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Human Hair as a Nutrient Source for Horticultural Crops

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Two pot experiments were conducted to evaluate noncomposted hair byproduct as a nutrient source for container-grown crops. Lettuce (Lactuca sativa 'Green Leaves') and wormwood (Artemisia annua 'Artemis') were grown in a commercial growth substrate amended with 0%, 2.5%, 5%, or 10% by weight hair waste or controlled-release fertilizer (CRF) or were watered with a complete water-soluble fertilizer (WSF). After harvest, yellow poppy (Glaucium flavum) was grown in the pots and substrate that previously grew wormwood, and feverfew (Tanacetum parthenium) was grown in the pots and substrate previously containing lettuce. The 5% hair treatment and the commercial fertilizer rates were calculated to provide the same amount of nitrogen (N) during production of lettuce and wormwood based on 50% N availability from hair. Yields in treatments containing hair or CRF or watered with WSF were higher than in the untreated control. The highest lettuce and wormwood yields occurred with CRF followed by WSF and 5% and 10% hair treatments. However, yield of yellow poppy was higher in the hair treatments than yields in inorganic fertilizer treatments or in the untreated control. Feverfew yields did not differ among fertility treatments, but yields in fertility treatments were higher than those of control. Lettuce leaf moisture content was lower, but soluble solids were higher in plants in the hair waste treatments than in the WSF or CRF treatments. Total phenolics in lettuce did not differ among treatments. Total aerobic and coliforms plate counts were similar for all samples, averaging 6.0 and 1.2 log cfu/g, respectively. Results from this study suggest that noncomposted hair waste could be used as a nutrient source for container-grown plants. Hair waste should not be used as a single nutrient source for fast-growing plants because of the time needed for degradation of the hair before release of plant nutrients.
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Human Hair as a Nutrient Source
for Horticultural Crops
Valtcho D. Zheljazkov
1,3
, Juan L. Silva
2
, Mandar Patel
2
,
Jelena Stojanovic
2
, Youkai Lu
2
, Taejo Kim
2
, and Thomas Horgan
1
ADDITIONAL INDEX WORDS. lettuce, feverfew, yellow poppy, wormwood, Artemisia
annua,Lactuca sativa,Glaucium flavum,Tanacetum parthenium, food quality,
phenolics, hair waste
SUMMARY. Two pot experiments were conducted to evaluate noncomposted hair
byproduct as a nutrient source for container-grown crops. Lettuce (Lactuca sativa
‘Green Leaves’) and wormwood (Artemisia annua ‘Artemis’) were grown in a
commercial growth substrate amended with 0%, 2.5%, 5%, or 10% by weight hair waste
or controlled-release fertilizer (CRF) or were watered with a complete water-soluble
fertilizer (WSF). After harvest, yellow poppy (Glaucium flavum) was grown in the
pots and substrate that previously grew wormwood, and feverfew (Tanacetum
parthenium) was grown in the pots and substrate previously containing lettuce. The
5% hair treatment and the commercial fertilizer rates were calculated to provide the
same amount of nitrogen (N) during production of lettuce and wormwood based
on 50% N availability from hair. Yields in treatments containing hair or CRF or
watered with WSF were higher than in the untreated control. The highest lettuce
and wormwood yields occurred with CRF followed by WSF and 5% and 10% hair
treatments. However, yield of yellow poppy was higher in the hair treatments
than yields in inorganic fertilizer treatments or in the untreated control. Feverfew
yields did not differ among fertility treatments, but yields in fertility treatments
were higher than those of control. Lettuce leaf moisture content was lower, but
soluble solids were higher in plants in the hair waste treatments than in the WSF
or CRF treatments. Total phenolics in lettuce did not differ among treatments.
Total aerobic and coliforms plate counts were similar for all samples, averaging 6.0
and 1.2 log cfu/g, respectively. Results from this study suggest that noncomposted
hair waste could be used as a nutrient source for container-grown plants. Hair waste
should not be used as a single nutrient source for fast-growing plants because of
the time needed for degradation of the hair before release of plant nutrients.
Anumber of waste materials and
byproducts (such as animal
manure, municipal solid waste
composts, and sewage sludge) are
used currently in agricultural crop
production. Human hair waste gen-
erated by barbershops typically would
be disposed of at waste sites,
landfilled, or composted along with
other municipal solid wastes. Pre-
vious research has demonstrated that
noncomposted human hair waste
with an addition of municipal solid
waste compost can be used as nutrient
source for crops (Zheljazkov, 2005).
However, there is no published
research on the use of human hair as
an exclusive nutrient source for
greenhouse container production,
although human hair waste based
products have been commercially
available to crop producers in the last
couple of years (SmartGrow, FL City,
FL).
The hypothesis of this study was
that commercially available noncom-
posted hair waste cubes would sup-
port plant growth and the
development of two consecutive
crops (double cropping) and could
be used as a sole nutrient source. The
objective was to compare the produc-
tivity of four crops grown in commer-
cial growth medium in pots with the
following treatments: untreated con-
trol, noncomposted hair cubes at
2.5%, 5%, and 10% by weight, a con-
trolled-release fertilizer (CRF), and
water-soluble fertilizer (WSF). As
model plants, we used four con-
tainer-grown crops: lettuce, worm-
wood, yellow poppy, and feverfew.
Materials and methods
PLANT GROWTH CONDITIONS.In
Mar. 2007, two to three lettuce or
wormword seeds were planted in each
cell of 48-cell (6 ·3.5 cm, 5 cm deep)
plastic trays filled with a commercial
growth substrate (Metromix 300;
Sun Gro Horticulture, Bellevue,
WA). After emergence, seedlings
were thinned to one plant per cell
and grown in a greenhouse under
natural daylight with day tempera-
tures of 22 Cto25C and a night
temperature of 18 C. The experi-
ment was initiated in Mar. 2007 and
continued through Sept. 2007, when
the second crops were harvested.
Twenty days after emergence, lettuce
seedlings were transplanted to 6-
inch-diameter pots containing 600 g
of the same growth substrate used for
transplant production, and worm-
wood was transplanted to 11-inch-
diameter pots containing 2800 g of
growth substrate. Two different size
pots were used to correspond to
wormwood and lettuce plant sizes.
