Introduction

Molasses (one of the important byproducts of sugar industry) is the chief source for the production of alcohol in distilleries. About eight (08) liters of wastewater is generated for every liter of ethanol production in distilleries known as Raw Spent Wash (RSW), which is characterized by foul odor, undesirable color, high biological oxygen demand (BOD: 5000-8000mg/L) and chemical oxygen demand (COD: 25000-30000mg/L)9. Raw Spent Wash is normally discharged into open land or near by water bodies resulting in number of environmental problems including threat to plant and animal lives. The RSW is highly acidic, containing easily oxidisable organic matter with very high BOD and COD13. Distillery spentwash contains highest content of organic nitrogen and nutrients16. By installing bio-methenation plant in distilleries, reduces the oxygen demand of RSW. The resulting spentwash obtained is called Primary Treated Spent Wash (PTSW) and primary treatment to RSW increases the nitrogen (N), potassium (K), and phosphorous (P) contents and decreases the calcium (Ca), magnesium (Mg), sodium (Na), chloride (Cl-), and sulphate (SO42-)12. The PTSW is rich in potassium (K), sulphur (S), nitrogen (N), phosphorous (P) as well as easily biodegradable organic matter and its application to soil has been reported to be beneficial to increase sugar cane26, rice6, wheat, rice yield14, groundnut quality23 and physiological response of soybean17. Diluted distillery spentwash could be used for irrigation purpose without adversely affecting soil fertility8101118 seed germination and crop productivity19. The diluted effluent irrigation improved the physical and chemical properties of the soil and further increased soil microflora7810. Twelve pre sowing irrigations with the diluted distillery spentwash had no adverse effect on the germination of maize but improved the growth and yield22. Diluted distillery spentwash increases the growth of peas found that shoot length, leaf number per plant, leaf area and chlorophyll content20. Higher concentration of distillery spentwash causes decreased seed germination, seedling growth, chlorophyll content in sunflowers (Helianthus annuus) and the distillery spentwash could safely used for irrigation purpose at low concentration1921. The distillery spentwash contained an excess of various forms of cations and anions, which are injurious to plant growth. The concentration of these constituents should be reduced to beneficial level by diluting the spentwash, which can be used as a substitute for chemical fertilizer24. The distillery spentwash could be used as a complement to mineral fertilizer to sugarcane2. The distillery spentwash contained N, P, K, Ca, Mg and S and thus valued as a fertilizer when applied to soil through irrigation water25. The application of diluted distillery spentwash increased the uptake of Zinc (Zn), Copper (Cu), Iron (Fe) and Manganese (Mn) in maize and wheat as compared to control and the highest total uptake of these were found at lower dilution levels than at higher dilution levels15. Mineralizations of organic material as well as nutrients present in the distillery effluent were responsible for increased availability of plant nutrients. The diluted distillery spentwash increase the uptake of nutrients of some top vegetables, nutrients of Cabbage and Mint leaf3, nutrients of Top vegetable1, Pulses, Condiments and Root vegetables4, nutrients of pulses in untreated and treated soil5. However, not much information is available on the impact of distillery spentwash on the nutrients, growth and yield of leafy vegetables. Therefore the present investigation is carried out to study the impact of different concentration of distillery spentwash irrigation on growth, yield and nutrients of leafy vegetables.

Materials and Methods

Before initiation of the experiment, a composite soil sample was collected from the experimental site at 25 cm depth. The soil sample was air dried, powdered and analyzed for physico-chemical properties using standard procedures (Table 1). 50% and 33% PTSW were used for the irrigation of leafy vegetables. The PTSW, 50% and 33% spent wash were collected from Chamundi Distilleries Pvt. Ltd. Maliyur, Mysore District. The physical and chemical parameters and amount of nitrogen (N), potassium (K), phosphorous (P) and sulphur (S) were analyzed using standard procedures (Tables 2 and 3). The leafy vegetables selected for the field experiment were Amaranth (Amaranthus gangeticus), Coriander leaves (Coriandum sativum), Fenugreek (Trigonella foenum graceum), Shepu (Peucedanum graveolens) and Spinach (Spinacia oleracea). The leafy vegetable seeds were sowed in the prepared block field and irrigated with raw water (RW), 50% and 33% distillery spentwash at the dosage of twice in a week and rest of the period with RW. The leafy vegetable plants were harvested at the time of maturity and proximate principles, vitamins, minerals and trace elements present in the plants were analyzed (Tables 4-8) and the extent of growth and thickness of leaf, stem and yield were recorded (Tables 9-13).

