Search

Long-term irrigation using wastewater from paper industry may cause seriously problems to the receiving soil. This work surveyed and monitored the soil quality of a wastewater irrigation wetland system in Yancheng City, Jiangsu Province in China in 2014 and 2015. Τhe wetland soil showed different soil properties and TX, AOX, heavy metal contents after long-term wastewater irrigation. Long-term irrigation also accumulated the heavy metals such as Cu, Cd, Zn, and Pb in the wetland soil. Compared to the control, TX in the irrigated soil increased by 47.7–69.8% (2014) and 61.5–83.1% (2015). AOX varied in concentration from 1.7 to 55.0 mg kg−1 (2014) and 11.0 to 53.0 mg kg−1 (2015). The long-term irrigation of wastewater to wetland systems caused the accumulations of heavy metals, TX, and AOX in the soil and the levels of accumulations were related to several factors including soil properties, wastewater quality, and irrigation time.

Purpose: Due to environmental concerns, efforts are made to replace the use of peat in horticultural growth media by organic wastes. Four growth media were prepared with the purpose of achieving ad...

The term paper-mill waste is used for different products: de-inked fiber sludge, primary fiber sludge, secondary sludge and mixtures. The aim of this study was to find out if any of these materials can be safely used on agricultural soils to induce net N immobilization of N, and thereby decrease nitrate (NO 3 ) leaching. Chemical characterization showed that secondary sludge derived from biological waste water treatment was a nutrient-rich material low in fiber content, whereas primary and de-inked fiber sludge were high in fiber content and low in nutrient content. Cellulose-C and hemi-cellulose-C amounted to 46% and 36% of the organic C present, respectively, and C/N ratios were around 130 in primary and de-inked fiber sludge. Incubation studies at 8°C over 2 months showed that the decomposability of primary and de-inked fiber sludge in soil was not significantly different. Both showed lower decomposability than secondary sludge. Concentrations of inorganic N in soil declined to very low levels after application of primary and deinked fiber sludge and their capacity for net N immobilization was 4.8-7.2 kg N t - 1 C added at 5°C. However, contents of Cu, Cd and polycyclic aromatic hydrocarbons in de-inked fiber sludge limit its use on arable land. Only primary fiber sludge was found to be suitable as a introgen catch fiber material for use on agricultural soils.

We developed a new direct hill seeding method, paper-mulched direct seeding (PMDS). In this method, recycled-paper sheets with rice (Oryza Sativa L.) seeds affixed are spread over a flooded paddy field just after puddling and leveling. Three or five rice seeds were sandwiched between biodegradable gauze or non-woven mesh, fixed to a hole (25 mm diameter) arranged on the sheet at a distance corresponding to the planting density. The sheet gave a very high percentage (98.3%) of germination in water culture of cultivar, Koshihikari. Koshihikari sown by the PMDS method showed a relatively high percentage of seedling establishment, ranging from 70 to 80%. Moreover, a high stability of seedling establishment was obtained by the PMDS method as compared with lowland hill seeding of non-germinated seeds without use of the oxygen supplying chemical, calcium peroxide. Frequencies of vacant hills in the PMDS plot of 5 cultivars, Akitakomachi, Dontokoi, Hinohikari, Hitomebore and Koshihikari, were very low, ranging from 0.40 to 2.33%. Although no herbicide was applied in the PMDS plot, only a few weeds, i.e., Scripus juncoides Roxb. var. ohwians T. koyama and Eleocharis kuroguwai Ohwi were observed, indicating that herbicides are not required in the PMDS. Little lodging was seen in the PMDS plot. The brown rice yield by the PMDS was 615 g m−2. These results clearly demonstrate that the PMDS is useful for hill seeding in flooded paddy fields.

Heavy metal contamination of soil poses risks and hazards to environment and human being. Many amendments were used to remediate the contaminated soil. In this report, paper sludge was used to reduce the bioavailability of Pb in soil, and the remediation mechanism was studied by investigating the redistribution of Pb speciation after paper sludge addition. In pot experiments, significantly increased weights of shoots (from 1.6 to 3.3 mg per plant) and roots (from 0.7 to 0.8 mg per plant), as well as significantly decreased Pb content in shoots (from 153.8 to 24.4 mg kg−1) and roots (from 467.1 to 38.0 mg kg−1) of rape were observed after paper sludge was added. The addition of paper sludge resulted in redistribution of Pb from the liable fractions (carbonate-bound Pb from 58.3 to 3.7%) to the Fe–Mn oxide-bound fraction (from 29.2 to 74.9%). Paper sludge addition increased the content of organic matters and pH of soil, and induced Pb redistribution, which ultimately inhibited Pb uptake and improved...

Food waste from a hospital was composted with waste paper, milk carton and topsoil in different combinations. The ready compost reflected the high content of N, P, K, S, Cl, Na and K in the food wa...

Naturally regenerated paper birch (Betula papyrifera Marsh.) is commonly removed from juvenile interior Douglas-fir (Pseudotsuga menziesii var. glauca [Beissn.] Franco) plantations in southern interior British Columbia, Canada, to increase conifer productivity and create a free-growing stand; however, this practice is expensive and contentious because of possible negative ecological impacts. One solution is to retain an optimal density of birch where growth gains of understory Douglas-fir are balanced against losses to Armillaria ostoyae (Romagn.) Herink and understory plant species diversity. We sought to find this optimal density by comparing four evenly applied birch density reduction treatments (0, 400, 1111, and 4444 retained birch stems ha−1) and an unthinned control (>7300 retained birch stems ha−1). The mortality rate of Douglas-fir due to Armillaria root disease increased non-significantly with thinning intensity. Mean diameter increment of surviving Douglas-fir improved the most where birch was ...

