Browsing by Author "Anderson, G. D."
Now showing 1 - 5 of 5
- Results Per Page
- Sort Options
Item Effects of Fertilizers on Botanical Composition and Productivity of Pasture on the Sandy Soils of the Tanganyika Coast(1968) Anderson, G. D.Marked changes in botanical composition and productivity of an indigenous pasture have taken place as a result of a single application of fertilizer. Over a period of three years, invasion and spread of legumes, particularly Dolichos argentis and the grass Panicum maximum, has occurred on fertilized plots. Basal cover increased from 40-45% on control plots to 90% on the better treatments under conditions of gang-mowing with no removal of herbage. Total dry matter yield, percentage legume in the sward and yields of crude protein from grass and particularly legume, were all markedly increased by application of double superphosphate. Muriate of potash gave further increases in yields of dry matter and crude protein above those of superphosphate, particularly with the legume. The nitrogen fertilizer applied three years earlier was still having some effect on dry matter and protein production. However, nitrogen application depressed the percentage legume in the sward and thus reduced the protein production from that source. Phosphorus produced a marked increase in the organic carbon content and consequently the exchange capacity of the topsoil. Treatments receiving potassium had the highest K contents, but those not receiving this element also showed a marked increase in it. This is thought to be due to the mulching effect of the mowing.Item The Introduction and selection of promising pasture plants for the Arusha and Kilimanjaro regions of Northern Tanzania I—Introduction: Problems of pasture research and development(1966) Naveh, Z.; Anderson, G. D.In the three latter zones, which lie mainly within the altitudes of 2,800-7,000 ft., improvement of pasture and fodder production are essential prerequisites to the economic development of a profitable livestock industry and export trade in animal products. However, each zone requires a different approach, dependent on the natural and socio-economic conditions.Item Promising Pasture Plants for Northern Tanzania(1968) Anderson, G. D.In the preceding papers in this series the agroecological zones of northern Tanzania have been described and work on Chloris and Cenchrus selections Glycine javanica ecotypes (and legumes, grasses and mixtures at Tengeru has been presented. The previous paper in the series dealt with the overall picture of the more promising species and some mixtures of them under cutting regimes. To this final paper, some practical considerations for the development of improved pasture productivity are discussed. These include tentative grass/ legume mixture for differing soil and climatic condition and suggestions on ways in which legume-rich mixtures may be established and maintained in a productive state. In this preliminary attempt to offer suggestions of practical value to progressive farmers, the information presented in the preceding papers, that gained from workers elsewhere and the personal knowledge and observations of the author, have all been combined. Time alone will tell whether all the views are substantiated, but it is strongly felt that some practical guidance to farmers should be given now. The advice offered is thought to be the best in the light of present knowledge and experience.Item Promising Pasture Plants for Northern Tanzania V. Overall Comparisons of Promising Plants(1968) Anderson, G. D.; Naveh, Z.The agro-ecological zones of northern Tanzania have been briefly described in an earlier paper (Naveh and Anderson, 1966A) and the detailed work at Tengeru has also been published (Naveh and Anderson, 1966B and 1967; Naveh, 1966). These and the Previously described trials were conducted to obtain a preliminary assessment of promising pasture plants and mixtures for the two zones on the volcanic soils of northern Tanzania, where pasture production has the greatest potential.Item Responses of Maize to Application of Compound Fertilizers on Farmer's Fields in Ten Districts of Tanzania(1969) Anderson, G. D.In many areas of Tanzania more than one essential element is lacking in the soil and needs to be applied as fertilizer to obtain optimum maize yields. Over much of the country both nitrogen and phosphorus are required together, while in some areas potassium is also essential if yields are to be raised above subsistence levels. Though responses to N or P alone are sometimes striking, it is frequently necessary to apply both to obtain an economic return above the fertilizer costs in the year of applic1tion, for the NP interaction is often very important. However, in many areas heavy fertilizer dressings are not necessary for good responses. Such applications in dry areas may fail to give economic returns, or cause a depression in yield compared with lighter dressings, and they can also bring about marked changes in the base status of the soil. Therefore, there is much to be said for applying light dressings of twin or triple-nutrient fertilizers. Quite apart from the insurance policy of alleviating all major deficiencies in one application, such compounds are usually much cheaper to transport than bulky single nutrient fertilizers. Use of compounds is also in line with the world trend towards greater predominance of these.
