Lettuce irrigation with wastewater from pistachios processing - - PowerPoint PPT Presentation

Lettuce irrigation with wastewater from pistachios processing Efgect on soil properties

• P. Kostopoulos1, A. Papadopoulos1,

Y . Troyanos1, Ch. Kolovos1, S. Kosmidis1, M. Psychogiou2, M.K.Doula1

1Benaki Phytopathological

Institute

2Agricultural University of Athens,

Cyprus 2016, Saturday, 25 June

Dehulling pistachio waste

Management practices: ■ Disposal in evaporation ponds ■ Disposal on soils and on water recipients

So far little is known regarding the fate of pistachio’s waste in Greece and in

• ther

Mediterranean countries. It is known, however, that, on average, 2m3/h of water are required for dehulling 1tn fresh nuts, while the processing of 1tn of pistachios produces almost 2.5tn of sludge, which consists of hulls, nuts and water.

Wastewater from pistachios dehulling

Parameters Value Electrical Conductivity (mS/cm) 6,4 (6,08) pH 5,22 Polyphenols, g L -1 5,5 COD g L -1 12 ΝΗ4

+ mg L-1

9,0 ΝΟ3

• mg L-1

102 Potassium g L -1 1,0 Calcium (%) (w/v) 0,03 Magnesium (%) (w/v) 0,01 Sodium mg L-1 180 PO4

3- mg L-1

91 Iron mg L-1 0,51 Copper mg L-1 0,13 Zinc, mg L-1 1,39 Mangannese, mg L-1 0,68 Boron, mg L-1 5,5 Chloride, mg L-1 1000 (2122)

Parameters Value Normal values T exture Sandy Loam Medium coarse Electrical Conductivity (μS/cm) 1250 < 2000 pH 7,39 6,1-7,8 Organic Matter (%) 5,6 > 2,0 T

• tal Nitrogen (mg/g)

3,4 > 1,5 CaCO3 (%) 28 0,2-5,0 Exchangeable K (cmoℓ+/kg) 0,80 0,3-1,2 Exchangeable Ca (cmoℓ+/kg) 30 Exchangeable Mg (cmoℓ+/kg) 1,8 0,4-1,5 Available P (mgP/kg) 33 5-20 Available Fe (mg/kg) 8,9 12-50 Available Cu (mg/kg) 1,3 0,9-3,0 Available Zn (mg/kg) 18 3,0-8,0 Available Mn (mg/kg) 4,4 15-50

Soil used for the experiment

The 10 weeks greenhouse experiment

Lettuce seedings were irrigated with 5 wastewater/water ratios treatments 1:10, 1:6, 1:2, No dilution and fresh water Each treatment 5 replicates in a Latin square experimental design Plants were irrigated twice a week by adding 100ml of liquid while leachates were collected at a weekly basis.

Leachates were further analyzed for electrical conductivity, pH, NO3

• , Cl-,

Na, K, polyphenols, Cu, Zn, Mn, and Fe. After experiment completion, the substrates were collected and analyzed for pH, EC, OM, polyphenols, total N, available P, exchangeable cations (K, Na, Ca, Mg), B, and available metals in order to assess potential impacts on soil properties after Leachates were further analyzed for electrical conductivity, pH, NO3

• , Cl-,

Na, K, polyphenols, Cu, Zn, Mn, and Fe. After experiment completion, the substrates were collected and analyzed for pH, EC, OM, polyphenols, total N, available P, exchangeable cations (K, Na, Ca, Mg), B, and available metals in order to assess potential impacts on soil properties after harvesting.

The experiment lasted 10

• weeks. During the 5th week

the plants were fertilized with KNO3 (13-0-46) by adding 6,2 g per pot

The effect of dilution was recorded in yield parameters.

Some important fjndings

Polyphenols in leachates Potassium in leachates Chlorides in leachates

mg/l mg/l mg/l weeks weeks weeks

And more….

weeks

Leachates’ Electrical Conductivity

mS/cm

Μ 1/10 1/6 1/2 F

1000 2000 3000 4000 5000 6000 7000 8000 9000

Soils Electrical Conductivity after the end of the experiment Treatments E C (μ S /c m )

Μ 1/10 1/6 1/2 F

2,6 2,65 2,7 2,75 2,8 2,85 2,9 2,95 3 3,05 3,1

Total Nitrogen in soils after the end of the experiment Treatments T

• tal Nitrogen (m

g/g)

Μ 1/10 1/6 1/2 F

2 4 6 8 10 12 14 16 18

Available Phosphorus in soils after the end of the experiment Treatments A v . P h

• s

p h

• r

u s ( m g / k g )

Μ 1/10 1/6 1/2 F

1 2 3 4 5 6 7 8 9 10

Exchangeable Potassium in soils after the end of the experiment Treatments E x c h . P

• t

a s s iu m ( c m

• l/

k g )

Μ 1/10 1/6 1/2 F

1 2 3 4 5 6 7

Soil Organic Matter after the end of the experiment T reatments Organic m atter (%)

Μ 1/10 1/6 1/2 F

0,5 1 1,5 2 2,5 3 3,5

Exchangeable Magnesium in soils after the end of the experiment Treatments E x c h . M g ( c m

• l/

k g ) Μ 1/10 1/6 1/2 F

0,00 10,00 20,00 30,00 40,00 50,00 60,00 70,00 80,00

Polyphenols in soils after the end of the experiment Treatments Polyphenols (mg/kg)

Considering soil parameters after experimentation and also soil quality thresholds (Doula et al., 2013), it can be proposed that the use of pistachio wastewater for irrigation after 1:10 (and also 1:6 after specifjc preconditions) could provide the anticipated and well known advantages

• f

wastewater reusing

• n

soils, while at the same time protects soils from overloading with salts and nutrients.

BUT…

…the obtained yield suggests 1:10 dilution as the optimum one…

MΑΡΤΥΡΑΣ 1/10 1/6 1/2 ΠΥΚΝΟ 10 20 30 40 50 60 70 80

Change in fresh weight of lettuce

T reatments Fresh weight (g)

14 % 29 % 53 % 73 % …still we are happy…

…for 10 weeks …

• We irrigated 20 times each

lettuce

• 2lt waste/water added to

each lettuce

• 200ml waste to each lettuce

and 10 lt waste for 50 lettuces

…and in Greece we produce almost 125.000.000 lettuces/y

Fresh water. 1:10. 1:6. 1:2 Waste.

Thank you for your attention

• Dr. Maria K. Doula

Benaki Phytopathological Institute Greece

… abou t soil

A B Γ E Z K N Ξ Ο Π Σ Τ Y

2 4 6 8 10 12 14

Under tree canopy 60-90cm E le c tr ic a l C o n d u c tiv ity., m

A E Z P Σ Y 2 4 6 8 10 12

Waste on soil 60-90cm

…

abou t soil

A B Γ E Z K N Ξ Ο Π Σ Τ Y

2 4 6 8 10 12

Under tree canopy 30-60cm E le c tr ic a l C o n d u c tiv ity, m

A E Z P Σ Y 2 4 6 8 10 12

Waste on soil 30-60cm