Food waste, waste paper and different topsoils were composted in different experiments. The composts were characterised by high contents of N, P, S, Na and K in the food waste, of Mg in the soil, and of Ca in paper and soils. The nitrogen catching was between 50 and 70% of the input. The lowest amounts were caught in the composts with sandy soils, the highest in a clay soil with high ignition loss.

This study assesses the economic and environmental impacts that have arisen from the adoption and use of genetically modified (GM) cotton and maize in Colombia in the fifteen years since GM cotton was first planted in Colombia in 2003. A total of 1.07 million hectares have been planted to cotton and maize containing GM traits since 2003, with farmers benefiting from an increase in income of US $301.7 million. For every extra US $1 spent on this seed relative to conventional seed, farmers have gained an additional US $3.09 in extra income from growing GM cotton and an extra US $5.25 in extra income from growing GM maize. These income gains have mostly arisen from higher yields (+30.2% from using stacked (herbicide tolerant and insect resistant cotton and +17.4% from using stacked maize). The cotton and maize seed technology have reduced insecticide and herbicide spraying by 779,400 kg of active ingredient (−19%) and, as a result, decreased the environmental impact associated with herbicide and insecticide use on these crops (as measured by the indicator, the Environmental Impact Quotient (EIQ)) by 26%. The technology has also facilitated cuts in fuel use, resulting in a reduction in the release of greenhouse gas emissions from the GM cotton and maize cropping area and contributed to saving scarce land resources.

Because of the large population, large demand, limited arable land and many environmental factors, continuous cropping have become a very common phenomenon in China. However, long-term continuous cropping has caused a series of serious soil-borne diseases, and the yield and quality of crops to drop, which seriously restricted the sustainable development of agricultural industry. Therefore, in order to improve the yield of pepper and reduce the occurrence of soil-borne diseases, it is essential to understand the effect of continuous cropping of pepper on soil microbial community composition and abundance. In this study, high throughput sequencing was used to study the effects of seven treatments of organic fertilizers and corn straw on soil microbial community and function of pepper continuous cropping. The results showed that the yield of all treatments was significantly higher than that of the control. The soil microbial diversity and community composition showed that Proteobacteria and Ascomycota were the most abundant phylum in all treatments. In conclusion, there were significant differences among the seven treatments and the treatment of fowl dung with corn straw was the best fertilizer combination to improve the yield and output value of pepper. Besides, the addition of fowl dung and corn straw not only can improve the community and functions of microorganisms, but also enhance the ability of disease resistance, and ultimately decrease the soil-borne diseases. The results will help to provide scientific basis for rational application of organic fertilizer and corn straw, and overcoming continuous cropping obstacles., Graphical Abstract

Intercropping can introduce greater plant diversity and functional complementarity in an arable crop system but inter- and intracompetition can between intercropped crops. The rhizo-box was established of apple-white clover intercropped system to examine the competitive relationship between intercropped crops on the Loess Plateau. The results showed that the competitive relationship between intercropped crops was dynamic and changed with the crop competitiveness. Crop competitiveness was characterized by root development, although intercropping inhibited the development and nutrient accumulation aboveground of apple trunks and branches, intercropped apples still maintained a larger root system than under monoculture and the root morphology of intercropped apples changed significantly. White clover had lower competitiveness than apple at the beginning of the year, which was reflected in the inhibited development in May. However in July and October, intercropped white clover had more biomass and nutrient accumulation than under monoculture., Graphical Abstract

Paper discs, pre-soaked in Richard's solution containing 10 ppm pimaricin, provided an effective “bait” for the selective isolation of Pythium spp. Discs buried in cultivated soils and undisturbed natural soils, or placed in a stream and reservoir, all yielded Pythium spp.

Overuse of the chemical compounds and toxic elements leads to problems and transmission of contaminants and pollutants to humans and other living organisms. One of the agricultural industries' byproducts is production of various composts from the organic raw materials and its best type is Vermicompost. In this study, effects of raw materials on qualitative and quantitative characteristics of vermicompost are discussed. To do so, sheep manure, pomegranate peels, spent mushroom compost either singly or double-, triple-, or four-fold chopped corn, sugar beet pulp, and sawdust were used. This research project was conducted in a completely randomized design experiment with 23 treatments with 3 replications. Results revealed that various bed combinations exert different effects on vermicompost quality such that the vermicomposting process led to a significant decrease in electrical conductivity and a significant increase in pH in most of the culture (seed) beds. Also, the levels of nitrogen, phosphorous...

This review aims to present an innovative concept of high value added lipids produced by heterotrophic microorganisms, bacteria and fungi, using carbon sources, such as sugars, acids and alcohols that could come from sugarcane vinasse, which is the main byproduct from ethanol production that is released in the distillation step. Vinasse is a rich carbon source and low-cost feedstock produced in large amounts from ethanol production. In 2019, the Brazilian Ministry of Agriculture, Livestock and Food Supply estimates that growth of ethanol domestic consumption will be 58.8 billion liters, more than double the amount in 2008. This represents the annual production of more than 588 billion liters of vinasse, which is currently used as a fertilizer in the sugarcane crop, due to its high concentration of minerals, mainly potassium. However, studies indicate some disadvantages such as the generation of Greenhouse Gas emission during vinasse distribution in the crop, as well as the possibility of contaminating the groundwater and soil. Therefore, the development of programs for sustainable use of vinasse is a priority. One profitable alternative is the fermentation of vinasse, followed by an anaerobic digester, in order to obtain biomaterials such as lipids, other byproducts, and methane. Promising high value added lipids, for instance carotenoids and polyunsaturated fatty acids (PUFAS), with a predicted market of millions of US$, could be produced using vinasse as carbon source, to guide an innovative concept for sustainable production. Example of lipids obtained from the fermentation of compounds present in vinasse are vitamin D, which comes from yeast sucrose fermentation and Omega 3, which can be obtained by bacteria and fungi fermentation. Additionally, several other compounds present in vinasse can be used for this purpose, including sucrose, ethanol, lactate, pyruvate, acetate and other carbon sources. Finally, this paper illustrates the potential market and microbial processes, using microorganisms, for lipid production.

