Inert materials such as polyurethane, impregnated with a suitable culture medium provided a homogeneous aerobic condition in the fermenter and impurities do not contribute to the final product. An additional advantage of using inert supports is the easy recovery of the product of interest, ease of performing balances because all nutrient concentrations in the middle of production are known, so one can study the effect of a given component of medium [60].

Recent studies have shown the superiority of polyurethane and polysulfone as immobilization support in comparison to polyacrylamide and alginate matrices. It has been reported a novel polyurathane gel bead fabrication technique for immobilizing Pseudomonas aeruginosa CSU. Preliminary studies conducted by them revealed that the P. aeruginosa CSU biomass immobilized within the polyurethane gel beads were effective in the removal of hexavalent uranium from low concentration acidic waters. Other authors have been immobilized phormidium laminosum on polysulfone and epoxy resins. They were successful in reusing the polysulfone immobilized biomass for ten consecutive biosorption/desorption cycles without apparent loss of efficiency after reconditioning it with 0.1 M NaOH. Immobilization of Citrobacter biomass in polysulfone matrix increased its metal loading capacity for lead, cadmium and zinc metals [57].

The vast majority of papers published on charophytes worldwide, deals with their taxonomy and systematics. Comparatively, very few papers were published dealing with their biology, including citology, genetics, ecology and physiology.

Measure of biomass is one possibility to estimate the macrophyte’s capacity to photo synthetize (Wetzel 1964) and the most used. Other possibilities include population density and biovolume. According to Wetzel (2001), the submersed macrophytes biomass is low if compared to that of other plants. The importance of the charophytes living at the littoral zone of lakes is directly related to the amount of submersed biomass, spatial structure and these plants association with other submersed and emerged macrophytes.

Literature regarding charophytes biomass is not rare neither profuse worldwide and dates mostly from 1980 on, when eutrophication was recognized to be one of the most important events of the century. While not profuse, literature available consents a pretty good overview on the subject.

The regular chemical determinations are [3]: (1) pH; (2) redox potential; (3) dissolved oxygen concentration (pO2); (4) exit-gas analysis; (5) on-line analysis of other chemical factors (ion-specific sensors, enzyme electrodes, microbial electrodes, mass spectrometers, fluorimeters).

In most processes there is a need for pH monitoring and control if maximum yield of a product is to be obtained. The pH may be further controlled by the addition of appropriate quantities of alkaline or acid solutions, depending of the characteristic pH trend evolution. Normally, the pH drift is only in one direction. pH measurement is carried out using a combined glass reference electrode that will withstand repeated sterilization at temperature of 120oC and pressures of 138kN/m2.

In most aerobic fermentations it is essential that the dissolved oxygen concentration does not fall below a specified minimal level. If in small fermenter the most used electrodes are galvanic, the polarographic electrodes are more commonly used in pilot or production bioreactors. For an increase of precision, they are both pressure and temperature compensated.

microbial consortia packed with different bacterial species. Each biogranule consists of millions of microorganisms per gram of biomass (Weber et al., 2007), formed via biological, physical and chemical forces. According to Calleja (1984), microbial granulation is a multicellular association in a physiological state that is causing the mixture of cells into a fairly stable and contiguous structure.

The main advantages of biogranules systems are mainly due to the biogranules good settling property and the fact that biogranules are formed without the need of any biomass carrier. The relatively large size and high-density biogranules give them a rapid settling rate, which enhances the separation of the treated effluent from the biomass and results in high solid retention time (SRT) (Ahn and Richard, 2003; Liu and Tay, 2004). Due to a better settling rate, the system also shows low suspended solid content discharged in the effluent (Wirtz and Dague, 1996).

Within the biogranules, the microorganisms are closely lumped together, hence generating syntrophic associations between the cells. This relationship occurs due to optimum distances between the cells at appropriate substrate levels and such condition enables high and stable performance of metabolism activities (Batstone et al., 2004).

The granulation system is first recognized in an up-flow anaerobic sludge blanket (UASB) system characterized by anaerobic biogranules. Much research has been carried out using innovative upflow sludge bed (USB) type reactors (Bachman et al., 1985; Lettinga et al., 1997). The applications of anaerobic granulation systems have been successfully demonstrated particularly in removing biodegradable organic matter from industrial wastewaters (Lettinga et al., 1980; Schmidt and Ahring, 1996). Later the attention has also been diverted to the development and applications of aerobic biogranules. The reason has been several drawbacks that have been observed in the anaerobic biogranules system, including long start-up periods, relatively high temperature requirements and ineffectiveness in dealing with nutrient and low organic strength wastewater (Liu and Tay, 2004).

