Soil nitrogen status in relation to land development and pasture productivity in the Brigalow region of Central Queensland
| Autor: | T. W. Graham |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
chemistry.chemical_classification
Total organic carbon geography geography.geographical_feature_category Acacia harpophylla biology chemistry.chemical_element Forestry biology.organism_classification Nitrogen Pasture Bulk density chemistry Agronomy Productivity (ecology) Soil water Environmental science Organic matter |
| Popis: | Changes in soil nitrogen status following the development ofnsome brigalow (Acacia harpophylla) soils were studied and thenimportance of these changes in relation to the productivity ofnperennial grass pastures was investigated.nA survey was made of pasture and crop areas on solodizednsolonetz and solodic soils of Central Queensland originally supportingnbrigalow (A. harpophylla)/ Dawson Gum (Eucalyptus cambageana)ncommunities. Comparisons were made of total soil nitrogen (% N andnkg N ha -1) and organic carbon %, together with bulk density, atnsites where undeveloped and developed areas of known history werencontiguous.nAt 28 per cent of sites studied, significant (Pl0.01) reductionsnin total soil nitrogen were measured. These losses varied from 14 ton34 per cent of the virgin levels and amounted to 290 to 712 kg N ha -1.nThere was a trend for the majority of developed sites to have lowernlevels of total nitrogen than their virgin counterparts but somenhigher levels were also apparent. Increases in nitrogen occurrednwhere permanent sown pasture areas had been renovated prior tonsampling. There was also a general trend towards increased bulkndensity following development.nSignificant reductions were site specific. This interactionnwas a result of diverse location of sites with their inherentnvariability and the variation in possible climatic and managementnfactors responsible for nitrogen losses. A large proportionn(151 to 534 kg N ha -1) of the nitrogen loss was unaccounted for. Itnwas postulated that accelerated decomposition of organic matter duento disturbance and exposure together with some removal of soil andnsurface organic matter could be responsible. n |
| Databáze: | OpenAIRE |
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