Madras Agric. J., 97 (7-9): 261-264, September 2010
Utilization of Human Urine as a Supplement to Fertilizers in Maize Production G. Sridevi*1 and C.A. Srinivasamurthy Department of Soil Science and Agricultural Chemistry University of Agricultural Sciences, Bangalore - 56 065, India
A field experiment was conducted in farmer’s field at Nagasandra village, Doddaballapura TK, Bangalore district to study the response of maize (Zea mays L.) crop by applying human urine as the source of nitrogen. The treatments were absolute control, recommended dose of fertilizers, recommended dose of nitrogen through human urine with and without gypsum and fertilizer applied to soil and different combinations of human urine and fertilizers. The results of the field experiment revealed that recommended dose of nitrogen through (human urine in 6 split doses with irrigation water + gypsum) increased the grain (8.10 t ha-1) and stover (33.88 t ha-1) yield of maize. The available nutrients content of soil viz., N, P and K in the experiment showed a progressive decline with the advancement of crop growth period. Significant increase in the nitrogen, phosphorus and potassium content of plant samples was observed in the crops when compared to control. The farmers can save Rs. 2500 ha-1 which they would otherwise been spent on fertilizers. The outcome of the study is human urine can be effectively used in agriculture for food production which will lessen our dependency on commercial fertilizer. Keywords: Gypsum, nitrogen, phosphorus, potash, human urine and maize yield
The consumption of fertilizer has increased by over 30 per cent globally from 1996 to 2008 and 56 per cent in developing countries. By 2025 AD, the annual nutrient requirement of our country would be around 45 million tons. The NPK fertilizer requirement of our country is 28 million tons but the quantity added through fertilizers is only 18 million tonnes with a gap of 10 mt being mined from soil. But there is no scope for increasing fertilizer production as there will be shortage of raw materials required for the manufacture of fertilizers. At the same time India currently generates over 110,000 million litres of wastewater a day. The appropriate and sustainable disposal of human waste is a significant problem during our times. In our urban areas less than 20% of sewage is currently treated before being let out into our lakes, rivers and groundwater. The results are: significant pollution of our lakes, rivers and groundwater. Besides drinking water quality problems, lake pollution with human sewage results in eutrophication and dead lakes. One of the best options in the present day context is to utilize human urine as a liquid fertilizer to meet part of the nutrient requirement of crops in an integrated way. The main objective of the study was use of urine diverting toilet (Ecosan- ecological sanitation) systems that produce a safe human derived fertilizer can potentially used for maize cultivation and for the improvement in life expectancy *Corresponding author email: sri233011@ yahoo.com
by enabling sustainable food production as well as proper waste water management. Human urine contains appreciable quantity of plant nutrients (especially Nitrogen, phosphorus, potassium, calcium, magnesium, zinc and iron elements), in readily available forms and hence can be used in agriculture as an alternative source of chemical fertilizers. On the other hand, there is lot of hesitation amongst people in handling this nutrient rich waste due to lack of knowledge and the aspersions that by consuming the produce grown using human urine they may suffer from various deadly diseases. The agricultural scientists are convinced about use of anthropogenic liquid waste for agricultural purposes. No information is available on the quantity and