Subscribe Now Subscribe Today
Research Article
 

Use of Uprooted Parthenium Before Flowering as Compost: A Way to Reduce its Hazards Worldwide



Prem Kishor, B.R. Maurya and A.K. Ghosh
 
Facebook Twitter Digg Reddit Linkedin StumbleUpon E-mail
ABSTRACT

Parthenium can be utilized to nourish the crops after composting. The present investigation was aimed to assess the combined effect of N through Parthenium Compost (PCN) and urea (U) along with Azotobacter chroococcum on growth and yield of Triticum aestivum L. Salient chemical characteristics of Parthenium Compost (PC) such as total nutrient content (N, P, K and S) and biological characteristics such as total number of bacteria, fungi, azotobacter and Phosphate Solubilizing Bacteria (PSB) were 3.66x106, 9.67x 104, 2.33x106, 7.67x105 and 2.67x106, respectively. Total N, P, K and S in Parthenium compost were 1.58, 0.33, 1.64 and 0.29%, respectively and total micronutrients such as Fe, Mn, Zn and Cu were recorded 7829, 304, 116 and 66 ppm, respectively. Results revealed that 100% N through Parthenium compost is detrimental to wheat. Judicious use of 50% N through each of Parthenium compost and urea along with Azotobacter chroococcum was found to be beneficial for better growth and higher yields of wheat. Increasing temperature of compost pit could not destroy 100% viability of Parthenium seeds. Embryo dormancy exists in seeds of Parthenium hysterophorus that break down by heat shock. Application of bloomed Parthenium compost generated new plants of Parthenium in wheat. This suggests that composting of uprooted Parthenium before flowering may reduce its spreading as well as menace of human health hazards worldwide.

Services
Related Articles in ASCI
Search in Google Scholar
View Citation
Report Citation

 
  How to cite this article:

Prem Kishor, B.R. Maurya and A.K. Ghosh, 2010. Use of Uprooted Parthenium Before Flowering as Compost: A Way to Reduce its Hazards Worldwide. International Journal of Soil Science, 5: 73-81.

