Growth and nutrient uptake among three wetland plant species occurring in Lake Victoria basin in Kenya

Abstract

Nutrient enrichment is one of the most serious threats to wetland ecosystems. Information is lacking, particularly concerning the response of wetland plants species in Kenya in regard to nutrient enrichment of wetlands. Understanding the mechanisms and adaptations that allow only certain species to thrive in the potentially stressful wetland environment requires the study of the biology of these plants. This study was carried out to investigate the growth and nutrient uptake among some selected wetland plant species in Lake Victoria basin, Kenya. Seedlings of Cyperas esculentus L., Aframomum angustifolium (Sonn.) and Phragmites australis (Cav.) Trin. Ex Steudel) were grown outdoors in pots. The pots were arranged in a completely randomised design under out-door conditions in the Botanic garden at Maseno University. Plants were provided with four nutrient dosage levels of 0 mg [no fertiliser added], 50 mg, 100 mg, 150 mg fertilizer [N: P: K, 10:26:10] per pot and replicated five times. The plants were irrigated daily with tap water for eight weeks. Data on growth which included shoot height, stem diameter, leaf number per plant, leaf area, leaf width, leaf length, shoot and root weights were determined. Leaf N and P was also determined. The data were analysed by analysis of variance (ANOVA) in SAS statistical package. Nutrient availability treatments significantly (P ≤ 0.05) influenced the growth and biochemical parameters investigated. Cyperas esculentus and A. angustifolium had higher rate of biomass accumulation as evidenced by increase in shoot and root weights compared to P. australis. Root-shoot ratios reduced with increasing nutrient concentration in C. esculentus and A. angustifolium, while that of P. australis increased up to 100mg treatment, then slightly reduced at 150mg treatment. Phragmites australis had significantly higher foliar P and N content than the other two species with increasing nutrient availability. There were significant interactions between nutrient treatments and species in most of the parameters measured. We recommend Phragmites australis as a better agroforestry plant species for reclaiming wetland areas.

Assessment of the Efficiency of a Pilot Constructed Wetland on the Remediation of Water Quality; Case Study of Litani River, Lebanon

“…Thus, the constructed wetland has contributed to reducing the level of pollution in the river. Such improvement in water quality can be at least partially attributed to the utilization of the planted macrophytes which have been shown by numerous studies to be highly efficient in the uptake of nutrients during their growth period, and to have a positive correlation between biomass production and nutrient uptake [20][21][22][23][24]. And, wetlands containing such types of plants remove larger quantities of nitrate than unplanted wetlands [25][26][27][28].…”

“…As the wetland matures and reaches equilibrium of annual growth and senescence of vegetation, the rate of ammonia removal would become less. Still, despite the high observed decrease in ammonia concentration, NH 3 levels in wetland outflow were generally above (mean of 0.95 mg NH 3 -N/L) the water quality criteria of 0.05-0.35 mg NH 3 -N/L for short-term exposures and 0.01-0.02 mg NH 3 -N/L for long-term exposures that are recommended to protect sensitive aquatic animals [15][16][17][18][19][20]. More comprehensive investigations are necessary to better understand the dynamics of the nitrogen cycle in the constructed wetland understudy.…”

Agro-Morphological Characterization of Kenyan Slender Leaf (Crotalaria brevidensandC. ochroleuca) Accessions

“…e quantitative data were collected on growth and agronomic traits including plant height, number of branches, petiole length, leaf length, leaf width, days to 50% flowering, days to first mature pod, pod length, pod width, number of pods per plant, number of seeds per pod, and weight of 1000 seeds. e leaf area was estimated at maximum leaf expansion using the formula A L � 0.73 (L L × W L ) adopted from Musyimi et al [18], where A L is the leaf area, L L is the leaf width, and W L is the maximum the leaf width.…”

Estimativa da capacidade extratora dos capins vetiver e tifton em sistemas alagados construídos

“…Considerando os resultados de extração de nutrientes pelas plantas nos SACs-EHSS, verificase que o aumento da concentração de nutrientes, expresso em termos da CE na solução nutritiva, resulta em maiores taxas de extração. De acordo com Musyimi et al (2010), a maior disponibilidade de nutrientes para as plantas pode aumentar a taxa de absorção pelo sistema radicular, favorecendo o acúmulo de nutrientes no tecido vegetal, bem como, o aumento da área foliar para transpiração e fotossíntese.…”