The experimental design was a
randomized complete block design
Units
To convert U.S. to SI,
multiply by U.S unit SI unit
To convert SI to U.S.,
multiply by
29,574 fl oz mL 3.3814 ·10
–5
29.5735 fl oz mL 0.0338
2.54 Inch(es) cm 0.3937
25.4 Inch(es) mm 0.0394
1 mmho/cm dSm
–1
1
28.3495 oz g 0.0353
0.1 ppm mg/100 g 10
1 ppm mgkg
–1
1
(F – 32) O1.8 FC(1.8·C) + 32
This is a contribution of the Mississippi Agricultural
and Forestry Experiments Station Journal article No
11266. This research was funded by USDA-ARS
Specific Coop. Agreement 58-6402-4-026 with CRIS
MIS-223010. The specific project was ‘‘Field Estab-
lishment of Medicinal Herbs and Potential for Com-
mercial Production’’ awarded to Dr. Jeliazkov
(Zheljazkov) and by MIS project awarded to Dr.
J.L. Silva.
We thank Dr. Crofton Sloan, Dr. Frank Matta, and
Dr. Normie Buehring of Mississippi State University
and the anonymous reviewers of the journal for
critically reading the manuscript and suggesting many
improvements.
1
Mississippi State University, North Mississippi
Research and Extension Center, 5421 Highway 145
South, Verona, MS 38879
2
Mississippi State University, Department of Food
Science, Nutrition, and Health Promotion, Box 9805,
Mississippi State, MS 39762
3
Corresponding author. E-mail: vj40@pss.msstate.
edu.
592 October–December 2008 18(4)
with four replicates. Factors were
crop (at two levels) and fertility (at
six levels). Lettuce and wormwood
were treated as one experiment, and
second crops yellow poppy and fever-
few were treated as a second experi-
ment. Experimental treatments were
as follows: hair waste cubes (Fig. 1;
donated by SmartGrow) were incor-
porated and thoroughly mixed into
the growth medium at 0%, 2.5%, 5%,
or 10% by weight (0, 70, 140, or 280
g, respectively) to provide 0, 11.6,
23.1, or 46.2 g/pot total N, respec-
tively. The hair waste cubes contained
16.5% N, 0.01% phosphorus (P),
0.01% potassium (K), 0.27% calcium
(Ca), 0.05% magnesium (Mg), and
0.23% sulfur (S), as analyzed by the
Mississippi State University Soil Test-
ing Laboratory (Mississippi State,
MS) using the method of Jones and
Steyn (1973) and averaged from
three replicates. Commercial fertilizer
treatments included a topdress of
CRF (Osmocote Plus 15N–9P–12K;
Scotts-Sierra Horticultural Products,
Marysville, OH) or fertilization with
100 mgkg
–1
of N with 1100 mL of
WSF (greenhouse-grade 20N–8.8P–
16.6K general purpose fertilizer;
Scotts-Sierra Horticultural Products)
every 7 d. The 5% hair treatment and
the commercial fertilizer rates were
applied to provide the same amount
of N during the production cycle
based on 50% N availability from the
hair waste as determined from pre-
vious research (Zheljazkov, 2005;
Zheljazkov et al., 2008). CRF pro-
vided 2.5 g N, 1.5 g P, and 1.99 g K
to each 6-inch-diameter pot, and
11.5 g N, 6.9 g P, and 9.3 g K to
each 11-inch-diameter pot. WSF pro-
vided 2.5 g N, 1.08 g P, and 2.06 g K
to each 6-inch-diameter pot, and
11.5 g N, 5.06 g P, and 9.6 g K to
each 11-inch-diameter pot.
Plants were grown in a green-
house with an average day/night
temperature of 28/20 C without
supplemental lighting for 50 d. Plants
were watered daily as needed, by
hand, making sure no leaching
occurred. Lettuce and wormwood
were harvested at commercial (mar-
ketable) maturity stage (six to eight
fully developed leaves, about 12
inches tall). Plants were cut about
1 cm above the substrate, and height
and fresh weight were recorded.
About half of the lettuce samples were
held at 4 ± 1 C until analyzed (less
than 4 d) or frozen (for phenolics).
The wormwood samples and remain-
ing half of the lettuce samples were
dried in a drying oven at 68 C for
72 h and weighed.
One week after the lettuce and
wormwood were harvested, feverfew
was planted into 6-inch-diameter
pots and yellow poppy was trans-
planted into 11-inch-diameter pots
containing the growth substrate from
the previous crop. CRF and WSF
were applied as described for the
previous crops. No additional hair
waste cubes were applied to the hair
treatments. The feverfew and yellow
poppy were grown for 20 weeks and
were harvested in the same way as the
previous crops.
Growth medium samples were
taken after the harvest of the second
crop, dried at room temperature, and
extracted for phyto-available nutri-
ents using the Lancaster soil test
method (Cox, 2001). Determination
of specific conductance (total soluble
salts) was done using a conductivity
meter (model 32; YSI, Yellow
Springs, OH) (Willard et al., 1968).
Nitrate-N was determined using a
nitrate electrode (Francis and
Malone, 1975).
Chemical and physical analysis
of lettuce was conducted in three
replicates from each treatment. Each
replicate was an average of three read-
ings. Water content of lettuce was
determined by drying at 65 C for
24 h [Association of Official Agricul-
tural Chemists (AOAC) method
930.04 (AOAC, 1997)]. The soluble
solids concentration (SSC; in per-
centage) in lettuce was evaluated
using a refractometer (Bauch &
Lomb, Rochester, NY). The temper-
ature was maintained at 21 C with
water circulating through the refrac-
tometer. The refractometer was cali-
brated using distilled water before
each reading. After calibration, 1
drop of filtered lettuce juice was
placed on a glass prism of the refrac-
tometer. The results were recorded
and expressed as percentage of SSC
(Stojanovic and Silva, 2007).
