Photosynthetic activity of sweet sorghum fertilised by sewage sludge

ABSTRACT

Sewage sludge is a promising fertiliser for sweet sorghum growing on marginal land. We investigate the effects of different doses of sludge on the characteristics of chlorophyll fluorescence. Two types of sewage sludge were used: without flocculant and treated with flocculant. Sludge application helps to reduce the amount of inactive chlorophyll in the reaction centres, increases photosynthetic activity, and reduces the sensitivity of the photosynthetic apparatus to adverse environmental factors. Flocculated sludge had the more beneficial effect, particularly at the early stages of development; the optimal dose was 40-60t/ha.

KEYWORDS:

• Sweet sorghum
• sewage sludge
• marginal land

Disclosure statement

No potential conflict of interest was reported by the author(s).

Correction Statement

This article has been corrected with minor changes. These changes do not impact the academic content of the article.

Notes

1. Dark carbon fixation: a light-independent process in the chloroplast where sugar molecules are formed from CO₂ and water molecules.

2. RFU: relative fluorescence unit.

3. QA: photochemical fluorescence quenching, in which electrons are transmitted away from PSII due to enzymes active in carbon fixation – which decreases the fluorescence of the sample.

Additional information

Funding

This study was supported by the Ministry of Education and Sciences of Ukraine.