frequency of application of human urine as a nutrient source and the impact of its application on soil properties, growth, yield and quality of crops. Hence studies which find answers to various questions related to use of human urine for agricultural purposes is the need of the hour as it helps to solve the problems of water pollution and to use the nutrient elements present in human urine in a productive way which otherwise may go as a waste. Standard procedure and protocol of using human urine in crop production is not well documented .In view of these considerations, the present investigation was undertaken to assess the
262 nutritive value of human urine with gypsum and without gypsum on crop yields. Materials and Methods Experimental Site
A field experiment was conducted in a farmer field (sandy loam soil) at Nagasandra village, Doddaballapura taluk, Bangalore district with hybrid maize as (C.V. NAH 2049) test crop during early kharif season of 2007-08. The experiment was laid out in a randomized block design (RBD) with ten treatments and replicated thrice. Initial soil characteristics (0-15 m layer) of the experimental site were sandy loam with 38.4 per cent coarse sand, 31.2 per cent fine sand, silt 11.6 per cent and 18.2 per cent clay respectively. The total pore space was 45 per cent. The soil pH 8.1 was alkaline in reaction (1:2 soil/water suspension), electrical conductivity 0.12 dSm-1 (1:2 suspension), organic carbon (Walkley and Black 1934) 0.2 per cent,
available nitrogen ( Subbiah and Asija 1956) 248.0 kg ha-1, available phosphorus (Olsen et al., 1954) 14.8 kg ha-1 and available 1 N ammonium acetate extractable available potassium 281 kg ha-1. The DTPA-extractable Fe, Mn, Cu and Zn contents (Lindsay and Norvell, 1978) were in sufficient range. The study included ten treatments which were arranged in a randomised complete block design with three replications. Composition of human urine
Initial nutrient composition of human urine was slightly alkaline (7.84) in reaction and has high amount of soluble salts with electrical conductivity of 9.2 dS m-1 and a low organic load [BOD -3.6 and COD-176.90 mg kg-1]. It also had small quantity of total dissolved solids averaging to 0.089 mg L-1. Human urine contained appreciable amount of N (0.45 per cent) and P (0.18 per cent), K (0.16 per cent), Ca (4.25 me L-1), Mg (5.15 me L-1) and Na (0.36 per cent)
Table 1. Effect of Human urine on pH, EC (dSm-1), Organic carbon (Per cent), grain and stover of maize crop Treatment
pH
EC (dSm-1)
Organic carbon (%)
Stover yield (t ha-1)
Grain yield (t ha-1)
T1 -
Control
7.97
0.11
0.22
T2 -
Recommended Dose of Fertilizer (RDF)
7.37
0.14
0.57
8.0
33.43
T3 -
Recommended Dose of Nitrogen (RDN) through human urine (Basal)
7.77
0.15
0.57
7.6
31.19
T4 -
RDN through human urine (Basal) + gypsum
7.62
0.21
0.57
7.7
31.28
T5 -
RDN through human urine (in 6 split dose with irrigation water)
7.17
0.38
0.57
8.0
33.27
T6 -
RDN through human urine in 6 split dose with irrigation water) + gypsum
7.82
0.22
0.65
8.1
33.88
T7 -
40% RDN through human urine (Basal) + 60% RDN through Urea
7.60
0.33
0.47
7.1
29.67
T8 -
40% RDN through human urine (Basal) + 60% RDN through Urea+ gypsum
7.22
0.29
0.49
7.9
32.54
T9 -
40% RDN Urea (Basal) + 60% RDN through human urine (in 6 split dose with irrigation water)
7.38
0.31
0.49
7.9
32.62
T10 -
40% RDN Urea (Basal) + 60% RDN through human urine (in 6 split dose with irrigation water) + gypsum
7.25
0.33
0.50
8.0
33.37
Mean
7.52
0.25
0.51
7.4
30.74
SEd
0.16
0.02
0.05
1.48
1.01
CD (P=0.05)
0.32
0.05
0.11
3.10
2.03
Note: Gypsum requirement -84 grams/litres, human urine require 42 litres. Recommended dose of 150: 75:40 kg ha-1N, P and K was applied in the form of urea, single superphosphate and muriate of potash and anthropogenic liquid waste as per the treatments.
