International Journal of Recycling of Organic Waste in Agriculture
Volume:1 Issue: 1, Autumn 2012

As objective of this study was focused on efficacy of composting of a recalcitrant organic waste material, co-composting of coir pith with cow manure and rice bran was endeavored to evaluate influence of initial C/N ratios, i.e., 30, 25, and 20, on physico-chemical changes, e.g., temperature, pH, organic matter (OM) degradation, and total nitrogen (TN) losses.

Results showed that OM and TN losses were significantly affected by C/N ratio (p < 0.05), whereas C/N ratio played insignificant role on temperature and pH evolution within the pile (p > 0.05) during composting process. OM and TN losses were highest within the first 2 weeks of thermophilic phase. Through the composting process, pile with 25 C/N ratio showed the highest biodegradation rate constant of organic matter (k = 0.309 day−1 ) and the highest TN losses (41.9%), while pile with C/N ratio of 30 showed the lowest N loss (−7.3%). However, for all three compost piles, maturity, as indicated by the pile temperature converging to the ambient temperature, was attained within 1 month post-composting.

Results suggested that simple pile turning yielded effective co-composting of coir pith under comparatively low C/N ratio. Considering the composting performance and the amount of coir pith to be utilized, the initial C/N ratio of 30 was considered suitable for coir pith composting.

In West Bengal, India, a huge amount of lignocellulosic jute waste products, in the form of unutilized cut pieces of jute caddies consisting 65% cellulose, 22.5% hemicellulose, and 11% lignin, is generated from jute industries. Naturally, the high percentage of lignocellulolytic material made it an attractive substrate for the hydrolytic cleavage of lignocellulolytic enzymes, namely xylanases and cellulases. The present study aims for the production of xylanolytic and cellulolytic enzymes by a fungal isolate Penicillium janthinellum MTCC10889 using a cheap medium containing residual jute caddies obtained from jute mill wastes and chemically defined basal medium under submerged fermentation.

The fungal isolate P. janthinellum MTCC10889 is an outstanding producer of endoxylanase and also cellulase. A central composite design was applied to optimize its lignocellulolytic as well as cellulolytic enzyme production in submerged-state fermentation. The impact of three quantitative variables, namely pH, temperature, and substrate concentrations, on enzyme production was investigated by using a chemically defined basal medium supplemented with jute caddy as substrate. Such optimum conditions were as follows: pH 7.47, temperature of 30.35°C, and substrate concentration of 1.70% for endoxylanase, and pH 7.51, temperature of 29.69°C, and substrate concentration of 2.11% for cellulase production.

A combination of one-factor-at-a-time approach is replaced by response surface methodology using central composite design, which resulted in 3.08- and 3.84-fold increases in the yields of endoxylanase (1,750 IU/ml) and endoglucanase (192 IU/ml), respectively. The highest endoxylanase and endoglucanase productions under optimized conditions were achieved within 48 h of growth.

In this study, wheat bran, an agricultural waste, was utilized as a low-cost carbon source for algal cultivation.

Treatment of lignocellulosic waste by two fungal species (Pleurotus ostreatus or Trichoderma viride) caused the accumulation of reducing sugar at a relatively high concentration (50.58 and 54.30 mg/g wheat bran) after 7 days of incubation, respectively. The soluble products of treated wheat bran increased the growth, carbohydrate, and protein contents of both Chlorella vulgaris and Scenedesmus obliquus under mixotrophic and heterotrophic conditions.

The obtained data suggest that soluble product of treated wheat bran could be used as an efficient medium for the mixotrophic and heterotrophic growth of both algal species

The Southern Guinea savanna zone of Nigeria is characterized by inherently low soil fertility status and rapid nutrient depletion especially soil organic matter. However, this zone is characterized by abundant agricultural land and is a potential for crop production. Field experiments were conducted in order to evaluate the effects of integrated use of agricultural waste materials and compound mineral fertilizer on soil and plant nutrient status, growth, and yield of maize in ultisol in the Southern Guinea savanna zone of Nigeria.