TOTAL PHENOLICS.Lettuce sam-
ples from each treatment and replica-
tion were ground by mortar and
pestle. A 5-g portion was homogen-
ized with 15 mL of high-performance
liquid chromatography-grade metha-
nol (Fisher Scientific, Fair Lawn, NJ)
in a homogenizer. The homogenizer
was washed with 5 mL of methanol,
which was combined with the first
homogenate. Samples were centri-
fuged at 10,000 g
n
for 15 min at
15 C. The volume of the supernatant
was recorded, and the pellet was
discarded. Total phenolics in let-
tuce extract were determined with
the Folin-Ciocalteu reagent by the
method of Singleton and Rossi with
gallic acid as the standard (Singleton
Fig. 1. Hair waste cubes used in this study. Coins are U.S. quarters ($0.25) with a
diameter of 24.26 mm (1 mm =0.0394 inch).
October–December 2008 18(4) 593
and Rossi, 1965). Twenty microliters
of sample was mixed directly in the
cuvette with 1.58 mL of water and
100 mL of Folin-Ciocalteu reagent
(Fisher Scientific). The cuvette was
incubated between 1 and 8 minutes,
and 300 mL of 20% sodium carbonate
was added. Samples were incubated at
room temperature for 2 h, and
absorbance was recorded at 765 nm.
COLOR.The color of lettuce
leaves was evaluated using a spectro-
colorimeter (Labscan Model 6000
0/45; Hunter Associates Labora-
tory, Fairfax, VA). The instrument
was calibrated with two standard tiles
(black and white) using a quartz-
halogen lamp. Each lettuce sample
was placed on a 10-mm-diameter
port. Three readings were taken on
two sides of each sample. The reflec-
tance values of ‘L’ (brightness), ‘a’
(redness+/greenness–), ‘b’ (yellow-
ness+/blueness–) were measured. Hue
angle value (tan
–1
b/a) and chroma or
saturation index [SI = (a
2
+b
2
)
1/2
]
were calculated according to Silva
et al. (2005).
MICROBIOLOGICAL ANALYSIS.A
sample of 25 g of lettuce was placed
in a stomacher bag (whirl-pak
TM
;
Nasco, Fort Atkinson, WI) to which
225 mL of 0.1% sterile peptone water
was added and the contents were
massaged in a stomacher (Sweard
Medical Limited, London) for 30 s
(Allende et al., 2004; Kim et al.,
2000). This was done to remove cells
from the lettuce and place them into
the solution. Total aerobic plate
counts (APC) were determined by
the spread plate method by using
0.1 mL of sampling dilution (Amer-
ican Public Health Association,
1992). Plate Count Agar (Difco;
Becton, Dickinson & Co., Lawrence,
KS) was used as the growth medium.
The APC plates were duplicated from
each dilution and were incubated in
an incubator (Precision Scientific,
Champaign, IL) at 37 C for 48 h.
The colonies were counted, and the
microbial counts were reported as log
colony-forming units (cfu) per gram
of lettuce. Total coliform counts were
determined from the same dilution
using violet red bile agar (Difco) and
incubating at 37 C for up to 48 h.
Coliform counts were expressed as
log cfu per gram.
Data analyses were performed
using analysis of variance in Quattro
Pro 10 (Corel Corp., Ottawa,
Canada). Means, whenever different,
were separated by using Fisher’s pro-
tected least significant difference
(LSD) test. (SAS version 9.1 for Win-
dows; SAS Institute, Cary, NC).
Results
The addition of hair waste cubes
to the growth medium at 5% or 10%
by weight increased lettuce and
wormwood yields relative to the
untreated control (Table 1). How-
ever, yields in the 5% or 10% hair
waste treatments were lower than
yields in the inorganic fertilizer treat-
ments. The highest yields of lettuce
and wormwood were obtained in the
CRF treatments, followed by the
WSF treatment. The yield response
of the second crops yellow poppy and
feverfew to the treatments was differ-
ent from the first crops. Overall, the
yellow poppy yields were greater in
the hair treatments, lower in the
commercial fertilizer treatments
(CRF or WSF), and the lowest in
the untreated control (the 0% hair
treatment; Table 1). The highest
yields were obtained in the 5% and
10% hair treatments, and yields in the
CRF exceeded those in the WSF
treatment. Feverfew yields in the fer-
tility treatments were not different,
but all were higher than in the
untreated control (Table 1).
All hair-treated lettuce and the
untreated control samples had lower
(P£0.05) moisture and higher (P£
0.05) SSC than the CRF or WSF
samples. The SSC of the CRF samples
was higher than that of the untreated
control or hair-treated samples,
whereas the SSC value of WSF sam-
ples was not different from all others
(Table 2). Total phenolics, color sat-
uration or chroma, and ‘b’ color
values did not differ (P>0.05) among
samples. Other color values varied
among samples, with no clear differ-
ences between hair-fertilized samples
and other treatments. Aerobic plate
counts were about 6 log cfu/g,
whereas total coliforms ranged 1.0
and 1.9 log cfu/g, with no clear
differences due to hair fertilization
(Table 2).
In general, the addition of hair
waste to growth medium resulted in
lower pH than the untreated control
as measured after the harvest of the
second crop (Table 3). Residual
nitrate-N concentrations were higher
in the 2.5% and 5% hair treatments
and CRF treatments than in the WSF
or control treatments. There was
a significant amount of residual P
in the inorganic treatments (CRF
or WSF) relative to the other treat-
ments. Residual K concentrations
were greatest in the inorganic fertil-
izer treatments, lower in the hair
treatments, and lowest in the control.
Residual zinc concentrations were
higher in the 10% hair and the CRF
treatments relative to the other treat-
ments. Residual sodium was higher in
the CRF, lower in the WSF, 10%, and
5% hair treatments, and lowest in the
control. Overall, hair treatments
resulted in increased total soluble
solids (TSS) than in the other treat-
ments. Because TSS concentrations
in the hair treatments were below
or at 0.3 mmho/cm [below 2 is
Table 1. Yields of lettuce, wormwood, feverfew, and yellow poppy grown in pots
with different treatments of hair waste and fertilizers.