Aerobic granulation systems have been used for organics, nitrogen, phosphorus and toxic substances removal, especially high strength wastewater (Yi et al., 2008; Kishida et al., 2009).

In most cases, the system is in the form of a sequencing batch reactor (SBR) (Beun et al.,

1999; Kim et al., 2008). The reaction phase of the system has been carried out either in anaerobic, aerobic or anoxic conditions, with or without mixing, depending on the purpose of the treatment.

In the catalytic activity tests, the formation of products were observed for 60 min, and significant heavy tar was not observed on the pipeline and tar traps. All experiments were performed at 923 K under nitrogen carry gas, space velocity 11000. All calculated results of gas yield and C_gas were the average of specific results from various specific sampling times, which started at 10 min after feeding biomass and then in 20 min intervals. The effects of the catalyst on gas yields (CH4, CO, CO2, H2 yield) are illustrated in Figure 10 (a). The bars from left to right show the results for non-catalyst, Ni/АЬОэ and Ni/BCC catalyst. Using Ni/BCC catalyst, CH4, CO, CO2 and H2 yields were almost the same as those of Ni/АЬОэ: 2.8, 15.6, 6.3, 23.1 [mmol/g-sample daf], respectively. Especially, both CO and CO2 yields increased drastically by 2 times and H2 by approximately 5 times compared to those of non­catalyst. This result indicates that Ni catalysts are quite effective to decompose tar to useful gases such as CO and hydrogen.

Biomass carbon balance is illustrated in Figure 10 (b). A detailed carbon balance could not be carried out because of difficulty in accurately estimating the tar yield. In a similar way as described above section, we defined C_gas, C_char, C_coke (Deposited carbon on the catalyst) and calculated C_tar:

C _ tar = 100 — (C _ gas + C _ char + C _ coke.

In the case of no catalyst, C_coke was not observed at all, because coke is assigned to the carbon deposited on the catalyst surface. For the case Ni/BCC catalyst, C_coke was estimated by the difference of carbon in fresh Ni/BCC and carbon in used Ni/BCC catalyst. The amount of C_char was almost constant in all of the cases. This is because the char is accumulated in the fluidized bed without contacting the catalyst particles. In the case of catalytic tar decomposition, the amount of C_gas increased drastically compared to no catalyst. The blank on the top of each bar in Figure 10(b) can be considered as a percentage of C_tar. For Ni/BCC and Ni/AhO3 catalysts, C_ tar was 12.3 and 8.9% and C_gas was 54.9 and 55.1%, respectively. The results show that the Ni/BCC catalyst could not perform as well as the Ni/Al2O3 catalyst to decompose tar under pyrolysis process. This result might be affected by a part of the deposited carbon being on some of the reactive surface of the Ni catalyst, while the raw Ni/BCC catalyst was calcined due to volatile release from the brown coal. However, the results show that both catalysts are quite active to decompose tar.

Figure 10. Comparison of different catalysts and non-catalyst without steam: (a) gas yields and (b) biomass carbon balance at 923 K and no steam (923 K, sv = 11000)

With, implementing innovative, environmentally sound and cost-effective production technologies for a variety of products, the integrated biorefinery is increasing the availability and use of bioenergy and bio-based products. The main objective of a biorefinery is to produce high-value low volume and low-value high-volume products by a series of producing processes. The processes are designed to maximize the valued products while minimizing the waste streams by converting low-value high-volume intermediates into energy. The high-value products can enhance the profitability, and the high-volume fuels will help to meet the global energy demand. The power produced from a biorefinery can also help to reduce the overall cost. Figure 1 shows the elements of a biorefinery, in which biomass is used to produce various useful products such as fuel, power, and chemicals by biological and chemical conversion processes [13].

Traditionally, the matured biorefinery pathways include bioconversion (aerobic and anaerobic digestion) and chemical conversion (bio-pulping). There are two most promising emerging biorefinery platforms. One is the sugar platform and the other is the thermo­chemical platform (syngas platform). In sugar biorefineries platform, biomass will be broken down into different types of component sugars for fermentation or other biological processing into various fuels and chemicals. In thermo-chemical biorefineries platform, biomass will be synthesized hydrogen and carbon monoxide or pyrolysis oil, the various components of which could be directly used as fuel [19].