Plants exhibit several restrictions under waterlogging conditions, including stomatal limitations, negative impacts on gas exchange, lower nutrient uptake and reduced growth. 24-epibrassinolide (EBR) is a polyhydroxylated steroid, with the advantages to be a natural and biodegradable molecule, presenting beneficial roles in metabolic and physiological processes. The aim of this research is to investigate whether EBR can protect soybean plants against damage caused by waterlogging and evaluate the responses associated with the root and leaf anatomy, photosynthetic machinery and biomass. This study used a completely randomized factorial design with two water conditions (control and waterlogging) and three concentrations of 24-epibrassinolide (0, 5 and 10 nM EBR). This steroid stimulated the activities of enzymes linked to the antioxidant system and resulted in minor damage to the chloroplast membranes. EBR maximized the efficiency of photosystem II and improved the gas exchange, which was explained by the higher density and index of the stomata in addition to the increased chlorophyll content and electron transport rate. In root structures, EBR mitigated the impact of waterlogging on vascular cylinder and metaxilem, suggesting maintenance and functions of these structures in plants stressed.

Intensive agricultural practices resulting in large scale habitat loss ranks as the top contributing factors in the global bee decline. Growing Genetically Modified Herbicide Tolerant (GMHT) crops as large monocultures has resulted extensive applications of herbicides leading to the degradation of natural habitats surrounding farmlands. Herbicide tolerance trait is beneficial for crops such as Canola (Brassica napus) that are extremely vulnerable to weed competition. While the trait in itself does not harm pollinators, growing genetically modified herbicide tolerant cultivars indirectly contributes towards pollinator declines through habitat loss. Canola, a mass-flowering crop is highly attractive to bee pollinators and the extensive adoption of the herbicide tolerant trait has led to depletion of non-crop floral resources. Extensive use of herbicide in and near fields with herbicide tolerant cultivars systematically eliminates semi-natural habitats around agricultural fields which consist of non-crop flowering plants. Planting pollinator strips provides floral resources for bees after crop flowering. We document the bee genera in canola and the adjoining pollinator strip. The overlap in bee genera reinforces the importance of pollinator habitats in agricultural landscape.

During the last few decades, phytoremediation process has attracted much attention because of the growing concerns about the deteriorating quality of soil caused by anthropogenic activities. Here, a tandem phytoremediation/biorefinery process was proposed as a way to turn phytoremediation into a viable commercial method by producing valuable chemicals in addition to cleaned soil. Two agricultural plants (Sinapis alba and Helianthus annuus) were grown in moderately contaminated soil with ca. 100 ppm of Ni and further degraded by a fungal lignin degrader-Phanerochaete chrysosporium. Several parameters have been studied, including the viability of plants, biomass yield, and their accumulating and remediating potentials. Further, downstream processing showed that up to 80% of Ni can be easily extracted from contaminated biomass by aqueous extraction at mild conditions. Finally, it was demonstrated that the growth of plants on the contaminated soil could be degraded by P. chrysosporium, and the effect of nickel and biomass pretreatment on the solid-state fermentation was studied. The proposed and studied methodology in this work could pave the way for successful commercialization of the phytoremediation process in the near future.

With advances in biogas technology, lignocellulosic material may be increasingly included in feedstock due to the abundance of raw materials. The main goal of this study was to evaluate fertilizing...

Crops that have been genetically modified (GM) to be tolerant to herbicides have been widely grown in the USA since 1996. The rapid and widespread adoption of this technology reflects the important economic and environmental benefits that farmers have derived from its use (equal to $21.7 billion additional farm income and a 225 million kg reduction in herbicide active ingredient use 1996-2012). During this time, weed control practices in these crops relative to the 'conventional alternative' have evolved to reflect experience of using the technology, the challenges that have arisen and the increasing focus in recent years on developing sustainable production systems. This paper examines the evidence on the changing nature of herbicides used with these crops and in particular how farmers addressed the challenge of weed resistance. The evidence shows that use of the technology has resulted in a net reduction in both the amount of herbicide used and the associated environmental impact, as measured by the EIQ indicator when compared to what can reasonably be expected if the area planted to GM HT crops reverted to conventional production methods. It also facilitated many farmers being able to derive the economic and environmental benefits associated with switching from a plough-based to a no tillage or conservation tillage production system. In terms of herbicide use, the technology has also contributed to a change the profile of herbicides used. A broad range of, mostly selective herbicides has been replaced by one or 2 broad-spectrum herbicides (mostly glyphosate) used in conjunction with one or 2 other (complementary) herbicides. Since the mid-2000s, the average amount of herbicide applied and the associated environmental load, as measured by the EIQ indicator, have increased on both GM HT and conventional crops. A primary reason for these changes has been increasing incidence of weed species developing populations resistant to herbicides and increased awareness of the consequences of relying on a single or very limited number of herbicides for weed control. As a result, growers of GM HT crops have become much more proactive and diversified in their weed management programs in line with weed scientist recommendations and now include other herbicides (with different and complementary modes of action) in combination with glyphosate, even where instances of weed resistance to glyphosate have not been found. The willingness to proactively diversity weed management systems in the GM HT crops is also influenced by a desire to maintain effective weed control and hence continue to enjoy the benefits of no tillage and conservation tillage. Nevertheless, despite the increase in herbicide use in recent years, the use of GM HT technology continues to deliver significant economic and environmental gains to US farmers.