Treatments combination used:
T1 T2 T3 T4 T5 T6 T7
-
Control RDF RDN through human urine (Basal) RDN through human urine (Basal) + gypsum RDN through human urine (in 6 split irrigations) - RDN through human urine (in 6 split irrigations) + gypsum - 40% RDN through human urine (Basal) + 60% RDN through Urea
T8 T9 T10
- 40% RDN through human urine (Basal) + 60% RDN through Urea+ gypsum - 40% RDN through Urea (Basal) + 60% RDN through human urine (in 6 split irrigations) - 40% RDN through Urea (Basal) + 60% RDN through human urine (in 6 split irrigations) + gypsum
Where, RDF- Recommended dose of fertilizer, RDN- Recommended dose of Nitrogen, ALWAnthropogenic liquid waste,(Balance of P and K were supplied through chemical fertilizers), Phosphorus
263 through single super phosphate and Potassium through Muriate of potash Note
Gypsum was used as an amendment, taking into account the solubility of gypsum, field capacity of the soil and quantity of anthropogenic liquid waste to be added to the soil. To attain hundred per cent saturation two grams of gypsum per litre of anthropogenic liquid waste is required. The total quantity of gypsum per plot was calculated based on the amount of anthropogenic liquid to be added for each plot. Soil samples were collected from 0-15 m depth after the harvest of maize crops. The samples were analyzed for available nitrogen, available phosphorus and available potassium.Maize grain and stover yields were recorded after the harvest in Kharif seasons. Statistical Analysis
The data obtained from the chemical analyses of soil and plant samples were subjected by Snedecor and Cochran (1967) for statistical analysis.
Results and Discussion Effect of human urine on grain and stover yield and quality of maize grain:
The highest grain yield (8.1 t ha-1) and stover yield (33.88 t ha-1) of maize was recorded with T6 treatment receiving RDN through human urine in 6 split doses + gypsum. This might be due to the ready supply of nitrogen and other plant nutrient elements through human urine (Table1). Nitrogen in particular has a positive response on overall improvement in crop growth, enabling the plant to absorb more nutrients thus empowering the plant to synthesis more quantity of photosynthates and accumulating them in the reproductive parts (Guzha, 2004 and Mnkeni Pearson, 2008). Nutrients in anthropogenic liquid waste are available to the plants because they are in ionic form and are absorbed rapidly and easily transported into plant parts. The above findings were confirmed by Mnkeni et al.( 2006).Another reason might be dry matter towards reproductive organs of the plants for higher plants. The better performance of crop in treatments receiving human urine may also be due to the presence of certain growth promoting substances like IAA in anthropogenic liquid waste (human urine).
Table 2. Effect of Anthropogenic liquid waste on major nutrients (kg ha-1) of harvest soil at different growth stages of maize crop Available nitrogen
Treatments
Available phosphorus
Available potassium
T1 -
Control
198.24
10.06
T2 -
Recommended Dose of Fertilizer (RDF)
243.92
15.39
236.28
T3 -
Recommended Dose of Nitrogen (RDN) through human urine (Basal)
245.98
13.42
261.58
T4 -
RDN through human urine (Basal) + gypsum
268.78
15.10
223.70
T5 -
RDN through human urine (in 6 split dose with irrigation water)
313.17
16.58
230.74
T6 -
RDN through human urine in 6 split dose with irrigation water) + gypsum
233.08
14.41
236.01
T7 -
40% RDN through human urine (Basal) + 60% RDN through Urea
212.60
15.79
218.27
T8 -
40% RDN through human urine (Basal) + 60% RDN through Urea+ gypsum
224.69
18.25
240.42
T9 -
40% RDN Urea (Basal) + 60% RDN through human urine (in 6 split dose with irrigation water)
199.17
16.08
242.68
T10 -
40% RDN Urea (Basal) + 60% RDN through human urine (in 6 split dose with irrigation water) + gypsum
197.80
17.07
230.72
Mean
233.74
15.21
227.53
9.72
0.19
4.81
18.61
0.41
10.03
SEd CD (P=0.05) Soil properties Effect of human urine on soil properties
The pH values were slightly decreased at harvest. The EC value of soil was slightly higher in treatments receiving urine and gypsum. The treatments which involved human urine were found to register higher values of organic carbon at all the stages of crop growth compared to chemical fertilizers treatments. The highest mean organic carbon content (0.63 per cent) was registered in treatment T6 which received RDN through human urine (in 6 split doses with irrigation water) + gypsum
197.57
(Table 2). This might be due to the presence of carbonaceous materials for decomposition by microorganisms and subsequent conversion to mineralized organic colloids besides adding them to the soil reserves. However, with time, it will undergo rapid decomposition and ultimately results in marginal increase in organic carbon content. The different treatments tried had significant influence on the available nitrogen and potassium content of the soil at harvest stage. There was a decrease in the available N and K contents of soil in all the treatments at harvest stages. (Table 1 and
264 Table.2) .This may be attributed to the losses of applied nitrogen through crop uptake, leaching and volatilization. Removal of both nitrogen and potassium by the crop with the advancement of crop growth is the main reason behind the lower available nitrogen and potassium content of soil at later stages of sampling (Schouwz et al., 2002).
