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11.
Earthworm species composition affects the soil bacterial community and net nitrogen mineralization 总被引：2，自引：1，他引：2
Maria B. Postma-Blaauw Jaap Bloem Jack H. Faber Jan Willem van Groenigen Ron G.M. de Goede Lijbert Brussaard 《Pedobiologia》2006,50(3):243-256
Knowledge of the effects of species diversity within taxonomic groups on nutrient cycling is important for understanding the role of soil biota in sustainable agriculture. We hypothesized that earthworm species specifically affect nitrogen mineralization, characteristically for their ecological group classifications, and that earthworm species interactions would affect mineralization through competition and facilitation effects. A mesocosm experiment was conducted to investigate the effect of three earthworm species, representative of different ecological groups (epigeic: Lumbricus rubellus; endogeic: Aporrectodea caliginosa tuberculata; and anecic: Lumbricus terrestris), and their interactions on the bacterial community, and on nitrogen mineralization from 15N-labelled crop residue and from soil organic matter.Our results indicate that L. rubellus and L. terrestris enhanced mineralization of the applied crop residue whereas A. caliginosa had no effect. On the other hand, L. rubellus and A. caliginosa enhanced mineralization of the soil organic matter, whereas L. terrestris had no effect. The interactions between different earthworm species affected the bacterial community and the net mineralization of soil organic matter. The two-species interactions between L. rubellus and A. caliginosa, and L. rubellus and L. terrestris, resulted in reduced mineral N concentrations derived from soil organic matter, probably through increased immobilization in the bacterial biomass. In contrast, the interaction between A. caliginosa and L. terrestris resulted in increased bacterial growth rate and reduced total soil C. When all three species were combined, the interaction between A. caliginosa and L. terrestris was dominant. We conclude that the effects of earthworms on nitrogen mineralization depend on the ecological traits of the earthworm species present, and can be modified by species interactions. Knowledge of these effects can be made useful in the prevention of nutrient losses and increased soil fertility in agricultural systems, that typically have a low earthworm diversity. 相似文献
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Conservation: limits of land sparing 总被引：1，自引：0，他引：1
Fischer J Batáry P Bawa KS Brussaard L Chappell MJ Clough Y Daily GC Dorrough J Hartel T Jackson LE Klein AM Kremen C Kuemmerle T Lindenmayer DB Mooney HA Perfecto I Philpott SM Tscharntke T Vandermeer J Wanger TC Von Wehrden H 《Science (New York, N.Y.)》2011,334(6056):593; author reply 594-593; author reply 595
14.
Nick van Eekeren Diederik van Liere Franciska de Vries Michiel Rutgers Ron de Goede Lijbert Brussaard 《Applied soil ecology》2009,42(3):254-263
The introduction of N2-fixing white clover (Trifolium repens) in grassland is a management measure that may contribute to sustainable grassland systems by making them less dependent on inorganic fertilizers. However, little is known about the impact of this measure on soil biota and ecosystem services. We investigated earthworms, nematodes, bacteria and fungi in an experiment in which white clover-only and a mixture of grass and white clover without fertilization were compared with grass-only with and without fertilization.In comparison with grass-only, white clover-only had a lower total root biomass and a lower C/N-ratio in the above- and below-ground plant biomass. These plant characteristics resulted in a lower bacterial biomass, a lower fungal biomass, a higher proportion of bacterivorous nematode dauerlarvae, a lesser proportion of herbivorous nematodes and a greater abundance of earthworms in clover-only.The quantity and quality (C/N-ratio) of the above- and below-ground plant biomass in the mixture of grass and white clover (20–30% clover in the DM) was comparable with grass fertilized with 150 kg N ha−1 of inorganic fertilizer. Differences between these treatments might show specific clover effects in the grass–clover mixture on soil biota other than quantity and C/N-ratio of the litter. However, the only differences were a higher proportion of bacterivorous nematode dauerlarvae and a different nematode community composition in grass–clover.The soil structure in white clover-only showed a higher proportion of angular blocky elements, a lower penetration resistance, a higher number of earthworm burrows, a higher potential N-mineralization and respiration than the soil in grass-only. This suggests that clover stimulates the ecosystem services of water infiltration and supply of nutrients, but is less conducive to soil structure maintenance. The grass–clover mixture differed from grass-only in a higher respiration and from clover-only in a higher percentage of soil crumbs. We suggest that when clover is introduced in grassland to reduce the reliance on inorganic fertilizer, the mixture of grass and clover maintains the positive impact of grass roots on soil structure and increases the supply of nutrients via the soil food web. Thus, a grass–clover mixture combines the agronomic benefits of the two plant types. 相似文献
15.