Application of organic waste alone and in combination with mineral fertilizer enhanced root and shoot biomass, leaf area development, and yield and components of maize. Treatment effects were significant on growth characteristics of maize (stem girth, leaf area, plant height and days to 50% tasselling, root and shoot biomass). Sole application of NPK fertilizer (400 kg/ha) was not significant over the combined use of poultry manure and NPK on girth, leaf area, and plant height. Mean values of stem girth, leaf area, and plant height ranged between 2.05 and 3.8 cm, 0.26 and 0.54 m2 , and 84.7 and 209.4 cm, respectively. Root and shoot dry weights were highest under sole NPK application compared with plots where either sole wastes or wastes in combination with reduced NPK were application of NPK fertilizer (400 kg/ha) was not significant over combined use of poultry manure and NPK on stem applied. Integrated use of agricultural wastes and NPK also enhanced root and shoot dry weights compared with sole application of wastes as well as seed weight per plant, 100-seed weight, and number of seeds per cob and grain yield. Among the agricultural wastes applied, poultry manure enhanced the growth and seed yield characteristics of maize. This treatment increased the seed weight per plant, number of seeds per cob, 100-seed weight and seed yield by 55.6%, 66.5%, and 55.4%, respectively over Chromolaena and neem seed cake. Chromolaena and neem seed cake produced similar grain weight per plant, 100-seed weight, number of seed per cob, and seed yield. Poultry manure significantly enhanced the growth and seed yield characteristics of maize over Chromolaena and neem seed cake.

Integrated use of organic wastes and mineral NPK fertilizer showed promising potential for improving soil fertility, growth, and yield of maize in the Southern Guinea savanna agroecological zone of Nigeria. It is recommended that poultry manure at 7 t/ha plus NPK fertilizer at 200 kg/ha be adopted for maize cultivation in the study area.

The swine production is a very important economic matter, occupying prominent position in the worldwide market. However, it appears as the greater impacting activity for the water resources. Researches point a swine manure production of 105.6 million m3 /year in Brazil, which resulted in a piggery wastewater rich in solids, nutrients, heavy metals, and pathogens. Moreover, the water consumption for swine production is approximately 15 L/animal/day in southern Brazil, resulting in an unsustainable water resource demand. Thereby, this study verifies the viability of two parallel stabilization reservoirs as a technology for polishing treated piggery wastewater. This technology has been shown effective in reducing organic matter, nutrients, and pathogens in the treatment of the effluents with low or high organic load rate. The reservoirs can improve effluent quality with minimal energy costs to simple operations. The technique would promote the value of the effluent through its reuse for agricultural irrigation. The study was conducted at a farm in the city of Braço do Norte, Santa Catarina, in southern Brazil; this region has one of the largest densities of pigs in the world, which causes serious environmental problems.

The effluent monitoring program included operation during both cold seasons (period I) and warm seasons (period II). The performance of the reservoirs improved continuously during the cold seasons, with the removal efficiencies of total biochemical oxygen demand (BOD5), total Kjeldahl nitrogen (TKN), and Escherichia coli reaching 52%, 64%, and 99.9%, respectively, with an effluent concentration of 144 mg·L−1 for BOD5 and 256 mg·L−1 for TKN. During the warm seasons, the BOD5, TKN, and E. coli removal efficiencies increased to 85%, 77%, and 99.9%, respectively, with an effluent concentration of 52 mg·L−1 for BOD5 and 136 mg·L−1 for TKN, which indicates that seasonal factors greatly influence the removal of these variables. E. coli concentrations were not verified into stabilization reservoirs on both periods.

The results of this study confirmed that the stabilization reservoirs are capable experimental units promoting improved quality of the treated effluent. A seasonal influence was evident. The results demonstrated that the effluent was a good alternative for unrestrained irrigation use. The microbiological quality complies with the World Health Organization recommendations. The reuse of this treated effluent can reduce pig manure impacts on the environment and water resources.

Agricultural waste has been proposed as an alternative energy resource to meet fossil fuel crisis, green house emission, and other environmental impacts worldwide. In Iran, rice husk and bagasse are main resources of biomass which can be used to produce syngas. This paper deals with a simplified model of combined gasification of coal and biomass processes considering chemical equilibrium.

It should be noticed that the CO2 which is produced from agricultural waste gasification is natural because the biomass absorbs CO2 from nature and gives it back after gasifying; however, mixing agricultural waste with coal leads to enrich syngas quality and gasifier efficiency.

