Changes in the content and accumulation of macroelements in different parts of the quinoa plant biomass Chenopodium quinoa willd

Abstract

The aim of the research was to determine the effect of harvest date on the content and accumulation of macroelements in quinoa cultivated for seeds. Chemical analyses of macroelement content were conducted on plant material collected during a field experiment at the Swojczyce Station in 2021 (Poland). Due to similar unfavorable weather conditions during the harvests period of 2021-2022, biomass from a single year only was used for analyses. The biomass was categorized into seeds, infructescence remnants, and stems. Quinoa plant biomass were collected at six 7-days intervals between August 18 and September 21. In the study assessed three quinoa varieties: Zeno, Titicaca, and Vikinga. For each varieties and harvest time, the concentrations of nitrogen (N), phosphorus (P), potassium (K), magnesium (Mg), and (calcium) Ca were determined. Macroelement uptake was calculated in mg per plant. The quinoa exhibited the highest N accumulation in the seeds, and the highest K accumulation in the infructescence remnants and stems. The Titicaca variety demonstrated the greatest uptake of N (over 600 mg), P (80 mg), K (980 mg), and Ca (160 mg) per plant. Magnesium accumulation was most pronounced in the Titicaca and Vikinga varieties (100 mg per plant of each). Plant biomass (r = 0.899) and infructescence remnants N uptake (r = 0.803) was highly correlated with total macroelements uptake. The result of this study should be taken into account when determining quinoa value as a forecrop.

Keywords: Biomass; Harvest date; Nutrients correlation; Varieties.

Fig. 1

Average monthly temperature and sum of rainfall in quinoa growing season comparison to multiyear weather data at Swojczyce Meteorological Station.

Fig. 2

Sowing and harvest dates of quinoa seeds.

Fig. 3

The air humidity at during quinoa plant harvest sampling period—polynomial trend line of 6th degree.

Fig. 4

The air temperature at during quinoa plant harvest sampling period—polynomial trend line of 6th degree.

Fig. 5

Quinoa biomass structure at different harvest term. Average from three varieties (n = 90).

Fig. 6

The effect of varieties on biomass structure differences. Average from six harvest date (n = 90).

Fig. 7

Structure of macroelements uptake in different harvest term of biomass (% in D.M.). Average from three varieties (n = 36).

Fig. 8

Structure of macroelements uptake by different variety biomass (mg per plant) (n = 36).

Fig. 9

Multi-correlation surface plot of total macroelement’s uptake. Effect of different quinoa plant biomass (n = 36).

Fig. 10

Correlation matrix between quinoa plant biomass and macroelements uptake. 1 Plant biomass (g D.M.); 2 Stem (g of D.M.); 3 Infructescence remnants (g of D.M.); 4 Seeds biomass (g of D.M.); 5 Stem (mg N); 6 Stem (mg Mg); 7 Stem (mg P); 8 Stem (mg Ca); 9 Stem (mg K); 10 Infructescence remnants (mg N); 11 Infructescence remnants (mg Mg); 12 Infructescence remnants (mg P); 13 Infructescence remnants (mg Ca); 14 Infructescence remnants (mg K); 15 Seeds (mg N); 16 Seeds (mg Mg); 17 Seeds (mg P); 18 Seeds (mg Ca); 19 Seeds (mg K); 20 Macroelements total (in mg).