DOI: 10.3923/ijss.2010.73.81

URL: https://scialert.net/abstract/?doi=ijss.2010.73.81
 

INTRODUCTION

Congress grass (Parthenium hysterophorus L.) is spreading very fast in grass lands and pastures and now has become an obnoxious weed to human all around the world. It is common in vertisols than an alfisols. It is also observed on road sides and wastelands. It can tolerate drought condition also to a certain extend under favorable conditions. Parthenium hysterophorus L. complete about three generation in a year. It is also reported that congress grass has remarkable power of regeneration. The weed left as such in the same area acts as a seed bank because of its higher seed production capacity and extended dormancy period. Parthenium is an exotic weed comes under Asteraceae family. Accidentally introduces in India, 1955 in Pune through the imported foodgrains (Dhawan and Dhawan, 1996). Present, it has occupied almost all parts of India and is attracting the attention of all (Dhawan and Dhawan, 1996). While, application of composted biomass to soil may increase soil physical quality and plant nutrition (Weber et al., 2007), it may also reduce mineralization of bio-labile compounds, thereby enhancing the role of Soil Organic Matter (SOM) as a sink of Organic Carbon (OC) (Piccolo et al., 2004). Compost amendments enhance SOM quality and quantity by an increased accumulation of various classes of organic compounds. Research on SOM following compost amendments has been mainly focused on changes of bulk OC (Pedra et al., 2007; Sebastia et al., 2007), microbial biomass, macro and micronutrients availability (Kowaljow and Mazzarino, 2007) and organic matter pools such as Dissolved Organic Matter (DOM) and humic substances (Adani et al., 2007). Parthenium extracts nutrients even from nutrient deficient soil and in cropped land can reduce up to 40% in yield (Swaminathan et al., 1990). Beneficial effect of organic sources such as FYM, crop residues and compost on soil properties and profitable crop yield has been well documented. Huge amount of locally available Parthenium can be utilized as a source of organic matter to prepare its compost resulting we can control its exotic weed and sustain the soil health. Kumar et al. (2007) also recorded higher yield of rice-wheat with the use of organic manures. They also reported that bio-fertilizers have added advantage in wheat production. Integration of FYM and Azotobacter with N, productivity and monetary returns of wheat can be increased by maintaining or improving soil fertility (Sarma et al., 2007). Composting cannot be considered a new technology, but amongst the waste management strategies it is gaining interest as a suitable option for manures with economic and environmental profits, since, this process eliminates or reduces the risk of spreading of pathogens, parasites and weed seeds associated with direct land application of manure and leads to a final stabilized product which can be used to improve and maintain soil quality and fertility (Larney and Hao, 2007; Pullicinoa et al., 2009). Composting of Parthenium is recommended as the seeds deprive their viability due to the higher temperature during composting. In spite of enough quantity of various essential macro and micro plant nutrients, composting of Parthenium is not practiced by farmers. The decomposition of Parthenium plant is done by composting and the composted product becomes enriched with mineralizable plant nutrients. Adoption of composting technology constitutes an essential component of organic farming. In India, nearly 7, 000 Million tones (Mt) of organic wastes and dairy wastes are produced yearly (Bhaiday, 1994). Composting is a one of the fastest and effective ways to recycle these organic materials in which the organic wastes can be compo-stabilized into compost. Compost is a rich source of macro-and micronutrients, vitamins, enzymes, antibiotics, growth hormones and immobilized micro flora (Bhawalker, 1991). The present investigation was aimed to assess the combined effect of N through Parthenium compost and urea along with Azotobacter chroococcum on growth and yield of wheat (Triticum aestivum L.). Parthenium compost provided N after mineralization, it is a slow process and takes more time. So, N requirement of wheat plants is fulfill by addition of nitrogen through urea for better growth and development of plants.

MATERIALS AND METHODS

Prepared Parthenium Compost
Flowered and unflowered plants of Parthenium hysterophorus were uprooted, chopped together and composted under tree shade at the Agricultural Research Farm, Institute of Agricultural Sciences, Banaras Hindu University Varanasi in a pit of size 4’x3’x2’during rainy season (August, 2006) and finally plastered with mud layer. Temperature of compost was recorded from different places of pit after a week of plastering using 1 m long probe thermometer. In a month’s time, the mud plaster was removed and content of pit was turned and mixed with water, then again plastered. Parthenium compost was ready in 14 weeks (10 November, 2006).

Sampling and Analysis of Parthenium Compost
Compost was sampled from ten points in the pile and mixed well (approximately 20 kg-wet weight). Samples for analysis were collected from this compost mixture in three replications and analyzed in Department of Soil Science and Agricultural Chemistry, Institute of Agricultural Sciences, B.H.U. Varanasi. The Parthenium compost was digested with nitric-perchloric acid (9:1), di-acid mixture for the other elements except nitrogen. Nitrogen was determined by colorimetric method using Nessler’s reagent and phosphorus was estimated by vanadomolybdate yellow colour method (Jackson, 1973). Potassium was estimated flame photometrically. Sulphur was determined by turbidimetric method of Chesnin and Yein (1951). The pH and EC of composted Parthenium were measured in soil and water suspension in ratio of (1:2.5) by pocket pH meter and pocket EC meter (Jackson, 1973). The population of total bacteria, fungi Azotobacter, actinomycetes and phosphate solubilizing bacteria in compost was determined by dilution plate counting technique using Thornton (1922), Thom and Raper (1945), Jenson’s medium, Kneknight and Munaier’s medium and Pikovskaya’s medium, respectively.

