Effects of land preparation on soil moisture content, weed control and groundnut yield in Gash Delta

This experiment was conducted at Gash Delta, for two consecutive seasons (2004/2005 and 2005(2006). It was laid in randomized complete block design with three replications. The objectives were to study the effects of two introduced tillage implements, which were scarifier field cultivator and singleacting disc harrow in comparison with the traditional implement used (2-blade disc plough) on groundnut yield along with their effects on weeds and soil moisture content, in addition to the tractor and implement performance. Compared to the traditional method of land preparation, scarifying and single-acting disc harrowing resulted in lower percentage of tractor travel reduction (7 and 6% respectively), lower actual time and cost of tillage operation (40 min/ha and 24 SDG/ha, respectively), higher actual speed (1.8 m/sec) and higher rate of work (1.2 ha/hr). However, no significant differences were detected between all tillage treatments for soil moisture content percent throughout the growing season. In the first season, scarifying significantly (P 0.05) reduced weed count/square m after tillage operation followed by single-acting disc harrowing, while in the second season scarifying resulted in very highly significant (P 0.001) lower weed count/square m. After manual weeding, no significant differences were evident for weed count/square m in the first season,whereas in the second season, significant reduction in weed/square m was obtained with scarifying. Accordingly, scarifying resulted in the lowest manual weeding time (2.9 ha/hr), followed by singleacting disc harrowing (4.3 ha/hr) compared to the traditional method (6.2 ha/hr). Moreover, the respective cost of manual weeding of tillage operations was 69, 110 and 155 SDG/ha. For the two seasons, tillage treatments (scarifying, single-acting disc harrowing and 2-blade disc ploughing) had no significant effects on dry weight of hay, but scarifying resulted in significant (P 0.05) increase in 100 seed weight for the second season only. However, in the first season, highly significant (P 0.01) higher crop yield was obtained with the use of scarifying (2058 kg/ha) followed by the single-acting disc harrowing (1460 kg/ha) compared to the traditional method (878 kg/ha), while in the second season, scarifying resulted in significantly (P 0.05) higher crop yield (2688 kg/ha) followed by single-acting disc harrowing (1875 kg/ha), but no significant difference was evident between disc harrowing and the use of the traditional method.Since scarifying and single-acting disc harrowing compared to the traditional method of 2-blade disc ploughing resulted in lower tractor speed reduction percent, higher actual speed and rate of work, decrease in tillage operation time and cost, reduction in weeds/square m after tillage operation and manual weeding, reduction in time and cost of manual weeding and higher increase in crop yield, they could be recommended for groundnut production in Gash Delta