Ground cover by three crops cultivated on marginal lands in southwestern Nigeria and implications for soil erosion

Resource-poor farmers in developing nations cultivate marginal lands, thereby exacerbating the problem of soil degradation through poor plant growth and ground coverage. An assessment of ground cover under such a practice will provide a guideline for soil conservation. Ground cover by leguminous cover crops (e.g., Mucuna pruriens, Pueraria phaseoloides and Vigna unguiculata), associated with yam, maize and rice was measured in three different experiments in southwestern Nigeria using beaded-string method while leaf area was measured using a flat-bed scanner. The leaf area was used in obtaining equivalent of ground cover fraction from the leaf area index. Ground cover by yam wa

Suitability Evaluation of Selected Wetland Soils in Nigeria for Rainfed Rice Cultivation

Thirty-eight wetland soils in four agro-ecological zones were evaluated for their suitability for rice (Oryza sativa L.) cultivation. The results indicated that climatic characteristics are near optimum. Currently, by non-parametric method, most (≥ 97%) of the pedons were found to be marginally suitable (S3). With the parametric method about 3% were highly suitable (S1), 74% marginally suitable (S3) and 23% not suitable (NS). Potentially by non-parametric method, 18% were of high (S1) and moderate (S2) suitabilities respectively, 58% were marginally suitable (S3) and 6% not suitable (NS). With parametric method, 24% were highly suitable (S1), 45 and 31% were of moderate (S2) and marginal (S3) suitabilities. The major limitations to rice cultivation on these soils are low CEC, organic carbon, exchangeable cations and available P, which may predispose rice plants to excessive Fe2+ uptake visually expressed as «bronzing » or «yellowing» symptoms. In this and similar environments in the region, good soil management is required before substantial improvement in rice production can be achieved

Evaluation of gravel concentration and soil strength in upland rice cultivation in Abeokuta, Southwestern Nigeria

No Abstract.Nigerian Journal of Soil Sciences Vol. 16 (1) 2006: pp. 67-7

Phosphorus response of maize grown on alfisols of southern Nigeria

Phosphorus plays an important role for food crop production in the forest zone of tropical Africa but very little information is available on the phosphate requirement for maize production there. Field trials were, therefore, conducted with maize (Zea mays L.) at two locations on Alfisols in southern Nigeria to investigate the P response and the residual effect of applied P. The experimental sites were recently cleared from fallow and the vegetation was removed after land clearing. On the Egbeda soil (Oxic Paleustalf), which is derived from basement complex rocks, five seasons of maize croppings were done from 1971 to 1973 using a split-plot design with three replications. Four periods of fresh P applications (major and minor seasons 1971 and major and minor seasons 1972), formed the main plots and each of these fresh P applications consisted of five P rates (0, 26, 52, 78 and 104 kg P/ha) which made up the sub-plots. Maize culture T2A ✕ TZB was planted at a spacing of 75 ✕ 25 cm (53,300 plants/ha). The minor season maize received supplementary irrigation. On the Alagba soil (Oxic paleustalf) which is derived from sedimentary rocks, five P rates (0, 20, 40, 80, and 160 kg P/ha) were compared using a randomized complete block design with four replications. Phosphate was broadcasted as single superphosphate and incorporated in the soil to the various treatments. The residual effects of applied P were followed up at both locations. With removal of fallow vegetation following land clearing, significant responses to P applications were observed at both locations. The P requirement for obtaining significant yield increases was not very high, ranging from 26 to 52 kg P/ha depending on season and location. Higher yield response to P was observed during the main season (April to July) than during the minor season (August to November) planting. At both locations significant residual effects of applied P was observed on maize yield and Bray P-1 soil test levels. On the Egbeda soil it was possible to build up and maintain adequate amounts of extractable P for two to three maize crops with one addition between 52 to 104 kg P/ha. Good relationship was observed between maize grain yield and Bray P-1 test values on the Egbeda soil. The critical Bray P-1 test values was estimated to be about 14 ppm P. Results of incubation studies showed that under laboratory conditions 2.5 to 3 ppm of fertilizer P was required to increase the Bray P-1 test level by 1 ppm for the Egbeda and Alagba soils respectively. Under field conditions for the Egbeda soil the P rate required was estimated to be 3.5 ppm P. The critical P in the ear leaf was estimated at 0.3% P. High rate of P application was shown to depress the Zn status in the ear leaf

Response of groundnut (Arachis hypogaea L.) in sole crop and in intercrop with cassava (Manihot esculenta Crantz) to lime in an Ultisol in Bas Zaire

