Range use and dynamics in the agropastoral system of southeastern Kenya

Occurrence of equilibrium and non equilibrium system dynamics in semiarid environments present serious management challenges. In these areas, resource management strategies are increasingly based on equilibrium rather than non equilibrium dynamics that assume simple system dynamics and strong coupling of animal-plant responses. This management approach underlies increasing trends of range degradation and low livestock productivity in these environments. To reverse these trends dictates greater understanding and alignment of grazing resource extraction strategies in space and time to prevailing system dynamics behaviour. In this study, range use patterns by free ranging herds under agropastoral herding were studied in two cycles of four consecutive grazing periods, in semiarid southeastern Kenya. The bites count and herd locations per area methods were used. While grazing thresholds in the system were derived from biweekly sward biomass measured by the quadrant technique in the growing period and stocking rates applied to a growth-consumption rate model. The analysis tested the responsiveness of the agropastoral herding strategies to the predominant system dynamics in the area. In this environment, high rainfall variability ranging from 71 to 98% is experienced across years and seasons, pointing to non-equilibrium dynamics in the system. The agropastoralists practiced seasonal range use and tracking strategies. During the dry season, areas of concentrated drainage; river valleys, bottomlands and ephemeral drainage ways absorbed a greater grazing load, taking 57.1 to 60% of the grazing time by the animals. In contrast, areas of limited moisture concentration, the open sandy/clay plains, were mainly exploited in the wet season and accounted for 52.6 to 55.6% of the grazing time. The agropastoralists tracked forage availability through use of multispecies livestock (cattle, goats and sheep) that exploited different grazing resources in space and time. These range use patterns and strategies tend to stabilize nutrient and energy flow to livestock and thus productivity throughout the seasons. Based on the growth-consumption rate model, grazing thresholds in the system are achieved at 13800, 13000, 4000 and 12300, 4600 and 12000, and 5600 and 11000 kgha-1 of grass biomass at, 2.5, 5, 7, 8 and 10 TLUha-1, respectively. 7 TLUha-1 represent the upper stocking rate limit in the system during the growing period. In this system, resource use strategies are in line with the predominantly non-equilibrium system behaviour. However, sedentary land use interventions and limiting farm sizes that restrict livestock mobility and negatively affect grazing resource diversity will undermine system stability and sustainable livestock production in the area.Key words: Agropastoralists, range use, system dynamics

Hydrologic properties of grazed perennial swards in semiarid southeastern Kenya

Identification of plant resources that persist under grazing pressure, support desirable levels of production and at the same time protect the grazing environment is central to sustainable livestock production. This study assessed the infiltration capacity and soil loss associated with perennial swards subjected to different levels of utilization using simulated rainfall. The hypothesis was tested that grazed perennial swards have similar hydrologic properties and threshold removal levels below which runoff increases markedly. Infiltration capacity for the perennial swards increased with increasing stubble height before leveling off towards the highest stubble height. A 50% removal of current growth was the upper limit above which runoffs from the swards increased rapidly. Aggregate stability, organic carbon and percent ground plant cover were the most significant attributes that influenced infiltration capacity. Panicum maximum and Enteropogon macrostachyus were the most suitable perennial swards with favourable soil physical properties and infiltration capacities in the study area. The results support the existence of a threshold level of sward stubble height for minimizing runoff.Key words: Perennial swards, water infiltration capacity, runoff thresholds

The challenges of rehabilitating denuded patches of a semi-arid environment in Kenya

Land degradation is a major problem in the semi-arid environments of Sub-Saharan Africa. Fighting land degradation is essential to ensure the sustainable and long-term productivity of the habited semiarid lands. In Kenya, grass reseeding technology has been used to combat land degradation. However, despite the use of locally adapted perennial grass species namely Cenchrus ciliaris (African foxtail grass), Eragrostis superba (Maasai love grass) and Enteropogon macrostachyus (Bush rye) failure still abound. Therefore, more land is still being degraded. The aim of this study was to determine the main factors which contribute to failures in rehabilitating denuded patches in semi-arid lands of Kenya. A questionnaire was administered to capture farmer perceptions on failures on rangeland rehabilitation using grass reseeding technology. Rainfall data was collected during the study period. Moreover, rehabilitation trials using the three grasses were done under natural rainfall. Results from this study show that climatic factors mainly low amounts of rainfall to be the main contributor to rehabilitation failures. 92% of the respondents asserted that reseeding fails because of low rainfall amounts received in the area. The study area received a total of 324 mm of rainfall which was low compared to the average annual mean of 600mm. Reseeded trial plots also failed to establish due to the low amounts of rainfall received. This showed how low rainfall is unreliable for reseeding. Other factors namely destruction by the grazing animals, pests and rodents, flush floods, poor sowing time, poor seed quality, lack of enough seed and weeds also contribute to rehabilitation failures in semi-arid lands of Keny