Results and Discussion

Table 1 shows the characteristics of experimental soil i.e., pH, electrical conductivity, amount of organic carbon, available nitrogen (N), phosphorous (P), potassium (K), sulphur (S) exchangeable calcium (Ca), magnesium (Mg), sodium (Na), DTPA iron (Fe), manganese (Mn), copper (Cu) and zinc (Zn).

Table 1.

Physico- Chemical Properties of the Soil.
Parameters a -%; b- µS;c- ppm
Coarse sanda 10.94
Fine sanda 42.86
Slita 26.32
Claya 19.88
pH value (1:2 solution) 8.15
Electrical conductivityb 451.0
Organic carbona 0.93
Available Nitrogenc 460.0
Available Phosphorousc 180.0
Available Potassiumc 65.0
Exchangeable Calciumc 150.0
Exchangeable Magnesiumc 190.0
Exchangeable Sodiumc 180.0
Available Sulphurc 230.0
DTPA Ironc 240.0
DTPA Manganesec 260.0
DTPA Copperc 8.00
DTPA Zincc 65.0

Table 2 shows the chemical composition of PTSW, 50% SW and 33% SW i.e., pH value, electrical conductivity, total solids (TS), total dissolved solids (TDS), total suspended solids (TSS), settelable solids (SS), chemical oxygen demand (COD), biological oxygen demand (BOD), carbonates, bicarbonates, total phosphorous (P), total potassium (K), ammonical nitrogen (N), calcium (Ca), magnesium (Mg), sulphur (S), sodium (Na), chlorides (Cl), iron (Fe), manganese (Mn), zinc (Zn), copper (Cu), cadmium (Cd), lead (Pb), chromium (Cr) and nickel (Ni) and also indicating the changes in parameters of PTSW, 50%SW and 33%SW.

Table 2:

Chemical composition of the distillery spentwash.
Chemicalparameters PTSW 50% PTSW 33% PTSW
pH 7.65 7.73 7.75
Electricalconductivitya 28800 19660 10020
Total solidsb 46140 26170 20870
Total dissolved solidsb 35160 16060 10140
Total suspended solidsb 10540 5680 4380
Settleable solidsb 10070 4340 3010
CODb 40530 18316 10228
BODb 16200 7818 4800
Carbonateb Nil Nil Nil
Bicarbonateb 13100 7400 4200
Total Phosphorousb 30.26 12.20 6.79
Total Potassiumb 7200 3700 2400
Calciumb 940 600.0 380.0
Magnesiumb 1652.16 884.16 542.22
Sulphurb 74.8 35.0 22.6
Sodiumb 480 260 240
Chloridesb 5964 3272 3164
Ironb 9.2 6.40 5.20
Manganeseb 1424 724 368
Zincb 1.28 0.72 0.41
Copperb 0.276 0.134 0.074
Cadmiumb 0.039 0.021 0.010
Leadb 0.16 0.09 0.06
Chromiumb 0.066 0.032 0.014
Nickelb 0.165 0.084 0.040
AmmonicalNitrogenb 743.68 345.24 276.64

PTSW - Primary treated spentwash; a- µS; b- mg/L

Table 3 shows the amount of N, P, K and S content in PTSW, 50%SW and 33%SW.

Table 3.

Amount of N, P, K and S (nutrients) in distillery spentwash.
Chemical parameters PTSW 50% PTSW 33% PTSW
Ammonical Nitrogen 743.68 345.24 276.64
Total Phosphorous 30.26 12.20 6.79
Total Potassium 7200 3700 2400
Sulphur 74.8 35.0 22.6

PTSW - Primary treated spentwash ; a- mg/L

Table 4 indicates the impact of distillery spentwash on the nutrients of Amaranth (Amaranthus gangeticus) leafy vegetable. It was found that the increased uptake of all parameters except calcium in the case of both 50% and 33% spentwash as compared to raw water. There was no impact of heavy metals like lead, cadmium and nickel on Amaranth leafy vegetable. However remarkable uptake of all the nutrients in the case of 33% spentwash was noticed.

Table 4.

