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.
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 |
| Table 2: | Effect of heat shocking on germination and viability of P. histerophorous seeds |
* 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 |
*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 |
*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.