Productivity and Nutritive Value of \u3ci\u3eUrochloa\u3c/i\u3e Grass Cultivars in Semi-Arid Tropical Kenya

There is increasing demand for high yielding and nutritious forages to meet the growing dairy farming in semi-arid Kenya. The productivity and nutritive value of seven Urochloa grass cultivars (Urochloa decumbens cv. Basilisk, U. brizantha cvs. Marandu, MG4, Piatá and Xaraes, U. humidicola cv. Llanero and U. hybrid cv. Mulato II) were evaluated in two diverse semi-arid environments, Katumani and Ithookwe in Kenya. At Katumani, the dry matter (DM) yield (5000 - 7500 kg/ha) was highest during the first harvest during the long rains (LR) 2014 season. Dry matter yield declined progressively with season and in the third season (LR 2015) only Xaraes achieved over 2000 kg/ha. All Urochloa cultivars died and no yield was recorded after the third harvesting season (LR 2015) due to prolonged dry season. At Ithookwe, all plants survived during the period of evaluation. Generally the DM yield was highest (4200 – 9200 kg/ha) in the second harvesting season during short rains (SR) 2014 with Llanero having the highest yield and Mulato II the lowest. Significant differences (P \u3c 0.05) in forage quality was recorded in calcium, phosphorus, ash, neutral detergent fibres (NDF) and lignin content. However, none of the cultivars consistently contained more than the other cultivars in all the forage quality parameters analysed. The cv. Xaraes had the highest calcium content and Marandu had the lowest while MG-4 contained the highest phosphorus and Basilisk the lowest. Mulato II contained the highest crude protein and lowest NDF. The study revealed that Urochloa could increase forage resources in the semi-arid regions of Kenya where annual rainfall exceed 700 mm without prolonged dry season

Climate Smart \u3ci\u3eUrochloa\u3c/i\u3e Grasses Improves Soil Health in the Semi-Arid Tropics of Kenya

The measurement of soil aggregates stability and soil microbial biomass can be used as an early indicator of long-term changes in soil quality. A study was conducted to quantify the amounts of shoots and roots biomass of Urochloa grass cultivars (commonly known as Brachiaria) and their effects on changes in the size distribution and stability of soil aggregates and on microbial biomass carbon (C), nitrogen (N) and phosphorus (P) in a structurally unstable sandy loam soil at Ithookwe and Katumani in semi-arid tropical Kenya. The Urochloa grass cultivars included Urochloa decumbens cv. Basilisk, U. brizantha cvs Marandu, MG-4, Piatã and Xaraes, U. humidicola cv. Llanero and U. hybrid cv. Mulato II. Rhodes and Napier grass were included in the treatments as controls. Roots biomass was evaluated using the soil-coring method to depths of 0 – 15 and 15 – 30 cm. Four aggregates-size fractions (\u3e 2000 μm, 250 – 2000 μm, 53 – 250 μm, and \u3c 53 μm) were isolated using the wet sieving method. Microbial biomass C, N and P were determined on field moist rhizosphere soil (18 - 23% by weight) from a depth of 10 cm using the chloroform fumigation-extraction technique. Shoots biomass of the Urochloa cultivars ranged from 3.0 to 11.3 t ha-1 and 5.5 to 8.3 t ha-1 at Ithookwe and Katumani sites respectively. Marandu, Xaraes, Basilisk and Piata had higher roots biomass than the controls (Rhodes grass and Napier grass). Aggregate stability differed among the grasses and was highest in soils under Mulato II and Marandu with mean weight diameters of 4.49 and 4.31 mm, respectively. Generally, microbial biomass N was higher in plots with grasses than in the bare plots. Among Urochloa cultivars, the highest microbial biomass C was recorded in plots with Mulato II and the lowest from the plots with MG-4

