Browsing by Author "Hosegood, P.H."
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Item Design And Installation of Semi-Enclosed Hydraulic Lysimetersa.(1965) Forsgate ,J.A.; Hosegood, P.H.; McCulloch, J.S.G.; East African Agricultural and Forestry Research OrganizationThe Glover and Forsgate lysimeter has been developed into a durable field lysimeter, with an effective drainage system; details of design, construction and calibration are provided for a tank 9 ft. square and 6 ft. deep. Inaccuracies due to temperature variation in the measuring column are discussed.Item Effects of Organic Mulch on Fertility of a Latosolic Coffee Soil in Kenya(1965) Robinson, J.B.D.; Hosegood, P.H.; East African Agriculture and Forestry Research Organisation, Kikuyu, KenyaMeasurements are reported on the influence of mulch on the chemical and physical characteristics of the soil and the chemical composition of the crop together with growth measurement on an indicator crop in the greenhouse and on mature coffee in the field. Mulch reduced soil acidity; increased organic carbon, Kjeldahl nitrogen, exchangeable potassium and available phosphorus and decreased exchangeable calcium and manganese. It increased total pore space, free-draining pore space and rate of rainfall acceptance in the top soil. Effects on the coffee were to increase phosphorus, potassium and in some cases nitrogen in the leaf, but reduce magnesium and calcium levels. Potassium and calcium levels were increased in feeder roots, Whereas in the ripe cherry the phosphorus level was increased but nitrogen, calcium and magnesium levels were reduced. The soil effects were reflected in increased growth of the indicator crop and mulch improved the growth of the coffee tree in a year of seasonal drought.Item Note on a Preliminary Study of the Effects of an East African Softwood Crop on the Physical and Chemical Condition of a Tropical Soil(1966) Robinson, B.D.; Hosegood, P.H.; Dyson, W.G.; East African Agriculture and Forestry Research Organization, Kikuyu, Kenya.Some soil physical and chemical properties were measured under a secondary indigenous forest cover and a 16-year-old stand of Cupressus lusitanica. No significant differences in the physical parameters were noted; but distinct differences in some of the chemical determinations, viz. nitrogen, exchangeable bases, exchangeable hydrogen and pH, were found particularly at the top of the soil profile; however, the sampling technique requires to be refined. Further detailed studies are planned.Item Observations on New Techniques for the Direct Sowing of Exotic Softwoods in East Africa(1965) Howland, P.; Hosegood, P.H.; East African Agriculture and Forestry Research OrganizationThe experiments described were carried out at the East African Agriculture and Forestry Research Organisation during 1963 with the object of developing reliable techniques for the establishment of exotic conifers by the direct planting of seed. The factors that militate against success have been shown to be: drought, the transposition or burying of seeds by soil erosion, and sun scorch of the tender seedlings. The date of sowing is also a factor probably affecting the degree of success obtained. The success of the sowings depends on the provision of 'aids' to augment the supply of available soil moisture and to ensure that there is adequate protection of the seeds and seedlings from physical hazards. A bamboo protective sleeve and a rainfall conductor stick have been shown to be effective in satisfying these requirements. The work includes investigations into the soil moisture balance in the first foot of soil, the root development of the young trees under the different treatment regimes and the effect of rainfall intensities on the collecting efficiency of the rainfall conductor sticks.Item The Physical Effects of Contrasting Tillage Treatments over Thirty Consecutive Cultivation Seasons(1964) Pereira, H.C.; Dagg, M.; Hosegood, P.H.Measurements of the changes in the physical properties of topsoil are reported from a I5-year factorial tillage trial in a plantation of arabica coffee. Two monsoon-type rain seasons per year gave thirty cycles of soil wetting, weed growth, tillage, and soil drying. Rainfall acceptance tests showed clean weeding to cause an average IS per cent. Reduction of infiltration from very heavy rainstorms, compared with the minimum weeding treatment. Where a grass mulch provided coarse organic matter for incorporation into the topsoil, a modified rotary hoe, described in a previous paper, proved even more successful than hand implements in maintaining soil structure. In the absence of grass mulching, the rotary hoe did more damage than the hand implements. The experiments demonstrated a sound technique for maintaining very good topsoil structure; Part III of this series showed that these methods also increase yields.Item Water Conservation by Fallowing In Semiarid Tropical East Africa(1958) Pereira, H.C.; Wood, R.A.; Brzostowski, H.W.; Hosegood, P.H.; East African Agriculture and Forestry Research Organization: Tanganyika Agricultural CorporationCrop yields and soil-moisture changes to 6-ft. depth were measured in two cycles of five 2-year groundnut rotations. Fallows kept bare, sown with protective grass cover, and allowed to regenerate volunteer weeds and grasses were compared with maize and with sorghum in alternate-year cropping with groundnuts. Soil moisture- tension changes were following by gypsum blocks and quantitative changes were measured by soil sampling Measurements were made of the root ranges at different growth stages of groundnuts, maize, sorghum, and teff; all lay within the 6-ft. depth. Annual rainfall totals for the four years of the experiments were 22, 8t, 13, 13 in. respectively. The volunteer cover removed all available water from 6 ft: and used more water than maize, sorghum, or groundnuts. Bare fallow conserved water and increased subsequent yields of groundnuts, but no fully satisfactory soil conservation measures were achieved. Protection of fallow by a heavy sowing of 'teff' grass provided efficient soil conservation and, with a seed-rate of 20 lb. of viable seed per acre, suppressed weeds and stored subsoil moisture. Groundnut yields of over 400 lb. kernels per acre were thus secured in a year of 8'5 in. total annual rainfall.