Treatment
z
First crop
y
Second crop
Lettuce Wormwood Yellow poppy Feverfew
----------------------- (g dry herbage/pot)
x
-----------------------
Control (0% hair) 108.7 e
w
85.3 e 5.2 e 9.4 b
2.5% hair 11.2 de 68.3 e 182.3 b 60.6
5% hair 121.2 cd 109.6 d 306.1 a 52.4 a
10% hair 132.9 c 163.1 c 344.1 a 55.2 a
CRF 486.7 a 418.6 a 113.0 c 80.2 a
WSF 326.4 b 243.3 b 44.2 d 48.9 a
z
Hair treatments were added once to the growth medium, at planting of the first crop. The 2.5%, 5%, and 10% hair
represent addition of hair to the growth medium by weight, whereas the control does not have hair addition.
Controlled-release fertilizer (CRF) was surface applied at planting of the first crop and again with the planting of
the second crop, whereas the water-soluble fertilizer (WSF) fertilizer was added on weekly basis.
y
First, lettuce and wormwood were grown in the treated pots. After harvest, yellow poppy was grown after
wormwood and feverfew after lettuce.
x
1 g = 0.0353 oz.
w
Means with the same letter within a column are not significantly different by Fisher’s protected least significant
difference test at P£0.05.
594 October–December 2008 18(4)
RESEARCH REPORTS
considered low (Bernstein, 1975)],
no further spot-plate screen was con-
ducted to identify specific salts in the
extract.
Discussion
Results from this study suggest
that once the degradation and miner-
alization of hair waste starts, it can
provide sufficient nutrients to con-
tainer-grown plants and ensure sim-
ilar yields to those obtained with the
commonly used fertilizers in horticul-
ture. However, it takes time for the
hair to start degrading and releasing
nutrients, as is reflected in lower
yields in the hair treatments relative
to the inorganic fertilizers for the
first crops, lettuce and wormwood.
Hence, this and previous research
(Zheljazkov, 2005) suggests that
unless sufficient time is allowed for
nutrient mineralization, hair waste
may not be suitable for fast-growing
vegetables such as lettuce unless
mixed with compost or other sources
of easily available nutrients. Human
hair is a keratinaceous substance that
is very resistant to degradation by
proteolytic enzymes such as trypsin
and pepsin due to the cross-linking
by disulfide bonds, hydrogen bond-
ing, and hydrophobic interactions
(Ignatova et al., 1999). Plausibly, that
resistance to mineralization is the
reason why this ‘‘waste’’ nutrient-rich
product is not used in production
of greenhouse crops as a nutrient
source. Because of the high N content
of human hair (16.5% N in the hair
used in this experiment), land filling
or surface disposing of hair waste,
especially on sandy soils, could result
in leaching of nitrates into surface
or groundwater. Human hair waste
could be composted, as has been
demonstrated with sheep wool (Das
et al., 1997; Plat et al., 1984; Verville,
1996), another similar keratinaceous
product. Composted wool has been
used in chickpea and wheat produc-
tion as a N source (Tiwari et al.,
1989a, 1989b). A major disadvantage
of composting of protein-rich feed-
stocks such as wool, however, is the
significant loss of N (Epstein, 1997).
Hence, there are environmental and
economic benefits for the use of non-
composted protein-rich materials as
N source for crops over the compost
prepared with such materials.
The major impact of hair fertil-
ization on lettuce quality was lower
moisture and higher SSC. This result
could lead to a ‘‘sweeter’’ flavor in
Table 2. Chemical analyses, leaf surface color, and microbial counts of lettuce grown at different fertility regimes.
Treatments
z
Water SSC
y
Phenolics
(mg/100 g)
x
L
w
a
v
b
u
Hue
t
Chroma
s
APC
r
TCC
r
--------(%) ------- ---- (cfu/g)----
Control
(0% hair) 90.4 b
q
5.9 a 33.7 ns 61.5 a –9.7 a 21.8 ns 113 b 24.2 ns 6.2 a 1.4 ab
2.5% hair 90.6 b 5.8 a 31.5 51.4 b –13.5 ab 21.0 123 a 25.0 6.0 ab 1.2 ab
5% hair 91.4 b 5.2 a 38.7 56.9 ab –13.2 ab 22.1 120 ab 25.8 6.0 a 1.0 b
10% hair 90.0 b 6.1 a 49.9 52.3 b –15.5 b 23.7 123 a 28.3 5.6 b 1.0 b
CRF 94.1 a 4.2 b 28.4 50.7 b –15.0 b 21.6 125 a 26.3 6.4 a 1.9 a
WSF 94.4 a 4.9 ab 25.5 54.7 ab –14.1 ab 21.9 123 a 26.0 6.2 a 1.3 ab
z
Hair and controlled-release fertilizer (CRF) were added once to the growth medium, and the water-soluble fertilizer (WSF) was added on weekly basis. The 2.5%, 5%, and
10% hair represent addition of hair to the growth medium by weight, whereas the control does not have hair addition.
y
SSC = soluble solids content.
x
1 mg/100 g = 10 ppm.
w
L = brightness value; the higher, the brighter.
v
a = redness value.
u
b = yellowness value.
t
Hue = atan (b/a).
s
Chroma = saturation index = (a
2
+b
2
)
1/2
.
r
APC = aerobic or total plate counts, TCC = total coliform counts (1 cfu/g = 28.3495 cfu/oz).
q
Means with the same letter within a column are not significantly different by Fisher’s protected least significant difference test at P£0.05.
Table 3. Growth medium pH, residual nitrate =N, extractable nutrients, and conductivity at harvest of wormwood and
feverfew
z
as a function of addition of fertilizer of hair waste.
