Restoration of ecosystem function in an abandoned sandpit: plant and soil responses to paper de-inking sludge

1. In minesoil reclamation, the establishment of a sustainable plant cover requires the improvement of limiting conditions and the re-initiation of carbon (C) and nutrient cycling. 2. The approach used in this study for reclaiming an abandoned sandpit in Quebec, Canada, was based on a heavy organic amendment as an attempt to accelerate the reconstruction of a functional ecosystem. 3. The one-time intervention consisted of incorporating paper de-inking sludge into soil at two rates (0 and 105 dry t ha–1), supplemented with nitrogen (N) at three rates (3, 6 and 9 g kg–1 sludge) and phosphorus (P) at two rates (0·5 and 1·0 g kg–1 sludge) followed by seeding (mid-summer) of Agropyron elongatum (Host) Beauv. (tall wheatgrass). 4. Standing biomass increased in the presence of sludge after both the first and second full growing seasons. High N application rates further increased yield, more importantly in the second season. The high P rate improved grass establishment in all cases. Ground cover increased with time and doubled in the presence of sludge whereas it declined in the absence of sludge. Phosphorus and N uptake was improved consistently in the presence of sludge. 5. Sludge application resulted in improved water retention and cation exchange capacities, and an increase in pH and bulk density of sandpit minesoil, all of which may have accounted for the significant improvement in plant responses. Levels of soil C and N suggest that this reconstructed system is approaching sustainability. 6. Adequate N and P supplements will accentuate the positive influence of sludge on revegetation

Deinking sludge influences biomass, nitrogen and phosphorus status of several grass and legume species

In a greenhouse study, deinking sludge was evaluated as a soil amendment supplemented with four nitrogen (N) fertilization levels for the growth of the grasses Agropyron elongatum (Host.) Beauv. (tall wheatgrass), Alopecurus pratensis L. (meadow foxtail), Festuca ovina var. duriuscula (L). Koch (hard fescue), and four levels of phosphorus (P) for the growth of the legumes Galega orientalis Lam. (galega), Medicago lupulina L. (black medic), Melilotus officinalis (L.) Lam (yellow sweet clover). Fertilizers were applied on the basis of sludge level to maintain uniform carbon (C)/N or C/P ratios across sludge treatments. In one experiment, sand was mixed with 0, 10, 20 or 30% sludge while, in a second experiment, mineral soil was mixed with 0, 27, 53 or 80% sludge (vol/vol). In sand mixtures of 30 and 20% sludge, grasses had similar or greater growth than in unamended mineral soil when N was added at about 6.5 and 8.4 g kg−1 deinking sludge, respectively. For all legumes but Medicago lupulina, P at about 0.8 g kg−1 sludge was required for these sand mixtures. In soil mixtures of 53 and 27% sludge, grasses grew well when supplemental N was about 5.3 and 6.9 g kg−1 sludge, respectively. Legumes required P at 0.5 and 1.2 g kg−1 sludge, respectively. In general, growth was closely related to total amount of added N or P in spite of the wide range of C/N or C/P ratios. When growing in media amended with sludge, grasses needed higher tissue N concentration for an equivalent growth than in control soil; legumes had similar tissue P concentration. The grasses Agropyron elongatum and Alopecurus pratensis as well as the legumes Melilotus officinalis and Galega orientalis are promising species for field testing, based on dry matter production. Deinking sludge can be used as soil amendment when adequate N and P supplements are provided. Key words: Soil amendment, papermill sludge, Agropyron elongatum, Alopecurus pratensis, Festuca ovina, Medicago lupulina, Galega orientalis, Melilotus officinali

Securing a permit from the United States Department of Agriculture for field work with genetically engineered microbes: a non-prohibitory process

With increased use genetically enginereed microbes in agriculture is it important scientists at academics institutions to know the appropriate U.S. governement agency for permit acquisition and to have and understanding of the permit process. Procedures for permit acquisition from the United States Department of Agriculture, Animal and Plant Health inspection Service (USDA/APHIS) for limited field releases of genetically engineered microbes are described. Permit scan be issued within 120 days of application are valid for 1 year and can subsquently be renewed 50 days

Examination of the contaminants and performance of animals fed and bedded using de-inking paper sludge

In the noncereal-producing areas, there is not enough straw to supply the amount required for animal bedding. However, pulp and paper mills produce tons of wood fiber wastes, including de-inking paper sludge (DPS), in which most toxic compounds are at their detection limit. Among the detected compounds in DPS, aluminum, copper, and polycyclic aromatic hydrocarbons (PAHs) are present and were selected as model molecules. In this context, broilers were submitted to a diet containing 0, 5, and 10% of their ration as DPS. In addition, broilers and pigs were grown on de-inking paper sludge and wood shavings beddings. The presence of aluminum and copper were evaluated in blood and bones, whereas the presence of PAHs was evaluated in fat, liver, meat, and urine or blood of broilers and pigs. Animal performances were also investigated. DPS bedding did not increase aluminum or copper contents of blood or bones or PAHs in animal tissues. Animal performances and health were similar on DPS and wood shaving beddings. Using DPS as bedding material provides an integrated source of disposal of DPS and animal manure

