Effect Of Depth Of Tillage On Soil Physical Conditions, Growth And Yield Of Sweet Potato In An Ultisol At Abakaliki, Southeastern Nigeria

A study was conducted at Abakaliki, southeastern Nigerian during the raining seasons of 2000 – 2001. The experiment evaluated the changes in some soil physical properties owing to depth of tillage, and the effect on growth and yield of sweet potato. The tillage depth treatments included zero tillage, 10cm, 20cm, 30cm and 40cm tillage depths. The soil physical properties measured were bulk density, penetrometer resistance and soil moisture content. Tilling the soil to depths of 20, 30 and 40cm significantly (P = 0.05) reduced soil bulk density by 13, 15 and 22 % respectively when compared with zero tillage. Penetrometer values were 54, 66, 74 and 78 % significantly higher on 10, 20, 30 and 40cm tillage depth plots than the untilled plots. The gravimetric moisture content was 20, 33, and 43 % significantly higher in the zero than the 20, 30, and 40 cm tillage depths respectively. Tilling the soil significantly increased crop growth and yield compared to untilled soil. Plants on the 40cm tillage depth produced the highest fresh potato tuber yield of 14.5 t ha-1. The study shows that improving soil physical properties, such as reduced bulk density, increased penetration and good drainage, promotes high crop yield. Key words: Tillage depth, soil properties; Potato yield Journal Of Agriculture And Social Research Vol. 5 (1) 2005: 41-4

Response of rice (Oryza Sativa) to organic and inorgainc manures in an Ultisol, in Abakaliki, Ebonyi State, Nigeria

A study was conducted to compare the response of rice to organic and inorganic manures at Abakaliki, Southeastern Nigeria. The experiment lasted between 2002 and 2003 cropping seasons (April-November). The organic manures were sewage sludge and poultry droppings, while the inorganic manure was Urea. The treatments were applied in four rates each of the organic and the inorganic manures. Significant differences (P = 0.05) in plant height, number of tillers and grain yield respectively, were observed between plants treated with inorganic and organic manures. However organic manure application doses of over 20 t ha-1 reduced plant growth and grain yield. Improvements in soil physical and chemical properties owing to organic manure application was observed to have led to comparable performance between the plants in plots treated with organic and inorganic manures. Sewage sludge and poultry droppings at the rates of 20 t ha-1 were therefore concluded to be a viable alternative to urea in rice production in the study area

Effects of shelterbelt on soil bulk density, particle density, total porosity and moisture contents in the dry northwestern Nigerian

The effect of shelterbelt at measurement position (60,120 and 180) on bulk density, particle density, total porosity and moisture contents of semi-arid soils in the extreme part of northwestern, Nigeria was studied. The effect of shelterbelt on the three measurement positions was compared with the unsheltered area. Changes in field capacity (fc) between measurement position 60m and the open showed statistically higher values than the open soil, and there was no significant difference between 120 and 180m, 180m and open and 120 and open measurement positions respectively. Permanent wilting point (PWP) differed significantly between the open and the protected area and among the blocks in the sheltered area. There was significant difference between the open and the sheltered area especially within the immediate vicinity behind the shelterbelt. Bulk density and total porosity did not show any significant difference. The establishment of the effect of shelterbelt on the studied parameters is important for effective management of dry land soils. Journal of Agriculture, Forestry and the Social Sciences Vol. 3 (2) 2005: pp.92-9