Treatments
y
pH
NO
3
-N
x
P
x
K
x
Ca
x
Mg
x
Zn
x
Na
x
EC
(mmho/cm)
w
----------------------------------------(mgkg
1
)
x
---------------------------------------
Control
(0% hair) 7.4 a 0.8 c
v
28 c 254 d 4,713 1,108 3.8 b 99 c 0.1
2.5% hair 5.9 d 3.2 b 31 c 396 c 4,008 1,094 3.4 b 115 bc 0.3
5% hair 6.1 d 4.3 b 26 c 430 c 4,450 1,214 3.2 b 131 b 0.2
10% hair 4.5 e 1.8 bc 36 c 239 d 3,576 983 6.9 a 128 b 0.3
CRF 6.4 c 6.2 a 97 a 930 a 5,561 1,425 6.0 a 179 a 0.1
WSF 6.9 b 1.3 c 53 b 701 b 5,235 1,300 2.5 b 130 b 0.1
z
First, lettuce and wormwood were grown in the treated pots. After harvest, yellow poppy was grown after wormwood and feverfew after lettuce.
y
Hair and controlled-release fertilizer (CRF) were added once to the growth medium, and water-soluble fertilizer (WSF) was added on weekly basis. The 2.5%, 5%, and
10% hair represent addition of hair to the growth medium by weight, whereas the control does not have hair addition.
x
NO
3
N = nitrate nitrogen, P = phosphorus, K = potassium, Ca =calcium, Mg = magnesium, Zn = zinc, Na = sodium (1 mgkg
–1
= 1 ppm).
w
EC = EC (1 mmho/cm = 1 dSm
–1
).
v
Means with the same letter within a column are not significantly different by Fisher’s protected least significant difference test at P£0.05.
October–December 2008 18(4) 595
lettuce, but the lower moisture may
result in decreased crunchiness. These
perceptions need to be determined
by a sensory panel. Total phenolics
did not differ, but there was a per-
ceived trend for hair-treated samples
to contain higher phenolics. Color
values had slight differences among
treatments, but not enough to be
discernible by the naked eye. This
observation tells us that consumers
may not be able to notice the differ-
ence among produce grown in these
different nutritional regimes. APC of
lettuce were average for this product,
about 6 log cfu/g (Valentin-Bon
et al., 2008), and hair treatment did
not have any effect. Total coliforms
were also below 2 log cfu/g (Gilbert
et al., 2000; Johnston et al., 2005),
indicating good handling practices
and the unlikelihood of enteropath-
ogens being present.
Overall, the amount of residual
nutrients in growth medium after the
harvest of the second crops was above
that of the control, indicating a pos-
sibility for additional cropping. Fur-
thermore, further mineralization of
hair waste would be expected in the
hair treatments, which might be able
to supply phyto-available nutrients
for a subsequent crop, as hair fibers
were visible in the growth medium at
the time of sampling. However, a
potential concern with the use of hair
as an amendment and nutrient source
for plants is the apparent decrease of
growth medium pH and increase
of TSS (Table 3). Similar reduction
of soil pH after the use of hair waste
addition has been previously reported
(Zheljazkov, 2005). The relatively
higher electrical conductivity in the
hair treatments might have been the
reason for the lower lettuce yields in
these treatments relative to the CRF
or WSF treatments, as lettuce is
known to be a salt-sensitive crop
(Kerns et al., 1999).
Further research is needed to
match nutrient release from hair
waste to crop requirements and to
estimate optimal rates of application
of hair waste to different container-
grown crops. Because human hair
may carry biohazards such as human
pathogens or chemicals, further
research is needed to address possible
health concerns of consumers and the
general public on the use of human
hair waste as nutrient source for edi-
ble crops.
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596 October–December 2008 18(4)
RESEARCH REPORTS
... A balanced fertilizer is also important for the growth of any plant and we used the most effective and moderate level of fertilizer according to [76]. Furthermore, fertilizers, iron fertilizer and keratin material have been reported to be effective in enhancing the growth of plants [77][78][79][80]. Iron oxide promoted the growth of rice through regulating the antioxidant enzyme activity and phytohormone contents. ...
... Waste hairs applied to soil can act as a good fertilizer source as hair protein contains a lot of amino acids, which, on decomposition, release essential plant nutrients. Human hair contains 51% carbon, 21% oxygen, 17% nitrogen, 6% hydrogen, and 5% sulphur, which makes waste human hair a good source of organic fertilizer [79]. Zeolite increases crop yield and biomass through improving soil physical and chemical properties, which include improving water holding capacity, facilitating root growth, decreasing the availability of HMs, and increasing N use efficiency through minimizing N lose and maximizing N recovery for the high CEC of zeolite, especially for ammonium (NH 4+ ) [81][82][83]. ...
Article
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Contamination of paddy soils with heavy metals and metalloids poses a risk to human health through the food chain. For safe agricultural production in contaminated paddy soils, “in situ” remediation through the unavailability of heavy metals from contaminated soils was investigated in order to develop cost-effective and eco-friendly approaches for soils contaminated with complexed heavy metals (HMs) and metalloids. In the present study, the effectiveness of different soil amendments, including sulfur-containing materials (hair or cysteine), manganese compounds as an antagonist and an oxidant, zeolite and iron oxide as adsorbents, and their combinations through coating or modification, was investigated by a pot experiment with rice plants and chemical analysis. Two levels of each treatment were made, termed X1 and X2, which were a single and double dose of each treatment respectively, while CaCO3 was used as a basal and pH enhancement amendment in all treatments to identify the best combination of the above treatments in the in situ remediation of heavy metals and metalloids. The rice plants were kept under the flooded condition. Results indicated that the bioavailability of As, Cd, Cr, and Pb in soil was significantly decreased with level two (X2) of iron oxide coated with modified hairs (T7 × 2) followed by level two (X2) of zeolite coated with KMnO4. The iron oxide coated with modified hairs (X2) decreased the concentrations of heavy metals and metalloids in rice plants in the order Pb ˃ As ˃ Cr ˃ Cd by 81%, 80%, 79% and 46%, respectively, followed by zeolite coated with KMnO4 (X2) in the order Pb ˃ As ˃ Cr ˃ Cd by 78%, 76%, 71%, and 31%, respectively, to control. The available content of these elements in soil was decreased in the order As>Cr>Pb>Cd by 67%, 66%, 64% and 60%, respectively, through iron oxide coated with modified hairs, followed by zeolite coated with KMnO4 in the order Pb ˃ Cr ˃ Cd ˃ As by 57%, 53%, 50%, and 46%, respectively, to control, which can explain the decreased bioavailability by these amendments. In addition, the maximum shoot dry and leaf area were noticed in the pots treated with iron oxide coated with modified hairs and zeolite coated with KMnO4. There is potential to use modified hairs (MHs) with iron oxide and KMnO4-coated zeolite as soil amendments to develop a cost-effective and efficient “in situ” remediation technology for As, Cd, Pb, and Cr-contaminated rice paddy soils, especially for the soils with complex contamination by Cd and As.
