The nature of interrelationships between soil pasteurisation, and increased soil N content, on the severity of Striga hermonthica infection in maize was studied in pot experiments in the screen-house. An initial experiment revealed that there was no significant difference in amount of S. hermonthica infection in maize grown in potted soil collected from Bida (98050N, 68010E) and Ibadan (78170N,...

The density of soil seed banks is normally highest at the soil surface and declines monotonically with depth. Sometimes, for a variety of reasons, peak density occurs below the surface but, except in severely disturbed soils, it is generally true that deeper seeds are older. In seasonally dry habitats that develop deep soil cracks during the dry season, it is possible that some seeds fall down ...

Resource partitioning has been hypothesized to play a role in the maintenance of tree diversity in tropical forests. We looked for evidence of light and soil moisture partitioning among seedlings of four native Malagasy tree species, the pioneer, gap-adapted species Harungana madagascariensis and the three shade-tolerant species Ocotea cymosa, Stephanostegia capuronii and Uapaca ferruginea. Fou...

Sterilized soil samples (20 g of soil per 50-ml flask), amended with 600 mug of glucose-carbon and 60 mug of NH(4)-N . g of dry soil, were inoculated with bacteria (Pseudomonas paucimobilis) alone or with bacteria and amoebae (Acanthamoeba polyphaga). We used wet-dry treatments, which involved air drying the samples to a moisture content of approximately 2% and remoistening the samples three ti...

Topography controls snowpack accumulation and hence growing-season length, soil water availability, and the distribution of plant communities in the Colorado Front Range alpine. Nutrient cycles in such an environment are likely to be regulated by interactions between topographically determined climate and plant species composition. We investigated variation in plant and soil components of inter...

structure of air-dry soils, pedality refers to dry aggregates. Dry aggregation is an important phase of structure Soil structural stability often decreases as the intensity of cultivation genesis in arid and semiarid soils, where it is transient, increases. The effect of three different management systems (grass, no-till, and till) on soil aggregate stability and sizes were studied in formed on...

Soil moisture hampers the estimation of soil variables such as clay content from remote and proximal sensing data, reducing the strength of the relevant spectral absorption features. In the present study, two different strategies have been evaluated for their ability to minimize the influence of soil moisture on clay estimation by using soil spectra acquired in a laboratory and by simulating sa...

Climate change models predict that future precipitation patterns will entail lower-frequency but larger rainfall events, increasing the duration of dry soil conditions. Resulting shifts in microbial C cycling activity could affect soil C storage. Further, microbial response to rainfall events may be constrained by the physiological or nutrient limitation stress of extended drought periods; thus...

Current models for seasonal climate prediction are limited due to poor initialization of the land surface soil moisture states. Passive microwave remote sensing provides quantitative information on soil moisture in a thin near-surface soil layer at large scale. This information can be integrated with a land surface process model through data assimilation to give better prediction of the near su...

This paper describes the findings of selenium measurement in three types of soil (semigley, pseudogley and hypogley) and in wheat grain cultivated in these types of soil in the vicinity of Koprivnica using hydrid atomic absorption spectrometry. The results showed relatively low selenium levels in all three types of soil (145-333 micrograms Se/kg dry weight) as well as the wheat grain (22-62 mic...