Effects of different phosphorus-efficient legumes and soil texture on fractionated rhizosphere soil phosphorus of strongly weathered soils
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Phosphorus (P) deficiency is one of the largest constraints to crop production in tropical Africa; so, it is necessary to better exploit soil P resources through increasing labile soil P using P-efficient plants. The aim of this study was to evaluate the effect of various P-efficient legumes on fractionated rhizosphere soil P in two contrasting textured soils of Tanzania, i.e., strongly weathered soils. We conducted a 30-day pot experiment, where white lupin (Lupinus albus L.; WL), cowpea (Vignaungui culate L.; CP), and pigeon pea (Cajanus cajan L.: PP) were grown with and without N application (0 and 50 kg N ha−1). Plant growth, P uptake, rhizosphere pH, and fractionated soil P were investigated. Plant P uptake decreased in the following order: WL > CP > PP in clayey soil and CP > PP > WL in sandy soil. We observed clear effects of all legumes on the rhizosphere soil P dynamics of all fractions in both soils, except for the labile P fraction in clayey soil. The effect of legume growth on the contents of less labile inorganic P fraction (NaOH-Pi) was significantly different between legumes; NaOH-Pi contents of WL was significantly lower than those of CP and PP. All legumes substantially increased the less labile organic P fraction, and its ratio was significantly higher in sandy soil. Our results suggest that WL had different P mobilization characteristics from CP and PP and that the effect of P-efficient legume cultivation on soil P availability should be more important in the inherently P poor sandy soil than in clayey soil.
KeywordsP fractionation White lupin Cowpea Pigeon pea Soil texture Sub-Saharan Africa
We thank Prof. J.J.T. Msaky and the staff of the Sokoine University of Agriculture for their kind technical support in the field and laboratory experiments in Tanzania. The Japan Prize Foundation in 2013 and Japanese Society for the Promotion of Science KAKENHI grant numbers 25850040, 24255019, and 24228007 financially supported this work.
- Kamh M, Horst WJ, Amer F, Mostafa H, Maier P (1999) Mobilization of soil and fertilizer phosphate by cover crops. Plant Soil 211:19–12Google Scholar
- Soil Survey Staff (2006) Keys to soil taxonomy, 10th edn. United States Department of Agriculture Natural Resources Conservation Service, WashingtonGoogle Scholar
- Tiessen H, Moir JO (1993) Characterization of available phosphorus by sequential extraction. In: Carren MR (ed) Soil sampling and methods of analysis, Canadian Society of Soil Science. Lewis Publishers, Boca Raton, pp 75–86Google Scholar
- Weisskopf L, Abou-Mansour E, Fromin N, Tomasi N, Santelia D, Edelkott I, Neumann G, Aragno M, Tabacchi R, Martinoia E (2006) White lupin has developed a complex strategy to limit microbial degradation of secreted citrate required for phosphate acquisition. Plant Cell Environ 29:919–927CrossRefPubMedGoogle Scholar