Secondary plant essential nutrients accumulation

Chapter 6: Agronomical and Morphological Analysis in Control and

6.4 Secondary plant essential nutrients accumulation

chemical fertilizers to treated water is required or not can be justified generally. The trace metal profile of the water was compared with standard guidelines. It was found that these pH (above 7), Total N%, AVP (ppm) elements must be present high in the hydroponic solutions for crop production (Pais & Jones, 1997). The treated wastewater AD(T1), AA(T2), and control water samples were excellent overall quality.

are supportive in agreement with the report given by Bohnet al. (1985) that the carbonate concentrations would be negligible at pH <9.0 in soil solution.

The field sample collected from control showed variation with the calcium carbonate value ranges between 19.29±0.82 and 20.27±0.10, while the test samples showed 20.34±0.04 and 21.39±0.04. The highest value was observed in the treated control CV1 and treated test sample T2V2 of the surface layer. While the highest value was observed in T2V1 of a test sample of the subsurface layer with the value of 24.46±0.27 ppm, the moderate value, yet the highest value of 21.85±0.07 ppm in the control sample. Accumulation of calcium carbonate in the subsurface layer is the indication of the formation of insoluble calcium carbonate. It may be observed that insoluble carbonate will develop only in sodium content, which correlates with the high EC value.

Calcium (Ca) elements are contained within safe limits as compared to FAO specifications. Calcium consumption of <400 ppm is recommended by the FAO.

According to previous research, high calcium levels are needed for optimal root growth in barley and cotton. To make a comparison between before and after the treated water, field samples of soil from both the test and control were taken and analyzed for estimation of microelements. It was observed that considerable variations were shown in the calcium content of the control and test sample. The Ca values recorded in field samples for wheat cultivation were ranged between 1.39±0.02 and 6.70±0.02 ppm in control Vs 2.30±0.01 ppm and 5.42±0.03 ppm in a treated test sample of the surface layer. The value was highest (6.70±0.02) in groundwater irrigated control CV2 followed by 5.42±0.03 ppm in treated test sample T2V2 of the surface layer.

While the highest value of calcium content was observed in T2V1 with 3.69±0.39 ppm, the moderate value, yet the highest (1.62±0.02 ppm) concentration among groundwater irrigated control CV2 of the subsurface layer. Maybe the indication of mineral absorption of microelements is higher in the subsurface layer than the field sample's surface layer. These samples are regarded as “acceptable” compared to FAO standards.

The high sodium element influences the clay particles' dispersion and swelling and hydraulic conductivity reduction. Both the control and test samples showed pronounced differences in their sodium, calcium, and magnesium content before and after treated samples. The models have a high in sodium content compared to calcium and magnesium. Any marked increase in sodium content did not produce a corresponding influence in the characteristics of soil. The total electrolytes determine the influence of sodium in the soil solution. A higher value of carbonates in soil has shown a high sodium level and a lesser calcium and magnesium level. The highest concentration of sodium was observed in control CV2 with the concentration of 34.04±0.74 ppm while in the treated T2V1 sample with the value of 12.35±0.03 ppm in the surface layer. The subsurface layer showed 8.46±0.06 ppm in the treated T2V1 sample while just 1.05±0.02 ppm in groundwater irrigated control sample CV2. The decrease in sodium concentration may indicate higher sodium ions in the subsurface layer than the surface layer.

168 Table 6.1: Elements accumulation before the treatment of irrigation wastewater treatment using a field experiment system depth for 0-30 cm

CV1 CV2 T1V1 T1V2 T2V1 T2V2

Carbonate 0.00±0.00 0.00±0.00 0.00±0.00 0.00±0.00 0.00±0.00 0.00±0.00

Bicarbonate 2.34±0.03^b 2.25±0.02^a 2.35±0.01^b 2.42±0.01^c 2.34±0.03^b 2.41±0.02^c

Calcium carbonate % 19.29±0.82^a 20.12±0.03^b 20.45±0.45^b 20.66±.12^b 20.72±0.33^b 20.41±0.33^b

Calcium 1.39±0.02^a 1.45±0.01^b 2.30±0.01^c 4.04±0.03^d 2.29±0.03^c 4.03±0.03^d

Magnesium 1.22±0.03^a 1.17±0.02^a 1.88±0.04^b 3.14±0.08^c 1.90±0.02^b 3.10±0.08^c