Shurong Wang

Additional information is available at the end of the chapter http://dx. doi. org/10.5772/51423

1. Introduction

1.1. What is fast pyrolysis?

Biomass is a CO2-neutral energy source that has considerable reserve. It can replace fossil feedstock in the production of heat, electricity, transportation fuels, chemicals, and various materials. Liquid bio-fuels, which are considered to be substitutes for traditional petrol liquid fuels, can be produced from biomass in different ways, such as high-pressure liquefaction, hydrothermal pyrolysis, and fast pyrolysis.

Fast pyrolysis is a technology that can efficiently convert biomass feedstock into liquid biofuels. The liquid obtained from fast pyrolysis, which is also called crude bio-oil, may be used as burning oil in boilers or even as a transportation fuel after upgrading. Fast pyrolysis is a process in which lignocellulosic molecules of biomass are rapidly decomposed to short — chain molecules in the absence of oxygen. Under conditions of high heating rate, short residence time, and moderate pyrolysis temperature, pyrolysis vapor and some char are generated. After condensation of the pyrolysis vapor, liquid product can be collected in a yield of up to 70 wt% on a dry weight basis (Bridgwater et al., 1999; Lu et al., 2009). The obvious advantages of the process are as follows:

1. Low-grade biomass feedstock can be transformed into liquid biofuels with relatively higher heating value, thus making storage and transportation more convenient.

2. The by-products are char and gas, which can be used to provide the heat required in the process or be collected for sale.

3. For waste treatment, fast pyrolysis offers a method that can avoid hazards such as heavy metal elements in the char and reduce pollution of the environment.

Many researchers have focused on the techniques of fast pyrolysis, and various configurations of reactor have been developed to satisfy the requirements of high heating rate, moderate reaction temperature, and short vapor residence time for maximizing bio-oil production. During the past decades, many types of reactor have been designed to promote

© 2013 Wang, licensee InTech. This is an open access chapter distributed under the terms of the Creative Commons Attribution License (http://creativecommons. org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

the large-scale and commercial utilization of biomass fast pyrolysis, such as the fluidized bed reactor (Luo et al., 2004; Wang et al., 2002), the ablative reactor ( Peacocke & Bridgwater, 1994), the rotating cone reactor (Muggen, 2010; Peacocke; Wagenaar, 1994) and Vacuum reactor (Bridgwater, 1999; Yang et al., 2001).

The specific methanogenic activity (SMA = gDQO-CH4-gVSS-1-d-1) is defined as the rate of methane production, expressed as COD, regarding biomass expressed as the content of volatile suspended solids (VSS). In anaerobic degradability test measures the rate of degradation of a compound relative to a standard compound that is acetic acid determining [36].

COD

Where: Slope = m=LCH4; Biomass = X [=] gVSS/L; Methane conversion у COD =0.35

Methanogenic activity and toxicity

Methanogenic activity were performed using the pressure transducer technique, which involves the monitoring of the pressure increase developed insealed vials fed with non­gaseous substrates or pressure decrease in vials pressurised with gaseous substrates. Strict anaerobic conditions must be maintained. The same technique can be used to perform the methanogenic toxicity tests. The fifty percent inhibition concentration (IC50) was defined as the methanogenic concentration that caused a 50% relative activity loss [35, 37].

The technique is as follows:

1. The sludge is left in mineral medium for 24 hours at 30-35 °C in order to consume the entire carbon source which may have been brought into water of the plant.

2. Methanogenic activity tests were conducted in 160 mL in serology bottles with an operating volume of 150 mL. The volume of volatile suspended solids was set at 2 g/L and COD concentration used was varied from 0.25, 0.5, 1, 2, 3 y 5 g/L using acetate as a carbon source, and staying a relationship of 0.125, 0.25, 0.5, 1, 1.5 y 2.5 gCOD/gVSS respectively.

3. The bottles were sealed with rubber stoppers, and incubated 24 h at 35°C.

4. Methane was determined by the displacement volume of a solution of 3% NaOH [38].

Figure 2 show a schematic representation of methane measuring.

