Impact of potassium fertilization and potassium uptake by plants on soil clay mineral assemblage in South Brazil
- 631 Downloads
Potassium (K) fertilization increases crop productivity, but in some cases, crop productivity is maintained even with inadequate or low K input. In both situations, the soil mineralogy plays a role that should be investigated. The aims of this study were to quantify the potassium concentrations in several soil compartments, determine the amount of K taken up by plants, and consider soil clay mineralogical changes and K dynamics, as response to K fertilization historic and successive crops.
A soil field experiment was conducted in south Brazil over a period of 15 years with different K doses, and a second experiment was conducted in a greenhouse with 11 successive plant cycles under two conditions: no K fertilization (K-poor context) and K fertilization of 30 and 90 mg kg−1 of soil (K-rich context).
In the K-poor context, illite was not found in clay fraction and the non-exchangeable K and available K forms were reduced, compromising both the K uptake by plants and the crop yield. In the K-rich context, the low amount of illite was found compared to K-poor context, while relative hydroxy-aluminum interlayered vermiculite (HIV) abundance decreased in detriment of kaolinite. Furthermore, all K compartments (K in plants, available K, structural K, and non-exchangeable K) were restored when high fertilization was applied to the soil.
For correct fertilization, the soil mineralogy and fertilization background should be taken into account to obtain high crop production and low K loss in agricultural lands. This will help to maintain soil K reserve, but the successive crops induce ion exhaustion, including K, affecting whole clay mineral assemblage.
KeywordsIllite–vermiculite interstratified 2:1 clay minerals K uptake X-ray diffraction Chemical gradient Crop yield
We thank the Fundação de Amparo à Pesquisa do Estado do Rio Grande do Sul (FAPERGS), the National Research and Innovation Council (CNPq/Brasilia-Brazil) for financial support and for a research fellowship granted to the authors E. C. Bortoluzzi, J. Kaminski, and D.R. dos Santos, and the CAPES-COFECUB under project Te 761-12 / 3504-11-5. The authors also thank Ph.D. Bruce Velde and the anonymous reviewers for help with some valuable comments.
- Barnhisel RJ, Bertsch PM (1989) Chlorites and hydroxy-interlayed vermiculite and smectite. In: Dixon JB, Weed SB (eds) Minerals in soil environments, 2nd edn. Soil Science Society of America. Madison, Wisconsin, pp 729–788Google Scholar
- Barré P, Velde B, Fontaine C, Catel N, Abbadie L (2008b) Which 2:1 clay minerals are involved in the soil potassium reservoir? Insights from potassium addition or removal experiments on three temperate grassland soil clay assemblages. Geoderma 146:216–223. doi: 10.1016/j.geoderma.2008.05.022 CrossRefGoogle Scholar
- Bortoluzzi EC, Poleto C (2006) Metodologias para estudos de sedimentos: ênfase na proporção e na natureza mineralógica das partículas. In: Poleto C, Merten GH (eds) Qualidade de sedimentos, 1st edn. ABRH, Porto Alegre, pp 83–140Google Scholar
- Brindley GW, Brown G (1980) Crystal structures of clay minerals and their X-ray identification. Mineralogical Society, Monograph n°5. Mineralogical Society, LondonGoogle Scholar
- CQFS RS/SC (Comissão de Química e Fertilidade do Solo - RS/SC) (2004) Manual de adubação, 10th edn. Sociedade Brasileira de Ciência do Solo, Porto AlegreGoogle Scholar
- Nachtigall GR, Vahl LC (1991) Capacidade de suprimento de potassio dos solos da regiao sul do Rio Grande do Sul. Rev Bras Cienc Solo 15:43–47Google Scholar
- Raheb A, Heidari A (2012) Effects of clay mineralogy and physico-chemical properties on potassium availability under soil aquic conditions. J Plant Nutr Soil Sci 12:747–761Google Scholar
- Tedesco M, Gianello C, Bissani C, Bohnen H, Volkweiss SJ (1995) Análise de solo, plantas e outros materiais, UFRGS, 2nd edn. Porto AlegreGoogle Scholar