International Journal of Recycling of Organic Waste in Agriculture
Volume:5 Issue: 2, Spring 2016

Rubber leaves are the abundant agro-waste and pineapple, the most economically important fruit crop in Tripura. So, in our present study, different amounts of rubber leaf vermicompost have been applied to the soils of pineapple plantation to determine their effects on earthworms—the soil ecosystem engineers, coupled with the vegetative growth and yield of pineapples.
During 30 months of field trial (2010–2012) in ICAR regional station, Lembucherra, West Tripura, the control plot (T0) received no fertilizer, while experimental plots were fertilized with four different amounts of vermicompost viz. T1 (5 tons ha−1 year−1), T2 (10 tons ha−1 year−1), T3 (20 tons ha−1 year−1) and T4 (30 tons ha−1 year−1).
A significant (p The present study reveals that crop yield is very much related to the particular concentration of vermicompost, beyond the level of which production declines and increase in vegetative growth, fruit weight and fruiting percentage of pineapple are strongly linked with the soil pH, av. P, av. K, clay content and the earthworm density of soils.

Catha edulis, commonly called as khat or chat is an evergreen plant cultivated in Ethiopia for its stimulant leaves. The young leaves are chewed as a part of social recreation and the older leaves along with the twigs are discarded. This forms the major part of municipal solid waste that is dumped in large quantity in Harar region. The present study was carried in Haramaya University, Ethiopia to decompose the khat wastes along with crop residues and different animal manures (cow dung, goat manure, poultry manure and swine manure) using the earthworm Eisenia foetida.
The collected khat wastes along with crop residues and different animal manures were vermicomposted and assessed for nutrient contents using standard procedures.
The result of the experiment indicated that all the parameters were improved by the decomposition using earthworms and the C/N ratio was within the limits that indicate the maturity of the compost. The organic carbon, organic matter, total nitrogen, phosphorus, copper, iron, zinc and manganese contents were analyzed and found to be improved after decomposition. The added crop residues and animal manures enhanced the decomposition process and manurial value of the khat leaf waste.
The nutrient content of the vermicomposts revealed khat to be a suitable substrate for vermicomposting thereby making efficient utilization of solid wastes. This can be an effective technology to reduce the solid waste and the resultant product can be used for improving soil fertility and crop production by the farmers.

The aim of this research was to assess the health risk of textile wastewater reuse as irrigation water on leafy vegetable (Basella alba) by comparing variable growth rate in different ration of wastewater and freshwater irrigation and assess their soil-to-plant transfer factor (TF) and health risk index (HRI).

Pot experiments were laid out with five treatments including control with three replications with different irrigation schemes with textile wastewater collected from the untreated point source. The irrigation scheme was, 100 % groundwater as control with four treatments as 75 % groundwater: 25 % wastewater, 50 % groundwater: 50 % wastewater, 25 % groundwater: 75 % wastewater and 100 % wastewater.

Soil-to-plant TF in different treatments including control were in the order of Pb (1.0–1.7) > Cu (1.3–1.5) > Cd (0.8–1.0) > Zn (0.1–1.1). TF values of Pb and Cu in the range from 1 to 1.7 indicating their accumulation in B. alba plants and their potential health risk by dietary exposure. The HRI for individual metal as well as cumulative HRI of the metals was less than unity (0.33) which indicated the consumption of the vegetables was considered to be safe for one harvest.

Over many seasons of irrigation with wastewater, level of salinity and heavy metals can accumulate on the agriculture land and their long term consumption may link to a chronic health risk. Hence, consumption of these vegetables on regular basis should be avoided.

The implications of increased applications of high quality cattle manure to agricultural systems in Africa on N2O emissions are still only partially understood.
A field experiment was carried out in a wetland in central Zimbabwe to determine the effects of cattle manure quality on emissions of N2O during the growing seasons of rape and tomato crops. The static chamber and gas chromatography techniques were used to capture and measure fluxes of N2O.
The substitution of low N by high N manure significantly increased N2O fluxes and total N lost through N2O emission. Emissions of N2O increase with increasing content of N in applied manure.
Given that N2O in agricultural soil is produced predominantly through the microbial transformations of inorganic N, the potential of a soil to emit N2O increases with the increasing availability of N and consequently the N content in applied manure. The applications of lower rate of high and low N manures were followed by lower emissions of N2O, a result that is favorable to the objective of lowering the contribution of agricultural sources to the global greenhouse gas emissions. The loss of N in emissions of N2O expressed per unit mass of harvested dry matter yield decreases with increasing manure application, dry matter yield and N uptake. Improved agronomic practices for increased crop productivity can be used as a mitigation factor for reducing the contribution of agriculture in the global emissions of N2O.

Research has shown that oil palm decanter cake (DC) serves as a potential source of nutrients for plant growth. This study therefore investigated the applicability of decanter cake (DC) as an amendment to soil for the growth of Solanum melongena (brinjal) at three ratios 10, 20, 30 % DC and suitable controls (0 %).
Seeds of brinjal were sown in soils amended with decanter cake at 10, 20, 30 % w/w and 0 % as control. Nutrient enrichment factors were calculated from the concentration of selected metals (Cu, Ca, Fe, Zn and Mg) in plant parts. The scanning electron micrographs were also taken to measure the stomatal opening/closing due to the effect of excess nutrients on the leaf structure.
Enrichment factor (EF) values in this study were all below 3 indicating low enrichment of metal ions from soil to plants. SEM studies of the leaf epidermis of the test plants revealed the closure of guard cells with increasing decanter cake treatments.
Decanter cake at 20 % amendments with soil could serve as a source of soil amendment for cultivation of S. melongena plants.

