Low nitrogen and phosphorus effects on wheat Fe, Zn, phytic acid and phenotypic traits

Brigitta Tóth; Makoena J. Moloi; Lóránt Szöke; Maryke Labuschagne

doi:10.17159/sajs.2021/8414

Authors

Brigitta Tóth Institute of Food Science, University of Debrecen, Debrecen, Hungary https://orcid.org/0000-0001-9603-8377
Makoena J. Moloi Department of Plant Sciences, University of the Free State, Bloemfontein, South Africa https://orcid.org/0000-0003-4511-2340
Lóránt Szöke Institute of Food Science, University of Debrecen, Debrecen, Hungary
Maryke Labuschagne Department of Plant Sciences, University of the Free State, Bloemfontein, South Africa https://orcid.org/0000-0003-0593-2678

DOI:

https://doi.org/10.17159/sajs.2021/8414

Keywords:

nutrient deficiency, phenotypic traits, plant height, dry weight, microelements

Abstract

In sub-Saharan Africa, crops are often grown under low nitrogen (N) and low phosphorus (P) conditions, which may impact on the nutritional components of the grains. The aim of this study was to investigate the effect of low N and low P and a combination of the two on iron (Fe), zinc (Zn) and phytic acid content in two commercial South African spring wheat cultivars (PAN3497 and SST806). Phenotypic traits were also investigated. Although cultivar effects were not significant, treatment effects were highly significant for the phenotypic and nutritional traits. Low P stress increased Fe and Zn levels, whereas low N stress had the opposite effect. In addition, low P stress inhibited phytic acid accumulation the most, suggesting that under this treatment, Fe and Zn were more available because of less interaction with phytic acid. Compared to the low N treatment, the low P treatment led to lower reductions in the number of tillers, plant height, stem thickness, number of seeds, weight of seeds and dry weight for both cultivars. While low P had positive effects on the nutritional value of wheat, the combination of low N and P treatment had a negative impact on most of the measured characteristics. Low N conditions had more negative effects on all measured characteristics than low P conditions and was very detrimental to wheat nutritional value and yield.

Significance:

Results from this study emphasise the impact of fertilisation and the impact of insufficient nitrogen and phosphorus fertiliser on wheat productivity.
Low nitrogen and phosphorus fertilisation impact grain microelement content and bioavailability which impact nutritional value.