... Wool waste is a rich source of nutrients, being composed of keratin proteins that contain abundant nitrogen, carbon and sulfur, playing an essential role in plant nutrition. It has been argued that the use of sheep's wool on the soil has produced beneficial effects on the productivity of several plant species (Górecki R.S., 2010;Zheljazkov V.D. et al., 2008;Zheljazkov V.D., 2005). Tables 4 and 5 present the results of the chlorophyll a analyzes. ...
... Lana is composed of protein (keratin) that contains abundant nitrogen, carbon and sulfur, which play an essential role in plant nutrition. It has been argued that the fertilization of soil with sheep's wool caused beneficial effects on the productivity of several plant species (Zheljazkov V.D. et al., 2008;Zheljazkov V.D., 2005). The results of fertilization research for variants (L) and (C) allow the formulation of a set of conclusions on green biomass and separat (Sorghum saccharatum). ...
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The research was conducted during 2012 - 2014. Under investigation were 4 sunflower hybrids (Helianthus annuus L.): hybrid Bacardy (an imitolerant hybrid by ClearField plus technology), hybrid Estiva (an imitolerant hybrid by ClearField technology), hybrid Sumico (a tribenuron-methyl tolerant hybrid by ExpessSun technology) and hybrid Arizona (a hybrid by conventional technology). Factor A included the years of investigation. Factor B, herbicides and tank mixtures, included 20 rates. It includes 3 variants by ClearField plus technology, 5 variants by ClearField technology, 5 variants by ExpessSun technology and 7 variants by conventional technology. Herbicide Pulsar plus by Clearfield plus technology and herbicide Listego by Clearfield technology, destroy completely all annual and perennial graminaceous and broadleaved weeds in sunflower crops, including Orobanche cumana Wall. Herbicide Express by ExpressSun technology, controls all perennial and annual broadleaved weeds. Tank mixture of Express with antigraminaceous herbicide Select super controlled successfully and all annual and perennial weeds. The highest seed yield is obtained at herbicide tank mixture Pulsar plus + Stomp aqua by Clearfield plus technology. Tank mixture Listego + Dash + Sharpen by Clearfield technology and Express + Trend + Select super by ExpressSun technology also lead to obtaining of high seed yields. Tank mixtures of herbicides Smerch, Pendigan, Wing, Raft, Pledge and Modown with Amalgerol premium by conventional technology have lower yields due to insufficient control of weeds as Xanthium strumarium L., Cirsium arvense Scop., Convolvulus arvensis L. in sunflower crops.
... But, presence of inter and intra-molecular disulfide bonds of cysteine (the major component of human hair), hydrogen bonding and other hydrophobic forces offer firm structural stability and resistance of keratin moiety against chemical attacks and ultimately limits its mineralization and subsequent release of plant nutrients [8]. Zheljazkov et al. [9] noticed that mineralization of WHH is very lengthy process which limits the application of hair waste for fast-growing vegetables. So, the cleavage of these intra and inter-molecular bonds is very crucial for their use as nitrogenous fertilizer. ...
Article
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Purpose To explore the potential of alkali hydrolysis techniques for valorizing waste human hair (WHH) into nitrogenous fertilizer and evaluation of their impact on growth, yield of mung bean and its rhizospheric soil. Methods WHH were thermochemically hydrolyzed by potassium hydroxide or mixed potassium hydroxide and calcium hydroxide solutions and resultant hydrolysates (HK and HKC, respectively) were treated as alternative source of nitrogenous fertilizer in different doses for cultivation of mung bean. Results The results showed that alkali mediated human hair hydrolysates (HHH) were rich in N and S and among them HKC had significantly higher N content. Soil amendment of 8 mL of HKC solution (WHH and water in 1:10 ratio and pH was adjusted to 7.5) per pot resulted in 20 and 9% higher grain yield and protein content of mung bean, respectively over recommended dose of N fertilizer. Application of HHH also enhanced available nutrient (N, P, K and S) contents in soil. Conclusions Our results suggested that alkali hydrolysis could be considered as an efficient valorization technique for WHH. Soil amendment of HKC render superior effects on growth and yield of mung bean in respect of recommended dose of N fertilizer and also maintain availability nutrients in soil. Graphical Abstract
... Nutrients content in plants fruit and straw was significantly higher under treatments having RDF + wool waste than treatments having STCR recommendation + wool waste. Similar results were also reported by Zheljazkov et al., (2008a) [20] , [7] , Shree et al., (2018) [17] . ...
Article
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A field experiment was conducted on influence of wool waste on nutrient content and uptake of bottle gourd (Lagenaria siceraria) in western Rajasthan at research farm of Agricultural Research Station, SKRAU, Bikaner during Kharif, 2018. The experiment consisted ten treatments viz., T1-Control, T2-Recommended dose of fertilizer, T3-wool waste@ 20 t ha-1 , T4-RDF + wool waste @ 20 t ha-1 , T5-RDF + wool waste @ 20 t ha-1 + 1 per cent FeSO4, T6-RDF + wool waste @ 20 t ha-1 + 1 per cent FeSO4 + 0.5 per cent ZnSO4, T7-STCR recommendation fertilizer dose, T8-STCR recommendation + wool waste @ 20 t ha-1 + 1 per cent FeSO4, T9-STCR recommendation + wool waste @ 20 t ha-1 + 1 per cent FeSO4 and T10-STCR recommendation + wool waste @ 20 t ha-1 + 1 per cent FeSO4 + 0.5 per cent ZnSO4. The experiment was laid out in randomized block design with three replications. Application of recommended dose of fertilizer with wool waste @ 20 t ha-1 and foliar spray of 1 per cent FeSO4 + 0.5 per cent ZnSO4 had significant effect on bottle gourd yield. Significantly higher nitrogen, potassium, sulphur, zinc and iron in fruit and straw was recorded with the application of RDF + wool waste @ 20 t ha-1 + 1 per cent FeSO4 + 0.5 per cent ZnSO4 as compared to control, whereas, phosphorus content was significantly influenced with RDF + wool waste @ 20 t ha-1 + 1 per cent FeSO4. Similarly, application of RDF + wool waste @ 20 t ha-1 + 1 per cent FeSO4 + 0.5 per cent ZnSO4 had significant effect on nutrient uptake by fruit and straw of bottle gourd.