Dry matter yields and hydrological properties of three perennial grasses of a semi-arid environment in East Africa

Enteropogon macrostachyus (Bush rye), Cenchrus ciliaris L. (African foxtail grass) and Eragrostis superba Peyr (Maasai love grass) are important perennial rangeland grasses in Kenya. They provide an important source of forage for domestic livestock and wild ungulates. These grasses have been used extensively to rehabilitate denuded patches in semi-arid environment of Kenya. This study investigated the dry matter yields and hydrological properties of the three grasses under simulated rainfall at three phenological stages; early growth, elongation and reproduction. Laboratory seed viability tests were also done. Hydrological properties of the three grasses were estimated using a Kamphorst rainfall simulator. Results showed that there was a significant difference (p > 0.05) in dry matter yields and soil hydrological properties at the different grass phenological stages. Generally, all the three grasses improved the soil hydrological properties with an increase in grass stubble height. C. ciliaris gave the best soil hydrological properties followed by E. macrostachyus and E. superba, respectively. E. macrostachyus recorded the highest seed viability percentage. C. ciliaris and E. superba were ranked second and third, respectively. C. ciliaris yielded the highest biomass production at the reproductive stage followed by E. superba and E. macrostachyus, respectively. Key words: Cenchrus ciliaris, Enteropogon macrostachyus, Eragrostis superba, rangeland

Influence of watering frequency on nutritional characteristics of cattle in Southeastern Kenya.

The effect of watering frequency on forage consumption, water intake and performance of Zebu-type steers was investigated under three treatments of daily watering (1/1) and two intermittent waterings __ once in two days (1/2) and once in three days (1/3). The study was carried out at a southeastern Kenyan rangeland dominated by Commiphora and allied shrubby genera, and perennial grasses such as Sporobolus pelucidus, Digitaria macroblephara and annual grasses, such as Eragrostis spp. Botanical and chemical composition of the diet selected by steers was determined from esophageal masticate samples. Forage consumption was estimated from total fecal collection and diet indigestibility. In addition, Ytterbium (Yb), a particulate phase marker dosed daily, was also used to estimate fecal output and intake for comparison with the total fecal collection. Steers were watered once in the evenings in metered 210 liter barrels. All steers were weighed approximately every two weeks. The study covered 159 days, which included four phenological stages of forage development: late maturity (March), growing stage (April), early maturity (June) and early dormancy (July). Total herbage production showed that there was sufficient forage for the steers throughout the study. Digestible organic matter (DOM) , crude protein (CP) amd digestible energy (DE) intake were highest (P<O.Ol) in April when forage was growing and decreased as forage advanced in maturity. Compared to daily watering, intermittent watering reduced (P<O.Ol) dry matter, DOM, NDF, CP and DE intake of steers drinking both (1/2) and (1/3). In March and April, intermittent watering reduced (P<O.Ol) free water consumption by 47-49% for steers watering (1/2) and 57-61% for steers watering (1/3) relative to the daily watering group. Steer performance was not influenced by watering frequency. Steers showed a faster growth rate (P<O.Ol) when forage was growing in April than the rest of the sampling periods. Fecal output and forage consumption estimated by total collection method and Yb excretion procedure showed that the Yb excretion procedure overestimated forage intake. Composition of the diet selected by steers was determined from esophageal masticate samples. Forage consumption was estimated from total fecal collection and diet indigestibility. In addition, Ytterbium (Yb), a particulate phase marker dosed daily, was also used to estimate fecal output and intake for comparison with the total fecal collection. Steers were watered once in the evenings in metered 210 liter barrels. All steers were weighed approximately every two weeks. The study covered 159 days, which included four phenological stages of forage development: late maturity (March), growing stage (April), early maturity (June) and early dormancy (July). Total herbage production showed that there was sufficient forage for the steers throughout the study. Digestible organic matter (DOM) , crude protein (CP) amd digestible energy (DE) intake were highest (P<O.Ol) in April when forage was growing and decreased as forage advanced in maturity. Compared to daily watering, intermittent watering reduced (P<O.Ol) dry matter, DOM, NDF, CP and DE intake of steers drinking both (1/2) and (1/3). In March and April, intermittent watering reduced (P<O.Ol) free water consumption by 47-49% for steers watering (1/2) and 57-61% for steers watering (1/3) relative to the daily watering group. Steer performance was not influenced by watering frequency. Steers showed a faster growth rate (P<O.Ol) when forage was growing in April than the rest of the sampling periods. Fecal output and forage consumption estimated by total collection method and Yb excretion procedure showed that the Yb excretion procedure overestimated forage intake