Nutrienrs of Amaranth (Amaranthus gangeticus) at different irrigations.
Parameters RW 50%PTSW 33%PTSW
Moisturea 85.9 86.4 86.9
Fata 0.2 0.3 0.35
Acid insoluble Asha 0.05 0.04 0.04
Proteina 3.9 4.2 4.5
Fibrea 0.8 1.2 1.25
Carbohydratea 5.4 5.6 6.0
Energyb 42 48 50
Calciumc 380 375 400
Magnesiumc 110 115 120
Sodiumc 200 240 250
Potassiumc 320 335 340
Ironc 3.0 3.1 3.2
Phosphorousc 75 79 84
Zincc 0.12 0.15 0.16
Manganesec 0.25 0.3 0.35
Copperc 0.04 0.06 0.066
Chloridesc 70 75 84
Leadc Nil Nil Nil
Cadmiumc Nil Nil Nil
Chromiumc 0.006 0.007 0.007
Nickelc Nil Nil Nil
Sulphurc 40 45 62
Carotened 5200 5250 5255
Vitamin-Cc 80 82 85

RW - Raw water; PTSW- Primary treated spentwash a- g; b-k.cal; c- mg; d- µg

Table 5 gives the impact of distillery spentwash on the nutrients of Coriander (Coriandum sativum) leafy vegetable. There was no negative impact of spent wash on the nutrients of Coriander leafy vegetable and heavy metals like lead, cadmium and nickel. Very good uptake of all the parameters in both 50% and 33% spentwash was observed as compared to raw water, but all the parameters are very good in 33% distillery spentwash.

Table 5.

Nutrients of Coriander leaves (Coriandum sativum) at different irrigations.
Parameters RW 50%PTSW 33%PTSW
Moisturea 86.4 86.8 87.1
Fata 0.5 0.7 0.7
Acid insoluble Asha 0.32 0.35 0.39
Proteina 3.5 3.7 3.8
Fibrea 1.5 1.8 1.85
Carbohydratea 5.4 5.6 5.9
Energyb 38 40 43
Calciumc 190 196 199
Magnesiumc 25 28 29
Sodiumc 52 60 64
Potassiumc 280 285 290
Ironc 1.3 1.5 1.52
Phosphorousc 60 68 70.5
Zincc 0.25 0.30 0.32
Manganesec 0.40 0.42 0.44
Copperc 0.08 0.10 0.12
Chloridesc 35 40 42
Leadc Nil Nil Nil
Cadmiumc Nil Nil Nil
Chromiumc 0.006 0.016 0.017
Nickelc Nil Nil Nil
Sulphurc 25 35 37
Carotened 6210 6250 6255
Vitamin-Cc 120 125 128

RW - Raw water; PTSW- Primary treated spentwash a- g; b-k.cal; c- mg; d- µg

Table 6 shows the impact of distillery spentwash on the nutrients of Fenugreek (Trigonella foenum graceum) leafy vegetable. Both 50% and 33% spentwash results good nutrients uptake as compared to raw water. However uptakes of all the nutrients are considerably good in the case of 33% than 50% spentwash and raw water irrigations.

Table 6.

Nutrients of Fenugreek (Trigonella foenum graceum) at different irrigations.
Parameters RW 50%PTSW 33%PTSW
Moisturea 86.2 86.4 86.6
Fata 0.4 0.6 0.6
Acid insoluble Asha 0.03 0.03 0.03
Proteina 4.0 4.8 4.9
Fibrea 0.8 0.9 0.98
Carbohydratea 5.1 5.4 6.0
Energyb 40 42 45
Calciumc 380 390 400
Magnesiumc 20 24 30
Sodiumc 60 62 75
Potassiumc 20 22 25
Ironc 1.4 1.8 1.85
Phosphorousc 40 45 50
Zincc 0.25 0.29 0.30
Manganesec 0.15 0.18 0.20
Copperc 0.08 0.1 0.16
Chloridesc 140 145 150
Leadc Nil Nil Nil
Cadmiumc Nil Nil Nil
Chromiumc 0.006 0.016 0.017
Nickelc Nil Nil Nil
Sulphurc 150 160 166
Carotened 2420 2500 2550
Vitamin-Cc 40 45 50

RW - Raw water; PTSW- Primary treated spentwash; a- g; b-k.cal; c- mg; d- µg

Table 7 indicates the impact of distillery spentwash on the nutrients of Shepu (Peucedanum graveolens) leafy vegetable. Very poor intake of the nutrients like calcium, magnesium, sodium, potassium and iron in the case of 50% distillery spentwash as compared to raw water and 33% distillery spentwash. But very good intake of carotene and vitamin-C in both the cases of spentwash irrigation were observed than raw water. In Shepu leafy vegetable, all the nutrients are very good in the case of 33% spentwash than 50% spentwash and raw water irrigation.