Feed Intake and Liveweight Gain of Goats Fed \u3ci\u3eUrochloa\u3c/i\u3e Grass

Crude protein and digestible dry matter are the most important components of a feed and determine animal performance. The natural pastures in Kenya are prone to great seasonal and spatial fluctuation in both quality and quantity. Consequently, there was need to explore other nutritious alternative feeds. Sixteen growing male Galla goats weighing 10 - 24 kg were used in a twelve weeks feeding trial in the coastal lowlands of Kenya. They were randomly allocated four grass diets consisting of Urochloa brizantha cvs. Piata and MG4, U. hybrid cv. Mulato II and Chloris gayana (Rhodes grass), which was used as the control. Regression analysis was conducted using daily weight gains as dependent variable against nutrient intake (dry matter, crude protein, acid detergent fiber, acid detergent lignin, neutral detergent fiber and ash). Crude protein intake gave a better prediction of daily gain (R2 = 0.89, P \u3c 0.001). Grass diet with high CP and digestibility values are most suitable for high ADG of Galla goats

Production of Giant \u3cem\u3ePanicum\u3c/em\u3e in Contrasting Environments in Semi-Arid Kenya

Giant panicum (Panicum maximum Jacq.) is a tall, vigorous perennial grass that is native to tropical and sub-tropical Africa. It is drought tolerant due to its deep and dense fibrous roots system and grows in a wide range of soil types. It is an important livestock feed and has been extensively cultivated in Brazil (Santos et al. 2006). Despite its wide genetic diversity in East Africa, its potential for livestock feed has not been exploited there due to limited research. Our research was aimed at evaluating the production of several giant panicum ecotypes in contrasting environments in semi-arid areas of Kenya

Milk Yield of Dairy Cattle Fed Common \u3ci\u3eUrochloa\u3c/i\u3e Grass in Kenya

Urochloa grass mainly grown in South America, East Asia and Australia has its origin in East and Central Africa. Its success in South America for animal production triggered interest in Kenya where the main forage species Napier grass was threatened by head smut and stunt diseases. Therefore, a study was carried out at Mtwapa research station in the coastal lowlands of Kenya under controlled condition to compare the lactation performance of dairy cattle fed on Urochloa hybrid cv. Mulato II, U. decumbens cv. Basilisk, U. brizantha cvs. Piata, MG-4 and Xaraes with Napier grass. An on-farm participatory study was conducted in eastern midlands of Kenya where farmers compared their local feeds (varied mixtures of Napier grass, maize stover and natural pastures) with either Piata, Xaraes, MG-4 or Basilisk). Results from the on-station experiment showed no significant differences (P \u3c 0.05) in daily milk yield between dairy cows fed Piata (4.7 kg) and those fed on Napier grass (4.6 kg) while cows fed on either Mulato II or Xaraes produced less (P \u3c 0.05) milk; 4.4 and 3.6 kg respectively. In the farmers’ trial, milk yield increased by 15 - 40% when they fed their cows on Urochloa grasses. The studies concluded that Urochloa grasses had potential to replace or compliment Napier grass in dairy feeding in Kenya towards increased milk production

Fungal Endophytes from the Aerial Tissues of Important Tropical Forage Grasses \u3cem\u3e Brachiaria \u3c/em\u3e spp. in Kenya

Most, if not all plants in natural ecosystems are symbiotic with mycorrhizal fungi and/or fungal endophytes. This association between plant and fungi is believed to be over 400 million years old when plants first colonized the land (Redecker et al., 2000). These fungal symbionts play important roles on plant ecology, fitness, and evolution; shaping plant communities; and the community structure and diversity of associated organisms. The importance of fungal endophytes in cool season grasses production and effects of endophyte on the livestock health (Examples fescue toxicosis and ryegrass staggers) have been extensively investigated (Smith et al., 2009; di Menna et al., 2012). However, current understanding of fungal endophyte community of warm season grasses (including Brachiaria spp.) and the impact of these endophytes on livestock production is very limited. Therefore, this study aims to analyse fungal endophytes community inhabiting in the aerial tissues of important tropical grasses Brachiaria species from Kenya, an East African country representing place of origin for most of the Brachiaria species