Biomass productivity of short rotation coppice has been studied for several fast growing species in many places of the world, showing an average annual production of 10 to 20 oven dry tonnes (odt) ha-1 in most places [82]. In intensively irrigated and fertilized willow plots

in southern Sweden, growth rates of > 30 odt ha-1 yr-1 have been recorded [83]. The potential production of a certain genotype can only be reached if resources (light, water and nutrients) are permanent available and without limitations, and in the absence of pests and diseases. An analysis of short rotation coppice yields in Sweden over the period 1989-2005 showed disappointingly low mean annual production figures of 2.6, 4.2 and 4.5 odt ha-1 during the first, second and third cutting cycles, respectively [20]. These low figures can partly be explained by the use of old clones, which have a much lower potential production than those which were released later [34] and which have a relatively high susceptibility to pathogens. Other reasons for this low productivity are site choice, as farmers have been reluctant to use the better soils for willow plantations, and a very poor management. Many of the early plantations never received fertilizer and suffered from a poor establishment due to inadequate weed control. However, annual average yields over 10 odt ha-1 have been reached in commercial plantations if fertilization was applied and adequate weed control performed

[84] , and did not require more than an average availability of water. Taking account of the water use efficiency of willow and precipitation during the growing season, Lindroth & Bath

[85] calculated the annual maximum yield to be 8-9 odt ha-1 for north-eastern, 9-10 odt ha-1 for eastern and 11-17 odt ha-1 for southern and south-western Sweden. Studies confined to the new willow clones which have been developed in cooperation between Svalof-Weibull and Long-Ashton research in UK between 1996 and 2002 confirm that willow breeding has been leading to higher yields in commercial practice. For the new clones, reported yields vary between 5 and 12 odt ha-1, with extremes between 2 and 18 odt ha-1 yr-1 [34, 86, 87, 88]. This large variation seems to be related to interactions between clones and sites [33, 89].

2. Conclusion

Willow short rotation coppice systems are relatively new as a farm crop and both farmers and extension workers in Sweden have gone through a learning process which is now leading to higher yields in commercial plantations. Traditional willow breeding and selection are already greatly contributing to increasing yields, and it is expected that future improvements of the willow varieties will result in a significant increase of the yields in the near future. Many of the early field research results are currently extended with more controlled experiments, and help to improve short rotation coppice management. Although the early commercial implementation of willow coppice did not meet the expectations with regard to yield, profitability and areal expansion of willow coppice, analyses of the early commercial fields contribute to the improvement of stand management, and of the planting, harvest and transport logistics. Further developments of willow coppice as multi-purpose systems, including environmental functions, are promising. Current research suggests that there is room for further improvements with regard to cutting quality, planting, weed control and fertilization, all of which will contribute to higher future yields.

Author details

Theo Verwijst[4], Anneli Lundkvist and Stina Edelfeldt

Department of Crop Production Ecology, Swedish University of Agricultural Sciences, Uppsala, Sweden

Johannes Albertsson

Department of Plant Breeding and Biotechnology, Swedish University of Agricultural Sciences, Alnarp, Sweden

Acknowledgement

We kindly acknowledge the financial support from The Swedish Research Council for Environment, Agricultural Sciences and Spatial Planning, Stockholm, Sweden; The Swedish University of Agricultural Sciences (SLU), and The Thermal Engineering Research Association (Varmeforsk), Sweden. We thank Nils-Erik Nordh for many of the photographs which illustrate this chapter. Inger Ahman, Nils-Ove Bertholdsson, David Hansson, Sten Segerslatt, Gunnar Henriksson, Stig Larsson, Gabriele Engqvist, Bertil Christensson and Sven Erik Svensson all are acknowledged for their advice and constructive co-operation in the different phases of our willow work. Erik Rasmusson, Eskil Kemphe, Fatih Mohammad, Vehbo Hot, Ingegerd Nilsson, Nils-Erik Nordh and Richard Childs are kindly acknowledged for practical help with the experiments. Finally we thank all the agriculturally skilled and hard working students that have helped us coping with all the experiments through the years.

The inputs used in varieties rice production under two farming system and their energy equivalents and output energy equivalent were illustrated in "Tables 3 and 4". About 848.7 h human labor, 37.2 h machinery power, 1000 m3 water, 5 L chemical poison and 127.2 L diesel fuel for total operations were used in varieties rice production under traditional on a hectare basis; Also 106.85 L depreciation power in this system was used. The highest use of nitrogen fertilizer (105.8 kg/ha), phosphorus (21 kg/ha) and potassium (82 kg/ha) were observed in Gohar rice. The lowest use seed in varieties rice production under traditional was observed in Gohar rice (30 kg/ha). About 663.3 h human labor, 47.3 h machinery power, 1000 m3 water, 5 L chemical poison and 142.1 L diesel fuel for total operations were used in varieties rice production under traditional on a hectare basis; Also 119.36 L depreciation power in this system was used. The highest use of nitrogen fertilizer (105.8 kg/ha), phosphorus (21 kg/ha) and potassium (82 kg/ha) were observed in Gohar rice. The lowest use seed in varieties rice production under traditional was observed in Gohar rice (20 kg/ha).