The western area of the Jilin province, a typical seasonal frost region, is located in the southern Songnen plain of China. Significantly salinized soils are widely distributed on the Songnen plain in western Jilin. Soil salinization can cause degradation of cultivated land and grass, which threatens the human environment. To investigate the treatment of saline-alkali soil, a laboratory test was conducted to evaluate the ability of sulfur-oxidizing bacteria to improve the performance of saline-alkali soil in western Jilin. The results showed that sulfur-oxidizing bacteria treatment was suitable for the soil from pH 7.5 to 8, and 50 ml thiobacillusthiooxidans showed the best improvement to the saline-alkali soil.

This research was conducted to evaluate the effects of calcium chloride (CaCl2) and calcium nitrate Ca(NO3)2 on nutrient concentrations and postharvest quality of papaya fruits. In the first experiment, plant stem height increased significantly after Ca(NO3)2 application compared to CaCl2. The calcium content in the peel and pulp for both sources [CaCl2 and Ca(NO3)2] significantly rose with increasing calcium concentrations, but there was a significantly higher content of calcium in fruit peel and pulp in the CaCl2 treatment. Magnesium and potassium in fruits decreased with increasing calcium concentrations. A reduction in anthracnose lesion diameter in the infected fruit with increasing calcium was observed in both CaCl2 and Ca(NO3)2 treatments. Ethylene production in fruits decreased with increasing calcium concentrations. In the second experiment, only CaCl2 was used as the calcium source, and results showed that the calcium content in fruit peel and pulp significantly increased at higher CaCl2...

Previously, we conducted a roadside survey to reveal the occurrence of genetically modified (GM) oilseed rape along a Japanese roadside (Route 51). In this study, we performed successive and thorough fixed-route monitoring in 5 sections along another road (Route 23). Oilseed rape plants were detected on both sides of the road in each section between autumn 2009 and winter 2013, which included 3 flowering seasons. In four sections, more plants were found on the side of the road leading from the Yokkaichi port than on the opposite side. In the fifth section, the presence of clogged drains on the roadside, where juvenile plants concentrated, caused the opposite distribution: oilseed rape predominantly occurred along the inbound lanes (leading to the Yokkaichi port) in 2010 and 2012. Unlike in our previous survey, glyphosate- or glufosinate-resistant oilseed rape plants were abundant (>75% of analyzed plants over 3 years). Moreover, a few individuals bearing both herbicide resistance traits were also detected in some sections. The spillage of imported seeds may explain the occurrence of oilseed rape on the roadside. The abundance of herbicide-resistant oilseed rape plants may reflect the extent of contamination with GM oilseed rape seed within imports.

The transgenic pollen spread is the main pathway of transgenic plant gene flow. The maximum distance of pollen dispersal (horizontal), the spatial dynamics of pollen movement (vertical), and the patterns of pollen dispersal are important considerations in biosafety assessments of genetically modified crops. To evaluate wheat (Triticum aestivum) pollen dispersal, we measured the pollen suspension velocity and analyzed pollen dispersal patterns under natural conditions in the Huanghuai River wheat-growing region in 2009. The pollen suspension velocity was 0.3–0.4 m/s. The highest pollen densities were detected in the north, northwest, and south of the pollen source. Pollen was dispersed over distances greater than 245 m in the northwest and northeast directions. At the pollen source center, pollen density decreased with increasing vertical height. In the north of the pollen source, the pollen density from 65 m to 225 m showed a wave-mode decrease with increasing height. The horizontal transport of pollen over longer distances fitted polynomial equations. In the north, the pollen density was highest at 45 m from the pollen source, and decreased with increasing distance. In the northwest, the pollen density showed a double-peak trend. In the northeast, pollen density was highest from 45 m to 125 m from the source. Wind speeds greater than the pollen suspension velocity and the duration of continuous gusts were the main factors affecting pollen dispersal. This information will be useful for determining the spatial isolation distances for hybrid seed production and for the commercial production of transgenic wheat.

Anaerobic digestion of manure is a widely accepted technology for energy production. However, only a minimal portion of the manure production in the EU is anaerobically digested and occurs predominantly in codigestion plants. There is substantial potential for biogas plants that primarily operate on manure (>90%); however, the methane yields of manure are less compared to coproducts, which is one of the reasons for manure-based biogas plants often being economically non-viable. Therefore, it is essential to begin increasing the efficiency of these biogas plants. This study investigated the effect of decreasing retention time and introducing a moderate amount of glycerin on the biogas production as methods to improve efficiency. An experiment has been conducted with two different manure types in four biogas reactors. The results of the study demonstrated that, first, it was possible to decrease the retention time to 10–15 days; however, the effect on biogas production varied per manure type. Secondly, the biogas production almost triples at a retention time of 15.6 days with an addition of 4% glycerin. The relative production-enhancing effect of glycerin did not vary significantly with both manure types. However, the absolute production-enhancing effect of glycerin differed per manure type since the biogas production per gram VS differed per manure type. Thirdly, the positive effect of the glycerin input declines with shorter retention times. Therefore, the effect of glycerin addition depends on the manure type and retention time.

SummaryWood properties of 10-year-old trees in Eucalyptus globulus plantations at three sites in Western Australia were examined. Silvicultural treatments applied at age two years were stocking (unthinned, 1250 stems ha–1; thinned to 600 stems ha–1 or 300 stems ha–1) and nitrogen fertiliser application (0 or 250 kg ha–1 elemental nitrogen) in factorial combination. The three sites differed markedly in their annual rainfall (620–1100 mm), open-pan evaporation and soil water-holding capacity. Wood cores were collected at breast height from a total of 263 trees (~15 trees for each site-by-treatment combination), and radial samples prepared for analysis by SilviScan to produce radial profiles of air-dry density and microfibril angle (MFA) and modulus of elasticity (MOE), and by radial near infrared (NIR) surface scanning to produce radial profiles of NIR-predicted Kraft pulp yield (KPY) and cellulose content (CC). Sampling interval was 0.025 mm for density and 5 mm for the other properties. For wood property ...