In this regard, an advanced coding was developed to simulate the thermodynamics of the co-gasifier and to find the produced syngas composition. The effects of moisture content, steam-to-biomass ratio, and gasifier temperature are then discussed on the system performance. Additionally, co-gasification of rice husk/coal was compared with co-gasification of bagasse/coal. The results indicated that adding coal to biomass increases lower heating value of syngas from 4,694 kJ/Nm3 to 5,321 kJ/Nm3 and gasifier efficiency from 71.29% to 77.85%.

While the increase in the number of coconut-based industries in Malaysia supports economic growth positively, it affects the environment negatively by generating large amounts of coconut wastes. This study has endeavored to assess the possibility of vermicomposting different types of coconut wastes and, in doing so, evaluated the potential of using the African nightcrawler (Eudrilus eugeniae) to decompose coconut wastes. The study was conducted over a 50-day duration using two different types of coconut wastes: coconut husk (CH) and spent coconut flakes (SCF). The nutrient content of the vermicompost at various stages of treatments was determined. Three different percentage ratios were used: {C1-W or B1-W (100% waste), C2-W or B2-W (70% waste + 30% goat manure), and C3-W or B3-W (50% waste + 50% goat manure)}. Twenty healthy adult E. eugeniae (each 0.02 to 0.03 kg) were introduced to each treatment.

Results showed that the degradation process was very fast in the spent coconut flakes which needed only 16 days for complete decomposition, while that in the coconut husk needed 2 months. Available phosphorous (P) and total potassium (TK) values declined in CH. The available P and TK in C3-W (50% waste + 50% goat manure) were less than the initial values by 26.6% and 53.69%, respectively. Moreover, P and TK values increased in SCF at the final stage as in B2-W (70% waste + 30% goat manure) which was 69.3% more than the initial level. The weights of the worms were recorded throughout the experimental period.

The study showed that vermicomposting could be an efficient method to convert coconut wastes into a valuable by-product.

The application of biosolid as a fertilizer in agricultural cultivation is a common practice in many countries. This study investigates the effects of sewage sludge and compost usage on soil chemical properties and Zea mays nutrition in comparison with those of iron and manganese sulfate solution. The experiment was carried out in a completely randomized block design with the following treatments: sewage sludge and compost with three levels (0, 25 and 50 t ha−1 ) and iron and manganese sulfate solution (1 g l−1 solution) with three replications.

The application of sewage sludge (50 t ha−1 ) had highly significant (P < 0.01) positive effects on cation exchange capacity and organic matter, total nitrogen, phosphorus, iron and manganese diethylenetetramine-pentaaceticacid-extractable in soil, and nitrogen, phosphorus, iron and manganese in plant. Also, compost application (50 t ha−1 ) increased significantly (P < 0.01) the electrical conductivity in soil and potassium in soil and plant. Dry biomass increased significantly (P < 0.01) from 7.7 to 28.7 g per pot with sewage sludge application (50 t ha−1 ).

Application of biosolid as fertilizer sources has become a common practice in Iran, especially in the agricultural lands. The reuse of these nutrients had some beneficial effects on soil fertility, such as increased cation exchange capacity, pH, organic matter, total nitrogen, phosphorous, iron and manganese. However, these benefits were limited by the presence of some potentially toxic trace metals in biosolid.

Two of the main concerns for wastewater reuse in agricultural irrigation are environmental and human security. Different research studies and practices have been developed recently in order to quantify the risk of possible environmental contamination of surface and groundwater resources as well as the risk to public health from enteric viruses. Other, far from negligible, related issues are largely of a socio-economic and technical character. For example, the social acceptance, especially by farmers, of wastewater reclamation and reuse in agriculture is influenced by specific local cultural, religious and socio-economic conditions. Economic and technical factors should also be taken into consideration, such as the water and wastewater treatment costs, the cost of maintenance, the employment of rural labour, the structure of irrigation networks and crop patterns. In this paper, the concept of sustainability in wastewater reclamation and reuse is formulated by using a general risk analysis framework and by taking into account all the above factors. The paper suggests a methodology for sustainable wastewater reuse in agriculture by considering not only technical and economic factors, but also environmental and social risks. Alternative strategies based on different treatment and irrigation technologies are evaluated using the multicriteria decision analysis technique. The methodology is illustrated in a case study of wastewater reclamation and agricultural reuse in the city of Thessaloniki, Macedonia, Greece