In "Figure 6" (traditional system) and "Figure 7" (semi-mechanized system), eight groups of reserves of production of studied figures according to percentage of total energy of reserve were observed. Results showed that highest shares of this amount were reported for machinery, water, diesel fuel, chemical fertilizer and depreciation for per diesel fuel in all varieties rice production respectively. The energy inputs of seed, human labor and chemical poison were found to be quite low compared to the other inputs used in all varieties rice production respectively.

The highest percent of compositions, amounts, production energy, and production energy to consumption energy ratio in rice paddy were obtained from starch as compared with protein and fat; the lowest consumption energy to production energy ratio in rice paddy was obtained from starch as compared with protein and fat "Table 8". Results of "Table 8" showed that breed varieties (Khazar, Hybrid and Gohar) because of suitable genetic specifications have higher operation in compared with local varieties (Hashemi and Alikazemi); the highest amounts (protein: 551.76, fat: 183.92 and starch: 6688), production energy (protein: 2207040 kg/ha, fat: 1655280 kg/ha and starch: 26752000 kg/ha), and production energy to consumption energy ratio (protein: 0.20, fat: 0.15 and starch: 2.41) in rice paddy of traditional system and highest amounts (protein: 627, fat: 209 and starch: 7600), production energy (protein: 2508000 kg/ha, fat: 1881000 kg/ha and starch: 30400000 kg/ha), and production energy to consumption energy ratio (protein: 0.21, fat: 0.16 and starch: 2.51) in rice paddy of semi-mechanized observed in Gohar rice.

The highest percent of compositions, amounts, production energy, and production energy to consumption energy ratio in rice husk were obtained from starch as compared with fat and protein; the lowest consumption energy to production energy ratio in rice husk was obtained from starch as compared with fat and protein "Table 9". Results of "Table 9" showed that breed varieties (Khazar, Hybrid and Gohar) because of suitable genetic specifications have higher operation in compared with local varieties (Hashemi and Alikazemi); the highest amounts (protein: 107.22, fat: 107.64 and starch:1045), production energy (protein: 428868 kg/ha, fat: 968715 kg/ha and starch: 4180000 kg/ha), and production energy to consumption energy ratio (protein: 0.04, fat: 0.09 and starch: 0.38) in rice husk of traditional system and highest amounts (protein: 121.84, fat: 122.31 and starch: 1187.50), production energy (protein: 487350 kg/ha, fat: 1100813 kg/ha and starch: 4750000 kg/ha), and production energy to consumption energy ratio (protein: 0.04, fat: 0.09 and starch: 0.39) in rice husk of semi-mechanized observed in Gohar rice.

The highest percent of compositions, amounts, production energy, and production energy to consumption energy ratio in rice straw were obtained from starch as compared with protein and fat; the lowest consumption energy to production energy ratio in rice straw was obtained from starch as compared with protein and fat "Table 10". Results of "Table 10" showed that breed varieties (Khazar, Hybrid and Gohar) because of suitable genetic specifications have higher operation in compared with local varieties (Hashemi and Alikazemi); the highest amounts (protein: 490.76, fat: 148.37 and starch:4941.83), production energy (protein: 1963036 kg/ha, fat: 1335321 kg/ha and starch: 19767316 kg/ha), and production energy to consumption energy ratio (protein: 0.18, fat: 0.12 and starch: 1.87) in rice straw of traditional system and highest amounts (protein:557.67, fat: 168.60 and starch: 6515.68), production energy (protein: 2230668 kg/ha, fat: 1517373 kg/ha and starch: 22462308 kg/ha), and production energy to consumption energy ratio (protein: 0.18, fat: 0.13 and starch: 1.86) in rice straw of semi-mechanized observed in Gohar rice.

