Soil microbial and faunal community responses to bt maize and insecticide in two soils.

The effects of maize (Zea mays L.), genetically modified to express the Cry1Ab protein (Bt), and an insecticide on soil microbial and faunal communities were assessed in a glasshouse experiment. Soil for the experiment was taken from field sites where the same maize cultivars were grown to allow comparison between results under glasshouse conditions with those from field trials.

Ancient manuring practices pollute arable soils at the St Kilda World Heritage Site, Scottish North Atlantic.

The impact of ancient fertilization practices on the biogeochemistry of arable soils on the remote Scottish island of Hirta, St Kilda was investigated. The island was relatively unusual in that the inhabitants exploited seabird colonies for food, enabling high population densities to be sustained on a limited, and naturally poor, soil resource. A few other Scottish islands, the Faeroes and some Icelandic Islands, had similar cultural dependence on seabirds.

Translocation of carbon by Rhizoctonia solani in nutritionally-heterogeneous microcosms.

Responses of Rhizoctonia solani to spatial heterogeneity in sources of carbon, and associated translocation of carbon (C), were studied in a simple microcosm system comprising two discrete domains of agar gels separated on a glass slide and overlain with a porous membrane. Two arrangements of the gel pairs were used, one containing two equally large resources (representing 'homogeneous' conditions) and one containing a large and a negligible resource (representing 'heterogeneous' conditions). The nutrient sources were a standard mineral salt medium with or without glucose as sole C source.

Isolation of ammonium-N as 1-sulfonato-iso-indole for measurement of delta15N.

The conversion of ammonium (NH(4) (+)) to 1-sulfonato-iso-indole has been examined as a method for natural abundance measurement of delta(15)N of NH(4) (+). The reaction is complete within 2 h and is based on the derivatisation of NH(4) (+) by o-phthaldialdehyde and sodium sulfite at a high pH, 11.2.

The natural abundance of (15)N in mat-forming lichens.

Natural abundance of (15)N and [N] was studied in thalli of mat-forming lichens collected from tundra and heathland sites in the northern and southern hemispheres. The study includes samples of British Cladonia portentosa from sites in regions of high and low N-loading and in heathland growing both directly on peat and independently of the soil substratum, in a canopy of prostrate gorse ( Ulex minor). In the mat-forming lichens examined, a non-random pattern in [N] and delta(15)N was characterised by a minimum in delta(15)N, which occurred most frequently at 20-40 mm below the thallus apex.