Potential use of leachate from composted fruit and vegetable waste as fertilizer for corn

Composting fruit and vegetable waste from grocery stores on farms is a challenge due to the large quantity of liquid that leaches out. This leachate needs to be characterized for its effects on plant growth and soil. It was acidic with high conductivity; the plant mineral nutrient contents derived from the leachate (in decreasing order) were K, N mainly as ammonium-N, Ca, Mg, Na, and P; the trace elements were quite low. The germination and rootlet growth of cress and corn increased with the dilution of the compost leachate. In greenhouse assays, the compost leachate exhibited phytotoxicity to corn when used at high application rates. The corn leaf area, shoot and root biomass, plant concentrations and uptake of N, P and K were similar among the 20 mM N-fertilized control and the 30–40 m3/ha leachate treatments. In a field study on sandy loam, corn yields and plant uptake of P and K were similar among the mineral fertilized control and split-application leachate treatments applied to meet the P or K requirements of corn. After harvest, the soil pH, conductivity, and total N, P, and K contents were not affected by the leachate treatments. These results demonstrate the opportunity of recycling plant nutrients from compost leachate of fruit and vegetable waste as fertilizer to meet crop nutrient requirements without phytotoxicity and trace elements threats

Root colonization of faba bean (Vicia faba L.) and pea (Pisum sativum L.) by Rhizobium leguminosarum bv. viciae in the presence of nitrate–nitrogen

There is a lack of knowledge concerning the effect of nitrate–nitrogen (NO3– –N) at levels known to inhibit nodule formation and functioning on root colonization of dinitrogen-fixing legumes. Firstly, this study investigated potential differences between Rhizobium leguminosarum bv. viciae 175F9 and its bioluminescent-labeled strain 175F9.lux on root colonization of faba bean (Vicia faba L.) and pea (Pisum sativum L.). These two strains similarly colonized the roots of both hosts. Secondly, this study evaluated the effects of 0 and 10 mol·m–3 NO3– –N on root colonization of faba bean and pea by strain 175F9.lux, over time. Averaged over both hosts and harvest dates, the presence of NO3– –N increased the rhizobial population and the root length colonized. In addition, our results showed that bioluminescence activity increased from 7 to 14 days after sowing and was not correlated to rhizobial population. Finally, to demonstrate that an increase in bioluminescence activity was not an indirect effect of nitrate on R. leguminosarum bv. viciae 175F9.lux, this study investigated the effects of increasing carbon (mannitol) and nitrogen (NO3– –N) concentrations on the rhizobial population and bioluminescence activity. The carbon source was more important than the nitrogen source to increase the rhizobial population and bioluminescence activity, which increased with increasing mannitol concentration, but not with increasing nitrate concentration. Results from this study demonstrated that NO3– –N increased rhizobial population, especially for faba bean, and the length of root colonized.Il manque de connaissances concernant les effets de l’azote sous forme de nitrate (NO3– –N), à des concentrations connues pour inhiber la formation de nodosités, sur la colonisation des racines des légumineuses fixatrices d’azote. Dans un premier temps, les différences potentielles entre la souche mère, 175F9, de Rhizobium leguminosarum bv. viciae et la souche 175F9.lux porteuse d’un marqueur de bioluminescence ont été étudiées sur la colonisation des racines de la féverole (Vicia faba L.) et du pois (Pisum sativum L.). Les deux souches ont colonisé les racines de ces deux plantes hôtes de façon similaire. Dans un deuxième temps, cette étude a évalué l’effet de 0 et 10 mol·m–3 de NO3– –N sur la colonisation de la féverole et du pois par la souche 175F9.lux. Selon la moyenne des deux souches aux deux dates de récolte, la présence de NO3– –N a augmenté la population des rhizobia et la longueur des racines colonisées. Les résultats ont aussi révélé que l’activité de la bioluminescence a augmenté de 7 à 14 jours après les semis, mais il n’y a pas eu de corrélation avec la population des rhizobia. Finalement, pour démontrer que l’augmentation de l’activité de la bioluminescence n’était pas une conséquence indirecte de l’effet de l’azote sur le R. leguminosarum bv. viciae, 175F9.lux, les effets d’une augmentation du carbone (mannitol) et de l’azote (NO3– –N) sur la population des rhizobia et de l’activité de la bioluminescence ont été mesurés. La source de carbone s’est révélée plus importante que la source d’azote pour augmenter la population des rhizobia et l’activité de la bioluminescence, qui a augmenté avec l’accroissement des concentrations de mannitol mais non avec celles de l’azote. Les résultats de cette étude ont démontré que le NO3– –N a favorisé la population des rhizobiums ainsi que la longueur des racines colonisées, particulièrement chez la féverole

