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

Abstract

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: 41-47