Verhage M Maia AS Plomp JJ Brussaard AB Heeroma JH Vermeer H Toonen RF Hammer RE van den Berg TK Missler M Geuze HJ Südhof TC 《Science (New York, N.Y.)》2000,287(5454):864-869
Brain function requires precisely orchestrated connectivity between neurons. Establishment of these connections is believed to require signals secreted from outgrowing axons, followed by synapse formation between selected neurons. Deletion of a single protein, Munc18-1, in mice leads to a complete loss of neurotransmitter secretion from synaptic vesicles throughout development. However, this does not prevent normal brain assembly, including formation of layered structures, fiber pathways, and morphologically defined synapses. After assembly is completed, neurons undergo apoptosis, leading to widespread neurodegeneration. Thus, synaptic connectivity does not depend on neurotransmitter secretion, but its maintenance does. Neurotransmitter secretion probably functions to validate already established synaptic connections. 相似文献
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L. Brussaard 《Biology and Fertility of Soils》1987,3(1-2):117-119
Summary Kleptocopry is the behaviour of adults or larvae of a certain species whereby dung masses are utilized which had been provisioned by individuals of another species for the latter's own brood. Aphodius coenosus is a kleptocoprid in nests of Typhaeus typhoeus. This is the first record of kleptocopry by A. coenosus and of a kleptocoprid in the nest of T. typhoeus. In the laboratory, newly emerged A. coenosus adults moved to the surface while back-filling their burrows. Back-filled burrows (approximately 3 mm in diameter) were also found in the field, together with back-filled burrows from T. typhoeus (approximately 14 mm in diameter). Ancient (ca. 10 000 years old) back-filling traces of the Typhaeus type reported earlier were also accompanied by small back-filling traces, similar to those made by A. coenosus. The traces made by kleptocoprid A. coenosus thus offer support to the hypothesis that the ancient large traces originate from large geotrupid dung beetles.Dedicated to the late Prof. Dr. M.S. Ghilarov 相似文献
18.
Elisée Ouédraogo Lijbert Brussaard Leo Stroosnijder 《Biology and Fertility of Soils》2007,44(2):343-351
A field experiment was conducted at Kaibo in southern Burkina Faso on an Eutric Cambisol during the 2000 rainy season to assess
the interaction of organic amendment quality and soil fauna, affecting soil organic carbon and sorghum (Sorghum bicolor L. Moench) performance. Plots were treated with the pesticides Dursban and Endosulfan to exclude soil fauna or left untreated.
Sub-treatments consisted of surface-placed maize straw (C/N ratio = 58), Andropogon straw (C/N ratio = 153), cattle dung (C/N ratio = 40), sheep dung (C/N ratio = 17) or compost (C/N ratio = 10) and the control.
Organic amendments were applied at a dose equivalent to the application of 40 kg N ha−1. The presence of soil fauna increased soil total carbon by 32% and grain yield production by 50%. The interaction between
high C/N ratio organic amendment, Andropogon straw (SA), and soil fauna reduced soil carbon build-up. We suggest that this is due to a priming effect of SA on soil organic
matter in the presence of soil fauna. We also suggest that the interaction between soil fauna and easily decomposable organic
amendment led to the smallest decrease in soil carbon build-up. It is concluded that in semi-arid West Africa, in the presence
of soil fauna, soil carbon build-up is more affected by the quality of organic amendments than the quantity of carbon inputs.
Sorghum grain yield production was significantly reduced in the absence of soil fauna. High C/N ratio organic amendment interacted
negatively with soil fauna in its effects on crop performance. We propose that the effect of soil fauna on soil carbon build-up
and crop performance can be optimised by using high quality organic matter or supplementing low-quality organic matter with
inorganic nitrogen in semi-arid West Africa. 相似文献
19.