Table 7.

Nutrients of Shepu (Peucedanum graveolens) at different irrigations.
Parameters RW 50%PTSW 33%PTSW
Moisturea 88.2 88.5 88.8
Fata 0.3 0.2 0.3
Acid insoluble Asha 0.02 0.03 0.03
Proteina 4.0 4.2 4.8
Fibrea 1.2 1.4 1.47
Carbohydratea 4.9 5.5 5.8
Energyb 38 45 50
Calciumc 340 330 370
Magnesiumc 105 90 110
Sodiumc 180 170 183
Potassiumc 280 270 300
Ironc 25 22 28
Phosphorousc 40 45 60
Zincc 0.10 0.12 0.15
Manganesec 0.2 0.3 0.35
Copperc 0.02 0.02 0.03
Chloridesc 60 62 65
Leadc Nil Nil Nil
Cadmiumc Nil Nil Nil
Chromiumc Nil Nil Nil
Nickelc Nil Nil Nil
Sulphurc 48 55 58
Carotened 1300 1380 1400
Vitamin-Cc 80 85 90

RW - Raw water; PTSW- Primary treated spentwash; a- g; b-k.cal; c- mg; d- µg

According to Table 8, in the case of Spinach (Spinacia oleracea) leafy vegetable, the intake of the parameters such as protein, fibre content, carbohydrate and energy are similar in raw water and 50% spentwash and the nutrients such as calcium, magnesium, sodium, potassium, iron, phosphorous, copper, carotene and vitamin-C uptake were very poor in the case of 50% spentwash as compared to raw water and 33% spentwash. However intakes of all the parameters are very good in the case of 33% spentwash than 50% spentwash and raw water irrigation.

Table 8.

Nutrients of Spinach (Spinacia oleracea) at different irrigations.
Parameters RW 50%PTSW 33%PTSW
Moisturea 93.5 93.7 93.8
Fata 0.4 0.4 0.5
Acid insoluble Asha 0.35 0.32 0.34
Proteina 1.8 1.8 2.0
Fibrea 0.2 0.2 0.26
Carbohydratea 2.3 2.2 2.4
Energyb 20 20 22
Calciumc 65 62 66
Magnesiumc 65 60 65
Sodiumc 52 50 55
Potassiumc 185 180 195
Ironc 1.0 0.9 1.02
Phosphorousc 16 15 18
Zincc 0.25 0.25 0.30
Manganesec 0.40 0.40 0.49
Copperc 0.09 0.08 0.10
Chloridesc 45 40 45
Leadc Nil Nil Nil
Cadmiumc Nil Nil Nil
Chromiumc 0.001 0.004 0.004
Nickelc Nil Nil Nil
Sulphurc 25 25 32
Carotened 5300 5200 5400
Vitamin-Cc 25 22 26

RW - Raw water; PTSW- Primary treated spentwash; a- g; b-k.cal; c- mg; d- µg

The growth rate of the Amaranth plants (Table 9) and Shepu plants (Table 10) i.e., thickness of the stem, height of the plants at 8th day, 18th day, 25th day and at the time of harvest and yield of the plants at the time of harvest were recorded. It was observed that the potential growth of plants i.e., stem thickness, height and yield are in the order, 33% SW > 50% SW > RW irrigation.

Table 9.

Thickness of stem, height and weight of Amaranth (Amaranth gangeticus).
Observations Thickness of stem Height of the plant
RW 50%PTSW 33%PTSW RW 50%PTSW 33%PTSW
8th day 1.2mm 1.8mm 2.0Mm 1.9cm 2.2cm 3.0cm
18th day 2.4mm 2.82mm 3.62Mm 22.0cm 23.5cm 30.0cm
25th day 3.1mm 3.92mm 4.24Mm 28.0cm 30.0cm 37.0cm
At Harvest 4.10mm 4.94mm 5.62Mm 34.0cm 38.6cm 42.0cm
Weight of 50 Nos. of plants bundle with root 0.145 kg 0.220 kg 0.290 kg — — —
Weight of edible portion of 50 Nos. of plants bundle 0.075 kg 0.110kg 0.150kg — — —

Table 10.

