Conference paper
Phosphorus turnover between rice crops in the rainfed lowlands from residual P fertiliser, rice straw and volunteer pastures
4th International Crop Science Congress (Brisbane, Australia, 26/09/2004–01/10/2004)
2004
Abstract
The fate of residual P fertiliser and P in crop residues in sandy rainfed lowland soils is poorly understood. Field experiments were undertaken to determine the effects of rice straw incorporation, and of residual fertiliser P on biomass of volunteer pastures and to quantify the fate of P recycled from them on subsequent rice growth. Returning rice straw with P fertilisation had additive effects on growth and yields of rice during the main wet season. Straw addition alone increased grain and straw yields on the nil-P and applied-P soils by about 10 and 5 %, respectively. Subsequently, in the early following wet season, the biomass of volunteer pastures responded significantly to the residual P and the straw incorporation. All soil P fractions significantly increased at 2 weeks after rice straw incorporation. The minor resin-P fraction fluctuated more over time compared to major soil P fractions (NaOH-Pi and NaOH-Po). Phosphate added with straw increased microbial biomass C but had only small effects on microbial biomass P. Microbial biomass P declined dramatically in the active growth stage of rice, suggesting strong competition for available P from crop uptake, whereas, microbial C increased progressively for up to 40 weeks after straw incorporation. In conclusion, the application of crop residues alone marginally increased rice productivity, soil P fractions and microbial biomass C and P, whilst greater increases were obtained with the combined application of P fertiliser with crop residues. There remains to be investigated the long-term impact of residual P fertiliser and organic inputs on crop yields, soil P forms and P turnover processes.
Details
- Title
- Phosphorus turnover between rice crops in the rainfed lowlands from residual P fertiliser, rice straw and volunteer pastures
- Authors/Creators
- S. Pheav (Author/Creator)R.W. Bell (Author/Creator)P.F. White (Author/Creator)G.J.D. Kirk (Author/Creator)
- Conference
- 4th International Crop Science Congress (Brisbane, Australia, 26/09/2004–01/10/2004)
- Identifiers
- 991005543420107891
- Murdoch Affiliation
- School of Environmental Science
- Language
- English
- Resource Type
- Conference paper
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