Pot Trial and Treatments
In a pot culture experiment, integration impact of Parthenium Composted Nitrogen (PCN), urea N (U) and Azotobacter chroococcum was studied on growth attributes and yields of wheat (Triticum aestivum L.). A glass house experiment was conducted in Department of Soil Science and Agricultural Chemistry, Institute of Agricultural Sciences, B.H.U. Varanasi with wheat during Rabi, 2006-2007 comprising eight treatments in complete randomized design with eight replications. Bulk soil collected from Indo-Gangetic alluvial plain of Varanasi had pH 7.5, EC 0.33 dS m-1 and organic C 0.45%. Available N, P2O5 and K2O were 251, 22 and 160 kg ha-1, respectively. Based on soil test, recommended dose of fertilizer N for wheat was 120 Kg ha-1. Required quantity of Parthenium compost for substituting a specific amount of N, basal dose of 60 kg N, 26 kg P and 33 kg K ha-1 through urea, single superphosphate and muriate of potash, respectively were mixed to soil as per the treatment before 10 days of sowing of wheat. Treatments included in the present study are T1 {100% N through Urea (U)}, {100% N through Parthenium compost (PCN)}, T3{75%N(U)+25%N (PCN)}, T4{50%N(U)+50%N (PCN)}, T5{25%N(U)+75%N(PCN)}, T6{T3+Azotobacter}, T7{T4+Azotobacter}, T8 {T5+Azotobacter}. Each pot was lined with polythene and filled with 5 kg of above soil. Wheat seeds (HUW 510) were treated with 10 days old Azotobacter chroococcum suspension (109 cells mL-1) with sticker (5% sugar and 2% gum acacia in water) and sown as per the treatments. Moisture of each pot was maintained as and when required. Five healthy and uniform plants in each pot were maintained after seedlings establishment. Remaining 60 kg N ha-1 was applied in two equal splits at tillering and flag leaf initiation. The recommended agronomic practices were adopted for raising the crop. At 60 DAS, four pots under each treatment were used to study tillers, plant height and root volume. Grain and straw yields of remaining four pots were recorded at crop harvest. Researchers have seen emergence of Parthenium in pots to which its compost was applied. Hence, effort was also made to search the reason for it to minimize the spread of Parthenium. Researchers have seen emergence of Parthenium in pots to which its compost was applied. Hence, effort was also made to search the reason for it to minimize the spread of Parthenium.

Viability of Parthenium Seed
Laboratory experiments were conducted in Department of Soil Science and Agricultural Chemistry, Institute of Agricultural Sciences, BHU Varanasi. Researchers was observed that Parthenium seed germinate in pots, where application of Parthenium compost. So, researchers know the reasons for germination of Parthenium in wheat pots that had received the Parthenium compost in above experiment because generally during composting increased the temperature of compost resulting, destroy the seed viability. Flowers of Parthenium were incubated at the temperature of 40, 45, 50, 55 and 60°C for 72 h. Unheated flowers were considered as control. Multilocational trials were carried out with Parthenium free permanent soil as well as compost pots to confirm the germination of heat shocked Parthenium seeds. Germination percentage of seeds separated from randomly selected heated flowers was determined in growth chamber at 25±0.5°C with 60% humidity. Viability of the seeds was studied by using Triphenyle Tetrazolium Choride (TTC).

Plant Sampling and their Analyses
Wheat grains and straw were harvested at maturity and air-dried for further processing. The dried grains were stored at room temperature for 3 months prior to analysis. The samples were analyzed in the laboratory for chemical parameters after tri-acid digestion. Protein content was determined from the formula: Nx 5.83 (AOAC, 1990). Phosphorus content was estimated photometrically via the development of a phospho-molybdate complex, as described by Taussky and Shorr (1953). Potassium content was determined by flame photometry. Micronutrients (Fe, Mn, Zn and Cu) were determined by atomic absorption spectrophotometer.

Statistical Analysis
All of the plant data were analyzed by complete randomized design, using Microsoft Excel and SPSS packages. Least Significance Difference (LSD) at p = 0:05 were tested to determine the significant difference (Gomez and Gomez, 1984). Statistical analysis of Parthenium seed Viability were computed for F-test.