References
The available phosphorus content of soil was significantly higher in RDF treatment compared to other treatments. The available P was found to decrease significantly in treatments receiving human urine. Each stage of the crop growth registered significant reduction in available P at harvest stage of the crop growth. The reduction in soil available phosphorus content in treatment receiving human urine with gypsum application to soil may be attributed to higher utilization of added phosphorus by the crop. Removal of phosphorus by the crop with the advancement of crop growth is also the reason behind the lower available phosphorus content with the progressive stages of sampling.
Lindsay, W.L. and Norvell, W.A. 1978. Development of DTPA soil test for Zn, Fe Mn and Cu. Soil Sci. Soc. Amer. J., 42: 421- 428.
Conclusion
From the results of the present study, it is concluded that the potential yield of maize can be obtained by using human urine. It is a viable and alternate source of chemical fertilizers.
Guzha, E. 2004. An assessment of community attitudes and effect of human excreta use on soil fertility, maize production in Manyame catchment. M.Sc. Thesis. University of Zimbabwe. Jackson, M.L. 1973. Soil Chemical Analysis. Prentice Hall of India Pvt. Ltd., New Delhi. P.75.
Mnkeni Pearson, N.S. 2008. Evaluation of human urine as a source of nutrients for selected vegetables and maize under tunnel house conditions in the Eastern Cape, South Africa. Waste Management and Research, 26: 132-139. Mnkeni, P.N.S., Jimenez Cisneros, B., Phasha, M.C. and Austin, L.M. 2006. Use of human excreta from urine diversion toilets in food gardens; Agronomic and health aspects' Report to water research commission N0.3: ISBN-1_77005-455-3, University of Fort Hare. Olsen,S.R., Col., C.L., Watanabe, F.S. and Dean, D.A. 1954. Estimation of available phosphorus in soils by extraction with sodium bicarbonate, USDA circ.939.nd grey water reuse. Licenciate thesis Royal Institute of Technology/Swedish Institute for Infectious Disease Control, Stockholm. Schouwz, N.L., Danteravanich, S., Mosbaek, H. and Tjell, J.C., 2002. Composition of human excreta - a case study from Southern Thailand. Science of the Total Environment Journal, 286:155-166. Snedecor, G.W. and Cochran 1967. Statistical methods. Oxford and IBH Publishing House, Calcutta.
Acknowldegement
This work has been funded by Arghyam, Bangalore and Krishi Vidhya Nirantra ,Bangalore through student research project 2006-2008. Sincere thanks are to University of Agricultural Sciences, Bangalore for providing fellowship.
Subbiah, B.V. and Asija, G.L.1956. A rapid procedure for estimation of available nitrogen in soils. Curr. Sci., 25: 259-260. Walkley, A. and Black, C.A. 1934. An examination of the method determining soil organic matter and proposed modification the chromic acid titration method. Soil Sci., 37: 29-38.
Received: July 13, 2010; Accepted: August 15, 2010
