Nursery Sterilization and Inoculation Regimes for Alder Production

Nursery experiments using common alder (Alnus glutinosa) toexamine the interaction of soil sterilization and inoculationwith Frankia are described. Seedling growth was stimulated whensoil was sterilized with methyl bromide or dazomet at currentrecommended rates, but nodulation was reduced. Inoculation withcultured Frankia or a crushed nodule suspension significantlyimproved nodulation, especially if the inoculant was appliedbefore seed germination. However, seedling growth was significantlylarger using cultured Frankia than the crushed nodule inoculant.If the latter is used to inoculate alder seedlings, a reductionin the recommended rate of dazomet application to c. 285 kgha^–1 is likely to encourage nodulation, though seedlinggrowth will be reduced slightly.     

The Use of Large Scale Ridge and Furrow Landforms in Forestry Reclamation of Mineral Workings

Large scale (30 m wide x 1.5 m high) ridge and furrow landformsare commonly used in forest reclamation schemes in Britain toaid the removal of excess winter rainfall and improve rootingconditions. An investigation of soil physical and hydrologicalproperties in relation to tree growth at three sites where ridgeand furrows have been used has shown that this system largelysucceeded in producing land with reduced waterlogging. In wetterparts of the country this has promoted tree growth, probablybecause roots can exploit a greater depth of aerated soil. Inthe drier east, however, the higher parts of the ridges wereassociated with poorer tree growth because they suffered longperiods of large soil water deficits. The effect of droughtwas exacerbated by poor root systems, probably resulting fromhigh soil bulk densities. The results support the use of the ridge and furrow system inareas where rainfall is high and soil moisture deficits low,but suggest that a modified system of lower amplitude may bewarranted in drier areas. The study also reveals a need formore research on cultivation techniques to alleviate soil compaction.     

The significance of gley features in soils derived from grey parent materials

Detailed observations of gley features in soils derived from grey Upper Greensand rocks have been compared with their moisture regimes as determined by water-levels in dipwells. There was good correlation between the incidence of grey ped face and matrix colours of low chroma, prominent ochreous mottling within the matrix and duration of waterlogging. Careful examination of soil macromorphology can be used, despite inherent greyness, to assess the drainage status and Wetness Class of these soils.
Physical and micromorphological analyses suggest that the wetness of some Upper Greensand soils is due to the combination of low vertical permeability in the underlying rock, and moderate horizontal permeability in the overlying horizons. Such circumstances allow perched water-tables to form in wet weather, sustained by lateral flow when rainfall has ceased.     

The Potential for Using Sewage Sludge in Forestry in England and Wales

The potential for using sewage sludge as a forest fertilizeron nutrient-deficient sites in England and Wales is evaluatedas the first part of a study covering the whole of Great Britain.Suitable areas within Forestry Commission forests are assessedusing the Forestry Commission subcompartment database, and Censusdata in respect of private woodlands. Most Forest Districtscontain forests which are likely to benefit from sewage sludgeapplication, mainly in the form of liquid sludge to thinnedstands, but also before and just after planting. The environmentaleffects of sludge application are discussed, and it is concludedthat at rates appropriate to forest fertilizing, there is littlerisk of toxicity or pollution.