Sodium 1.09±0.06^a 0.95±0.02^a 1.35±0.02^b 1.90±0.02^c 1.35±0.03^b 1.90±0.03^c

Potassium 0.27±0.03^a 0.74±0.02^b 0.78±0.03^b 1.33±0.02^c 0.78±0.01^b 1.31±0.02^c

Chloride 1.36±0.0b3 0.88±0.02^a 2.32±0.01^c 4.82±0.02^d 2.33±0.02^c 4.83±0.02^d

Sulphate 1.33±0.01^a 1.31±0.01^a 2.11±0.02^b 3.72±0.20^d 2.10±0.01^b 3.60±0.04^c

Iron 3.90±0.06^d 3.26±0.02^b 3.20±0.05^a 3.34±0.07^c 3.20±0.02^a 3.92±0.04^d

Copper 0.07±0.02^b 0.09±0.01^c 0.05±0.02^a 0.08±0.01^b 0.06±0.01^a 0.05±0.02^a

Manganese 0.82±0.04^b 0.95±0.04^c 0.73±0.01^a 0.68±0.02^a 0.73±0.02^a 0.82±0.02^b

Zinc 1.05±0.04^b 1.38±0.02^c 2.05±0.04^d 0.53±0.02^a 2.06±0.02^d 0.44±0.03^a

Data are expressed as mean ± SD for three different samples in each group. Values not sharing a common superscript letter in the same row differ significantly at P < 0.05 (DMRT).

169 Table 6.2: Elements accumulation after the treatment of irrigation wastewater treatment using a field experiment system depth for 0-30 cm

CV1 CV2 T1V1 T1V2 T2V1 T2V2

Carbonate 0.00±0.00 0.00±0.00 0.00±0.00 0.00±0.00 0.00±0.00 0.00±0.00

Bicarbonate 2.70±0.04^a 2.80±0.02^b 3.60±0.01^c 3.00±0.07^a 4.33±0.04^d 5.38±0.03^e

Calcium carbonate % 20.27±0.10^a 20.14±0.01^a 20.60±0.04^a 20.34±0.04^a 21.26±0.13^b 21.39±0.04^b

Calcium 3.42±0.05^c 2.60±0.02^e 5.79±0.02^b 6.70±0.02^a 6.00±0.06^d 5.42±0.03^c

Magnesium 2.31±0.17^d 1.72±0.27^e 4.76±0.02^b 5.76±0.05^a 4.29±0.16^d 3.92±0.05^c

Sodium 4.32±.18^c 3.46±0.74^d 29.44±0.15^a 34.04±0.18^a 12.35±0.03^b 11.42±0.02^b

Potassium 1.36±0.07^b 1.07±0.02^c 1.35±0.03^b 2.02±0.02^a 3.11±0.06^d 4.05±0.04^e

Chloride 7.63±0.06^f 5.83±0.02^e 27.06±0.01^b 23.96±0.01^a 14.73±0.07^c 15.30±0.08^d

Sulphate 2.81±0.02^d 2.51±0.02^c 2.42±0.02^c 1.65±0.02^b 0.83±0.02^a 1.03±0.02^a

Iron 3.95±0.05^c 3.18±0.06^c 5.15±0.04^b 6.22±0.02^a 17.51±0.36^e 10.39±0.43^d

Copper 0.09±0.01^a 0.11±0.01^b 0.08±0.01^a 0.09±0.01^a 0.12±0.02^b 0.14±0.02^b

Manganese 0.94±0.01^c 0.78±0.01^c 1.20±0.01^b 1.36±0.02^a 1.62±0.02^d 1.96±0.02^d

Zinc 1.04±0.04^c 0.56±0.02^e 0.58±0.03^a 5.32±0.02^a 2.33±0.02^d 0.97±0.02^b

Data are expressed as mean ± SD for three different samples in each group. Values not sharing a common superscript letter in the same row differ significantly at P < 0.05 (DMRT).

