A comparison between conservation and conventional tillage systems for Maize production
The experiment entitled A Comparison Between Conservation and Conventional Tillage Systems For Maize Production was conducted at Kabete (Nairobi, Kenya) during the short rainy season of 1989/90. A 3x2 factorial experiment consisting of three tillage treatments (no-tillage, minimum tillage and conventional tillageJ with two methods of weed control (manual weed control and chemical weed control J was used for the experiment. All treatments were replicated three times on a randomized complete block design. The results showed that the highest draught and fuel requirements were obtained from the conventional tillage treatment; the lowest were from the no-tillage treatment, w h i Le minimum tillage was intermediate. As compared to conventional tillage, minimum tillage and no-tillage saved 47.4% and 59.6% per hectare in draught requirements respectively. Moreover, minimum tillage saved 50.3% and no-tillage saved 78.2% of fuel per hectare as compared to conventional ti 11 age. The different ti 1 I age systems, when tested for both draught and fuel requirements, showed highly significant differences .. X I V The most rapid emergence of maize seedl ings, as indicated by emergence rate index, was obtained from the minimum tillage treatment where weeds were control led with chemicals and the slowest was from the conventional tillage treatment where weeds were also control led with chemicals. There was, however, statistically no significant tillage effect and no significant weed control methods effect on emergence rate. The re s u l t s indicated the longest maize plant growth was for minimum tillage treatment where weeds were controlled with chemicals, while the shortest maize plant growth was observed in the no-tillage treatment where weeds were controlled manually. However, there was no significant difference among tillage systems for length of plant growth. The minimum tillage with manual weed control plot had the highest yield and the no-tillage with manual weed control plot had the lowest yield. However, when tested for statistical difference, ti 1 lage systems did not significantly affect yield. The greatest residue mass production was achieved from the conventional tillage with manual weed control treatment while the lowest was from the notillage with manual weed control treatment. Analysis of variance indicated a significant difference at 5% level xv among tillage systems, while there was no significant difference between weed control methods and no interaction between tillage systems and weed control methods on residue production. The result from economic analysis showed that the minimum tillage treatment where weeds were manually controlled was most profitable as compared to al I the other treatments. The results of the experiment strongly indicate that the minimum tillage with manual weed control system should be employed by farmers in t.he area during the short rains, as it has been found to perform better than the other systems. However, it is recommended that further investigations be carried out to substantiate the result obtained during the short rains and t.o see whether they also apply to the long' rains.