RESULTS

Manurial Value of Parthenium Compost
Table 1 shows the manorial value of Parthenium compost. The electrical conductivity and pH of Parthenium compost was found to be higher 1 dS m-1 and 7.8, respectively. Total N, P, K, S, Fe, Mn, Zn and Cu content in Parthenium compost was 1.58, 0.33, 1.64, 0.29, 7829, 306, 116 and 66, respectively. Viable number of total bacteria, fungi, Azotobacter, Actinomycetes and Phosphate solubilizing bacteria were observed 3.66x106, 6.67x104, 2.33x106, 7.67x105 and 2.67x106, respectively in per g compost.

Effect of Temperature on Viability of Parthenium Seed
At maturity of compost, seed bearing flowers of Parthenium were observed as brown and hard. Though, it has been reported that seeds of Parthenium don’t have dormancy period and are capable to germinate anytime when moisture is available. viability and generation of seed were recorded up to 60°C. Germination of seeds separated from different batches of unheated flowers were tested several times in growth chamber without much delay showed zero percent of germination though seeds showed an average of 75-80% cell viability (Table 2).


Table 1:

Chemical and biological characteristics of Parthenium compost

Image for - Use of Uprooted Parthenium Before Flowering as Compost: A Way to Reduce its Hazards Worldwide

Table 2:

Effect of heat shocking on germination and viability of P. histerophorous seeds

Image for - Use of Uprooted Parthenium Before Flowering as Compost: A Way to Reduce its Hazards Worldwide

* Soil and compost pots in two locations. **In growth chamber

Table 3:

Effect of integrated use of composted P. hysterophorous on growth and yields of wheat

Image for - Use of Uprooted Parthenium Before Flowering as Compost: A Way to Reduce its Hazards Worldwide

*N: Nitrogen through Urea. **PCN: Nitrogen through Parthenium compost, CD: Critical difference at 5%

Effect of Integrated Use of Composted P. hysterophorous on Growth and Yields of Wheat
The mean plant height (cm), total number of tillers, root volume (cc pot-1) and root length (cm) pertaining to different treatments recorded at 60 days of wheat plant has been shown in Table 3. Scanning of data revealed that the mean plant height ranged from 43 to 67 cm. Treatment T7gave significantly greater plant height than T4 where recommended dose of nitrogen was applied in the ration 1/2:1/2 through urea and Parthenium compost (PCN) with inoculation of Azotobacter chroococcum. Treatment T6, T7 and T8 were superior to T3, T4 and T5. Application of 100% N through composted Parthenium (PCN) resulted in significant reduction in plant height, tillers and root volume of plant and ultimately grain and straw yield of wheat as compared to 100% N through urea (Table 2).


Table 4:

Effect of integrated use of Parthenium compost, urea and Azotobacter on macro and micro nutrients acquisition of wheat

Image for - Use of Uprooted Parthenium Before Flowering as Compost: A Way to Reduce its Hazards Worldwide

*N: Nitrogen through Urea, **PCN: Nitrogen through Parthenium compost, CD: Critical difference at 5%, NS: Not significant

This may be due to the allelopathic potential of Parthenium (Oudhia et al., 1997; Oudhia, 2000). Higher growth and yields of wheat was recorded with 50% N through urea +50% N through composted Parthenium. However, use of 25% N through urea +75% N through composted Parthenium caused significantly inferior growth attributes and yield of wheat as compared to 50% N through each of composted Parthenium+urea. Thus, maximum 50% of N can be supplemented through composted Parthenium beyond which it exhibits harmful effect on crop (Singh et al., 1999; Rakesh and Bajpai, 2001).

Effect of Parthenium Compost on Nutrients Acquisition of Wheat Crop
Table 4 clearly show that integrated use of Parthenium compost and Azotobacter increased nitrogen phosphorus, potassium and sulphur acquisition in wheat than urea and Parthenium compost. The maximum uptake N (0.67g pot-1), P (0.16 g pot-1), K (0.68 g pot-1) and S (0.22 g pot-1) were recorded with treatments T7, where 50% N through each of urea and composted Parthenium were applied with Azotobacter. This may be due to increasing availability of nitrogen, phosphorus, potassium and sulphur in soil when integrated application composted Parthenium. A similar trend was recorded for acquisition of Mn and Zn also. Copper uptake was affected non significantly by the application of composted Parthenium.

DISCUSSION

A good quantity of inorganic nutrients in Parthenium plants exhibited significance of its utilization as compost in agriculture. Rivero et al. (2004) suggested that compost increases the quality of the soil organic matter by contributing to a higher level in the soil of the most beneficial humic substances, which may change the balance between beneficial and detrimental micro-organisms. The total N, P, K and Fe content of Parthenium compost was higher than FYM. Parthenium seeds may have embryo dormancy (Ramamoorthy et al., 2003) which probably is broken down by high temperature. Viability as well as germination percentage of seeds decreased with increase in temperature. However, all viable seeds could not show normal germination. Since, vegetative generation of Parthenium occurs from the root crown of the plant. This indicates that Parthenium seeds have heat acclimation potential to save their viability against heat shock. White thin scale which envelops the Parthenium seed probably acts as semi-insulator may protects the seed viability against the heat shock. Further, germination of heat shocked Parthenium seeds may be due to synthesis of Heat Shock Proteins (HSPs) which has been implicated in improved thermal tolerance in seeds by stabilizing other proteins which easily get denatured by heat (Vierling, 1991; Hurkman, 1998). Therefore, cutting of Parthenium either pre or post flowering for composting is not a solution to reduce its hazards until they are uprooted. Singh and Singh (2005) also reported 29.9, 18.8, 35.5 and 15.2% increase in yield owing to FYM application at 15 t ha-1 and vermin-compost at 7.5, 10 and 15 t ha-1, respectively over no organic manure. Yadav (2005) also reported similar results. Inoculation of Azotobacter chroococcum significantly enhanced growth and yield of Triticum aestivum as compared to their respective uninoculated treatment combinations. Inoculation of Azotobacter chroococcum produced 33-130% more volume of roots as compared to its corresponding uninoculated treatment indicating synergistic effect of composted Parthenium on activity of organophilic Azotobacter chroococcum. Treatment T7 gave significantly higher plant height (cm), number of tillers, root volume (cc) and yield of grain and straw compare to all other treatments, where integrated use of 50% recommended dose of N through each of urea and (PCN)composted Parthenium (T7) along with Azotobacter chroococcum was beneficial to target higher yield of wheat. It was due to Azotobacter chroococcum reduces contents of auxin and gibberellin inhibitors and which causes increase the multiplication of cell and thus help in elongation of plants (Qureshi, 1985). As similar result was found in case of total number of tillers, root volume and root length. The increase in tillers was probably because of greater supply of nitrogen with efficient utilization for cell and formation of nucleic acids. As similar results was observed in case of acquisition N, P, K, S, Mn and Zn (Gupta et al., 1986). Application of nitrogen through Parthenium compost exhibited lowest value of nutrients acquisition because application of full dose of nitrogen through composted Parthenium adversely affected the plant growth and lower supply of nutrients. Composted Parthenium probably had allelopathic effect and affected metabolic processes of wheat plant.

CONCLUSION

The nutrient composition of composted Parthenium (PCN) was higher than FYM. Application of recommended dose of nitrogen (120 kg ha-1) through PCN caused lower values of growth, yield and uptake of nutrients by wheat. Inoculation of Azotobacter chroococcum along with 50% of nitrogen through each of the urea and PCN gave greater values of growth, yield and nutrient acquisition of wheat. On the basis of these finding it was concluded that integrated nutrient supply approach inclusion of Azotobacter certainly will be useful in improving the growth and yield of wheat. Hence, recycling of Parthenium plants by composting seems to be an efficient way for utilizing the tremendous agricultural weeds. Composting is a resource for low external input sustainable agriculture and is also a good method for solving control weeds and pollution problems.

ACKNOWLEDGMENTS

We acknowledge HOD, Soil Sci. and Agril. Chemistry for providing necessary facilities to carry out this research work. We thank Dr. P. Prakash, Plant Physiology and Ram Prasad, Sr. Horticulture Supervisor, Inst. of Agril. Sciences, Banaras Hindu University, Varanasi, India for their assistance in viability and germination test of seeds.

REFERENCES

1:  AOAC, 1990. Official Methods of Analysis. 15th Edn., Association of Official Analytical Chemists, Washington, DC., USA., pp: 200-210
Direct Link  |  

2:  Adani, F., P. Genevini, G. Ricca, F. Tambone and E. Montoneri, 2007. Modification of soil humic matter after 4 years of compost application. Waste Manage., 27: 319-324.
Direct Link  |  

3:  Bhaiday, M.R., 1994. Earthworms in agriculture. Indian Farm., 44: 31-34.

4:  Bhawalker, U.S., 1991. Vermicomposting technology for LEISA. Proceedings of the Seminar on Low External Input Sustainable Agriculture, Amsterdam, Netherlands.

5:  Chesnin, L. and C.H. Yein, 1951. Turbimetric determination of available sulphate. Soil Sci. Soc. Am. Proc., 15: 149-151.

6:  Dhawan, S.R. and P. Dhawan, 1996. Regeneration in Parthenium hysterophorus L. World Weeds, 2: 244-249.

7:  Gomez, K.A. and K. Gomez, 1984. Statistical Procedure for Agricultural Research. John-Wiley and Sons Inc., New York

8:  Gupta, A.P., R.S. Antil and V.K. Gupta, 1986. Effect of pressmud and zinc on the yield and uptake of zinc and nitrogen by corn. J. Indian Soc. Soil Sci., 34: 810-814.

9:  Hurkman, W.J., 1998. BiP, HSP70, NDK and PDI in wheat endosperm: II Effects of high temperature on protein and mRNA accumulation. Physiol. Plant, 103: 80-90.
CrossRef  |  Direct Link  |  

10:  Jackson, M.L., 1973. Soil Chemical Analysis. 2nd Edn., Prentice Hall of India Pvt. Ltd., New Delhi, India
Direct Link  |  

11:  Kowaljow, E. and M.J. Mazzarino, 2007. Soil restoration in semiarid Patagonia: Chemical and biological response to different compost quality. Soil Biol. Biochem., 39: 1580-1588.
CrossRef  |  Direct Link  |  

12:  Kumar, A., H.P. Tripathi and D.S. Yadav, 2007. Correcting nutrient for sustainable crop production. Indian J. Fert., 2: 37-44.

13:  Larney, F.J. and X. Hao, 2007. A review of composting as a management alternative for beef cattle feedlot manure in southern Alberta, Canada. Bioresour. Technol., 98: 3221-3227.
CrossRef  |  

14:  Oudhia, P., S.S. Kolhe and R.S. Tripathi, 1997. Allelopathic effect of white top (Parthenium hysterophorus L.) on chickpea. Legume Res., 20: 117-120.

15:  Oudhia, P., 2000. Allelopathic effect of Parthenium hysterophorus L. and Ageratum conzoides on wheat var. sujata. Crop Res., 20: 563-566.

