Mineralization of the carbon and nitrogen of plant material added to soil and of the soil humus during incubation following periodic drying and rewetting of the soil

1968 ◽  
Vol 28 (2) ◽  
pp. 226-245 ◽  
Author(s):  
D. A. van Schreven
Keyword(s):  
Plant Material ◽  
Soil Humus ◽  
Carbon And Nitrogen ◽  
Drying And Rewetting

The turnover of organic carbon and nitrogen in soil

1990 ◽  
Vol 329 (1255) ◽  
pp. 361-368 ◽  
Keyword(s):  
Plant Material ◽  
Field Experiments ◽  
Compartment Model ◽  
Soil Organic Nitrogen ◽  
Carbon And Nitrogen ◽  
First Order ◽  
Complex Process ◽  
Two Compartment Model ◽  
Term Field

Although the decomposition of plant material in soil is an extremely complex process, relatively simple models can give good fits to the decay process. Thus a two-compartment model gives a close representation, over the first few years, of the decay of 14 C-labelled plant material in soil. A model containing a single homogeneous humus compartment decomposing by a first-order process is surprisingly useful for soil organic nitrogen over periods measured in decades. More sophisticated multicompartmental models are now widely used to represent turnover in soil. One of these, the Rothamsted turnover model, is described in detail and shown to give a useful representation of data from the Rothamsted long-term field experiments.

Decomposition of plant material in Australian soils. II. Residual organic 14C and 15N from legume plant parts decomposing under field and laboratory conditions

Soil Research ◽  
1984 ◽  
Vol 22 (3) ◽  
pp. 331 ◽  
Author(s):  
M Amato ◽  
RB Jackson ◽  
JHA Butler ◽  
JN Ladd
Keyword(s):  
Plant Material ◽  
Calcareous Soil ◽  
Laboratory Studies ◽  
Plant Parts ◽  
Drying And Rewetting ◽  
Legume Plant ◽  
Medicago Littoralis ◽  
Average Residual ◽  
Medicago Species ◽  
Field And Laboratory Conditions

14C- and 12N-labelled Medicago littoralis and Medicago truncatula plant parts, ground or unground, were added at a rate equivalent to 50 kg nitrogen ha-l to a calcareous soil in the field and allowed to decompose for two years. Both plant types behaved similarly but the various plant parts decomposed to different extents. After 4 weeks' and 2 years' decomposition respectively, the residual organic 14C in soil from leaves of both Medicago species accounted for about 62% and 20% of input, from stems 70% and 24% and from roots 80% and 32%. Average residual organic 15N accounted for 64% and 40% of leaf 15N, 87% and 56% of stem and 81% and 50% of root 15N. Grinding had no effect on the residual 14C and 15N of plant parts. After 2 years' decomposition the proportion of residual and 15N present as labelled biomass was greatest for leaf residues. Results from laboratory studies of 20 weeks' decomposition of ground and unground Medicago littoralis plant parts under continuously moist and intermittently dry and rewetting conditions were consistent with field results. Grinding significantly promoted pod decomposition under most incubation conditions. Drying and rewetting promoted decomposition of the plant parts. Pods were affected more than other parts. The longer the time moist following drying, the greater the decomposition. The more frequent the drying and wetting cycles, the greater the decomposition.

scholarly journals THE CHANGES OF CHEMICAL PARAMETERS OF PEAT-FORMING PLANTS DURING DECOMPOSITION PRO-CESSES ON KARST-SUFFUSION MIRES OF THE MIDDLE-RUSSIAN UPLAND

2020 ◽  
pp. 283-292
Author(s):  
Elena Mikhaylovna Volkova ◽  
Ol'ga Ivanovna Boykova ◽  
Nikolay Viktorovich Khlytin
Keyword(s):  
Plant Material ◽  
Ash Content ◽  
Chemical Parameters ◽  
Sphagnum Mosses ◽  
Carbon And Nitrogen ◽  
Peat Deposits ◽  
Plant Remains ◽  
Chemical Composition Of Plants ◽  
Weight Method ◽  
Microscopy Method

