Evaluation of pasture restoration techniques on degraded bare surfaces in the rangelands of Uganda

Mugerwa Swidiq

National Livestock Resources Research Institute-Uganda

Before pasture restoration

After pasture restoration

Introduction Uganda’s rangelands cover

approximately 43% of the total land area.

They support about 95% of the

cattle population in Uganda.

The rangelands are deteriorating rapidly due to overgrazing, termite activity and indiscriminate tree cutting.

Large bare surfaces have emerged at the expense of palatable pasture

The bare surfaces are associated with reduced water infiltration, excessive soil erosion and silting of downstream water reservoirs.

Introduction cont’d Cover 1986 2000 2004

Hectares % Hectares % Hectares % Bare ground 1,264 0.36 5464 1.55 18,263.1 5.2 Bush 51613 14.7 44500 12.66 35684 10.2 Coniferous 0 0 5110 1.46 6150.9 1.75 Grassland 90,020 25.6 84408 24.02 78,199 22.3 SSF 13149 3.74 40914 11.64 54709 15.6 Water 26156 7.44 27437 7.81 24555 6.99 Wetland 14495 4.13 17581 5 14986 4.26 Woodland 154742 44.03 126025 35.86 118892 33.8

Goal of the study: To restore palatable pasture vegetation on degraded bare surfaces so as to improve animal productivity and livelihoods of millions of Ugandans dependent on extensive grazing production systems for survival

The soils of the bare surfaces are crusted limiting water infiltration Even when water infiltration and soil fertility are enhanced , no

vegetation establishes implying that the soil seed bank is also depleted by erosion forces

Experimental procedures Study site: Nakasongola

District (01°18’N 32°30’E). Climate: Mean daily

maximum temperature is 300C-- Annual rainfall: 500-1000mm.

Soils: The soils are are relatively homogeneous and strongly weathered with high sesquioxide content (Haplic Ferralsols)

Vegetation: open savannah woodland with tall grasses.

Restoration treatments evaluated 1. (R)-resting bare surfaces

from animal activity

2. (RR)-resting bare surfaces+ reseeding with appropriate pasture seed

3.(NR)- Night kraaling herds of cattle on bare surfaces coupled + resting the surfaces from animal activity

4.(NRR)- Night kraaling herds of cattle on bare surfaces + reseeding of kraaled surfaces with appropriate pasture species + resting the surfaces from animal activity

5. (C)-control (no reseeding, night kraaling and resting)

Results: effect of restoration treatments on soil properties Selected soil variables Treatments

C R RR NR NRR

pH 3.0 3.5 3.3 5.8 6.2

Soil organic matter (%) 1.08 1.18 1.3 3.3 3.5

Soil nitrogen (%) 0.04 0.04 0.09 0.2 0.25

Av. Phosphorus (mg/Kg) 1.28 1.70 1.34 5.38 5.5

Potassium (Cmole/Kg) 0.25 0.25 0.25 2.5 2.7

Results: Dry matter yield, percentage ground cover and species richness different restoration treatments under different seasons

% Cover DM Species Season Treatment Bare Forbs Grass (kg/ha) (No. /m2) WET NRR 2.4 40.7 56 4500 9 NR 11.5 14.5 74 3700 9 RR 50.4 18 31 1940 9 R 70.8 0 29.2 1600 5 C 100 0 0 0 0 DRY NR 28.7 3.4 68.2 3200 2 NRR 29.1 16.3 54.5 3130 4 RR 72 8.4 20.1 1680 2 R 86.1 0 13.6 1160 1 C 100 0 0 0 0 SE 5.3 3.9 5 396 0.82

Significance Season *** *** * *** *** Treatment *** *** *** * *** Season/Treatment * *** ns ns ***

*** Significant at p < 0.001, ** Significant at p < 0.01, * Significant at p < 0.05 and ns- Non significant.

Results: Effect of treatments and seasons on chemical composition and

digestibility of pasture

%DM Season Treatment CP NDF OMD Ca P ASH Wet NRR 10.4 57 65 0.11 0.04 6.6 NR 8.1 77.8 55 0.1 0.13 7.5 RR 6.9 72 51 0.09 0.09 5.9 R 4 83.5 47 0.07 0.07 5.3 C - - - - - - Dry NRR 7.4 71.7 46 0.07 0.08 13 NR 6.3 83.3 44 0.07 0.13 10 RR 3.8 76 42 0.06 0.17 10.1 R 2.2 85.7 37 0.08 0.05 6.6 C - - - - -

SE 0.55 5 1.84 0.03 0.097 0.89 Significance Season *** ** *** ns ns *** Treatment *** ** *** ns ns *** Season*Treatment ns ns *** ns ns ns

*** Significant at p < 0.001, ** Significant at p < 0.01, * Significant at p < 0.05 and ns- Non significant.

Conclusion

The results are suggestive that resting night kraaled bare surfaces from animal activity coupled with reseeding is an effective pasture restoration technique that significantly improves soil properties, pasture production, nutritive quality and reduces the proportional of bare surfaces on degraded bare surfaces.

Acknowledgement

CGIAR “Challenge Program on Water and Food”.

National Agricultural Research Organisation-Uganda

Makerere University- Uganda

Participating farmers

Thank you for listening

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