Ecological footprint (EF) has received considerable attention as a useful indicator in the context of sustainable development. So far, EF has been used in numerous studies by academies, organizations and government au...Ecological footprint (EF) has received considerable attention as a useful indicator in the context of sustainable development. So far, EF has been used in numerous studies by academies, organizations and government authorities. However, the results of these studies failed to be comparable directly with each other due to imprecise data sets, unmodified accounting methods of pasture and fossil energy, ignored secondary products, undefined process of calculating yield factors and improper biocapacity for biodiversity. In this paper, we elaborated on EF estimating methods from six categories of consumption in order to overcome the limitations above. We adopted precise data and revised methods, calculated EF of some secondary products, introduced weighted factor to calculate yield factors and adjusted biocapacity by an appropriate amount. Meanwhile, we investigated the resource consumption of Liaoning Province in 2006 to assess EF. Its results showed that Liaoning Province overused its natural capital and was in an unsustainable state. We concluded that two specific problems that had arisen in EF assessment and gave some suggestions for Liaoning Province to improve its unsustainable state.展开更多
Soil in greenhouses is likely to suffer a gradual decline in aggregate stability. Determination of the effects of different fertiliser practices on soil aggregate stability is important for taking advantage of solar g...Soil in greenhouses is likely to suffer a gradual decline in aggregate stability. Determination of the effects of different fertiliser practices on soil aggregate stability is important for taking advantage of solar greenhouses. Soil aggregate stability and iron （Fe） and aluminium （A1） oxide contents were investigated in a 26-year long-term fertilisation experiment in greenhouse in Shenyang, China, under eight fertiliser treatments： manure （M）, fertiliser N （FN）, fertiliser N with manure （MN）, fertiliser P （FP）, fertiliser P with manure （MP）, fertiliser NP （FNP）, fertiliser NP with manure （MNP）, and control without any fertiliser （CK）. A wet sieving method was used to determine aggregate size distribution and water-stable aggregates （WSA）, mean weight diameter and geometric mean diameter as the indices of soil aggregate stability. Different fertiliser treatments had a statistically significant influence on aggregate stability and Fe and A1 oxide contents. Long-term application of inorganic fertilisers had no obvious effects on the mass proportion of aggregates. By contrast, manure application significantly increased the mass proportion of macroaggregates at the expense of microaggregates. All treatments, with the exception of FNP, significantly increased the stability of macroaggregates but decreased that of microaggregates when compared with CK. Aggregation under MP and MN was better than that under M and MNP; however, no significant differences were found among inorganic fertiliser treatments （i.e., FN, FP, and FNP）. A positive relation was found between pyrophosphate-extractable Fe and WSA （r=0.269）, but no significant relations were observed between other Fe and Al oxides and aggregate stability.展开更多
文摘Ecological footprint (EF) has received considerable attention as a useful indicator in the context of sustainable development. So far, EF has been used in numerous studies by academies, organizations and government authorities. However, the results of these studies failed to be comparable directly with each other due to imprecise data sets, unmodified accounting methods of pasture and fossil energy, ignored secondary products, undefined process of calculating yield factors and improper biocapacity for biodiversity. In this paper, we elaborated on EF estimating methods from six categories of consumption in order to overcome the limitations above. We adopted precise data and revised methods, calculated EF of some secondary products, introduced weighted factor to calculate yield factors and adjusted biocapacity by an appropriate amount. Meanwhile, we investigated the resource consumption of Liaoning Province in 2006 to assess EF. Its results showed that Liaoning Province overused its natural capital and was in an unsustainable state. We concluded that two specific problems that had arisen in EF assessment and gave some suggestions for Liaoning Province to improve its unsustainable state.
基金supported by the National Natural Science Foundation of China(No.31171997)the Fifth Session of Geping Green Action-123 Project of Liaoning Environmental Research and Education,China(No.CEPF2012-123-1-4)the Innovative Graduate Training Program of Shenyang Agricultural University of China
文摘Soil in greenhouses is likely to suffer a gradual decline in aggregate stability. Determination of the effects of different fertiliser practices on soil aggregate stability is important for taking advantage of solar greenhouses. Soil aggregate stability and iron （Fe） and aluminium （A1） oxide contents were investigated in a 26-year long-term fertilisation experiment in greenhouse in Shenyang, China, under eight fertiliser treatments： manure （M）, fertiliser N （FN）, fertiliser N with manure （MN）, fertiliser P （FP）, fertiliser P with manure （MP）, fertiliser NP （FNP）, fertiliser NP with manure （MNP）, and control without any fertiliser （CK）. A wet sieving method was used to determine aggregate size distribution and water-stable aggregates （WSA）, mean weight diameter and geometric mean diameter as the indices of soil aggregate stability. Different fertiliser treatments had a statistically significant influence on aggregate stability and Fe and A1 oxide contents. Long-term application of inorganic fertilisers had no obvious effects on the mass proportion of aggregates. By contrast, manure application significantly increased the mass proportion of macroaggregates at the expense of microaggregates. All treatments, with the exception of FNP, significantly increased the stability of macroaggregates but decreased that of microaggregates when compared with CK. Aggregation under MP and MN was better than that under M and MNP; however, no significant differences were found among inorganic fertiliser treatments （i.e., FN, FP, and FNP）. A positive relation was found between pyrophosphate-extractable Fe and WSA （r=0.269）, but no significant relations were observed between other Fe and Al oxides and aggregate stability.
