Land suitability assessment for tea plantation in Rwanda: case study: Gisakura Tea Plantation

Abstract

Abstract Lack of information on land suitability for Tea plantation has induced yield variability and unproductive expansion in different agro ecological zones of Rwanda. This study was conducted in Gisakura tea plantation in Nyamasheke district in the Western Province of Rwanda. The objective was to assess soil chemical and physical suitability and site matching for tea plantation. The soil samples were taken at depths of topsoil (0-20 cm), middle soil (20-40cm) and subsoil (4060cm) on both upland and lowland where new tea plantation would be established for extension of tea plantation. Soil chemical and physical properties were analyzed in laboratory using standard methods. Results showed that the soil was well drained with sandy loam and loamy sand texture. The analytical data show the high soil aggregate stability (0.64±0.051, 0.62±0.051 and 0.62±0.051 for the topsoil, middle soil and subsoil respectively), and low bulk density with maximum and minimum values of 0.2389±0.02005g/cm3 and 0.2776±0.02005g/cm3. The soil moisture retention characteristics have shown that soil water content decrease as the pressure increase and maximum water retention in upland and lowland was 72.6% and 66.9% while the minimum was 62.2% and 58.3% respectively. Chemically, the soil reaction was strongly acidic (pH values of 4.41±0.175, 4.065±0.175 and 3.954±0.175 units for the topsoil, middle soil and subsoil respectively) with medium to high exchangeable acidity. The soil was non saline with the electrical conductivity of 0.0518±0.00814dS/m, 0.0485±0.00814dS/m and 0.0416±0.00814dS/m for the topsoil, middle soil and subsoil respectively. The organic carbon was medium to high (518±0.721%, 0.0485±0.721% and 0.0416% for the topsoil, middle soil and subsoil respectively) and the organic matter content was high (10.79±1.244%, 9.91±1.244% and 6.08±1.244% for the topsoil, middle soil and subsoil respectively). The soil had very low total nitrogen (0.0709±0.00848%, 0.0661±0.00848% and 0.0362±0.00848% for the topsoil, middle soil and subsoil respectively), medium total phosphorous (0.02063±0.003385%, 0.02125±0.003385% and 0.02±0.003385% for the topsoil, middle soil and subsoil respectively) and deficient of available phosphorous (6.45±0.694ppm, 5.35±0.694ppm and 3.85±0.694ppm for the topsoil, middle soil and subsoil respectively). In order to improve the productive capacity of this soil to obtain high tea yield, remedial measures aiming at correcting the deficiencies should include liming to increase pH level to the level of availability of nutrients and utilization of organic manure with addition of inorganic fertilizers to provide the optimal level of nutrients.

Keywords: Tea plantation, land suitability, physical chemical suitability.