Thickness of stem, height and weight of Shepu leaves (Peucedanum graveolens).
Observations Thickness of stem Height of the plant
RW 50%PTSW 33%PTSW RW 50%PTSW 33%PTSW
8th day 0.6mm 0.9mm 1.24mm 1.5cm 2.0cm 2.2cm
18th day 1.5mm 2.1mm 3.02mm 10.0cm 12.0cm 15.0cm
25th day 2.0mm 2.62mm 3.82mm 16.0cm 19.0cm 25.0cm
At Harvest 2.72mm 3.10mm 3.92mm 23.0cm 25.0cm 30.0cm
Weight of 50 Nos. of plants bundle with root 0 .050 kg 0.095kg 0.110kg — — —
Weight of edible portion of 50 Nos. of plants bundle 0.035 kg 0.075kg 0.090kg — — —

The growth rate of the Coriander plants (Table 11), Fenugreek plants (Table 12) and Spinach plants (Table 13) i.e., thickness of the leaf, height of the plants at 8th day, 18th day, 25th day and at the time of harvest and yield of the plants at the time of harvest were recorded. It was observed that the potential growth of plants i.e., leaf thickness, height and yield are in the order, 33% SW > 50% SW > RW irrigation.

Table 11.

Thickness of leaf, height and weight of Coriander (Coriandum sativum).
Observations Thickness of leaf Height of the plant
RW 50%PTSW 33%PTSW RW 50%PTSW 33%PTSW
8th day 0.01mm 0.02mm 0.03mm 2.0cm 2.5cm 3.0cm
18th day 0.03mm 0.06mm 0.08mm 8.0cm 9.0cm 10.0cm
25th day 0.04mm 0.07mm 0.09mm 11.0cm 12.0cm 19.0cm
At Harvest 0.06mm 0.1mm 0.12mm 13.0cm 14.5cm 25.0cm
Weight of 50 Nos. of plants bundle with root 0.045 kg 0.050 kg 70.00 kg — — —
Weight of edible portion of 50 Nos. of plants bundle 0.040kg 0.040kg 0.060 kg — — —

RW - Raw water; PTSW- Primary treated spentwash

Table 12.

Thickness of leaf, height and weight of Fenugreek (Trigonella foenum graceum).
Observations Thickness of leaf Height of the plant
RW 50%PTSW 33%PTSW RW 50%PTSW 33%PTSW
8th day 0.2mm 0.3mm 0.45mm 2.5cm 4.0cm 5.0cm
18th day 0.7mm 0.8mm 1.0mm 20.0cm 25.0cm 29.0cm
25th day 1.0mm 1.09mm 1.2mm 26.0cm 33.0cm 37.0cm
At Harvest 1.28mm 1.39mm 1.65mm 31.0cm 36.0cm 39.0cm
Weight of 50 Nos. of plants bundle with root 0.080 kg 0.115kg 0.125kg — — —
Weight of edible portion of 50 Nos. of plants bundle 0.045 kg 0.070 kg 0.085kg — — —

RW - Raw water; PTSW- Primary treated spentwash

Table 13.

Thickness of leaf, height and weight of Spinach (Spinacia oleracea).
Observations Thickness of leaf Height of the plant
RW 50%PTSW 33%PTSW RW 50%PTSW 33%PTSW
8th day 0.08Mm 0.1Mm 0.14mm 4.0Cm 5.5cm 6.3cm
18th day 0.31Mm 0.34mm 0.39mm 14.0Cm 15.0cm 17.0cm
25th day 0.52Mm 0.55mm 0.58mm 23.0Cm 24.0cm 27.0cm
At Harvest 0.60Mm 0.64mm 0.68mm 24.0Cm 27.0cm 30.0cm
Weight of 50 Nos. of plants bundle with root 0.170 kg 0.180 kg 0.330kg — — —
Weight of edible portion of 50 Nos. of plants bundle 0.120 kg 0.150 kg 0.250kg — — —

RW - Raw water; PTSW- Primary treated spentwash

Conclusion

Irrigation with 33% and 50% distillery spentwash and raw water for leafy vegetables, it concludes that, the uptake of all nutrients are very good in both 50% and 33% spentwash except in the case of Shepu and Spinach as compared to raw water. There was a good response in the improvement of nutrients in cultivation of all types of leafy vegetables in 33% spentwash than 50% spentwash and raw water irrigation. The growth and yield of all leafy vegetables are highly potential in 33% spentwash irrigation than compared to 50% spentwash and RW. 33% spentwash irrigation favours the effective absorption of N, P, K resulting the efficient growth, yield and nutrients in leafy vegetables. As a result no external fertilizers required for the cultivation. This saves the cost of cultivation and increase the profit by adopting spentwash irrigation.