A literature review has been undertaken to investigate the potential of anaerobic digestion for material recovery and energy production from cattle manure. These wastes constitute 8–20% total solid, with a volatile solid content of 70–85%. The biodegradable fractions include about 11% hemicellulose, 26–53% cellulose, and 11% lignin. Anaerobic digestion of cattle manure was studied under various operating conditions using different types of bioreactors and it allows the conversion of 50–75% of organic matter to methane with an organic loading rate of 1–6 g VS/L day. Continuous two-stage configuration involving a first-stage thermophilic reactor and mesophilic second reactor emerges to be superior and the most effective technologies for anaerobic digestion of cattle manure. It was demonstrated that 41% of volatile solids were converted to methane at an organic loading rate of 5.82 g VS/L day. The methane yield was found to be 620 L/kg VS added.

SummaryProcessing young, small-diameter eucalypt logs into veneer is a burgeoning industry across southern China. However, plantations supplying these logs are mostly managed on silvicultural regimes which are appropriate for pulpwood and little information is available on alternative regimes for eucalypt plantations with respect to veneer yields and quality. Log size along with a range of tree and log traits were assessed on 12-year-old eucalypts in six spacing treatments, ranging from 666 to 2 222 trees ha−1, in a field trial in southern China. Logs harvested from these were rotary peeled for veneer; recovery percentages plus a range of quality and value traits were assessed on the outturn. Log volumes, small-end diameters and individual log values varied significantly between spacing treatments, but total veneer recoveries (as a percentage of log volume) and veneer values per unit volume did not. The spacing treatment providing the highest veneer value per unit area was that with the highest stocking; ...

The bioavailability and leachability of heavy metals play a major role in the toxicity of heavy metals in the compost applied for soil conditioning. A rotary drum composter was used for the study of heavy metal bioavailability and leachability during water hyacinth composting with a mixture of cattle manure, sawdust and lime. Lime was added in 1, 2 and 3% to the mixture of water hyacinth, cattle manure and sawdust at a ratio of 6:3:1 respectively. Influences of physico-chemical parameters on heavy metal bioavailability and leachability were studied during the process. The bioavailability of heavy metals solubility and diethylene triamine penta-acetic acid extractability was examined. The toxicity characteristics leaching procedure (TCLP) test was performed for assessing the hazardous properties of compost. The nutrients and the total concentration of heavy metals were increased during the composting process. The lime was very effective in reducing water solubility, plant availability and leachabil...

Food waste, straw, paper and topsoil were composted in different combinations. The catching of nitrogen was more than 90% when using different amounts of straw and of a small amount of paper. It wa...

Composting olive oil pomace could solve the problem of disposal, by recycling this organic waste for agricultural purposes. Furthermore, application of composted organic waste could be a way to sustain both soil fertility and production, especially in organic farming. Therefore, the aim of this research was to evaluate the phytotoxicity and the effects of application of olive pomace composts on emmer performance and soil properties. Two types of olive pomace composts, with a different initial C/N ratio, were stopped at the active phase and processed until maturation. The obtained four olive pomace composts were compared with a commercial fertilizer in a two-year field experiment. Before the field trial, a bioassay was performed to assess phytotoxicity both for the raw pomace and the not-stabilized composts. Growing and yielding data for emmer were determined during the two-year period and soil characteristics were measured at the start and at the end of the experiment. The composts were not phyto...

In this study, the main physical, physiochemical, and chemical properties of hazelnut husk have been determined for the suitability as a container growing medium. Four substrates were prepared based upon decomposition degree: raw (H(1)), medium decomposed (H(2), H(3)), and strongly decomposed hazelnut husk samples (H(4)), to determine the optimum growing medium parameters. Particle size was the key parameter to determine the physical properties, which was decreased with the increasing decomposition degrees. The main physical parameters were in the ranges for the ideal growing medium characteristics for H(4). Except for raw material (H(1)), chemical characteristics such as pH, electrical conductivity (EC), carbon (C)/nitrogen (N), and nutrients were within acceptable ranges. The results indicated that hazelnut husk could be an alternative growing media component for containerized crops, if optimum particle size within the range of 0-2mm is obtained, for both aeration and water holding requirements.

Plants are able to discriminately allocate greater biomass to organs that grow under higher resource levels. Recent evidence demonstrates that split-root plants also discriminately allocate more resources to roots that grow under dynamically improving nutrient levels, even when their other roots grow in richer patches. Here, we further tested whether, besides their responsiveness to the direction of resource gradients, plants are also sensitive to the steepness of environmental trajectories. Split-root Pisum sativum plants were grown so that one of their roots developed under constantly-high nutrient levels and the other root was subjected to dynamically improving nutrient levels of variable steepness. As expected, plants usually allocated a greater proportion of their biomass to roots that developed under constantly high resource availability; however, when given a choice, they allocated greater biomass to roots that initially experienced relatively low but steeply improving nutrient availabilities than to roots that developed under continuously-high nutrient availability. Such discrimination was not observed when the roots in the poor patch experienced only gentler improvements in nutrient availability. The results are compatible with the notion that responsiveness to the direction and steepness of environmental gradients could assist annual plants to increase their performance by anticipating resource availabilities foreseeable before the end of their growing season. The results exemplify the ability of plants to integrate and utilize environmental information and execute adaptive behaviours which, until recently, were attributed only to animals with central nervous systems.

