Physico‐chemical characterization of humic‐metal‐phosphate complexes and their potential application to the manufacture of new types of phosphate‐based fertilizers

• Published in: Journal of plant nutrition and soil science Vol. 177; no. 2; pp. 128 - 136
• Main Authors: Urrutia, Oscar, Erro, Javier, Guardado, Inaki, San Francisco, Sara, Mandado, Marcos, Baigorri, Roberto, Claude Yvin, Jean, Ma Garcia‐Mina, José
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY‐VCH Verlag 01-04-2014; WILEY-VCH Verlag; Wiley-VCH; Wiley Subscription Services, Inc
• Subjects: Agronomy. Soil science and plant productions; Biological and medical sciences; Chemical, physicochemical, biochemical and biological properties; fertilizer; Fertilizers; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; humates; humic complexes; humic substances; manufacturing; Nitrogen, phosphorus, potassium fertilizations; Organic matter; phosphorus; Phosphorus fertilization; phosphorus fertilizers; Physics, chemistry, biochemistry and biology of agricultural and forest soils; Plant growth; potassium; shoots; sodium; soil; soil fertility; soil organic matter; Soil science; Soil-plant relationships. Soil fertility; Soil-plant relationships. Soil fertility. Fertilization. Amendments; superphosphate; system optimization; Phosphates; Organic matter; Soil fertility; Property of soil; Metal complex; Soil quality; Phosphorus; humic substances; Phosphate fertilizer; Potential; soil organic matter; Organic acids; fertilizer; Soils; Type; Phosphorus compound; Soil science; Humic substance; Soil plant relation; Physicochemical properties; humic complexes
• ISSN: 1436-8730; 1522-2624
• DOI: 10.1002/jpln.201200651

The aim of this review is to describe the main physicochemical characteristics of diverse types of humic‐metal‐phosphate acid complexes. The effects of these complexes on phosphorus (P) fixation in soils with different pH values and physicochemical features and on plant phosphorus uptake are also discussed. Humic‐metal‐phosphate complexes have apparent stability constants in the same range as those of metal‐humic complexes, in solutions with diverse pH and ionic‐strength values. Likewise, the molecular‐size distribution of humic‐metal‐phosphate complexes as a function of pH is similar to that of potassium or sodium humates and metal‐humic complexes. Humic‐metal‐phosphate complexes are able to decrease phosphate fixation in soils and increase plant growth and phosphate uptake. Phosphorus fertilizers containing humic‐metal‐phosphate complexes proved to be efficient to improve plant growth and P uptake with respect to conventional fertilizers such as single superphosphate. The values of parameters related to plant phosphorus‐utilization efficiency (PUt E) suggest that the regulation of root acquisition of phosphate from these complexes could involve the interregulation of a system for the optimization of metabolic P utilization in the shoot and another system involving stress responses of roots under phosphorus deficiency.