Impact of changes in land use and land cover on feed resources in the Ethiopian highlands


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Poster prepared by Kahsay Berhe, Zerihun Woldu, Don Peden, Dirk Hoekstra and Alemayehu Mammo, Hohenheim University 2012

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Impact of changes in land use and land cover on feed resources in the Ethiopian highlands

  1. 1. Impact of changes in land use and land cover on feed resources in the Ethiopian highlands Kahsay Berhe1, Zerihun Woldu2, Don Peden1, Dirk Hoekstra1 and Alemayehu Mammo3 1International Livestock Research Institute (ILRI), P.O. Box 5689, Addis Ababa, Ethiopia 2Addis Ababa University, P.O. Box 1176, Addis Ababa, Ethiopia 3DC Office of planning, Washington DC 2009, USA Corresponding author: Introduction Livestock are sources of food, draft power, cash income, fertilizer and energy among others. Ethiopia owns a large number of livestock (45,930,163 TLU) (FAO 2010), the highest in Africa. The main sources of livestock feed in the Ethiopian highlands are crop residues and natural pasture. The contribution of livestock is limited, because of poor availability and quality of feed resources, among others. Much of the change occurred on cultivated land (Fig. 4). The increase in cultivated land was 125%, which was mainly at the expense of the grasslands. Out of the total cultivated land in 1971/72, 80% remained under the same land cover while 1281 ha (17.8%) was converted to grasslands in 2000. The reason for the conversion to grasslands could indicate that the land is no more suitable for agriculture. The increase of cultivated land from 7,186 in 1971/72 to 16,204 in 2000 is population driven, i.e. number of households increased from 2,064 to 5,518 while total population increased from 9,288 to 35,940 over the study period, respectively. The study area The study site falls within 38051 43.63 to 39004’ 58.59 E and 8046 16.20 to 8059 16.38 N, located on the western margin of the great East African Rift Valley in the Oromia region of Ethiopia (Fig. 1). Ten peasant associations surrounding Yerer Mountain with a total population of 35,940 persons in 2000 and an area of 28,741 ha were selected for the study. Net grassland - 9388 +2148 ha -11536 ha 10,034 ha 1281 ha +10453 ha -1435 ha 369 ha 28 ha 839 ha Net cultivated + 9018 50 ha 1236 ha 266 ha 65 ha 89 ha Net wet & water body +253 Net shrubland +117 +1325 ha -1208 ha +331 ha -78 ha Figure 4. Land use and land cover dynamics 1971/72 and 2000 Feed resources Figure 1. The study area Objective The objectives of the study were to describe the land use and land cover (LULC) changes over three decades and assess implications to livestock feed resources and recommend appropriate interventions. The household survey indicated that feed is sufficiently available during October to January, severely in short supply during May to September, while the remaining months are intermediate. From among the cultivated crops, teff and wheat were the major sources of crop residue, contributing to about 82% of the total residue (Table 1). Based on the procedures for estimating crop residues from cultivated areas, a mean value of 1.52 t/ha DM was obtained (Table 2). According to WBISPP (2001) 0.36 t/ha DM was also available as crop aftermath. Both figures were used for multiplying the cultivated area to obtain total amount of crop residue in the study area. Based on WBSIPP (2001) procedure, 1.45 and 0.83 t/ha was obtained from the other LULC types for 1971 and 2000, respectively (Table 2) . Materials and methods Table 1. Estimated yearly dry matter (t/ha) obtainable from different crop residues for the sample farmers in 2000. LULC analysis for the study area Crop type • • • • District maps (1:50,000 scale) to delineate study area, 1971/72: Seventeen black and white aerial photos, 2000: Landsat ETM+ satellite image of February 2000, Digital image processing and visual interpretation of satellite images and aerial photos Feed resources per ha from various LULC categories • Cultivated land: Survey from 132 households (hh) • Other LULC types: WBISPP, 2001 Livestock and hh population • 1971/72: Topographic map to determine number of hh and CSO (1974) data to determine human and livestock population • 2000: Secondary data Animal feed requirement • Livestock daily minimum feed DM requirement (Berhanu et al. 2004) All the above resources were used to compare available feed vs needs of the various livestock types for both periods. Total area (ha)* Wheat Teff Chickpeas 94.00 92.60 34.50 Faba bean Rough pea Field pea Barley Lentils Maize Total 11.20 6.70 6.60 6.20 1.10 1.80 255.70 12.30 6.18 5.23 6.75 0.61 1.40 1.42 1.54 3.30 1.86 1.56 2.04 12.25 6.64 12.04 8.80 0.66 2.00 431.21 on three years’ mean data (2001-2003) from household survey. **Obtained from various sources (Kahsay 2004). ***Assuming that 70% of the crop residue will be used as livestock feed. Table 2. Estimated yearly feed DM obtainable from different land cover types from the study area for 1971 and 2000 Multiplying factor DM yield (t/ha/yr) 1.52** + 0.36*** 1.45**** (1971); 0.83**** (2000) Cultivated land All other land cover categories Total Area (ha)* 1971 2000 7,186 16,204 21,365 12,224 DM production (t) 1971 2000 13,510 (30.4%) 30,464 (75%) 30,979 (69.6%) 10,146 (25%) 28,551 Results and discussion The 1971/72 land cover analysis (Fig. 2) showed that majority of the study area was under grasslands accounting for 18,784 (65.4%), while it was 9,396 ha (32.7%) in 2000 (Fig. 3). Cultivated land on the other hand increased from 7186 (25%) in 1971/72 to 16,204 ha (56.4%) in 2000. In 1971/72 majority of the shrublands were covered with Juniperus procera and Acacia albida trees, while the area under these trees has dramatically decreased in 2000. 