摘要:

Abstract.When sewage sludge is surface‐applied to grassland, herbage may become contaminated with heavy metals from adhering solids, posing a risk to the health of grazing livestock and possibly increasing the entry of heavy metals into food products. A field trial examined factors influencing sludge adhesion to leaf surfaces and changes in the concentration of heavy metals in herbage over time. Metals differed in their persistence on leaves. The time required for metal concentrations in herbage to reach background levels depended on herbage growth, the dry solid content of sludges, their rate of application and the height of the grass when the sludge was applied. The implications of the results for the length of a safe no‐grazing period following sludge application are discussed in the context of UK and EC legislation governing sludge use on agricultural l

ISSN:0266-0032    

DOI:10.1111/j.1475-2743.1992.tb00905.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Abstract.To assess the effect of different land uses on soil properties, five land use types (fallow,Gmelina, arable, secondary forest and cocoa plots) on a sandy loam Alfisol (Typic Kandiudalf) were compared in terms of surface (0–15 cm) soil pH, exchangeable acidity, K, Ca and Mg, extractable P, total N, organic matter, gravimetric moisture, temperature and bulk density. There were significant differences (P≤ 0.05‐P≤ 0.001) between the land use types for all the properties except exchangeable acidity and moisture. All the land use types differed significantly from each other in at least four properties. Fallow and secondary forest differed in nine properties, fallow and cocoa in seven and fallow andGmelinain six. In terms of the number of properties with high variability (CV ≥ 35%), the order was arable, secondary forest and cocoa (4)>Gmelina(3)>f

ISSN:0266-0032    

DOI:10.1111/j.1475-2743.1992.tb00906.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Abstract.The electrical conductivity of pig slurry suggests that addition of this waste to soils in arid and semi‐arid areas could cause salinization. Changes in electrical conductivity and soluble salt concentration in two calcareous soils indicated a salinity risk after 24 months of pig slurry addition at rates of 400 m2/ha/yr or more. Salinity risk increased with soil water‐holding capacity. Water‐soluble potassium concentrations showed a greater increase than other cations in the soils because of the large amount present in the slurry. The proportion of soluble potassium in the soil depended on the soil's cation exchange capacity and on the composition of the clay fra

ISSN:0266-0032    

DOI:10.1111/j.1475-2743.1992.tb00907.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Abstract.The suitability of the University of Zambia farm for selected crops was assessed using the principles and concepts of the FAO Framework for Land Evaluation. Moisture and nutrient availability were foundtobe the most limiting land qualities, but moisture availability is a more important consideration because the farm is managed with high inputs. Heavy dependence on rainfall makes the farm very vulnerable to drought which has had a devastating impact on yields in recent years.Soyabean, potato and wheat are the best‐suited crops. Sunflower is not recommended because of the low market value. Maize is not a suitable crop because of its sensitivity to water stress and nutrient availability. Rhodes grass is recommended in mapping units where other crops have little economic value.The FAO Framework for Land Evaluation can be used in Zambia. It can identify land utilization types that are physically and economically suitable. Based on these findings an appropriate land use plan of the University Farm has been developed and implemente

ISSN:0266-0032    

DOI:10.1111/j.1475-2743.1992.tb00908.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Book review in this ArticleAcid Soil and Acid Rain (2nd edition) By I.R. Kennedy.Proposals for the Classification, Description and Mapping of Soils in Urban Areas By J.M. Hollis (Soil Survey and Land Research Centre).

ISSN:0266-0032    

DOI:10.1111/j.1475-2743.1992.tb00909.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

ISSN:0266-0032    

DOI:10.1111/j.1475-2743.1992.tb00910.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY