Keywords
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| Wastewater, Phosphorus, Lens culinaris, Yield |
INTRODUCTION
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| Inorganic fertilizers are essential for the cultivation of crops, as without them, the plants cannot grow and develop up to their full potential. However, excessive use of inorganic fertilizers is an important source of pollution as their nutrients run off the land due to heavy rainfall or leached through the soil reaching to the ground water. On the other hand their long term presence in soil also leads to acidification. Large quantities of wastewater are being produced by exponentially increasing population, urbanization and industrialization thereby causing a serious threat to the environment. Therefore, use of wastewater in agriculture is gaining importance now a days because of its value as a potential irrigant and a nutrients donor as confirmed by the finding of Aziz et al. (1994, 1995), Pradhan et al. (2001), Akhtar et al. (2006). Thus this practice can make it possible to conserve the limited water resources and also to prevent pollution of water bodies. Keeping these points in mind, an attempt was made to use the wastewater collected from a city wastewater drain situated along the Aligarh-Mathura road, commonly in use for irrigation of various agricultural crops, for the cultivation of leguminous crop. |
MATERIALS AND METHODS
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| A pot experiment was conducted during the rabi season of 2002-2003 in the net house of the Department of Botany, Aligarh Muslim University, Aligarh, to study the effect of city wastewater on lentil (Lens culinaris) cv. DLP-15. 10” size earthen pots were filled with 5 kg soil containing soil and farmyard manure in 3:1 ratio. Seeds were sown @ of 10 seeds potâÃâ¬Ãâ1 and after germination, the seedlings were limited to maintain one plant potâÃâ¬Ãâ1. Each pot has 3 replications. The crop was grown under two different concentrations of city wastewater, which was mixture of sewage and household water plus industrial effluents i.e. 50%WW and 100%WW and tap water which was used as ground water (GW), applied at alternate day @ 250 ml potâÃâ¬Ãâ1. In addition to this crop was supplied with four levels of phosphorus i.e. P0, P10, P20 and P40 along with 20 kg N haâÃâ¬Ãâ1 and 30 kg K haâÃâ¬Ãâ1 applied basally one day before sowing to avoid seed injury. The source of nitrogen, phosphorus and potassium were supplied on the form of commercial grade urea, single super phosphate and muriate of potash respectively. The parameters observed were plant fresh weight, plant dry weight, nodule number plantâÃâ¬Ãâ1, seed yield plantâÃâ¬Ãâ1 and biomass. Growth parameters were studied at pre-flowering, flowering and post-flowering stages, whereas biomass and seed yield was recorded at the time of harvest. Water samples were analysed for various characteristics, (APHA, 1989) and Ghosh et al. (1983) procedures were followed for soil analysis. The data was statistically analysed as described by Gomez and Gomez (1984). |
Results and Discussion
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| Wastewater proved beneficial, in comparison to groundwater for all the parameters including, the seed yield and biomass. Among the two concentrations of wastewater 100%WW proved superior to 50%WW and can be directly used without dilutions as it is generally utilized away from the source and already diluted by way of mixing with the domestic wastewater thrown into the same drain. This may be because of the presence of some essential nutrients present in wastewater like nitrogen, phosphorus and potassium in addition to calcium, magnesium, sulphur and chloride (Table 1). Similar views have also been expressed by Aziz et al. (1993), Khan et al. (2003) and Shah et al. (2005). Analysis of wastewater exhibited more electrical conductivity (EC), chemical oxygen demand (COD), biological oxygen demand (BOD). However, values of most of the parameters were within limits of CPCB (1995) or FAO (1994), except BOD, COD and Mg. The role of these nutrients is well established as nitrogen is involved in cell division, expansion (Gardner et al., 1985); phosphorus in energy transfer, nucleic acids, cell membrane, phosphoproteins (Hewitt, 1963) and nodulation (Andrew, 1977); potassium in photosynthesis, leaf area and cofactor of may enzymes (Mengel and Kirkby, 1996) and Mg in chlorophyll and middle lamella in addition to an essential element for various enzymatic reactions. |
| Among the various doses of phosphorus P20 proved optimum being at par with higher dose, P40 showing luxury consumption. As wastewater contained sufficient amount of phosphorus, which could have been utilized by the plants and therefore, additional fertilizer dose of phosphorus was saved (Table 2). It may be pointed out that the presence of additional amount of nutrients like P in the soil medium has increased the root proliferation and nodulation. Phosphorus has a role in stimulation of nodulation through its effect on rhizobia. It may also be noted that legumes show an evident preference to phosphorus fertilizer (Raju and Verma, 1984) in comparison with nitrogenous fertilizers, which is generally compensated through N2 fixation. Yield is the final manifestation of morphological and physiological traits, which depends upon various environmental factors including water and nutrients. Therefore, in the present study, 11.69% higher yield was recorded under wastewater application (Table 3) due to the increase in morphological parameters because of wastewater and phosphorus application. |
Tables at a glance
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References
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- Andrew, C.S. 1989. In : Exploiting the Legume Rhizobium Symbiosis in Tropical Agriculture (Eds. C.A.S. Whitney and E. Bose). pp. 253-274. Univ. of Hawaii, Honolulu.
- APHA 1989. Standard Methods for Examination of Water and Wastewater. 17th ed. American Public Health Association, Washington DC.
- Aziz, O., Samiullah, Inam, A. and Khan, N.A. 1993. Effect of treated Mathura Oil Refinery effluent on the performance of lentil (Lensculinaris L. Medic). Chem. Environ. Res. 2 (3&4) : 295-299.
- Gardner, F.P., Mitchell, L.R. and Pearce, R.B. 1985. Physiology of Crop Plants. Iowa State University Press, USA.
- Ghosh, A.B., Bajaj, J.C., Hasan, R. and Singh, D. 1983. Soil and Waste Testing Methods. A Laboratory Manual. Indian Agricultural Research Institute (IARI), New Delhi.
- Gomez, K.A. and Gomez, A.A. 1984. Statistical Procedures for Agricultural Research. 2nd ed. John Wiley and Sons, New York.
- Hewitt, E.J. 1963. Mineral nutrition of plants in culture media. In : Plant Physiology: A Treatise. Vol. 111. pp. 97-133, F.C. Steward (ed.), Academic Press, New York.
- Khan, N.A., Gupta, L., Javid, S., Khan, M., Inam, A. and Samiullah 2003. Effect of sewage wastewater on morphology and yield of Spinacia and Trigonella. Indian J. Plant Physiol. 8(1): 74-78.
- Mengel, K. and Kirkby, E.A. 1996. Principles of Plant Nutrition. 4th Ed. Panima Publishing Corporation, New Delhi.
- Raju, M.S. and Verma, S.C. 1984. Response of Bengal gram (Cicerarietinum L.) varieties to phosphate fertilization in relation to F.Y.M. application and Rhizobium inoculation. Legume Res. 7 : 23-26.
- Shah, R.A., Javid, S. and Inam, A. 2005. Effect of sewage irrigation and nitrogen rates on the growth and productivity of triticale. Poll. Res. 24 (2) : 267-274
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