The presence of Cadmium (Cd) in the agricultural soils affects horticultural cultivars and constrains the crop productivity. A pot experiment was performed using five cultivars of mustard (Brassica juncea L.) to evaluate the difference in their response to Cd toxicity under greenhouse conditions. The pots containing reconstituted soil were supplied with different concentration of CdCl2 (0, 25, 50, 100 or 150 mg Cd kg−1 soil). Increasing concentration of Cd in the soil resulted in decreased growth, photosynthesis and yield. Maximum significant reduction in growth, photosynthesis and yield were observed with 150 mg Cd kg−1 soil in all the cultivars. Our results indicate that the cultivar Alankar is found to be more tolerant to Cd stress, recording higher plant dry mass, net photosynthesis rate, associated with high antioxidant activity and low Cd content in the plant leaves and thus less oxidative damage. Cultivar RH30 experienced maximum damage in terms of reduction in growth, photosynthesis, yield characteristics and oxidative damage and emerged as sensitive cultivar. The data of tolerance index of Alankar were found to be higher among all tested mustard cultivars which indicate its higher tolerance to Cd. Better coordination of antioxidants protected Alankar from Cd toxicity, whereas lesser antioxidant activity in RH30 resulted in maximum damage. Cultivars of mustard were ranked with respect to their tolerance to Cd: Alankar > Varuna > Pusa Bold > Sakha > RH30, respectively.

The most common renewable fuel today and suitable alternative to replace fossil fuels is ethanol that can be blended with petrol or used as neat alcohol in engines. Ethanol is currently produced from sugar (Brazil) or grain (starch, USA). However, this raw material base will not be sufficient because the increasing demand for fuel ethanol and the lower than expected reduction of greenhouse gases. An alternative is the production of bioethanol from agroindustrial wastes containing abundant cellulosic fibers and carbohydrates such as grape pomace, sugar beet pomace, barley and rice straw, corncobs, sunflower stalks and heads, cotton waste, brewer's spent grain, forest residues etc. Lignocellulosic raw materials and agroindustrial wastes minimize the potential conflict between land use for food (and feed) production and energy feedstock production. This review summarizes recent developments in the bioconversion processes, the new technologies required and the advances achieved in recent years to brin...

Trace elements, especially toxic metals, are considered to be one of the main sources of pollution in the environment, since they have a significant effect on its ecological quality. The present study aims to develop a simple biosorptive-flotation method to remove Cu(II) from aqueous solutions using sugar beet pulp (SBP) as sorbent and oleic acid (HOL) as surfactant. SBP as an agricultural plant waste (which is an effective and inexpensive sorbent) was used as native sugar beet pulp (NSBP), i.e. without treatment, or after treatment with an acid (ASBP) or a base (BSBP). The main parameters (initial pH, sorbent, Cu2+ ions and surfactant concentrations, shaking times, temperature, ionic strength and the presence of foreign ions) that influence the flotation process were examined. Under the optimum experimental conditions, at pH 7 and at room temperature (~ 25°C), about 100% of Cu(II) was removed. The recommended procedure was successfully applied to recover Cu2+ ions spiked in aqueous solution and i...

Numerous fungicide applications are often needed to control powdery mildews in greenhouse-grown crops, and consequently there is an increasing demand for alternative means to control them. In commercial greenhouses, attack of powdery mildew caused by Podosphaera xanthii in cucumbers and P. pannosa in cut roses was controlled by weekly sprays of C-Pro CE601, a dilution of grapefruit seed extract (GSE). The raw material of GSE, delivered by Citricidal®, is a glycerolic extract from seed and juiceless pulp of grapefruits (Citrus paradise). In both cultures C-Pro at 2000 ppm achieved as good control as treatments with penconazole or triforine. The mean level of attack by powdery mildew on leaves of cut roses one week after the last of three weekly treatments, was 9.8, 12.9 and 40.5% for penconazole, C-Pro (2000 ppm), and untreated, respectively. In cucumbers, there was less difference between the untreated control and the different treatments, but for all times of assessments, C-Pro and triforine wer...

The objective of this study was to develop an easy method of estimating available nitrogen in poultry manure compost using near infrared spectroscopy (NIRS). A scanning monochromator was used to obtain the reflectance spectra from 1,100 to 2,500 nm of samples of dried and milled poultry manure compost. Second derivative spectra and multiple regression analysis were used to develop calibration equations for total nitrogen (T-N) and uric acid nitrogen (UA-N). Standard error of prediction (SEP) of the best calibrations for T-N and UA-N were 4.74 mg g−1 and 4.32 mg g−1, respectively. The correlation between available nitrogen, which was obtained using incubation experiments, and UA-N in the compost samples was extremely high (r = 0.99999, SE = 0.61 mg g−1). In conclusion, the estimation of available nitrogen from UA-N values using NIRS is a practical method of analyzing poultry manure compost.

Productivity of the soil with waste material (WM), i.e., bagasse, coir dust, rice chaff and rice straw decomposed for two months at various temperatures and soil moisture were investigated by analyzing the chemical properties and growth of maize cultured on the soil for 45 days. The soil with decomposed WM (WM soil), tended to show lower pH values than the soil without WM soil (control) as a whole. The values of electric conductance were higher in WM soil, especially in the soil with decomposed rice chaff and rice straw referred to as rice-chaff and rice-straw soils, respectively. The total N content tended to be higher in the WM soil except for coir dust soil. The total C content tended to be higher in all WM soils. The difference in the content of total N and total C between WM and control soils was remarkable in bagasse soil. The change of the chemical properties of the soil did not apparently correlate with the rate of CO2 generation during incubation of WM soils, but pH, electric conductance, content of total N and total C contents were higher in the soils generating CO2 at a rate of 40 to 80 ppm min−1, in bagasse or rice straw soils. The dry matter production of maize on WM soils was positively correlated with the rate of CO2 generation. It was suggested that the WM soils generating little CO2, such as the soil with bagasse or rice straw decomposed in a dry condition, tended to inhibit maize growth owing to low pH and shortage of available nitrogen by rapid decomposition just after the start of maize growth. The wet WM soils generating CO2 format a rate of 40 to 80 ppm min−1, e.g., bagasse and rice straw soils might be favorable for dry matter production of maize.