The entrance of untreated wastewater or disposal leachate to water resources such as surface water, groundwater or irrigation water increases the risk of contaminant accumulation. Removal or deduction of water contaminant concentration is then crucial before entering water to the natural resources or its transfusion directly to the soil as irrigation water. Four studies were carried out in a pilot plant to evaluate the effect of natural zeolite to decrease chemical and biological index of compost factory leachate. Land treatment was considered as the main strategy; however, some pounding and column experiment was implemented as well. Wastewater chemical and biological indexes were analyzed. These indexes consisted of Na, K, Mg, Ca, Co3, HCO3, Ni, Cd, Pb, Cr, chemical oxygen demand (COD), fecal coliform and total coliform (TC). In addition, soil was analyzed for EC, pH, cation and anion.

In the first study, three types of zeolite derived from Semnan, Mashhad and Miyaneh mines were tested with four sizes (70, 140, 270 and 840 μm) at 25°C in summer 2007. It was concluded that high value of the cation concentration in the leachate causes neither adsorption of remaining cation nor heavy metals. There was no statistically significant difference between the zeolite sizes and the heavy metal adsorption. The results also showed that the adsorption ratios were 52%, 23% and 40% for Na, Ca and Mg, respectively. In the second study, a loamy sand soil was enriched by adding 5% and 10% of the zeolite. The result uncovered that adding 10% of the zeolite to the soil brings about more elements' absorption in comparison to application of the 5% zeolite. Irrigation with the leachate reduced soil specific yield significantly. In the third study, a complete randomized design experiment was used with six treatments (two kinds of soil, loamy sand and clay loam, and three levels of zeolite, 0%, 5% and 10%) and three replications performed in the lysimeter size. The results revealed that irrigation with the leachate reduces soil bulk density, infiltration rate and saturated hydraulic conductivity. Heavy metals could not be absorbed by loamy sand soil, whereas clay loam soil had a high ability to absorb heavy metals and reduce the salinity. In loamy sand and clay loam soil, 10% zeolite had a significant effect on heavy metals' absorption. The result of subsequent study (the same setup as the third study) exhibited the fact that the COD was significantly decreased by application of 5% zeolite, whilethis reduction occurred via applying 10% of zeolite in TC.

In short, this research indicated that the wastewater can be treated in a simple, economically process of land treatment through application of a clay loam soil texture with a cation pre-treatment.

Improving levels of organic matter in desert soils is necessary for their cultivation. A two-year study (2008 to 2010) was conducted on a sandy clay loam soil at the experimental research farm of the Omdurman Islamic University, Sudan to determine the effect of application of crop residue, sewage sludge, and humentos on selected soil properties in wheat-guar crop rotation system. Treatments were recommended inorganic fertilizer (125 kg N ha−1 and 92 kg P ha−1 ), recommended inorganic fertilizer with crop residues, crop residue, sewage sludge (10 t ha−1 ), humentos soil conditioner (200 L ha−1 ), and control.

Results showed that soil physical properties were not significantly changed except soil water holding capacity. Application of crop residues with recommended fertilizer and sewage sludge for three seasons significantly increased cation exchange capacity and organic carbon by 57.15 % to 60.95 % and 61.0 % to 65.2 %, respectively. Moreover, combined application of crop residues with recommended inorganic fertilizer and sewage sludge had significantly decreased topsoil pH.

The results showed that judicious combined application of organic wastes with inorganic fertilizers could be a useful practice in sustaining fertility of poor sandy soils.

Different substrates have several materials which could have direct and/or indirect effects on plant growth and development. Therefore selecting the best substrate between the various materials is imperative to plant productivity. This research was carried out with using a completely randomized design with three treatments and seven replications. The treatments were including perlite, date-palm waste and soil. During plant growth irrigation rate, temperature, humidity, pest control for all treatments were similar. Cucumis Stativus cultivar was used for seeds. During plant growth Papadopolus formula with fertigation method used for nutrient solution. Some physiochemical characteristics of cultivation substrates were measured. The growth indices of cucumber plant were measured at the end of growth period. Results showed that higher amount of yield, biomass weight, SD, plant height, root weight, LAI and fruit TSS related to date-palm waste that had a significant difference with soil at 5% level but generally had not any significant difference at 5% level as compared with perlite substrate.

