Effect of Some Tillage Systems on Surface Runoff and Soil Erosion in Northern Gedarif Area, Sudan

Abstract

A study was carried out for three consecutive seasons (2005/06
, 2006/07 and 2007/08) under rain- fed condition, to investigate the effect
of some tillage systems on surface runoff and soil erosion in northern
Gedarif. The study was conducted at the pilot farm of the Faculty of
Agricultural Sciences and Environment, University of Gedarif ,in the
northern area of Gedarif State ( Latitude 12° 45′ N, Longitude 35° 15′ E
and 540 m above sea level ). The experimental design was randomized
complete block with three replications. Treatment were three tillage
systems: No tillage or zero tillage (ZT), offset disc as post harvest tillage
(PHT) and wide level disc, farmers practices as control ( WLD ). Rain
gauge was used to measure the rainfall, whilst the surface runoff and soil
losses were measured using runoff plot technique. Total recorded annual
rainfall was 368.1mm (2005), 463.6 mm (2006) and 495.2 mm (2007)
which was spread over 32, 30 and 32 rainy days during the first , second
and third growing seasons, respectively. The results showed that the
second season had the best distribution and satisfaction pattern. It
recorded 15 %, 36 %, 26 % and 5 % for July, August, September and
October, respectively, compared to 24 % ,53 % 13 % and 2 % ; and 29
% ,41 % , 21 % and 1 % for first and third seasons in the same months.
Zero tillage treatment showed more runoff and soil loss than PHT and
WLD. In terms of accumulation, ZT produced more runoff by 28 % and 9
% and soil loss by 53 % and 28 % over PHT and WLD respectively for
first season ,30 % and 13 % runoff and 28 % and 13 % soil loss for the
second season and 55 % and 23 % runoff and 105 % and 24 % soil loss
for third season . The post harvest tillage reduced average annual runoff
and soil loss to the lowest values compared to the Wide level disk and
Z T.