The purpose of this research was to investigate the compostability of waste residuals from a strawboard manufacturing facility. Phase 1 used bench-scale reactors to compost various recipes using three feedstock materials (straw, process unders, and livestock lagoon sludge) at different moisture levels for a nine-week period. Water addition and the addition of unders to tbe compost mixture increased degradability. The livestock lagoon waste did not significantly improve degradability. Phase 2 focused on tbe straw feedstock, investigating tbe effects of straw particle size using four unsbredded:shredded straw ratios (by volume): 100:0; 67:33; 33:67; and 0:100. The recipes were composted in 140 L rigid plastic containers for a period of 180 days at a moisture content of 70% (wet basis). Volatile solids (VS) and lignocellulose degradation was greatest for recipes containing both shredded and unsbredded straw, with tbe recipe containing 67% shredded straw performing the best (35%. VS removal). Pure unshredded and shredded straw bad VS reductions of 29%- and 26%, respectively. Total volume reductions ranged from 80 to 90%. Hemicellulose was completely degraded for all recipes by day 95. By day 180 cellulose content had decreased from 3.75 to 0.75 g/g ash for all four recipes. By day 180, lignin degradation was greatest for recipes containing botb shredded and unsbredded straw (reduction from 1.0 to 0.4 g/g ash) while lignin content decreased from 1.0 to 0.6 g/g ash for the other recipes. It was concluded that recipes containing a mixture of sbredded and unshredded straw provided better composting conditions.

The leaching losses of nitrogen from a range of farm effluents and wastes, including pig slurry, dairy pond sludge, farm‐dairy effluent, and cow urine are compared on a Templeton fine sandy loam. At similar rates of application, leaching losses decreased in the following order: cow urine>pig slurry>farm‐dairy effluent>dairy pond sludge. The susceptibility to leaching is determined by the forms of the N in the waste, and a high N:C ratio alone is not an adequate predictor of leaching intensity. Nitrate is most susceptible to leaching, followed by ammonium and organic forms of N. Splitting the applications of effluent into two or four portions applied at different times reduced the overall quantity of nitrate leached by c. 30%, depending on the waste. Similarly, reducing the overall rate from 400 to 200 kg N/ha also reduced the N leaching loss by c. 30%, depending on the particular waste. It is recommended that the land application of farm waste be based on a knowledge of the propensity of differen...

New Zealand dairy and pig farms generate significant amounts of effluents that contain high concentrations of nutrients such as nitrogen (N), potassium (K), and phosphorus (P), and various trace contaminants (e.g., heavy metals, organic compounds, and endocrine‐disrupting chemicals). Land application is a preferred option for farm effluent management. Regulations have been imposed to limit the land application of farm effluent to 150–200 kg N ha−1 to minimise potential leaching loss of nitrate to groundwater. However, focusing mainly on nutrient recycling from farm effluent application has resulted in the effects of other effluent constituents, such as microbial pathogens, heavy metals, odorants and oestrogens, on the receiving ecosystems being overlooked. In this literature review, we assess land‐applied farm effluents and their beneficial and potentially adverse effects on the receiving environment. Long‐term application of farm effluent based on N loading can lead to P and heavy metal accumula...

Winter management practices involving the use of stand‐off pads to reduce problems due to cows grazing on wet soils may require storage of cow manure for extended periods prior to field application. Gaseous losses of nitrogen (N) and sulphur (S) from stored cow manure can be considerable, and these gases are offensive and undesirable. Laboratory incubation studies were conducted to measure gaseous loss of ammonia (NH3) and hydrogen sulphide (H2S) from stored cow manure under aerobic and anaerobic conditions. The potential of adding a range of natural materials, including soil, untreated pine bark, sawdust and wood savings, to the manure to reduce these gaseous emissions was investigated. Aerobic incubation of manure resulted in a higher emission of NH3 than anaerobic incubation, while anaerobic incubation resulted in higher emissions of H2S. The effectiveness of natural materials in reducing losses of NH3 was investigated under anaerobic conditions, and pine bark was found to be the most effectiv...

Changes in the concentrations of selective legume-seed germination inhibitors in raw and composted sewage sludge were analyzed to clarify their generation process. Their fate in soils was also investigated by the determination of the inhibitors which remained after incubation in two soils, a regosol and an andosol amended with sludge compost. The inhibitors, i.e. 3,4-dichlorophenylacetic acid (3,4-DCP), 3,4-dichlorobenzoic acid (3,4-DCB), 3,4,5-trichlorophenylacetic acid (3,4,5-TCP), and 3,4,5-trichlorobenzoic acid (3,4,5-TCB) were extracted efficiently with water and a larger amount was extracted with alkaline methanol from the composted sludge. Higher concentrations of 3,4-DCP and 3,4,5-TCP were extracted with alkaline methanol from the sludge than from the composted sludge, but the inhibitors were hardly extracted with water from the sludge. After composting of the raw sludge for 2 weeks, the concentrations of water-soluble forms of 3,4-DCP, 3,4,5-TCP increased remarkably. Heating of the raw s...

Seedlings of three rice (Oryza sativa L.) varieties (one indica, ARC5955; and two japonica, Nipponbare and Koshihikari) with or without pre-colonization by the arbuscular mycorrhizal fungus Funneliformis mosseae were transplanted into an upland field and grown to maturity. Pre-colonization had no effect on the yield of Nipponbare or Koshihikari. However, pre-colonized ARC5955 exhibited a strong tendency toward increased yield, which was accompanied by increases in the percentage of ripened grain and the 1000-grain weight. The rice roots were also colonized by indigenous arbuscular mycorrhizal fungi in the field, but these had only limited effects on shoot biomass and grain yields. We speculate that F. mosseae may have exhibited priority effects, allowing it to dominate the rice roots. There was no significant difference in the contents of most mineral elements in the shoots of pre-colonized ARC5955 at harvest, indicating that some other factor is responsible for the observed yield increase.

