Muchemi, Juma Peter2026-03-172026-03-172025-10https://ir-library.ku.ac.ke/handle/123456789/32773A Thesis Submitted in Partial Fulfilment of the Requirements for the Award of the Degree of Master of Science (Plant Ecology) in the School of Pure and Applied Sciences of Kenyatta University, October 2025 Supervisors: 1.Francis W. Kariuki 2.Benson M. MwangiRice and fish are major food and nutritional security, employment and income sources in Kenya. Rice is third most important staple food while fish is considered as a poor man`s rich food in proteins, Omega-3 fatty acids and mineral nutrients. Both crops are produced under intensive monoculture system which has constrained their sustainable production leading to huge deficits. To bridge the production gap, the current intensive monoculture production mode needs to be transformed into an ecological intensification system through integrated rice-fish farming. The aim of this study was to assess suitability of Basmati 370 (B) and IR 2793 (IR) rice varieties for integrated rice-fish farming in Bunyala Irrigation Scheme. The two rice varieties were grown in 2 blocks in separate plots of the same size with and without Nile tilapia (Oreochromis niloticus L.) fish. Each was replicated twice in each block in a complete random block design. The plots with fish were modified by constructing fish refugia in the periphery, each of an area of 52 m2 and a depth of 1m. In rice–fish cultures no feeds and agrochemicals were used. Selected water physico-chemical parameters (dissolved oxygen, pH, temperature, electrical conductivity) were monitored in situ weekly at 0900 and 1600hrs. Alkalinity and Nitrates (NO3-N) were determined through titration and calorimetric methods respectively. Fish and rice growth and yield indices were measured monthly for a period of 226 days. After harvesting at 120 and 135 DAT for IR and B respectively, Basmati, and integrated IR and B plots were irrigated again to produce ratoons as a second rice crop and allow fish to mature. Data on water physico-chemical parameters and fish and rice growth and yield indices collected were subjected to ANOVA and significantly different means of the treatments were separated using Tukey`s test at 5 % probability. Except total alkalinity, the selected water physico-chemical parameters were within suitable range for rice and fish growth. IR rice variety produced significantly (p ≥ 0.05) higher rice yield in both rice monoculture and rice-fish cultures at 4616 ± 313.53 and 4136 ± 183.83 kg ha-1 respectively. Basmati yielded 3944 ± 327.90 and 3656 ± 192 kg ha-1 under monoculture and integrated culture respectively. The net income was significantly (p ≤ 0.05) higher in Basmati fish culture (121887.824 ± 8763.3) followed by Basmati monoculture (88491.633 ± 14150.96) and then IR fish culture (61568.131 ± 7061.3) while the lowest was IR monoculture (40835.387 ± 8361.8). The two integrated rice fish cultures did not differ significantly (p ≥ 0.05) in fish yields. Fish recovery rate was below 50% which was attributed to predation and poaching by humans. The higher net income from integrated rice-fish cultures than from rice monocultures could be attributed to lower production cost due to savings from the agrochemicals costs and the additional income from fish sales. Higher income from integrated rice-fish cultures is an indication that both IR and B rice varieties are suitable for integrated rice-fish farming and could be used as an incentive for adoption of integrated type of farmingenThesis