Ascochyta lentis renamed Ascochyta fabae f. sp. lentis

Sixty-eight isolates of Ascochyta lentis, the causal agent of ascochyta blight of lentil (Lens culinaris) were obtained from locations around the world. The variability of these cultures for six cultural and seven morphological characters was compared with that of 13 isolates of A. fabae, the causal agent of ascochyta blight of faba bean (Vicia faba). In greenhouse and field trials, lentil and faba bean were inoculated with cultures isolated from both species to assess the degree of host specificity. Multivariate analysis of the cultural and morphological characters could not separate the two species. However, differences in host specificity were clear cut, with isolates infecting only the host from which they were originally isolated. We advocate that A. lentis be synonymized with A. fabae and propose two special forms: A. fabae f. sp. fabae for isolates pathogenic on faba bean and A. fabae f. sp. lentis for isolates pathogenic on lentil.Soixante-huit isolats de VAscochyta lentis, l'agent de la brûlure ascochytique de la lentille (Lens culinaris) ont été obtenus de diverses parties du monde. La variabilité de six caractéristiques culturales et de sept caractéristiques morphologiques de ces isolats a été comparée à celle de 13 isolats de VA. fabae. Ce dernier induit la brûlure ascochytique de la féverole (Viciafaba). Les analyses multivariées des caractéristiques culturales et morphologiques n'ont pu différencier les deux espèces. Lors d'essais en serre et en champ, des plants de lentille et de féverole ont été inoculés avec des souches isolées de ces mêmes espèces. Des différences marquées de spécialisation ont été notées. Les isolats qui provenaient d'une espèce de plante sensible n'ont infecté que cette espèce. Nous proposons A. lentis comme synonyme de A. fabae et l'adoption de deux formes spéciales: A. fabae f. sp. fabae pour les isolats pathogènes de la féverole et A. fabae f. sp. lentis pour les isolats pathogènes de la lentille

Selection of rhizobial strains differing in their nodulation kinetics under low temperature in four temperate legume species

Abstract Background Winter climate change including frequent freeze‐thaw episodes and shallow snow cover will have major impacts on the spring regrowth of perennial crops. Non‐bloating perennial forage legume species including sainfoin, birdsfoot trefoil, red clover, and alsike clover have been bred for their adaptation to harsh winter conditions. In parallel, the selection of cold‐tolerant rhizobial strains could allow earlier symbiotic nitrogen (N) fixation to hasten spring regrowth of legumes. Methods To identify strains forming nodules rapidly and showing high N‐fixing potential, 60 rhizobial strains in association with four temperate legume species were evaluated over 11 weeks under spring soil temperatures for kinetics of nodule formation, nitrogenase activity, and host yield. Results Strains differed in their capacity to form efficient nodules on legume hosts over time. Strains showing higher nitrogenase activity were arctic strain N10 with sainfoin and strain L2 with birdsfoot trefoil. For clovers, nitrogenase activity was similar for control and inoculated plants, likely due to formation of effective nodules in controls by endophyte rhizobia present in seeds. Conclusions Selection based on nodulation kinetics at low temperature, nitrogenase activity, and yield was effective to identify performant rhizobial strains for legume crops. The use of cold‐tolerant strains could help mitigate winter climatic changes

Characterization of opine-utilizing bacteria isolated from Québec

Twenty-three opine-utilizing strains of bacteria have been isolated from about 100 soil and crown gall samples, and tested for the following characters : type of opine utilized, fluorescence on King's B medium, virulence on general hosts, biotype, sensitivity to agrocin 84, number of plasmid species, and conjugal transfer of the capacity for opine catabolism. Seven strains were virulent on general hosts and were therefore identified as Agrobacterium tumefaciens, and four produced a fluorescent pigment on King's B medium, a property characteristic of some Pseudomonas species.Vingt-trois couches de bactéries utilisatrices d'opines ont été isolées à partir d'une centaine d'échantillons de sol et de tumeur du collet. Ces souches ont ensuite été évaluées pour les caractères suivant : type d'opine utilisés, fluorescence sur le milieu B de King, virulence pour des hôtes à grande sensibilité, biotype, sensibilité à l'agrocine 84, nombre de type de plasmides et transfert conjugatif de la faculté de cataboliser des opines. Sept souches se sont montrées virulentes pour des hôtes à grande sensibilité et appartiennent donc à l'espèce Agrobacterium tumefaciens. quatre souches ont produit un pigment sur le milieu B de King, ce qui est un caracrère typique de certaines espèces de Pseudomonas