DOI: 10.5061/dryad.kprr4xhb5
title: Data from: Biofertilizers from wastewater treatment as a potential source of mineral nutrients for growth of amaranth plants

description: Exploring alternative fertilizers is crucial in agriculture due to the
 cost and environmental impact of inorganic options. This study
 investigated the potential of biofertilizers derived from sewage treatment
 on the growth and physiology of Amaranthus cruentus plants. Various
 treatments were compared, including control treatments with inorganic
 fertilizer and treatments with biofertilizers composed of microalgae,
 biosolids and reclaimed water. The following traits were investigated:
 photosynthetic pigments, gas exchange, growth, and leaf nutrient
 concentrations. Results show that the concentrations of N, P, Cu, Fe Zn
 and Na nutrients, in the dry microalgae and biosolids, were quite high for
 the needs of the plants. The wet microalgae presented high concentration
 of Cu, Fe and Zn nutrients while reclaimed water contained high
 concentration of N, K, Ca and S. Na and Zn nutrients increased in the leaf
 of plants treated with dry microalgae and biosolid, respectively. At the
 beginning of the flowering phase, total chlorophyll and carotenoids
 contents were lower for plants grown with wet microalgae while for plants
 grown with higher doses of biosolid or reclaimed water total chlorophyll
 was increased, and carotenoids were not affected. Lower photosynthetic
 pigments under wet microalgae resulted in lower photosynthetic rates. On
 the other hand, amendments with dry microalgae and biosolid increased
 photosynthetic rates with the biosolid being the most effective. Higher
 applications of biosolid, wet and dry microalgae produced a considerable
 increase in shoot biomass of amaranth, with the dry microalgae being the
 most effective. Additionally, reclaimed water obtained after tertiary
 treatment of sewage with microalgae and biosolids applied alone showed
 promising effects on plant growth. Overall, these findings suggest that
 organic fertilizers derived from sewage treatment have the potential to
 enhance plant growth and contribute to sustainable agricultural practices.
description: The experiment was carried out in the greenhouse at the
 Department of Biological Sciences at the Sao Paulo State University/Bauru
 Campus, under natural photoperiodic conditions and minimum and maximum
 average temperature of 17 and 33 <sup>o</sup>C, respectively.
 The seeds were sown in 4 L plastic pots filled with vermiculite. The
 microalgae were cultivated in a transparent box with 50 L of anaerobically
 pre-treated sewage with 5 L of inoculum of native microalgae from sanitary
 wastewater. After the microalgae cultivation the reclaimed water and the
 sedimented microalgae were collected. The sludge was obtained in the third
 chamber of the baffled anaerobic reactor, which had three chambers with a
 total volume of 597 L and HDT of 8 h.  After collecting, the sludge was
 oven dried at 60 <sup>o</sup>C. Then, it was crushed and
 ground in a mill to facilitate the  absorption by the plants. At
 approximately 7 day intervals, the height (cm), the diameter (mm) of the
 stem at insertion of cotyledons and the number of visible leaves were
 measured. For gas exchange measurements were used an infrared gas analyzer
 (LCpro Portable Photosynthesis System, ADC Bioscientific Ltd., Hoddesdon,
 UK). Total chlorophyll and carotenoids were  <br>expressed on a leaf
 area basis (g m<sup>-2</sup>). At the end of the experimental
 period, plants of each treatment were selected randomly for dry matter
 determinations.  Chemical analysis of microalge, reclaimed water, biosolid
 and amaranth leaves were made. The data were submitted
 to simple analysis of variance (ANOVA) by using the software SPSS/PC 9.0
 for Windows. Statistical analysis was applied to each group of plants
 separately. Quantitative changes in the different variables were analyzed
 using a test<br>of multiple comparison to determine differences
 between treatments at 5% significance level.
description: *Instructions about how the experiment was conducted in a greenhouse to
 evaluate the potential of biofertilizer on amaranth growth and gas
 exchange. The data files contain the results of the experiment.* The
 experiment was carried out in the greenhouse at the Department of
 Biological Sciences at the Sao Paulo State University/Bauru Campus, under
 natural photoperiodic conditions and minimum and maximum average
 temperature of 17 and 33°C, respectively. The seeds were sown in 4 L
 plastic pots filled with vermiculite. After one week, the plants were
 thinned to one per pot. Each pot received 250 mL of 20% or 70% full
 strength Long Ashton (LA) solution from sowing and continued three times a
 week. Three disks were collected (Disk diameter = 14,64 mm) per plant.
 Measurements were done in a spectrophotometer. nm = wavelength. Total
 chlorophyll and carotenoids were extracted from leaf discs of known area
 in 80% aqueous acetone according to Lichtenthaler, 1987, and the
 concentration expressed on a leaf area basis (g
 m<sup>−2</sup>). nm = wavelength. At approximately 7-day
 intervals, the height (cm), the diameter (mm) of the stem at insertion of
 cotyledons and the number of visible leaves were measured. A millimeter
 ruler was used for height measurements and a digital caliper (KingTools)
 was used for stem diameter measurements. An infrared gas analyzer (LCpro
 Portable Photosynthesis System, ADC Bioscientific Ltd., Hoddesdon, UK) was
 used for measurements of gas exchange. The measurements were made inside
 the greenhouse under natural conditions. The measurements were made on the
 youngest fully expanded leaf. Photosynthetically active radiation (PAR) of
 1000 μmol m<sup>−2</sup> s<sup>−1</sup> was
 supplied by a lamp coupled on the top leaf chamber. Ci = Internal
 CO<sub>2</sub> concentration; E = Transpiration; gs = stomatal
 conductance; A = photosynthesis. Dry matter of shoot after 60 days of
 sowing, after oven drying for 48 h. Observations about the xlsx files:
 ***1\. File Chlorophyl\_v4\.xlsx:*** Three leaf disks (disks diameter =
 14.64 mm) were collected per plant. Total chlorophyll and carotenoids were
 extracted from leaf discs of known area in 80% aqueous acetone according
 to Lichtenthaler (1987) and the concentration expressed on a leaf area
 basis (g m<sup>−2</sup>).  Measurements were taken using a
 spectrophotometer. Measurements were done in a spectrophotometer. nm =
 wavelength. ***2\. Dry\_matter\_v4\.xlsx:*** Dry matter of shoot after 60
 days of sowing, after oven drying for 48 h. The symbols X and - in the
 table means missing values. ***3\. Gas\_exchange\_v4\.xlsx:*** An infrared
 gas analyzer (LCpro Portable Photosynthesis System, ADC Bioscientific
 Ltd., Hoddesdon, UK) was used for measurements of gas exchange. The
 measurements were made inside the greenhouse under natural conditions. The
 photosynthetic active radiation of 1000 µmol m<sup>-2</sup>
 s<sup>-1</sup> was supplied by a light unit mounted on the
 leaf chamber. The measurements were made on the youngest fully expanded
 leaf. Ci = Internal CO<sub>2</sub> concentration; E =
 Transpiration; gs = stomatal conductance; A = photosynthesis ***4\.
 Height\_Diameter\_Number\_Leaves\_v4\.xlsx:*** At approximately 7-day
 intervals, the height (cm), the diameter (mm) of the stem at insertion of
 cotyledons and the number of visible leaves were measured. A millimeter
 ruler was used for height measurements and a digital caliper (KingTools)
 was used for stem diameter measurements.