Formation of ternary organic acids-Fe-P complexes on the growth of wheat (Triticum aestivum)

Abstract

Phosphorus (P) reacts with chemical and mineralogical constituents in the soil, mainly in tropical and subtropical soils. Therefore, strategies have been used to reduce the adsorption of P to the soil, among them, the formation of complexes that could decrease P adsorption to the soil. Two experiments were carried out to evaluate the formation of organic acid-Fe-P complexes in the laboratory and the efficiency of these complexes on the growth of wheat plants (T. aestivum) grown under greenhouse conditions. In experiment 1, seven low-molecular-weight organic acids (OA) were selected and a protocol for the formation of complexes between organic acid and Fe3+ at pH 4.0 was performed. After stirring, P was added to the organic acid-Fe complex to form the ternary complex. The remaining P was evaluated to determine the amount of P in the complex. In experiment 2, the three OAs which had the largest amount of complexes were selected, together with a treatment with soluble P and a control. Wheat was grown in potted soil in a greenhouse for 34 days. The amount of ternary organic acid-Fe-P complexes formed varied from 5 to 42% of the added P. However, when these complexes were added to the soil, in treatments with greater amount of complex formed there was lower growth of wheat. Thus, the ternary complex with organic acid-Fe-P has little effect on the performance of wheat plants.

Soil-plant-microbiota interactions to enhance plant growth

“…Microbial activity leads to the solubilization of nutrients by redox reactions, acidification of the environment, chelation of cations and competition with phosphate for adsorption sites in the soil (Altomare et al, 1999;Yadav and Verma, 2012). All these mechanisms depend on organic matter metabolism (Lovley and Chapelle, 1995;Schmitt et al, 2018).…”

“…Due to this reason, solubilization of mineral P is thought to be more efficient in alkaline soils, in which Ca-P complexes are present, than in naturally acid soils in which phosphates are complexed with Fe and Al ions (Solano et al, 2008;Yadav and Verma, 2012). In acid soils, low-molecular weight organic acids, produced as byproducts of the metabolism of carbon, increase P availability for plants, not by acidification, but by inhibiting P adsorption in reactive sites of the soil (Schmitt et al, 2018). Andrade et al (2003) showed the capacity of organic acids in reducing P adsorption and precipitation due to the blockage of P sorption sites.…”

Comparison of pulp sludge compost effectivity of three different decomposers to the growth of geronggang (Cratoxylon arborescens) seedlings

“…Asam sitrat, malat dan oksalat merupakan asam organik yang paling efektif dalam mengurangi sifat meracun Al karena dapat membentuk lima hingga enam struktur ikatan stabil dengan Al (Ma, 2000). Asam sitrat dan oksalat diketahui dapat membentuk kompleks dengan fosfor sehingga adsorpsi fosfor oleh mineral maupun khemikalia dalam tanah berkurang (Schmitt et al, 2018). Di sisi lain, produksi asam organik oleh mikroba akan menurunkan pH tanah.…”