THE EFFECT OF DIFFERENT MECHANICAL MANIPULATIONS ON SOIL PROPERTIES AND WHEAT PRODUCTION

Abstract

An experiment was conducted in the Demonstration farm of the faculty of Agricultural Studies at Sudan University of Science and Technology for two consecutive seasons (2002/2003 and 2003/2004) to determine the effect of five tillage systems on soil physical and mechanical characteristics and wheat production. These five systems are as follow: 1. Conventional tillage (Disking, Offset disk harrowing and leveling). 2. Tilling with Offset disk harrow. 3. Tilling with Rorovator. 4. Tilling with Field cultivator. 5. Tilling and sowing with a combined machine (Rotoplanter). The experiment was executed using the Randomized Complete Block Design where the area was divided into four replications and twenty plots of (10×5) m2 each. Sowing was then done manually for all treatments except for Roroplanter whereas it done mechanically after doing the necessary adjustment. Application of irrigation water, fertilizers, pesticides and weeding was done equally and simultaneously for all treatments and the results obtained were as follow: No significant difference was shown regarding the parameters of infiltration rate, bulk density, moisture content and soil resistance to penetration; whereas a significant difference (p<0.05) was revealed in weed population as the highest was in minimum tillage with field cultivator of (153.00 and 151.75) and the lowest was in both conventional tillage and minimum tillage xi with rotovator of (96.00 and 92.50) and (83.75 and 93.50) in the first and second season respectively. The results also showed a significant difference in root length and weight of dry roots (p<0.05) whereas the highest value in root length was recorded by both minimum tillage with offset disk harrow and rotovator of (13.38 and 13.75 cm) and (12.48 and 13.50 cm), since the lowest was in minimum tillage with field cultivator of (11.08 and 11.93 cm) in the first and second season respectively. And in weight of dry roots as the highest was also in both minimum tillage with offset disk harrow and rotovator of (1.73 and 1.95 gm) and (2.03 and 1.75 gm), whereas the lowest was in minimum tillage with field cultivator of (1.40 and 1.13 gm) in the first and second season respectively. The highest production (ton/ha) in the first season was achieved by both minimum tillage withrotovator and offset disk harrow of (3.50 and 3.48 ton/ha) whereas the highest in the second season was given by both minimum tillage with rotovator and conventional tillage of (3.98 and 3.93 ton/ha) respectively. Direct seeding represented by field cultivator and manual sowing had given relatively good results in cracking heavy clay soils compared to other treatments although no herbicides was used.