The field experiments were conducted to utilize the sugarcane pressmud in the farming of Solanum melongena as an organic fertilizer.
For growing of S. melongena, six agricultural fields were selected for the six amendments of sugarcane pressmud, viz., 0 % (garden soil as control), 20 % (20 % sugarcane pressmud 80 % garden soil), 40 % (40 % sugarcane pressmud 60 % garden soil), 60 % (60 % sugarcane pressmud 40 % garden soil), 80 % (80 % sugarcane pressmud 20 % garden soil) and 100 % (100 % sugarcane pressmud). S. melongena was grown in sugarcane pressmud-amended soil till harvest and impact of sugarcane pressmud on the soil and agronomical characteristics of S. melongena were determined.
The results showed that the sugarcane pressmud was rich in various nutrients and produced significant (P Mn > Cd > Cu > Fe > Cr for the soil and Fe > Mn > Cu > Zn > Cd > Cr for S. melongena in both growing seasons after treatment with sugarcane pressmud.
This study concluded that application of sugarcane pressmud treatments increased the soil fertility and as a result agronomical performance of S. melongena. Therefore, it can be used for the soil amendments in the lower proportion (up to 40 %) to improve the yield of S. melongena.

In Bangladesh, the sludge of textile effluent treatment plant has been considered as a potential environmental threat due to its huge volume and chemical content. Thus, the present study was carried out to assess the reuse possibility/potentiality of textile sludge in agricultural applications.
Textile sludge was applied at different loading ratios (0–100 % sludge) with soil for the pot cultivation of red amaranth (Amaranthus gangeticus); subsequently, chemical analyses were carried out on the harvested plants.
The results showed that the content of plant nutrients nitrogen (N), phosphorus (P), potassium (K) and iron (Fe) in sludge was significant compared to organic manure along with a high content of total organic carbon (TOC). The growth parameters (height, number of leaves, leaf area and root length) of red amaranth were affected by the application of textile sludge. Maximum plant growth was observed in the 100 % sludge treatment group, maybe because of the high content of plant nutrients. However, the root length and number of leaves were not significantly affected by the sludge. The plant analyses implied that addition of textile sludge did not increase the content of copper (Cu), cobalt (Co), cadmium (Cd), nickel (Ni) and manganese (Mn), but lead (Pb), chromium (Cr), zinc (Zn) and iron (Fe) content crossed the maximum permissible limit set by FAO/WHO.
Textile sludge can improve the nutrient contents of pot soil and growth of red amaranth, which is revealed by pot experiments. Therefore, it can be used as soil improver if Pb, Cr, Zn and Fe content can be controlled in the textile sludge.

Sphagnum peat moss has been a primary component of soilless potting media for decades. Concerns over the sustainability of harvesting peat have fostered a search for renewable media components. Anaerobically digested dairy fiber (ADDF), a by-product of methane production, shows promise as an alternative to peat.
Poinsettias (Euphorbia pulcherrima ‘Classic Red’) were grown in media containing peat-perlite in a 4:1 ratio or peat-ADDF-perlite in a 2:2:1 ratio. Bulk density, container capacity, water-holding capacity, pH and EC of both mixes were evaluated before planting. Shoot height, shoot fresh weight, shoot dry weight and leaf tissue nutrient concentrations of plants were measured at commercial maturity. PourThru samples were taken from pots regularly to evaluate phosphate leaching potential from ADDF.
There were no differences in physiochemical properties between mixes. Poinsettias grown in the peat-ADDF-perlite were significantly taller and had greater shoot fresh weight, shoot dry weight and leaf tissue N, P, Mn, Na and Zn concentrations than control plants. PourThru samples from pots containing peat-ADDF-perlite had greater phosphate concentrations than peat-perlite for approximately 5 weeks.
The ADDF used in this trial can be used as a 50 % substitute for peat in potting media for poinsettias and contains significant amounts of plant available nutrients. Additional nutrients supplied by ADDF should be carefully managed as they can contribute to plant growth or leaching pollution. Using ADDF in media could provide growers with a local, renewable substitute for peat and provide supplemental income to dairy farmer.

The seemingly harmful effect of chemical insecticides to the environment, plants and human health, has led to prominent role of entomopathogenic fungi (ENPF) as biopesticide. However, the success of ENPF as biocontrol agent depends on their amenability to easy and cheap mass multiplication. Solid state fermentation (SSF) has emerged as an appropriate technology for management of agro-industrial residues and for their value addition. In this study, the potentiality of agricultural by-products for mass multiplication of Beauveria bassiana was determined.
Two sets of SSF experiments with agricultural by-products [tea leaf waste, wheat bran, husk of rice, pigeon pea and urad, and seed cake of jatropha and pongamia] as substrates; one with fortification of nutrients, while other with no nutrient addition were performed. The substrates (200 g) were inoculated with B. bassiana spore suspension (1 × 108 spores/ml) and incubated at 28 °C for 14 days. After the incubation period, B. bassiana spore concentrations were enumerated.
Maximum spore production was observed in rice husk, while jatropha seed cake showed least spore production. Addition of nutrient supplements in the substrates showed slight (pongamia seed cake) to significant (rice husk, tea leaf waste) increase in spore production. The results showed constant increase in spore production with increase in C/N ratio of the substrates.
Mass production processes directly influences the cost, shelf life, virulence, and field efficacy of fungal pathogens. The results from this investigation are expected to pave the way towards commercialization of B. bassiana by augmenting the research in fungal mass production.