Browsing by Author "Mtakwa, Peter Wilson"

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Evaluation of soil fertility status and land suitability for smallholder farmers’ groundnut and maize production in chisamba district, Zambia
(nternational Journal of Plant & Soil Science, 2016) Chirwa, Meki; Mrema, Jerome Peter; Mtakwa, Peter Wilson; Kaaya, Abel K; Lungu, Obed I
A study was conducted to determine the soil fertility status and the suitability of land for the smallholder farmers’ sustainable production of groundnut and maize in Chisamba District of Zambia. Composite soil samples (0 – 30 cm) were collected from the fields of 18 randomly selected major groundnut producing villages. The soils were analysed for various chemical and physical properties. Then focused group discussions as instruments of data collection were used to capture information on market availability for groundnuts. The simple limitation method was used to compute land suitability. The results showed that most (63.63%) of the soils were strongly acidic, with the mean pH of 4.95±0.35. The mean of CEC was 3.63±2.73 cmol / kg. There was a highly significant and positive relationship between pHCaCl2 and the concentration of Ca (r = 0.653, P = .000), Mg (r = 0.614, P = .000) and K (r = 0.651, P = .000). There was also a positive highly significant relationship between N and SOM (r = 0.487, P = .004). A positive and highly significant relationship between gender of the smallholder farmer and sale of groundnuts at markets of nearest towns (r = 0.202, P = .005) was observed. It was observed that 72.22% of the groundnuts producing areas of Chisamba District were marginally suitable (S3) for groundnut production. It was also observed that 68.75 % of the soils in the study area were marginally suitable for maize production. It was concluded that the major soil fertility limiting factors were soil acidity, low CEC, SOM, Ca, Mg, K and N. The major socio-economic limiting factor was the non-availability of stable markets.
Pedological Characterization of Soils Developed from Volcanic Parent Materials of Northern Province of Rwanda
(Science publishing group, 2016-10) Uwitonze, Providence; Msanya, Balthazar Michael; Mtakwa, Peter Wilson; Uwingabire, Solange; Sirikare, Sylvere
Soils formed from volcanic materials have high potential for agricultural production and support high human population densities. This study was carried out on soils developed from volcanic parent materials of Northern Province of Rwanda aiming largely on pedological characterization but to a certain extent on assessment of potentials of soils for production of major crops in the area. Three representative pedons namely Kinigi Pedon 1 (KNG-P1), Kinigi Pedon 2 (KNGP2) and Gahunga Pedon 1 (GHNG-P1) were identified and described. Sixteen soil samples were collected from different pedogenic horizons and analyzed in the laboratory for physico-chemical properties. Pedons were classified using USDA Soil Taxonomy and FAO-WRB for Soil Resources. Potentials and limitations of the soils were also identified. Results show that soils were shallow to very deep and well drained. Topsoils were very dark coloured with colour values of ≤ 2 in all pedons. Texture was generally loamy with bulk densities of < 0.47 g/cm3 in Pedons KNG-P1 and KNG-P2 while they ranged from 0.94 to 1.34 g/cm3 in Pedon GHNG-P1. Topsoils were medium acid (KNG-P1, KNG-P2) and mildly alkaline (GHNG-P1), with high to very high OC ranging from 3.97 to 13.03%. CECsoil was high (> 32 cmol (+)/kg) in Pedons KNG-P1 and KNG-P2. Base saturation was low (< 30%) in Pedons KNG-P1 and KNG-P2 while it was high (> 50%) in Pedon GHNG-P1. pHNaF was > 9.5 in Pedons KNG-P1 and KNG-P2 reflecting exchange complex dominated by amorphous materials and/or humus complexes. Phosphorus retention capacity ranged from 6.25% to 99.58% and only Pedons KNG-P1 and KNG-P2 met the “andic properties” requirement of PRC ≥ 85%. Melanic index values indicated that these two pedons were characterized more by fulvic than humic acids. Nutrient imbalance with reference to basic cations was common in all studied soils, implying suboptimal nutrient uptake and toxicity. Fe2O3, SiO2 and Al2O3 were the dominant oxides in the studied soils. Degree of weathering of studied soils was low as indicated by their weathering indices. Using field and laboratory data, Pedons KNG-P1 and KNG-P2 classified as Andisols/Andosols and GHNG-P1 as Mollisols/Phaeozems. Land units represented by Pedons KNGP1 and KNG-P2 were rated as marginally suitable while land unit represented by Pedon GHNG-P1 was rated as moderately suitable for the major crops of the area. Application of P fertilizers coupled with efficient placement was recommended to enhance P, and soil conservation should be underscored in study area.
Pedological characterization of soils developed on gneissic granites in the Congo Nile watershed divide and central plateau zones, Rwanda
(2016-09) Uwingabire, Solange; Msanya, Balthazar Michael; Mtakwa, Peter Wilson; Uwitonze, Providence; Sirikare, Sylvere
Pedological characterization was carried out on soils developed on gneissic granites of Southern Province of Rwanda. Three representative soil profiles (GSK-PI, GSK-P2 and TMB-PI) were identified, described and sampled using standard manuals. A total of nineteen soil samples were analyzed in the laboratory for physicochemical properties. Soil classification was carried out using two international systems of classification. The potentials and limitations of the soils were also identified. All studied pedons were very deep, well drained with loamy to clayey topsoil textures overlying dominantly clayey subsoil textures. The deeper subsoil ofPedon TMBPI consisted of loamy and sandy textures. Pedons GSK-PI and GSK-P2 depicted eluviation-illuviation process as indicated by presence of clay cutans in subsoils. Analytical data showed low bulk and particle densities and high porosity in topsoils ranging from 1.02 to 1.34 g/crrr', from 2.18 to 2.59 g/cm! and from 48.34 to 53.23%, respectively. Topsoilsof studied soils were strongly to slightly acidic with pH ranging from 5.49 to 6.59 while subsoils were strongly acidic to medium acidic with pH range between 5.13 and 5.86. The studied pedons had very low to medium total nitrogen and organic carbon respectively ranging from 0.15 to 0.24% and from 1.6 to 2.5%, both decreasing with depth. Topsoil and subsoil cation exchange capacity of the soils respectively ranged from low (9.8 - 21.6 cmol (+)/kg) to medium (4.2 - 13.2 cmol (+)/kg). Base saturation of the studied pedons was rated as low « 50%) throughout all horizons of studied pedons. Whereas topsoil available phosphorus ranged from low to medium (6.4 - 15.7 rug/kg) and decreased with depth, phosphorus retention capacity was < 50% and increased with depth in Pedons GSK-PI and GSK-P2 but didnot show any definite trend in PedonTMB-PI. All studied pedons indicated suboptimal nutrient ratios with reference to the basic cations, implying potential nutrient imbalance and toxicity of these nutrients. SiD" AI,O, and Fe,O, ranged from 45.4 to 58.4%, 17.0 to 27.0% and 16.7 to 24.3%, respectively. On the basis of silt/clay ratios, the degree of weathering of the studied pedons followed the trend GSK-PI>GSK-P2>TMB-PI. According to USDA Soil Taxonomy, the studied pedons classified as Ultisols (GSK-PI and GSK-PI) and Inceptisols (TMB-PI), respectively, correlating to Alisols and Cambisols of WRB for Soil Resources. The studied soils were generally rated as having low fertility and only marginal suitability for the major crops of the area. Specific land management and cropping systems were recommended for sustainable utilization of soils.