Influence of Climatic and Edaphic Factors on Resilience and Productivity of Herbaceous Foragit Species in Machakos and Tharaka Nithi Counties, Kenya
| dc.contributor.author | Karugia, Elijah Samuel Kamau | |
| dc.date.accessioned | 2026-04-23T05:54:11Z | |
| dc.date.available | 2026-04-23T05:54:11Z | |
| dc.date.issued | 2023-03 | |
| dc.description | A Thesis Submitted of the Requirements in Fulfillment for the Award of the Degree of Doctor of Philosophy in the School of Pure and Applied Sciences of Kenyatta University | |
| dc.description.abstract | Rangelands are extensive tracts of land with natural vegetation used as forage by both domestic and wild ungulates. Currently rangelands cover about 80%o of total landmass, host about 30o/o of total human population and produce about 60Yo of all beef consumed in Kenya. This study was informed by the scanty documented information on how seasonal variation in climatic and edaphic factors affect key hprblle_gyljtryg* species' resilience and herbage quality and yields particularly iuari( aqdlffi,fr.q rangeiffis in'Kenya. It was bonducted for three years (2013 to early 2016) and irivestifffia the influence of climatic and edaphic factors on resilience and herbage production among key herbaceous forage species in Kivaa and Ntugi rangelands in Eastern Kenya. Stratified random sampling was applied and belt transects of 200m by 10m established in each randomly picked block (strata). Twenty experimental plots of 5m by 5m were randomly established along each belt transect. Key herbaceous forage species were identified through purposive sampling and local experience-based herbage preference (LEBHP). Soil nutrients were analyzed using Kjeldahl, and Calorimetric among other methods. Herbage samples were analyzed for various nutrients using Atomic Absorption Spectrophotometer (AAS). Crude protein was analyzed by multiplyingoh Nitrogen OJ) in forage samples by a factor of 6.25. The data collected were analyzed using ANOVA, regression, correlation, T-test and F-test using PAST, STATA and CANOCO softwares. It was found that Dichanthium annulatum (Forsk.) Stapf., Digitaria abyssinica (A. Rich.) Stapf and Rhynchelytrum repens (Willd.) C.H. Hubb was the most valuable and resilient forage species in the two rangelands. Precipitation significantly influenced herbage quality during wet and dry seasons (p:0.002 and p:0.046 respectively) but not yields (p > 0.05). Precipitation also significantly influenced range condition during wet and dry seasons (p:0.006). Soil texture influenced moisture content while the latter significantly and positively influenced herbage production during wet and dry seasons (p : 0.042 and p=0.006 respectively). Soil bulk density positively and significantly influenced forage species biomass production in Ntugi in2014 (r: 0.513, P : 0.019) and in 2016 ((r:0.632,P : 0.0059) at P < 0.05. Soil Nitrogen (lrtr), Potassium (K), Magnesium (Mg), Iron (Fe), Copper (Cu) and Zinc (Zn) significantly influenced forage quality while Soil Phosphorus (P), N, K, Mg, Fe and Cu positively influenced herbage yields. This study concluded that climate and soil significantly influenced resilience and herbage quality and yields among key herbaceous forage species. Species diversity, NDVI and LULC should be used to augment traditional range condition rating methods. The three key forage species should be studied further to develop ecotypes suitable for different eco- climatic zones. | |
| dc.identifier.uri | https://ir-library.ku.ac.ke/handle/123456789/32949 | |
| dc.language.iso | en | |
| dc.publisher | Kenyatta University | |
| dc.title | Influence of Climatic and Edaphic Factors on Resilience and Productivity of Herbaceous Foragit Species in Machakos and Tharaka Nithi Counties, Kenya | |
| dc.type | Thesis |