The variety of biosphere functions of mire ecosystems is associated with the intensity of vertical growth of peat deposits, which is correlated with the rate of decomposition of plant remains. This process depends on the complex of ecological conditions and accompanies by changes in the chemical composition of plants. For studying of dynamics of the chemical parameters of the main peat-forming plants on the model karst-suffusion mire, an experiment was conducted with the laying of plant material in the peat. Plant samples were placed in peat to a depth of 5–7 cm in different parts of the mire, which is corresponded to the original place of species growing. After 1 and 2 years, the samples were removed from the peat and elemental analysis was carried out on the CHN-analyzer Carlo Erba 1100, ash content was determined by weight method and the degree of decomposition of plant remains was done by microscopy method. The results shows, that during the 2-year experiment the degree of decomposition of plants remains was changed by different ways. The herbs are least resistant for decomposition in the peat, but sphagnum mosses are the most resistant. The process of decomposition of plant remains is accompanied by a decreasing of ash content in vascular plants and increasing in sphagnum mosses, which is associated with their ability to accumulate surface runoff substances and atmospheric dust. During the transformation of plant material the content of carbon and nitrogen are changing. The C/N ratio indicates an uneven proportion of carbon and nitrogen at different stages of decomposition in different plant species, which correlates with the degree of decomposition.

Fine-scale variability in the dietary sources of grazing invertebrates in a temperate Australian saltmarsh

2010 ◽  
Vol 61 (5) ◽  
pp. 615 ◽  
Author(s):  
Neil Saintilan ◽  
Debashish Mazumder
Keyword(s):  
Plant Material ◽  
East Coast ◽  
Nitrogen Isotope ◽  
Marsh Surface ◽  
Floristic Diversity ◽  
Carbon And Nitrogen ◽  
C4 Grass ◽  
Sporobolus Virginicus ◽  
C3 Species ◽  
Stable Isotope Signatures

Saltmarsh floristic diversity declines with increasing latitude on the Australian east coast, with the dominant tropical C4 grass Sporobolus virginicus being replaced progressively by a suite of mostly succulent C3 species. The temperate Towra Point saltmarsh consists of a mosaic of vegetation communities, including stands of the C4 saltmarsh grass Sporobolus virginicus, and the C3 succulents Suaeda australis and Sarcocornia quinqueflora. The contrasting stable isotope signatures of these plants provide an opportunity to determine the extent to which plant material is contributing to the diet of grazing invertebrates inhabiting these communities. The grazing crabs Parasesarma erythrodactyla and Helograpsus haswellianus, and the snail Littoraria luteola, were sampled for their carbon and nitrogen isotope signatures. In the Sarcocornia communities, crab and snail δ13C signatures could not be matched to the signature of dominant plants, but were close to the fine benthic material on the marsh surface. In the Sporobolus community, the δ13C signatures of the same species were enriched and closer to that of the dominant plant. Results suggest that grazing herbivores feed over very small spatial ranges within mosaics of vegetation on locally sourced benthic material, with S. virginicus plant material making a contribution to dietary carbon where present.

Metabolic signalling and the partitioning of resources in plant storage organs

1999 ◽  
Vol 133 (3) ◽  
pp. 243-249 ◽  
Author(s):  
NIGEL G. HALFORD
Keyword(s):  
Dry Weight ◽  
Wild Relatives ◽  
Crop Plants ◽  
Wild Plants ◽  
Young Plant ◽  
Carbon And Nitrogen ◽  
Cultivated Potato ◽  
Metabolic Signalling ◽  
Storage Organs ◽  
Plant Storage

The most important harvested organs of crop plants, such as seeds, tubers and fruits, are often described as assimilate sinks. They play little or no part in the fixation of carbon through the production of sugars through photosynthesis, or in the uptake of nitrogen and sulphur, but import these assimilated resources to support metabolism and to store them in the form of starch, oils and proteins. Wild plants store resources in seeds and tubers to later support an emergent young plant. Cultivated crops are effectively storing resources to provide us with food and many have been bred to accumulate much more than would be required otherwise. For example, approximately 80% of a cultivated potato plant's dry weight is contained in its tubers, ten times the proportion in the tubers of its wild relatives (Inoue & Tanaka 1978). Cultivation and breeding has brought about a shift in the partitioning of carbon and nitrogen assimilate between the organs of the plant.

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