... The ideal way to address the perennial problem of hair waste disposal would be to develop products or systems that utilize human hair as a resource. To date, hair has been used in fertilizer, oil spill remediation, construction material reinforcement, oil filtration, amino acid extraction, textile and fiber stuffing, molded furniture and objects, and heavy metal removal applications (Zheljazkov et al., 2008;Murthy et al., 2004;Gupta, 2008;Gupta, 2014). Additionally, the use of human hair is being researched in areas as diverse as concrete reinforcement (Akhtar and Ahmad, 2009), tissue regeneration (Yoo et al., 2010), biomaterials engineering (Hirao et al., 2005), superconducting system composites (Michael et al., 2010), catalytic nanoparticle platforms (Deng et al., 2016), suturing material (Erog˘lu et al., 2003), and microelectrodes (Xu et al., 2009). ...
Article
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This report focuses on the application of a biodegradable biowaste [human hair-(HHR)], to produce a mild steel corrosion inhibitor. The performance of HHR extract in inhibiting metallic corrosion in 1 mol/L HCl was investigated. The analysis of the metal corrosion behavior using electrochemical and weight loss techniques revealed that HHR exhibits an efficient corrosion-mitigating effect via adsorption on the metal surface following a Langmuir isotherm. Tafel-plot results revealed the mixed-mode corrosion protection behavior of HHR. Surface analysis using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), atomic force microscopy (AFM), and Fourier transform infrared (FT-IR) spectroscopy provided evidence for the precipitation of a protective HHR film on the metal surface.
... Use of hair is often cited in agricultural applications as a fertilizer mainly because of the nitrogen content of hair proteins. Horticultural crops like lettuce and wormwood were studied for application of human hair as a nutrient source fertilizer [12]. Hair waste increased the yield of basil, thorn apple, peppermint, and garden sage by acting as a source of nitrogen nutrient [13]. ...
Article
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Hair waste in large amount is produced in India from temples and saloons, India alone exported approximately 1 million kg of hair in 2010. Incineration and degradation of waste human hair leads to environmental concerns. The hydrothermal process is a conventional method for the production of hair hydrolysate. The hydrothermal process is carried out at a very high temperature and pressure, which causes the degradation of heat-sensitive essential amino acids, thereby depleting the nutritional value. This work deals with alkaline hydrolysis of human hair using acoustic and hydrodynamic cavitation, and comparison with the conventional method. The optimal operating conditions for highest efficiency was observed, for the hydrolysis of 1 g of sample hairs in 100 mL of solution, at 4:1 (KOH: hair) ratio, soaking time of 24 h, the ultrasonic power density of 600 W dm-3 (20 KHz frequency and input power 200 W) or hydrodynamic cavitation inlet pressure of 4 or 7 bars. Cavitation results in rupture of disulfide linkages in proteins and mechanical effects lead to cleavage of several hydrogen bonds breaking the keratin sheet structure in hair. Breakdown of bonds leads to a decrease in viscosity of the solution. 10 % and 6 % reduction in viscosity is obtained at optimal conditions for ultrasonic and hydrodynamic cavitation treatment, respectively. FTIR analysis of produced hair hydrolysate confirmed that the disulfide bonds in hair proteins are broken down during cavitation. The amino acid of hair hydrolysate, prepared using cavitation, has a relatively higher digestibility and nutritional value due to the enhancement of amino-acid content, confirmed using amino acid analysis. Cavitation assisted hair hydrolysate has a potential application in agricultural engineering as a fertilizer for improvement of the quality of the soil and land. Cavitation based hair hydrolysate can also be used as an environmentally friendly and economical source of essential amino acids and digestibles for animal or poultry feed.
... Waste wool have higher content of C and N than the rest used organic manures, so, its disposal in soil for agriculture production may be good option for its use as a fertilizer apart from safe disposal. Sheep wool is made up of keratin (protein) and contains an adequate amount of essential plant nutrients viz., N, C and S (G� orecki and G� orecki, 2010), K, Na, P, Mg, Fe, Mn, and Zn (Zheljazkov et al., 2008) and it can be a more balanced organic fertilizer for plants. ...
Article
Wool is a biodegradable fiber, rich in nutrients and can be recycled in soil as a fertilizer for maximum benefits. The present study was planned with the hypothesis that waste wool could be used as a nutrient source or manure to forage crops and aim of this study was to identify practicable recycling options of sheep based wastes in agriculture. In our study, we have compared the effect of different sheep based organic wastes on soil health, crop productivity and water use. Application of waste wool in soil significantly improved the fertility status of soil, and considerable improvement was also observed in organic carbon and nitrogen, i.e. around 30.8 and 32.6% higher over control. The activities of soil enzymes were 10–30% and 3–20% higher in waste wool treatment as compared to control and sheep based manures, respectively. Application of waste wool not only improved soil health but produced 50% higher grain and dry fodder yield of barley over control. The improvement in physical properties of soil with waste wool resulted in higher water use efficiency of the system. Our study will help in distinguishing choices for safe use of organic wastes along with up gradation of soil health and crop water utilization, particularly in nutrient poor soils of arid and semi-arid region of India.
Article
The potential of human hair extract (HRE), a biodegradable biowaste extract, to protect copper surface and inhibit metallic corrosion in 1 M HCl was investigated using electrochemical and weight loss techniques. The results revealed that HRE exhibits an efficient corrosion-mitigating effect via adsorption onto the metal surface following a Langmuir isotherm. A maximum inhibition efficiency (IE %) of 92.47% was achieved using 100 ppm of the HRE inhibitor. Tafel plot results revealed the mixed-mode corrosion protection behavior of HRE. Surface analysis using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and atomic force microscopy (AFM) provided evidence for the precipitation of a protective HRE film on the metal surface. The interaction of HRE with copper was investigated using Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) spectroscopy; they confirmed the above conclusions.