1.10 0.92 0.79 1.09 0.55 0.78 *Based LULC type LULC change Average grain Total crop Conversion factor Crop residue (t DM)*** yield (t/ha)* production (t) (straw:grain ratio)** 1.42 133.29 2.06 192.49 1.00 92.32 2.47 160.11 1.05 36.23 1.31 33.22 44,489 (100%) 28,428 40,610 (100%) * Kahsay (2004) ** Based on Table 1, total crop residue (air dried)/total area multiplied by 90% to convert to DM yield/ha ***Air dried crop aftermaths at 0.4 t/ha/yr (WBISPP, 2001), but data multiplied by 90% to convert it to DM ****As per procedures by WBISPP (2001) Feed utilization/balance Considering minimum daily maintenance and 20% production requirements for livestock in the study area, annual feed needs were calculated to be 23,551 (1971) and 63,922 t DM (2000) (Table 3). As can be seen from the table, there is a substantial increase in cattle population over the study period (Table 3) because of increase in the need for more draft power due to expansion of cultivated land. Accordingly, available feed (Table 2) exceeded requirements (Table 3) by about 21,000 t in 1971, but fell short by about 23,000 t in 2000. Feed requirements for 2000 increased by over 170% due to increased livestock numbers (Table 3). Therefore, feed resources in the study area only met about 64% of the minimum annual energy required (plus additional 20% for production) by livestock. In the central highlands of Ethiopia, other similar works also reported that farms produce only 60% of the feed needed by livestock. This analysis further indicated that about 75% of the DM to come from crop residues (including crop aftermath) in 2000 which only contributed about 30% in 1971. In earlier works, it was also reported that 71% of the feed supply for Ada’a district (part of the study area) to originate from crop residues. Table 3. Daily and annual DM feed for MEm plus 20% production requirement for working animals in the study area Livestock type Daily DM requirement (kg/head/d)* Cattle (local) 4.33 Total number of livestock Total annual DM feed requirement (t)**** 1971** 11737 2000*** 31462 1971 18549.7 2000 49724.1 Sheep 3349 8153 764.0 1859.9 Goats 0.625 4958 9091 1131.0 2073.9 Donkeys 3.00 2375 8164 2600.6 8939.6 Horses Figure 2. Land Use and Land Cover: 1971/72 0.625 4.20 138 633 211.6 970.4 Mules 4.20 192 231 294.3 354.1 23551.2 63922.0 Total *Berhanu et al. (2004). **Computed based on CSO (1974). ***Obtained from four Offices of Agriculture and Rural Development (2003). **** Values obtained by multiplying daily DM requirement by total number of livestock and 365 days to get annual requirement. In the past decade, several research and development organizations (amongst others the Improving Productivity and Market Success (IPMS) Project) have worked on the introduction of improved feed technologies to boost the development of livestock commodity value chains. These technologies had important impact on feed resource availability in the study area, like the introduction of newly released teff varieties which reportedly yield about 3 and 5 t of grain and crop residues, respectively. Similarly, improved management of grazing areas by regulating livestock access and introduction of cut and carry in other IPMS districts showed biomass yields of up to 10 t. Similarly, to reduce the need for draft power, the project also introduced conservation tillage. Conclusion As is the case in most highlands in Ethiopia, human population growth was the major driving force behind the LULC changes, which in turn influenced livestock number, feed type and availability in the study area. Farmers’ priorities are to grow food crops rather than forages or fodder for livestock. Cultivated area increased substantially at the expense of grasslands. As a result, there is greater reliance on crop residues and on-farm production of fodder to feed stock. The failure of available feed sources to meet even the maintenance needs of existing livestock indicates that production from livestock will remain low unless strategies are developed to match existing livestock population. While this trend is alarming, recent research and development activities in many areas, including the study area, show that feed from existing grasslands and crop residues could easily increase using cut and carry system and newly released high yielding varieties, respectively. Such new developments should, however, be integrated and follow multifaceted approaches for creating a resilient ecosystem, including working on improving the quality of crop residues and developing intensive livestock management systems, among others. Figure 3. Land Use and Land Cover: 2000