The use of safe staining techniques in the evaluation of mycorrhizal colonization is critical to the continued understanding of this important symbiosis. Several procedures being utilized currently involve regulated and/ or toxic chemicals. The integration of unregulated and nontoxic chemicals into these procedures is important to alleviate potential dangers currently used chemicals pose. We eliminated all regulated reagents by combining portions of several previously published staining and root preservation procedures. A block digester for plant tissue digestion was used as a heating unit and proved to be easier to use, quicker and more reliable than either a water bath or a circulating air oven. Optimum clearing time in KOH varied from 8 to 10 min and 30 to 40 min for wheat, sweet corn, and dry bean roots, respectively. We also successfully used both drying and freezing of roots for storage prior to staining. These modified procedures were quick and easy and provided reliable temperature contro...

Leaching of plant nutrients and heavy metals during the composting of two different types of household waste was investigated. It was found that the resulting leachate contained high concentrations of salts and heavy metals, and had to be collected and treated. Household wastes from local villages mixed with manure lost 4–6 times more plant nutrients than drier compost derived from household and park wastes from the town of Uppsala. With the exception of potassium, plant nutrient losses were negligible. The wetter composts lost up to 2% of their content of heavy metals during the three months of composting, whereas losses from the dry compost were less than 0.1%. The local compost was of better quality than the municipal waste, which contained high concentrations of cadmium and lead.

In the backdrop of global warming and increase in temperatures, wheat productivity worldwide would be limited. This study was therefore undertaken to analyze the heat stress response in 12 different cultivars of Indian wheat. Three developmental stages were used i.e. germination stage, seedling stage and anthesis stage, to characterize thermotolerant and thermosusceptible cultivars on the basis of different physiological and molecular parameters. Lethal temperature stress on germinating seeds showed a clear reduction in percentage germination. At the seedling stage, higher decrease in Fv/Fm, total chlorophyll content, membrane injury and carbon isotope discrimination was observed in thermosusceptible cultivars. Results similar to seedling stage were obtained at anthesis stage. PSII efficiency of late-sown cultivars and timely-sown cultivars also indicated that thermosusceptible cultivars are more prone to terminal heat stress than thermotolerant cultivars. Heat Susceptibility Index (HSI) was calculated on the basis of physiological parameters. Based on HSI, thermotolerant and thermosusceptible cultivars were identified. HSI revealed comparatively low heat susceptibility in K7903, CBW12 and C306 and high heat susceptibility in PBW343, HD2329 and HD2428. On the basis of HSI, expression analysis of stress induced genes was performed between 2 tolerant cultivars C306 and K7903 along with 2 susceptible cultivars, HD2329 and PBW343. Higher expression of stress induced genes was observed in the 2 thermotolerant cultivars C306 and K7903 as compared to the 2 thermosusceptible cultivars HD2329 and PBW343. Thus further reconfirms that stress inducible genes can be employed for categorizing cultivars into susceptible and tolerant groups.

Enhancement of callus induction and its regeneration efficiency through in vitro techniques has been optimized for 2 abiotic stresses (salt and air desiccation) using 3 rice genotypes viz. BR10, BRRI dhan32 and BRRI dhan47. The highest frequency of callus induction was obtained for BRRI dhan32 (64.44%) in MS medium supplemented with 2, 4-D (2.5 mgL(-1)) and Kin (1.0 mgL(-1)). Different concentrations of NaCl (2.9, 5.9, 8.8 and 11.7 gL(-1)) were used and its effect was recorded on the basis of viability of calli (VC), relative growth rate (RGR), tolerance index (TI) and relative water content (RWC). It was observed that in all cases BRRI dhan47 showed highest performance on tolerance to VC (45.33%), RGR (1.03%), TI (0.20%) and RWC (10.23%) with 11.7 gL(-1) NaCl. Plant regeneration capability was recorded after partial air desiccation pretreatment to calli for 15, 30, 45 and 60 h. In this case BRRI dhan32 gave maximum number of regeneration (76.19%) when 4 weeks old calli were desiccated for 45 h. It was observed that air desiccation was 2-3 folds more effective for enhancing green plantlet regeneration compared to controls. Furthermore, desiccated calli also showed the better capability to survive in NaCl induced abiotic stress; and gave 1.9 fold (88.80%) increased regeneration in 11.7 gL(-1) salt level for BRRI dhan47. Analysis of variance (ANOVA) showed that the genotypes, air desiccation and NaCl had significant effect on plant regeneration at P < 0.01.

Cotton (Gossypium hirsutum L.) is one of the most commercially important fiber crops in the world. Compared with other crops, cotton represents a recalcitrant species for regeneration protocols. The development of efficient and rapid regeneration protocol for elite Indian cotton variety could help improve the quality characteristics and biotic or abiotic stress tolerance. Here we report a novel regeneration protocol in Indian cotton cultivar Narashima. The maximum number of multiple shoots obtained was 16 per explants, performance which has never been achieved in any prior reports. The embryo apex explants were isolated from 2 d old in vitro growing seedlings. Explants were cultured on MS medium containing different plant growth regulator combinations in order to induce multiple shoots. Among the tested combinations, the 2 mg/l of 6-benzylaminopurine (BAP) and 2 mg/l kinetin (KIN) proved to be most suited for achieving the maximum number of multiple shoots. The elongation of multiple shoots was obtained in media supplemented with gibberellic acid (GA3). The regenerated plants were successfully hardened in earthen pots after adequate acclimatization. This method avoids callus tissue, the stage of regeneration which may lead to somaclonal variation. The important feature of the presented method is shortening of regeneration time, as well as the induction of a high number of multiple shoots per explants. The present protocol may provide an efficient and rapid regeneration tool for obtaining more stable transformants from embryo apex explants of Indian cotton cultivar Narashima.