Hydrologic properties of grazed perennial swards in semiarid southeastern Kenya

Identification of plant resources that persist under grazing pressure, support desirable levels of production and at the same time protect the grazing environment is central to sustainable livestock production. This study assessed the infiltration capacity and soil loss associated with perennial swards subjected to different levels of utilization using simulated rainfall. The hypothesis was tested that grazed perennial swards have similar hydrologic properties and threshold removal levels below which runoff increases markedly. Infiltration capacity for the perennial swards increased with increasing stubble height before leveling off towards the highest stubble height. A 50% removal of current growth was the upper limit above which runoffs from the swards increased rapidly. Aggregate stability, organic carbon and percent ground plant cover were the most significant attributes that influenced infiltration capacity. Panicum maximum and Enteropogon macrostachyus were the most suitable perennial swards with favourable soil physical properties and infiltration capacities in the study area. The results support the existence of a threshold level of sward stubble height for minimizing runoff

Feeding value of Acacia tortilis pods in goats

Fresh Acacia tortilis pods were mixed with low quality native grass hay to form 5 rations - T 1 (100% hay), T 2 (25% pods + 75% hay), T 3 (50% hay + 50% pods), T 4 (75% pods + 25% hay) and T 3 (100% pods). Male goat groups (3 in each group) were fed these rations. Performance of goats improved with increase in pods inclusion up to 75%. T 1 animals lost weight and showed high morbidity. Acacia pods inclusion up to 75% in diets improved nutrition value of range livestock diets

The performance of Husani dairy goats under water restriction in the arid western lowlands, Eritrea

Eighteen adult Husani female goats of approximately equal age and body weight, and in their late pregnancy were purchased from Eritrean western lowlands. They were randomly assigned to three watering regimes (treatments): once in 24 h (T1), once in 48 h (T2) and once in 72 h (T3). The goats were browsed together in the same ecological area to ensure access to a similar diet. They also received the same husbandry and veterinary car

Constraints of rehabilitating degraded semi-arid lands of Kenya using indigenous perennial grasses

Land degradation which among others include loss of vegetation is rampant in Kenya, destroying both the fragile arid and semiarid lands and the non-arid areas. Efforts to rehabilitate semiarid areas by re-vegetation has often failed. This study was carried out to determine factors responsible for these failures. The study was conducted in the semi-arid district of Kibwezi. Three (3) grass species Cenchrus ciliaris, Enteropogon macrostachyus and Eragrostis superba were used for revegetating the land, while agro-pastoralists in the area were interviewed through questionnaires to get their perceptions on the failures of reseeding. Low rainfall, poor seed quality, lack of enough seed, flush floods, destruction by grazing animals were found to be factors limiting the success of reseeding

The Role of Moisture in the Successful Rehabilitation of Denuded Patches of a Semi-Arid Environment in Kenya

This study investigated the role of moisture in the successful rehabilitation of denuded patches in semi-arid lands of Kenya and the primary productivity of three perennial rangelands grasses namely Cenchrus ciliaris (African foxtail), Enteropogon macrostachyus (Bush rye) and Eragrostis superba (Maasai love grass) at three phenological stages (early growth, elongation and reproduction) as pure stands and two-grass mixtures. The grasses were sown on either rainfed (Sites 1 and 2) or simulated rainfall conditions (site 3). Site preparation in all the 3 sites involved mechanical bush clearing, use of fire and creation of micro-catchments using an ox-drawn plough. Soils in site 3 were sandy clay loams and those in sites 1 and 2 were sandy clays. There was total failure in establishment sites 1 and 2 under natural rainfall. Site 3 had good germination and subsequent establishment. These results were attributed to the moisture conditions in the three sites. There was a significant difference (