 cm depth. The trend was the same for the 15 – 30cm depth. When compared with the Soil Science Society of American average bulk density values for particular textures, the core method appeared most suitable for the sandy and loamy soils; giving values of 1.615 and 1.4l0gcm-3 for the sandy and loamy soils at the 0-15cm depth and 1.598 and 1.468 g cm3 at the 15 – 30 cm depth. The clod method also appeared to be most reliable for the clay soils, giving values of 1.070 and 1.239gcm-3 for both the 0- 15 and 15-30cm depths.
Keywords soil texture, bulk density; core, clod and excavation methods.
Influence of oil palm bunch refuse ash and urea on soil physic-chemical properties and okra yield in South-Eastern Nigeria
NNAH, M.B, IKPE, F.N., OSAKWE, J.A and MBONU, O.A.(2010). Influence of oil palm bunch refuse ash and urea on soil physic-chemical properties and okra yield in South-Eastern Nigeria. Acta Agronomica Nigeriana. Vol. 10(2):117 – 124.
Abstract:
A field trial was conducted at Korokoro Tai, Tai Local Government Area and the Teaching and Research Farm of the Rivers State University of Science and Technology, Nkpolu-Oroworukwo, Port Harcourt both in South-Easthern Nigeria to determine the influence of soil palm bunch refuse ash (OBRA) and urea (a nitrogenous fertilizer) on the soil physicochemical properties and yield of Okra. The trial was conducted on Typic paleudult of the coastal plain sands of Rivers State and the experiment was designed in a split plot fitted into a randomized complete block design. It was laid simutaneously in the early planting season (March to June) of 2009, with the main plots as the rates of O, 4and6tha’ of OBRA while the sub-plots were assigned urea levels of o,50,I00,150, AND 200kg ha’. Results showed that the soils were deficient in organic matter (OM), total nitrogen, magnesium and potassium with acidic reaction. The OBRA was relatively high in the cations and phosphorus but low in nitrogen with alkaline reaction of 8.5. OBRA and urea increased soil pH, Om, N, P Ca and Mg at harvest. The highest pod yield was measured in plots amended with 6t ha-1 OBRA/50kg N ha-1 as 7.55t ha-1 and 7.59t ha-1 at Korokoro Tai and UST respectively. This was followed by plots amended with 4t ha-1 OBRA/l00kg N ha-1 and 6.6t ha-1 OBRA/l00kg N h-1 at Korokoro Tai and UST respectively. Relative to the control the highest pod yield increased by 33%. The higher the number of pods, the higher the total pod weight. The application of OBRA, which contains a little amount of nitrogen, reduced the nitrogen requirement for the optimum yield of okra. The trend for almost all the yield parameters consistently showed that the higher the OBRA rate applied, the lower the N requirement of okra. Oil palm bunch refuse ash is therefore recommended with urea at the rate of 6t ha’ OBRA/50kg N ha-1 or 4t ha’ OBRA/100kgN ha-1 as soil amendment with great potentials to ameliorate the soil acidity and keep the soil more fertile with increase in available nutrients and maintenance of optimum pH.
Keywords: Oil palm bunch refuse ash, fertilizer, okra, yield, coastal plain sands.
Effect of time of mulch and fertilizer Application on the field performance of Ginger in the Guinea Savanna Zone of Nigeria.
AMADI, D.S., IKPE, F.N., NWONUALA, A.I. AND MBONU, O.A (2011) Effect of time of mulch and fertilizer Application on the field performance of Ginger in the Guinea Savanna Zone of Nigeria. Acta Agronomica Nigeriana. Vol. 11(1&2) 34-39.
Abstract:
A field experiment was carried out in 2008 and 2009 at the Teaching and Research Farm of the Rivers State University of Science and Technology, Port Harcourt to investigate the yield of Amaranthus as influenced by oil palm bunch residue ash(OBRA) (‘0,4,and 6 t ha’) and urea (0, 50, 100 and 150 kg N ha’) applications. The experiment was (3X4)X4 factorial laid out in randomized complete block design ‘RC’BD) on a Typic paleudult of the acid sands of Port Harcourt. The application of OBRA and urea increased soil pH, organic matter nitrogen, phosphorus, ca/c/urn and magnasium at harvest. The application rate of 6t ha’ OBRA/50 kg Nha4 gave the maximum yield of 3.6 and 3.2 tha-4 in 2008 and2009, respectively while the application rate of 4 t ha’ OBRA / 50 kg Nha-4 gave a sustainably economic yield of3. 0 and 2.0 t ha’ in 2008 and 2009, respectively Fresh leaf yield gathered from control plots was 0.6 and 0.7 t ha’ in 2008 and 2009, respectively.
Keywords: Oil palm Bunch Residue Ash, Urea, Amaranthus, Yield, Acid Sands and Soil Chemical Properties.