Effects of pruning of various shrub species on maize yield in the northern Guinean zone of Mali

Both mineral fertilisation and ploughing in prunings of woody species have positive effects on maize yields.

Field of maize plants with a plot marker sign

Condition of plants in T1 elementary plot = Recommended mineral fertilisation (RMF) = 100 kg cereal complex/ha and 150 kg urea/ha (Source: S. Macalou)

Incorporation of the leaf biomass of Gliricidia sepium + Leucaena leucocephala at Farako (Source: S. Macalou)

6 people working in a crop field holding green leaves

Incorporation of leaf biomass from Gliricidia sepium alone in Farako (Source: S. Macalou)

Vegetative state of maize plants 35 days after sowing in Farako (Source: S. Macalou)

Condition of plants in elementary plot T6 = biomass of Guiera senegelensis 3 t/ha (Source: S. Macalou)

Condition of plants in elementary plot T3 = biomass of Gliricidia sepium 3 t/ha (Source: S. Macalou)

Germination rates, densities at stripping and harvest of maize plants

The analysis of variance showed no significant difference between the different treatments for the germination rate of maize. The germination rates recorded ranged from 87% to 96%. These good germination rates show that the procedure of burying the prunings (green manure) did not have a negative influence on the germination of the maize seeds. After disking, the average maize density was 52,712 plants/ha. This is well below the theoretical density of 62,500 plants/ha. The analysis of variance did not reveal any significant difference between the 21 fertilisation options (P= 0.748).

Grain maize yield (kg/ha)

Grain maize yield varied according to treatment (fertilisation options) and a significant difference was observed (P = 0.007). The average yield was 1828 kg/ha. The highest yield was obtained with treatment T1 (3488 kg/ha), which was statistically equivalent to treatments T3, T7, T12, T20 and T21.

These results show that mineral fertilisation has a positive effect on grain maize yield. However, ploughing in woody species prunings at a rate of 3 t/ha alone or in combination with half the recommended mineral fertiliser significantly increased maize grain yield.