Recent trend of declining sustainability in agricultural production is appearing as a major threat to most of the Asian countries. To combat the situation, increasing importance is now being paid on incorporation of organic materials for rejuvenating the health condition and, hence, the productivity of these soils. Large scale availability of conventional organic manures being a big problem nowadays, major attention is being paid on recycling of different kinds of organic wastes for this purpose. Apart from abatement of environmental pollution, such reuse of organic wastes in agriculture helps in the improvement of various physical, chemical and biological properties of the soils and, thus, helps in sustaining the soil health. While recycling different organic wastes in agriculture, it is essential to process the materials through an adequate period of composting for improving their usability in the soils. However, due to some short comings of traditional composting systems, the technology of recycling of organic wastes has not been widely accepted so far. Under this situation, vermicomposting has recently emerged as a simple but efficient biotechnology for recycling wide ranges of organic wastes with the help of some specific groups of earthworms. In view of the growing popularity of this biotechnology, various aspects of waste recycling in agriculture through vermicomposting have been dealt in this communication.

The present investigation was undertaken to assess the residual influence of organic materials and biofertilizers applied to rice and wheat on yield, nutrient status, and economics of succeeding mung bean in an organic cropping system. The field experiments were carried out on the research farm of IARI, New Delhi during crop cycles of 2006 to 2007 and 2007 to 2008 to study the effects of residual organic manures, crop residues, and biofertilizers applied to rice and wheat on the performance of succeeding mung bean. The experiment was laid out in a randomized block design with three replications. Treatments consisted of six combinations of different residual organic materials, and biofertilizers included residual farmyard manure (FYM) and vermicompost (VC) applied on nitrogen basis at 60 kg ha−1 to each rice and wheat crops, FYM + wheat and rice residues at 6 t ha−1 and mung bean residue at 3 t ha−1 in succeeding crops (CR), VC + CR, FYM + CR + biofertilizers (B), VC + CR + B, and control (no fertilizer applied). For biofertilizers, cellulolytic culture, phosphate-solubilizing bacteria and Rhizobium applied in mung bean.

Incorporation of crop residue significantly increased the grain yield of mung bean over residual of FYM and VC by 25.5% and 26.5%, respectively. The combinations of FYM + CR + B and VC + RR + B resulted in the highest increase growth and yield attributing characters of mung bean and increased grain yield of mung bean over the control by 47% and net return by 27%.

The present study thus indicate that a combination of FYM + CR + B and VC + CR + B were economical for the nutrient need of mung bean in organic farming of rice-based cropping system.

Low-cost and suitable microcrystalline cellulose powders for use in the pharmaceutical industry can be derived from agricultural residues. Most commercial microcrystalline cellulose powders are produced from dissolving pulp obtained from expensive hard woods using concentrated acids. α-Cellulose was extracted from an agricultural residue (corn cob) using a non-dissolving method. The spectroscopic, thermal and physicochemical properties of the derived α-cellulose and microcrystalline cellulose powders were compared with AvicelW PH 101 (Fluka, New South Wales, Australia), a commercial brand of microcrystalline cellulose (MCCA), using standard methods.

X-ray diffraction showed that the microcrystalline cellulose samples obtained from maize cobs had diffraction pattern characteristics of both cellulose I and cellulose II, whereas MCCA had that of cellulose I; however, all the microcrystalline cellulose samples had similar crystallinity index (CI) values. Infrared spectroscopy results showed that the microcrystalline cellulose samples had comparable CI values and molecular structure. Thermogravimetric analysis and differential scanning calorimetry data showed quite similar thermal behaviour for all cellulose samples. Comparison of physicochemical properties of the microcrystalline cellulose powders obtained from maize cob and MCCA mainly suggests that all the celluloses have similar flow and compression properties.

For almost all of the characterizations carried out, it was observed that the microcrystalline cellulose powders obtained from corn cob had similar characteristics to the MCCA, showing that it can be a good low-cost alternative to the expensive commercial brand.