Summary 0[ 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[ 1[ 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[ 2[ The one!time intervention consisted of incorporating paper de!inking sludge into soil at two rates "9 and 094 dry t ha Ð0 #\ supplemented with nitrogen "N# at three rates "2\ 5 and 8 g kg Ð0 sludge# and phosphorus "P# at two rates "9=4 and 0=9 g kg Ð0 sludge# followed by seeding "mid!summer# of Agropyron elongatum "Host# Beauv

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. 1997. Deinking sludge influences biomass, nitrogen and phosphorus status of several grass and legume species. Can. J. Soil Sci. 77: 693-702. 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. Dans ces mêmes substrats, les légumes ont nécessité du P à environ 0.8 g kg -1 résidus. Pour les substrats à base de sol minéral, la croissance dans les substrats ayant 53 et 27% résidus a été comparable à celle du sol témoin lorsque les graminées ont reçu du N à 5.3 et 5.9 g kg -1 résidus, et les légumineuses du P à 0.5 et 1.2 g kg -1 résidus, respectivement. En général, plus la quantité totale de N ou de P ajoutée était grande, meilleure était la croissance malgré les différences dans les rapports C/N et C/P. Pour une croissance équivalente, la concentration en N des tissus des graminées était plus élevée pour les substrats avec résidus que pour le sol témoin; tandis que la concentration en P des tissus des légumineuses était similaire. Les résidus de désencrage sont un bon amendement organique lorsque additionnés adéquatement de N et de P.

The experiment was conducted to determine the effects of CO, enrichment (900 μl·liter-1, 8 hours/day) in combination with supplementary lighting of 100 μmol·s-1·m-2(16-h photoperiod) on tomato (Lycopersicon esculentum Mill.) and sweet pepper (Capsicum annuum L.) seedling growth in the greenhouse and subsequent yield in the field. Enrichment with CO2 and supplementary lighting for ≈ 3 weeks before transplanting increased accumulation of dry matter in shoots by ≈ 50% compared with the control, while root dry weight increased 49% for tomato and 6270 for pepper. Early yields increased by =1570 and 11% for tomato and pepper, respectively.

Replenishment of soil C and N is essential for sustainable revegetation of minesoils. Our study investigated paper de‐inking sludge as the organic amendment for revegetating an abandoned sandpit in Québec, Canada. Sludge was incorporated at 0 (check) and 105 Mg dry matter ha−1 before seeding tall wheatgrass (Agropyron elongatum (Host) Beauv.). Nitrogen (at 315, 630 and 945 kg N ha−1) and P (at 52.5 and 105 kg P ha−1) were also applied to all plots. Distribution of C and N was determined periodically in two sizes (<53 μm and >53 μm) and two densities (<1.8 g cm−3 and >1.8 g cm−3) of soil fractions during 823 d. After 823 d, C concentrations were 43 and 69% of those of Day 5, for the low and high N rates, respectively. With time, the proportion of C in the heavy (>1.8 g cm−3) fraction increased from 20 to 55%, but remained near 20% in the fine (<53 μm) fraction. Increasing N rates increased C conservation mainly in the coarse (>53 μm) fraction. The amount of N recovered in all fractions decreased after Day 86, in accordance with a previous litter bag study. Although inorganic N was positively correlated with total N in all fractions, the fine fraction was the best indicator of the size of the mineral N pool. Addition of sludge to the sandpit favored the restoration of C and N pools, and high levels of mineral N increased this effect. Residues became denser but remained relatively coarse during their decomposition.