Field trials were carried out in M'Vuazi, Bas Zaire, to test the response of groundnuts (cv P43), planted sole or intercropped with cassava (cv Kinuani), to lime application. Groundnuts responded significantly to low rates of lime (250-500 kg ha-1). Maximum cost, benefit ratio of 1:7 was obtained when 500 kg lime ha-1was applied. Whether it was planted sole or intercropped with cassava, critical soil Ca level for groundnuts was estimated at 0.6 cmol kg-1. There was no cassava root yield response to the lime application at a soil Ca level of 0.11 cmol kg-1. Lime application below 2000 kg ha-1 did not significantly change the surface soil pH and did not affect the subsoil chemical properties. The main effects of lime on groundnuts were, therefore, to supply adequate Ca to: (1) produce maximum number of mature pods and (2) diminish the incidence of unfilled pods

Alley farming research at the International Institute of Tropical Agriculture (IITA)

Alley agriculture in Africa. In Alley cropping, food crops are grown in alleys formed by hedgerows of trees or shrubs, preferably legumes. The hedgerows are cut back at planting and at intervals during cropping to provide mulch and manure for crops growing in the alleys, and to prevent shading and to reduce competition with associated food crops. The incorporation of small ruminants production by the International Livestock Center in Africa (ILCA) (Okali and Sumberg, 1985) into the alley cropping system, using supplementary browse produced from the hedgerows on a cut and carry basis has led to the development of the alley farming concept. Alley farming can, therefore, be defined as an agroforestry system which seeks to exploit the potentials of multipurpose trees (MPTs) primarily for the maintenance of soil fertility and consequently for improved crop and livestock production

Enhancing soil fertility and maize yield using liming amendments

The low fertility level of some soils of the Western Highlands of Cameroon prompted a study of the response of maize (Zea mays L.) and some major soil chemical properties to liming. The first manufactured local lime “Agri 56” was tested along with 3 imported types (calcitic, slaked, and dolomitic), each one at four rates (2, 5, 10 and 15 tons ha-1), replicated three times in a randomized complete block design. Data were collected for 4 years. Maize yields were increased with increased lime rates, but not significantly after 2 tons ha-1. There was no interaction between liming rate and source. Liming source had no significant effect on maize yields; however, Agri 56 generated the highest yield. Soil pH was increased with increase in liming rates though not significantly, and exchangeable Al was neutralized completely after 2 tons ha-1. Soil calcium and magnesium contents significantly (p>0.05) increased with increments in lime rates. The significance to maize cropping is discussed.Le faible niveau de fertilite des sols des Hauts Plateaux de l'Ouest a suscit6 une etude des r6ponses au chaulagedu mais (Zea mays) et des proprietes chimiques du sol. La chaux produite localement, "Agri 56," a ete testee comparativement a trois types importes (dolomite, chaux vive et carbonate de calcium), chacun applique d quatredoses (2, 5, 10 et 15 tonnes ha-1), repete 3 fois dans des blocs completement randomises. Les donnees ont 6tecollectees pendant quatre ans. ll n'y a pas eu d'interaction entre le niveau de chaulage du sol et le type de la chaux.L'augmentation de rendement du mais a suivi celle des niveaux de la chaux, mais pas significativement a plus de 2tonnes ha-l. La source de la chaux n'a eu aucun effet significatif sur les rendements du mais; mais "Agri 56" a donn6le meilleur rendement. ll y a eu un accroissement du pH du sol suite a I'elevation du taux de la chaux et I'Alechangeable a ete completement neutralisd a plus de 2 tonnes ha'1. Les quantit6s de calcium et magnesium du solont significativement (p>0.05) augment6 aprds I'application des niveaux croissants de chaux. Les resultats obtenussur mai's sont discute

Soil and water management for rice production in Nigeria

Paper presented at the West Africa International Conference on Hunger Without Frontiers, West African Society for Agricultural Engineering (WASAE 2004), Kumasi, Ghana, 20-24 September 2004Rice (Oryza sativa L.) is a unique crop grown in virtually all agro-ecological zones in Nigeria. Much emphasis has been placed on the chemical properties of soils on which rice is grown while there is sparse information on the effect of soil physical properties on grain yield of rice. Field experiments were conducted on upland and wetland soils as they relate to water management for rice production in Nigeria. Results showed that soils with higher clay contents in the top and sub-soils gave higher grain yields of rice compared with soils that are of sandy texture. In terms of agro-climatic characteristics Nigeria could be classified as being highly suitable (S1) for rice cultivation. However, considering the top and subsoil clay contents, these soils are only marginally suitable (S3) for rice production. Soil texture, soil surface relief, groundwater level, as well as number of days of submergence significantly affected the growth and grain yield of rice on lowland soils while clay contents in the subsoil is a significant factor in water retention for upland rice cultivars. These factors must be given proper attention in managing water for rice production in Nigeria