共 22 条
- [1] Ahn, Soil factors affecting rainfel agriculture in semi-arid regions with particular reference to the Sahel Zone of Africa, Tech. Comm., 8, (1977)
- [2] FAO-UNESCO, Soil Map of the World, 1, (1988)
- [3] Gilbert, The mulching of coffee Arabica E. Afr. J., 11, pp. 75-79, (1945)
- [4] Hulugalle, Properties of tied ridges in the Sudan Savannah of The West Semi-arid Tropics, Proc. Fifth Int. Conser. Conference. Land conservation for future generations, 18th–29th Jan. 1988, Bangkok, Thailand, 2, pp. 693-711, (1988)
- [5] Jones, Land Forming Effects on Dryland Sorghum Production in the Southern Great Plains1, Soil Science Society of America Journal, 45, pp. 606-611, (1981)
- [6] Jones, Mitawa, Cultivation techniques and soil moisture conservation on arable land, Food Grain Production in Semi Arid Areas, pp. 492-508, (1986)
- [7] Lal, The effect of soil texture and density on the neutron probe calibration for some tropical soils, Soil Sci., 40, pp. 589-606, (1974)
- [8] Lal, Role of mulching techniques in tropical soils and water management. IITA Ibadan, Nigeria Tech. Bull., 1, (1975)
- [9] Liniger, Water conservation for rainfed farming in a semi-arid zone, Northwest of Mt. Kenya (Laikipia Highlands), Ph.D. Thesis, (1988)
- [10] Macartney, Studies on the effects of different cultivation techniques on crop establishment, yield and soil water relationships in Tanzania, Ph.D. Thesis, (1970)