Evaluation of fallow and cover crops for nematode suppression in three agroecologies of south western Nigeria

A study was conducted in three agroecological zones of south-western Nigeria to evaluate the effect of siam weed (Chromolaena odorata) and mucuna (Mucuna utilis) cover/fallow crops on plant-parasitic nematode population. The natural bush regrowth was used as control. Plant-parasitic nematodes were identified and counted during the fallow periods. Eleven genera of nematodes were identified and three (Meloidogyne, Pratylenchus, and Helicotylenchus) species were predominant across the trial locations.Other important genera present were Scutellonema, Tylenchorhynchus and Rotylenchus species. Nematode population densities of pre-crop were lowest in Alagba soil (Rhodic lixisols) at Ikenne in the wet forest zone of Nigeria. The populations in Iwo soil (Rhodic haplustalf) at Ibadan, a dry forest zonewas lower than in the Temidire soil (Plinthic luvisol) at Ilora in the derived savannah of south-western Nigeria. There was significant suppression of nematode population densities under the different crops as the fallow period increased. The population reduction in the different locations depended on the nematode species and the cover crops. The natural bush re-growth had the least effect on the nematode suppression at the end of the fallow period. On the average, siam weed fallow reduced nematode population densities by 67-79%, mucuna by 64-72% and the natural bush by 30-49% across the trial locations. For effective nematode suppression with fallow cropping, proper determination of the principal nematode species predominant in an environment is essential

Quality Assessment and Suitability Evaluation of Soils under Tuber-based Cropping System in Katsina Ala Local Government Area, Benue State, Nigeria

Crop yields together with economic and social benefits of farming depend in part on land management and soil quality. Soil management and cropping systems have long-term effects on agronomic and environmental functions. This study aimed at assessing soils under yam-based cropping systems for quality and suitability so as to enhance sustainable production. The study was carried out in Katsina Ala local government area of Benue state where yam is a major crop. Sixteen modal profile were dug, described for characterization and suitability evaluation. Ten cluster locations were selected and twenty soil samples randomly collected within each cluster. The soils were subjected to laboratory analyses and results subjected descriptive statistics. Suitability of the soils for yam, citrus and groundnut were evaluated using parametric approach and soil quality of the area was assessed using Relative Soil Quality Indices (RSQI). The soils encountered are sandy to silty in nature with some having plinthite at depth. The soils, classified as Alfisol, Entisol and Inceptisol are moderately (S2) to highly suitable S1) for the three crops and have moderate to high quality for crop production with percentage soil quality index ranging from 60. 37 to 74.31 %. Soils of the study site are of good quality and are suitable for production of yam, citrus and groundnut. However, because yam is a great feeder and tropical soils are fragile making them prone to degradation, there is need for maintenance of soil fertility through organic matter management for sustainable use

Variability of surface and subsurface properties of an ultisol as function of topography in Sandstone landscape of Southwestern Nigeria

No Abstract.Global Journal of Pure and Applied Sciences Vol. 13 (1) 2007: pp. 27-3

Combination of soil classification and some selected soil properties to improve yield prediction: An experience from southwestern Nigeria

The advantage in the combined use of soil classification and top soil analysis for explaining crop yield variation was examined. Soil properties and yields of maize (Zea mays L) on different soil types were measured on farmers' fields for 2 years. Yield prediction improved from 2 per cent at the Order and Association levels to 31 per cent at the Series level in the 1st year. The following year, it improved from 5-6 per cent (at the Order and Association levels) to 39 per cent (at the Series level). Regression of yield on soil properties showed that, with one soil property in the regression, yield prediction improved from 30 per cent at the Order level to 37 per cent at the Association level and 38 per cent at the Series level. With five properties in the regression, yield prediction improved from 42 per cent at the Order level to 44 per cent at the Association level and 66 per cent at the Series level. With 10 properties in the regression, yield prediction improved from 50-51 per cent (Order and Association levels) to 84 per cent at the Series level. Combinaison de la classification de sol et quelques propriétés de sol sélectionnées pour améliorer la prédiction de rendement: Une expérience de sud-ouest du Nigéria. Résumé L'avantage d'utilisation de la combinaison de la classification de sol et d'analyse de la couche arable pour l'explication de la variation de rendement des cultures, était étudié. Les propriétés de sol et les rendements de mais (Zea mays L.) sur les différents types de sol, étaient évalués sur les champs des cultivateurs pour 2 ans. La prédiction de rendement améliorait de 2 pour cent aux niveaux d'Ordre et d'Association à 31 pour cent au niveau de Séries dans la 1e année. L'année suivante l'amélioration était de 5-6 pour cent (aux niveaux d'Ordre et d'Association) à 39 pour cent (au niveau de Séries). La régression de rendement sur les propriétés de sol révélait que, avec une propriété de sol en régression, la prédiction de rendement améliorait de 30 pour cent au niveau d'Ordre à 37 pour cent au niveau d'Association et 38 pour cent au niveau de Séries. Avec cinq propriétés en régression la prédiction de rendement améliorait de 42 pour cent au niveau d'Ordre à 44 pour cent au niveau d'Association et 66 pour cent au niveau de Séries. Avec 10 propriétés en régression, la prédiction de rendement améliorait de 50-51 pour cent (aux niveaux d'Ordre et d'Association) à 84 pour cent au niveau de Séries. Ghana Jnl agric. Sci. Vol.33(1) 2000: 15-2

Planning sustainable soil management under intensified crop production system in Nigeria: an ecosystem approach

No abstractKeywords: sustainable; management; intensified; crop production; ecosystemGlobal Journal of Agricultural Sciences Vol. 4(1) 2005: 45-5

Levels and geochemical fractions of Cd, Pb and Zn in valley bottom soils of some urban cities in southwestern Nigeria

The valley bottom soils of urban cities are sink for municipal and industrial solid and liquid wastes. These valleys are used by urban farmers to grow vegetables for the consumption of urban dwellers.Knowledge of total content of heavy metals is not enough to fully assess the environmental impact of these soils. Therefore the determination of metal fractions in solution is very important to understandtheir behaviour and their mobility capacity to the vegetables grown on them. Sequential extraction procedure was used to speciate Cd, Pb and Zn from eleven locations from the cities of Lagos, Ibadan,Akure, Ikare, Ondo and Okitipupa in southern western Nigeria into seven operational defined geochemical species; available, carbonate, easily reducable, organic, amorphous Fe-Mn oxide, crystalline Fe-Mn oxide, and detrital (residual). All the metal investigated were significantly associated with non-residual fractions. The highest amounts of metals in non-residual fractions were found inorganic fractions while the lowest were found in oxide species. The residual fractions contained on average 65 - 66% for Pb, 8 - 50% for Cd and 25 - 29% for Zn. Assuming that mobility and bioavailabilityof these metals are related to the solubility of the geochemical forms and that the decrease in the order of extraction sequence, the potential bioavailability of these metals were: Cd > Zn > Pb. The mobilityindexes of the metals correlated negatively and significantly with total contents of the metals. Correlation among species of each metal indicates a dynamic equilibrium between labile and non-labileforms of the non-residual fraction

Heavy metals in an urban valley bottom soil in South-western Nigeria

No Abstract. Discovery and Innovation Vol. 17(1&2) 2005: 85-9