PLANT SHOOTS AND ROOTS BIOMASS OF BRACHIARIA GRASSES AND THEIR EFFECTS ON SOIL CARBON IN THE SEMI-ARID TROPICS OF KENYA

Grassland management practices that improve carbon uptake by increasing productivity or reducing carbon losses can lead to net accumulation of carbon in soils. A study was conducted to quantify the amounts of shoots and roots biomass of Brachiaria grass cultivars and their effects on soil carbon in two sites, Ithookwe and Katumani in semi-arid tropical Kenya. The grass cultivars were Brachiaria decumbens cv. Basilisk, B. brizantha cvs. Marandu, MG4, Piatã and Xaraes, B. humidicola cv. Llanero and B. hybrid cv. Mulato II. These were compared with two locally cultivated grasses (Chloris gayana cv. KAT R3 and Pennisetum purpureum cv. Kakamega 1). The grass treatments were evaluated with fertilizer application (40 kg P applied at sowing and 50 kg N ha-1 in each wet season) and with no fertilizer application. Shoots biomass of the Brachiaria cultivars ranged from 3.0 to 11.3 t ha-1 and 5.5 to 8.3 t ha-1 at Ithookwe and Katumani sites respectively in year 1. The highest shoots biomass recorded at Ithookwe was from cv. Piata while cv. MG4 gave the highest biomass at Katumani. Similar trends were recorded in year 2 of growth though the shoots biomass was lower at Katumani. However, the yields were significantly lower than those recorded from control, Napier grass in both years. The cv. Marandu, Xaraes, Basilisk and Piata had higher roots biomass than the controls (Rhodes grass and Napier grass) indicating greater potential for the Brachiaria grasses to sequester more carbon in the soil. The results of this study indicate that introduction of Brachiaria grasses in the semi-arid tropics of Kenya and in other similar environments can help increase soil carbon stocks that would mitigate the adverse effects of climate change and have greater economic returns

Growth and Yield Evaluation of \u3ci\u3eUrochloa\u3c/i\u3e Grass Cultivars in Sub-Humid Region of Kenya

Livestock production in sub humid region of Kenya is constrained by inadequate and low quality pasture. A study was conducted to evaluate growth and productivity of eight improved Urochloa grass cultivars in lower midlands, upper midlands and lower highlands agro-ecological zones (AEZ) in Eldoret, Kitale and Alupe respectively, western Kenya. The grass cultivars were; Urochloa brizantha cvs. Marandu, Xaraes, Piata, and MG-4, U. decumbens, cv. Basilisk, U. humidicola cvs. Humidicola and Llanero and Urochloa hybrid cv. Mulato II. Rhodes grass (Chloris gayana) and Napier grass (Pennisetum purpureum cv. Kakamega 1) were included as controls. At establishment stage, growth parameters (height, cover and spread) and dry matter yield (DMY) were monitored at 14 weeks after seedling emergence (WAE) and standardization cut conducted to stimulate uniform plant growth. Thereafter (production stage), the plants were repeatedly harvested for DMY determination at 6, 8 and 12 weeks intervals. The growth parameters and DMY varied significantly (p \u3c 0.05) among the cultivars in all the AEZ in all the measurement dates. Napier grass recorded the highest mean height (60 to 120 cm) at the end of establishment period while among Urochloa cultivars, MG-4, Basilisk and Xaraes recorded the highest mean height and plot cover across all AEZs. All Urochloa cultivars gave significantly (p \u3c 0.05) lower DMY than Napier grass in Kitale and Alupe while Basilisk and Xaraes recorded similar DMY to Napier grass in Eldoret. In Eldoret, Xaraes recorded the highest DMY (2.54 t ha-1) while in Kitale and Alupe the highest DMY was recorded in MG-4 (3.7 t ha-1) and Basilisk (4.72 t ha-1), respectively. Increasing cutting interval increased DMY but reduced nutritive value of Urochloa cultivars in Kitale. Basilisk, MG-4, Xaraes and Piata showed potential to establish and grow well across AEZs and to maximize production and nutritive value cutting at 8 weeks interval is recommended