The highest percent of compositions, amounts, production energy, and production energy to consumption energy ratio in rice biomass were obtained from starch as compared with protein and fat; the lowest consumption energy to production energy ratio in rice biomass was obtained from starch as compared with protein and fat "Table 11". Results of "Table 11" showed that breed varieties (Khazar, Hybrid and Gohar) because of suitable genetic specifications have higher operation in compared with local varieties (Hashemi and Alikazemi); the highest amounts (protein: 1087.52, fat: 355.91 and starch:12259.26),

production energy (protein: 4350060 kg/ha, fat: 32032260 kg/ha and starch: 49037040 kg/ha), and production energy to consumption energy ratio (protein: 0.41, fat: 0.30 and starch: 4.65) in rice biomass of traditional system and highest amounts (protein:1235.80, fat: 404.44 and starch: 13930.87), production energy (protein: 4943180 kg/ha, fat: 3639978 kg/ha and starch: 55723120 kg/ha), and production energy to consumption energy ratio (protein: 0.47, fat: 0.35 and starch: 5.29) in rice biomass of semi-mechanized observed in Gohar rice.

Results of "Table 12" showed that breed varieties (Khazar, Hybrid and Gohar) because of suitable genetic specifications have higher operation in compared with local varieties (Hashemi and Alikazemi); the highest paddy yield (8360 kg/ha), consumption energy (11084731 kcal/ha), production energy (30614320 kcal/ha) and production energy to consumption energy ratio (2.76) in rice paddy of traditional system and highest paddy yield (9500 kg/ha), consumption energy (12093473 kcal/ha), production energy (34789000 kcal/ha)

and production energy to consumption energy ratio (2.88) in rice paddy of semi-mechanized observed in Gohar rice. Energy per unit for rice varieties under to farming system was equaled. Highest Consumption energy to production energy ratio for rice varieties under to farming system was observed in Hashemi rice. Energy balance efficiency (production energy to consumption energy ratio) in this study was calculated 2.76 and 2.88; showing the affective use of energy in the agro ecosystems rice paddy production.

Results of "Table 13" showed that breed varieties (Khazar, Hybrid and Gohar) because of suitable genetic specifications have higher operation in compared with local varieties (Hashemi and Alikazemi); the highest husk yield (2090 kg/ha), consumption energy (11084731 kcal/ha), production energy (5577583 kcal/ha) and production energy to consumption energy ratio (0.50) in rice husk of traditional system and highest husk yield (2357 kg/ha), consumption energy (12093473 kcal/ha), production energy (6338163 kcal/ha) and production energy to consumption energy ratio (0.52) in rice husk of semi-mechanized observed in Gohar rice. Energy per unit for rice varieties under to farming system was equaled. Highest Consumption energy to production energy ratio for rice varieties under to farming system was observed in Hashemi rice. Energy balance efficiency (production energy to consumption energy ratio) in this study was calculated 0.50 and 0.52; showing the affective use of energy in the agro ecosystems rice husk production.

Results of "Table 14" showed that breed varieties (Khazar, Hybrid and Gohar) because of suitable genetic specifications have higher operation in compared with local varieties (Hashemi and Alikazemi); the highest straw yield (11413 kg/ha), consumption energy (11084731 kcal/ha), production energy (23065673 kcal/ha) and production energy to consumption energy ratio (2.08) in rice husk of traditional system and highest paddy yield (12969 kg/ha), consumption energy (12093473 kcal/ha), production energy (26210349 kcal/ha) and production energy to consumption energy ratio (2.17) in rice husk of semi — mechanized observed in Gohar rice. Energy per unit for rice varieties under to farming system was equaled. Highest Consumption energy to production energy ratio for rice varieties under to farming system was observed in Hashemi rice. Energy balance efficiency (production energy to consumption energy ratio) in this study was calculated 2.08 and 2.17; showing the affective use of energy in the agro ecosystems rice straw production.

Results of "Table 15" showed that breed varieties (Khazar, Hybrid and Gohar) because of suitable genetic specifications have higher operation in compared with local varieties (Hashemi and Alikazemi); the highest biomass yield (19773 kg/ha), consumption energy (11084731 kcal/ha), production energy (56590326 kcal/ha) and production energy to consumption energy ratio (5.37) in rice biomass of traditional system and highest biomass yield (22469 kg/ha), consumption energy (12093473 kcal/ha), production energy (6430278 kcal/ha) and production energy to consumption energy ratio (6.10) in rice biomass of semi — mechanized observed in Gohar rice. Energy per unit for rice varieties under to farming system was equaled. Highest consumption energy to production energy ratio for rice varieties under to farming system was observed in Hashemi rice. Energy balance efficiency (production energy to consumption energy ratio) in this study was calculated 5.37 and 6.10; showing the affective use of energy in the agro ecosystems rice biomass production.