Long-term effect of tillage and manure application on soil organic fractions and crop performance under Sudano-Sahelian conditions 总被引：1，自引：2，他引：1
A. Mando B. Ouattara M. Sdogo L. Stroosnijder K. Ouattara L. Brussaard B. Vanlauwe 《Soil & Tillage Research》2005,80(1-2):95-101
Human-induced degradation of natural resources in general and of soil in particular, is a major problem in many regions, including the Sudano-Sahelian zone. The combined effects of tillage and manure application on Lixisol properties and on crop performance were investigated at Saria, Burkina Faso, to find efficient soil management practices to improve soil fertility. A randomized block design with four treatments (hand hoeing only, hand hoeing+manure, ploughing only, oxen ploughing+manure) in three replications was started in 1990. Ten years later, total soil organic (SOC), particulate organic matter and C mineralization were measured. Initial SOC concentration was 4 mg/g and dropped to 2.1 mg/g soil in ploughed plots without manure and to 2.5 mg/g soil in hoed plots without manure. Manure addition mitigated the decrease of SOC in ploughed plots and even built up SOC in hoed plots, where it increased to 5.8 mg/g soil. Manure had a large effect on the fractions in which SOC was stored. In ploughed plots, a large amount of SOC was stored in physical particles >0.25 mm, while in hand hoed plots the maximum SOC was stored in finer fractions. In the topsoil, hoeing and manure resulted in a higher SOC than ploughing with no manure. However, in the 15–25 cm layer, particularly in September, particulate organic matter was greater in ploughed plots with manure than in hoed plots with manure. Crop yields were highest on ploughed+manure plots and lowest on ploughed plots with no manure. We conclude that applying manure annually mitigates the negative effect of ploughing and hand hoeing on SOC and related properties and therefore can contribute to the sustainability of the agricultural system in the Sudano-Sahelian zone. 相似文献
20.
Nick van Eekeren Herman de Boer Jaap Bloem Ton Schouten Michiel Rutgers Ron de Goede Lijbert Brussaard 《Biology and Fertility of Soils》2009,45(6):595-608
We studied the effect of five fertilizers (including two adjusted manure slurries) and an untreated control on soil biota
and explored the effect on the ecosystem services they provided. Our results suggest that the available N (NO3− and NH4+) in the soil plays a central role in the effect of fertilizers on nematodes and microorganisms. Microorganisms are affected
directly through nutrient availability and indirectly through grass root mass. Nematodes are affected indirectly through microbial
biomass and grass root mass. A lower amount of available N in the treatment with inorganic fertilizer was linked to a higher
root mass and a higher abundance and proportion of herbivorous nematodes. A higher amount of available N in the organic fertilizer
treatments resulted in a twofold higher bacterial activity (measured as bacterial growth rate, viz. thymidine incorporation),
a higher proportion of bacterivorous nematodes, a 30% higher potential N mineralization (aerobic incubation), and 25–50% more
potentially mineralizable N (anaerobic incubation). Compared to inorganic fertilizer, organic fertilization increased the
C total, the N total, the activity of decomposers, and the supply of nutrients via the soil food web. Within the group of
organic fertilizers, there was no significant difference in C total, abundances of soil biota, and the potential N mineralization
rate. There were no indications that farmyard manure or the adjusted manure slurries provided the ecosystem service “supply
of nutrients” better than normal manure slurry. Normal manure slurry provided the highest bacterial activity and the highest
amount of mineralizable N and it was the only fertilizer resulting in a positive trend in grass yield over the years 2000–2005.
The number of earthworm burrows was higher in the treatments with organic fertilizers compared to the one with the inorganic
fertilizer, which suggests that organic fertilizers stimulate the ecosystem service of water regulation more than inorganic
fertilizer. The trend towards higher epigeic earthworm numbers with application of farmyard manure and one of the adjusted
manure slurries, combined with the negative relation between epigeic earthworms and bulk density and a significantly lower
penetration resistance in the same fertilizer types, is preliminary evidence that these two organic fertilizer types contribute
more to the service of soil structure maintenance than inorganic fertilizer. 相似文献