Participatory Evaluation and Selection of Improved \u3ci\u3eUrochloa\u3c/i\u3e Grass Cultivars in Kenya

Low adoption of superior agricultural technologies has been attributed to insufficient attention given to farmers’ priorities and perceptions while developing technologies. There is therefore a need to involve farmers in development of new forage technologies in order to increase adoption. Participatory variety selection (PVS) was conducted on eight Urochloa grass cultivars in the coastal lowlands, eastern midlands, central highlands and northwestern highlands of Kenya to select cultivars that are more adaptable in each region. The eight Urochloa cultivars; U. brizantha cvs. Marandu, Xaraes, Piatã, MG4, U. decumbens cv. Basilisk, U. humidicola cvs. Llanero and Humidicola, and U. hybrid cv. Mulato II were evaluated against cultivated local grasses; Rhodes grass (Chloris gayana cv. KATR3) and Napier grass (Pennisetum purpureum cv. Kakamega 1). In each region, farmers were engaged in development of selection criteria through focus group discussions. For each criterion, farmers’ scored on individual grass cultivars using a Likert scale of 1 to 4 with higher scores indicating high cultivar preference. Farmers considered 12 to17 plant attributes in the selection of the most suitable forages for planting. The attributes included plant height, colour, spread, biomass among others. MG4 was the most preferred Urochloa cultivar in eastern midlands, central and northwestern highlands while Mulato II was most preferred in coastal lowlands. The study concluded that, the selected Urochloa cultivars met the farmers’ needs and were advanced for on-farm testing and evaluation for livestock benefits

Soil Microbial Carbon, Nitrate and Ammonium Nitrogen Dynamics in \u3ci\u3eUrochloa\u3c/i\u3e Grass Cultivated in Sub-Humid Kenya

A study was conducted to monitor the dynamics of available soil phosphorus (P), soil microbial biomass carbon (SMBC), nitrogen (SMBN), ammonium and nitrate nitrogen under seven Urochloa grass cultivars at Kitale, Kenya. The Urochloa cultivars: Urochloa brizantha cvs. Marandu, MG-4, Piata, Xaraes, U. decumbens cv. Basilisk, U. hybrid cv. Mulato II and U. humidicola cv. Llanero was compared with two popularly grown forages, Rhodes grass (Chloris gayana cv. KAT R3), Napier grass (Pennisetum purpureum cv. KK1) and annual weeds. The treatments were tested in a randomized complete block design arranged in a split plot treatment structure with two rates of fertilizer N (0 and 100 kg N ha-1yr-1) and P (0 and 40 kg P ha-1) assigned to the main plots and the grass cultivars assigned to the subplots. After 80 weeks, moist rhizosphere soil was sampled at 0 – 10 cm depth to determine microbial biomass. Application of fertilizer N and P did not significantly (P \u3e 0.05) influence SMBC, SMBN, ammonium N (NH4+N) and nitrate N (NO3-N). However, significant (P = 0.001) changes in soil properties, including NH4+N and NO3-N due to grass cultivars, were observed. After 80 weeks, the bare plot, annual weeds and Napier grass accumulated higher pools of ammonium and nitrate N, but the microbial biomass (SMBC and SMBN) in these treatments were lower than in Urochloa grasses. Soil pH was also low, while NO3-N was high indicating increased nitrification in the bare and Napier grass plots. Ammonium N was the most dominant form of inorganic N in Llanero and Piata due to increased plant uptake or reduced nitrification rates. The results suggested that the change in the SMBC and SMBN in the Urochloa grasses was regulated by the nitrate and ammonium N and soil pH