16:  Pedra, F., A. Polo, A. Ribeiro and H. Domingues, 2007. Effects of municipal solid waste compost and sewage sludge on mineralization of soil organic matter. Soil Biol. Biochem., 39,: 1375-1382.
CrossRef  |  Direct Link  |  

17:  Piccolo, A., R. Spaccini, R. Nieder and J. Richter, 2004. Sequestration of a biologically labile organic carbon in soils by humified organic matter. Climatic Change, 67: 329-343.
CrossRef  |  Direct Link  |  

18:  Pullicinoa, D.S., L. Massaccesia, L. Dixonb, R. Bolb and G. Gigliottia, 2009. Organic matter dynamics in a compost-amended anthropogenic landfill capping-soil. Eur. J. Soil Sci., 61: 35-47.
CrossRef  |  Direct Link  |  

19:  Qureshi, J.N., 1985. Effect of Azotobacter on Nitrogen Contents and Yield of Maize, Wheat and Sorghum in Kenya. In: Biological Nitrogen Fixation in Africa, Ali, S.H., S.O. Keya (Eds.). University of Nairobi, Nairobi Kenya

20:  Rakesh, B. and R.P.K. Bajpai 2001. Effect of integrated nutrient management on root growth of wheat in a rice wheat cropping system. Agric. Sci. Digest, 21: 1-4.

21:  Rivero, C., T. Chirenje, L.Q. Ma and G. Martinez, 2004. Influence of compost on soil organic matter quality under tropical conditions. Geoderma, 123: 355-361.
CrossRef  |  

22:  Sarma, A., S. Harbir and R.K. Nanwal, 2007. Effect of integrated nutrient management on productivity of wheat (Triticum aestivum) under limited and adequate irrigation supplies. Indian J. Agron., 52: 583-586.
Direct Link  |  

23:  Sebastia, J., J. Labanowski and I. Lamy, 2007. Changes in soil organic matter chemical properties after organic amendments. Chemosphere, 68: 1245-1253.
CrossRef  |  

24:  Singh, J. and K.P. Singh, 2005. Effect of organic manures and herbicides on yield and yield attributes of wheat. Indian J. Agron., 50: 289-291.

25:  Singh, S., R.D. Singh and R.P. Awasthi, 1999. Organic and inorganic sources of fertilizers for sustained productivity in rice wheat sequence on humid-hilli soil of Sikkim. Ind. J. Agron., 50: 313-314.

26:  Swaminathan, C., R.S. Rai and K.K. Smesh, 1990. Allelopathic effect of Parthenium hysterophorus L. on germination and growth of a few multi purpose trees and arable. Int. Tree Crops J., 6: 143-150.

27:  Taussky, H.H. and E. Shorr, 1953. A microcolorimetric method for the determination of inorganic phosphorus. J. Biol. Chem., 202: 675-685.
PubMed  |  Direct Link  |  

28:  Thom, C. and K.B. Raper, 1945. Manual of the Aspergili. Williams and Wilkins Co., Baltimore, USA

29:  Thornton, H.G., 1922. On the development of standardized agar medium for counting soil bacteria with special regard to the repression of spreading colonies. Ann. Applied Biol., 2: 241-274.
CrossRef  |  Direct Link  |  

30:  Vierling, E., 1991. The roles of heat shock proteins in plants. Annu. Rev. Plant Physiol. Plant Mol. Biol., 42: 579-620.
CrossRef  |  Direct Link  |  

31:  Weber, J., A. Karczewska, J. Drozd, M. Licznar, S. Licznar and E. Jamroz, 2007. Agricultural and ecological aspects of a sandy soil as affected by the application of municipal solid waste composts. Soil Biol. Biochem., 39: 1294-1302.
Direct Link  |  

32:  Yadav, A.S., 2005. Effect of organic farming practices on wheat. M.Sc. Thesis, NDUA and T, Kumarganj, Faizabad.

33:  Ramamoorthy, M., B. Uthayakuar, J.S. Rajapandian and A. Muthusankaranarayanan, 2003. Integrated weed management for parthenium. The Hindu, Online Edition of India's National News Paper, Dec. 4. http://www.hindu.com/seta/2003/12/04/stories/2003120400101700.htm.

©  2021 Science Alert. All Rights Reserved