Article
Human hair natural fiber is mainly considered a waste in our society and its disposal can cause a major environmental impact. Hence, its valorization as a biosorbent of pollutants such as heavy metals is an interesting route to explore since it can reduce the amount of waste and at the same time contributes to the circular economy strategy. In this work, the ability of two kinds of human hairs, used as biosorbents to remove Cr(III), Ni(II), Co(II), Mn(II), Cu(II), Zn(II), Cd(II) and Pb(II) ions from multiple-metal aqueous solutions, were examined and compared under different operating conditions. The influence of the time, pH and initial metal concentration on the metal uptake were studied. The biosorption kinetics and isotherm were also modeled observing that pseudo-second-order kinetic model and Langmuir model fitted successfully experimental data. Moreover, biosorption process did not significantly modify the morphology and the chemical structure of the hair samples, which was proved by SEM and FT-IR studies. These kinetic results underline the satisfactory capacity of human hair for the biosorption of Pb(II), Cu(II) and Cr(II) (values up to 95%), pointing up the high efficacy of human hair for the removal of heavy metal ions from aqueous media.
Article
Hair-silver nanoparticle (Ag NPs) composites were fabricated using a green one- or two-step process through a combination of heat treatment with thermal or UV reduction. In the one-step process, untreated hair was thermally reduced in the range of 250-450℃ after Ag ion adsorption, resulting in a partial oxidation of Ag. In the two-step process, the Ag ions were thermally reduced using heat-treated hair as starting material for the Ag ion adsorption to exclude the partial oxidation of Ag during the formation of hair/Ag NP composites. In an alternative two-step process, hair/Ag NP composites were prepared by reducing the heat-treated hair using UV irradiation. The crystalline structure and oxidation state of the Ag NPs in the hair/Ag NP composites was analyzed via X-ray photoelectron spectrometry (XPS) and X-ray diffractometry (XRD). The results indicate that the two-step process with heat pre-treatment of hair effectively generated pure Ag NPs in the composites. The catalytic activity of the hair/Ag NP composites was investigated with UV-Vis spectrophotometry using the degradation reaction of methylene blue (MB). The hair/Ag NP composites can potentially be applied for the treatment and purification of dye pollutants.
Article
Full-text available
The hypothesis of this work was that uncomposted sheep wool and human hair could be used as nutrient source for nonedible high-value plants. Pot and field experiments were conducted to assess uncomposted sheep wool-wastes and human hair-wastes as a nutrient source for high-value crops and to evaluate the effect of these waste materials on soil microbial community and mycorrhizae. In the pot experiments, addition of uncomposted wool- or hair-waste to soil increased yields from pot marigold (Calendula officinalis L.) and valerian (Valeriana officinalis L.). In the field experiment, wool-waste was added to purple foxglove (Digitalis purpurea L.) at rates of 0, 15.8, and 31.7 t ha(-1). Wool additions to soil increased foxglove yields over the next two seasons by 1.7 to 3.5 times relative to the control. Overall, addition of wool- or hair-waste to soil increased NH(4)-N and NO(3)-N in soil, increased total N (and protein) concentration in plant tissue, and stimulated soil microbial biomass. Scanning electron microscopy (SEM) and energy dispersive x-ray (EDX) analyses indicated that some of wool and hair in soil from the pot and field experiments, after two seasons and several harvests, retained their original structure, a significant concentration of S, some N, and were not fully decomposed. High rates of wool addition to soil in field experiments resulted in shifts in the microbial community composition, while a low rate of wool-waste addition did not affect the microbial community relative to the unamended control. Our results suggest that the addition of uncomposted wool-waste or hair-waste of only 0.33% by weight to soil would support at least 2 to 3 harvests of crops, without the addition of other fertilizers. Uncomposted wool and hair-wastes can be used as a nutrient source for high-value crops.
Article
Marked significant responses in chickpea and wheat growth were observed by the use of differently amended wool-waste compost at 10 t ha−1. The trends in responses were found to be accrued in accordance with respective reduction in C:N ratios of the degraded wool-waste compost. Maximum responses in respect of nodulation and pod formation in chickpea and also in yield of wheat crop were obtained by the application of 10% dung and 2% rock phosphate treated wool-waste compost. Similar trends were recorded with respect to nutrient uptake by crops.
Article
study was conducted to compare and correlate the Mehlich 3 soil extraction method with the Lancaster soil extraction method. This study compared calcium (Ca), magnesium (Mg), potassium (K), and phosphorus (P) concentrations in 422 soil samples from eight fields, which varied greatly in soil type, texture, and fertility. Each soil sample consisted of 10 subsamples collected from 0 to 15 cm deep. Soil fertility was determined using both the Mehlich 3 soil test method and the Lancaster soil test method. Ca, Mg, K, and P extracted by the two methods were compared using linear regression. The Lancaster method consistently extracted higher concentrations of the nutrients than did the Mehlich 3 method for low soil Ca concentrations. As soil Ca increased, differences between the two methods diminished until a point was reached where the methods extracted equal amounts of the nutrients. After this point, the Mehlich 3 methods extracted more of the nutrients than did the Lancaster method. This was attributed to the neutralization of the acidity in the first stage of the Lancaster method. Despite these differences, good correlations were found between the two methods for Ca, Mg, and K, with R-2 for the regression equations ranging from 0.73 to 0.80. However, P levels were not highly correlated (R-2 = 0.39) between the two methods, indicating that estimates of this nutrient determined with one method were not comparable to estimates made with the other.
Article
Channel catfish (Ictalurus punctatus) fillets were treated with hydrogen peroxide (HP), ozonated water (OZ), and ascorbic acid plus salt (AS) or salt solution (BR). All treatments except AS decreased (p 0.05) Aeromonas, while OZ did not decrease Staphylococcus and Acinetobacter. All treatments except 5 ppm OZ reduced (p 0.05) initial TCC and PPC. At 0.7% HP, BR, and 10 ppm OZ fillets showed odor spoilage after 8,10 and 10.5 d, respectively. Fillets treated with HP, OZ, and BR had higher (p 0.05) TBARs than control fillets. HP treated fillets had lower (p 0.05) Hunter ‘L’ values, while BR treated fillets had higher ‘a’ and lower (p 0.05) Hunter ‘L’, ‘b’, and SI values than controls.