Role of light fraction soil organic matter in the phosphorus nutrition of Eucalyptus globulus seedlings

• Published in: Plant and soil 2006-02, Vol.280 (1/2), p.127-134
• Main Authors: O'Hara, C.P., Bauhus, J., Smethurst, P.J.
• Format: Article
• Language: English
• Subjects: Agricultural soils; Agronomy. Soil science and plant productions; Animal and plant ecology; Animal, plant and microbial ecology; Autoecology; Bioassays; Biological and medical sciences; Chemical, physicochemical, biochemical and biological properties; Dry matter; Forest soils; Fractionation; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; Light; Nitrogen; Nutrition; Organic matter; Organic phosphorus; Organic soils; Phosphorus; Physics, chemistry, biochemistry and biology of agricultural and forest soils; Plant nutrition; Planting density; Plants and fungi; Sand; Seedlings; Soil biochemistry; Soil organic matter; Soil science; Soil-plant relationships. Soil fertility; Soil-plant relationships. Soil fertility. Fertilization. Amendments; Soils
• ISSN: 0032-079X; 1573-5036
• DOI: 10.1007/s11104-005-2675-8

Different fractions of soil organic matter (SOM) may contribute to varying degrees to phosphorus (P) recycling and supply. This study investigated the potential for light fraction SOM to contribute to plant P nutrition using a bioassay with Eucalyptus globulus (Labill.) seedlings. Light fraction SOM, which has been subject to only limited decomposition, was isolated from bulk soil using a density floatation procedure. Seedlings were grown in sand with a P-free nutrient solution and either light fraction SOM from five different native eucalypt forest plots as a source of added P or in sand with no added light SOM (controls). Growth (dry matter accumulation) and P acquisition by seedlings of four of the treatments grown with light fraction organic matter was 2–3 times greater than that of control seedlings. Daily rates of P acquisition ranged from 0.13 μg P day-1 (control) to 0.29–0.50 μg P day-1 for seedlings grown with added organic matter. Whilst the study indicates that light fraction SOM can contribute to the P nutrition of eucalypt seedlings, accordingly, further research into the nutritional role of light fraction SOM is warranted.