Potassium is the most widely absorbed among many elements, and its role has already been established beyond doubt. Excess concentrations of potassium are not hazardous in soil. With the analysis of potassium content, it was found that the use of treated wastewater for irrigation increased the accumulation of potassium content compared to the level of potassium content in the control sample before the supply of groundwater or wastewater in soil. The recorded highest values of field samples concerning potassium concentrations were 4.05±0.04 ppm or (405 µg/100 mL) and2.02±0.02 ppm (202 µg/100 mL) in T2V2 and control CV2, respectively. The suggested concentration of potassium in the control sample ranges between 0 – 2 mg L-1 while the value should be below 30 mg L-1 in treated water (Pescod, 1992; Ayers

& Westcot, 1985). The subsurface layer showed 1.61±0.02 ppm in the treated T2V2 sample while 0.31±0.01 ppm in groundwater irrigated control sample CV2. The decrease in potassium concentration may indicate higher potassium ions in the subsurface layer than the surface layer. The results are regarded as “acceptable”

according to the FAO standards.

Chloride in high concentrations can damage plants by inhibiting potassium absorption (Silberbush et al., 2005). The permissible chloride levels in treated irrigation water were less than <30 mg/L. The use of treated wastewater in the test sample substantially accumulated high chloride residues after the field application in soil compared to the water before application. The recorded most elevated values of groundwater irrigated control CV1 and wastewater treated test sample T2V2 concerning chloride concentrations were 27.06±0.06 ppm or (2700 µg/100 mL) and 15.30±0.08 ppm (1530 µg/100 mL) in CV1 and T2V2, respectively. Compared with the surface layer, the sub-surface layer showed the highest chloride concentration was

observed in treated T2V1 samples with ppm' value. 11.36±0.39 ppm while the irrigated control had just 1.13±0.12 ppm. The importance of T2V2 had moderate chloride (9.36±0.04) content in the sub-surface layer compared to the highest value of 15.30±0.08 ppm in the surface layer. The increased amount of chloride present in the field sample's surface layer and its comparison with the less amount in the subsurface layer indicated the root system's highest chloride absorption rate. The values are regarded as “acceptable” according to the FAO standards (3000 µg/100 mL).

The accumulation of higher concentrations of sulphate in T1V2 was 3.72±0.20 ppm compared with the groundwater irrigated control CV1 (2.81±0.02 ppm) of surface soil justifies the efficiency of treated wastewater for crop production. Compared with the subsurface layer, the sulphate value in T1V1 was 0.83±0.02 ppm while 1.39±0.04 in control CV1. The subsurface layer had the highest sulphate concentration recorded in T2V2 with the value of 7.12±0.02 ppm, while it was 1.43±0.02 in control CV1. The results of sulphate showed a pronounced decrease in the subsurface layer compared with the surface layer.

The field sample collected from control showed variation in the iron value ranges between 3.90±0.06 ppm and 6.22±0.06 ppm, while the test samples showed 3.18±0.02 and 17.51±0.36 ppm. The highest value was observed in the irrigated control CV2 and treated test sample T2V1 of the surface layer. While the highest value was observed in T2V1 of the subsurface layer's test sample with the value of 16.42±0.12 ppm, the moderate value, yet the highest value of 4.81±0.03 ppm in the control sample.

Depletion of iron in the subsurface layer may indicate heavy uptake of iron content by the root system. The highest copper (Cu) and Manganese (Mn) values were recorded in treated T2V2 field samples compared with their most elevated Cu, and Mn values of

groundwater treated control CV2 of the surface layer. The results showed a pronounced decrease in their Cu and Mn values in sub-surface field samples compared to the surface layer's Cu and Mn values. While the decreased rate of these two elements was observed in the groundwater irrigated control CV2 and in the treated test sample T2V2 of the surface layer. The field sample collected from control showed variation in the zinc content. The value ranges between 1.04±0.04 ppm and 5.32±0.02 ppm, while the test samples showed 0.44±0.03 and 2.33±0.02 ppm.

The highest value was observed in the groundwater irrigated control CV2 and treated test sample T2V1 of the surface layer. While the highest value was observed in T2V1 of the test sample of the subsurface layer with the value of 0.55±0.02 mg/Kg, the moderate value, yet the highest value of 1.02±0.01 mg/Kg in the control sample.

Depletion of zinc in the subsurface layer may indicate maximum intake of zinc in the root system.