Significant Biomass Production Research Articles

Characterization of the interactions between architecture and source-sink relationships in winter oilseed rape (Brassica napus) using the GreenLab model.

This study aimed to characterize the interaction between architecture and source-sink relationships in winter oilseed rape (WOSR): do the costs of ramification compromise the source-sink ratio during seed filling? The GreenLab model is a good candidate to address this question because it has been already used to describe interactions between source-sink relationships and architecture for other species. However, its adaptation to WOSR is a challenge because of the complexity of its developmental scheme, especially during the reproductive phase. Equations were added in GreenLab to compute expansion delays for ramification, flowering of each axis and photosynthesis of pods including the energetic cost of oil synthesis. Experimental field data were used to estimate morphological parameters while source-sink parameters of the model were estimated by adjustment of model outputs to the data. Ecophysiological outputs were used to assess the sources/sink relationships during the whole growth cycle. First results indicated that, at the plant scale, the model correctly simulates the dynamics of organ growth. However, at the organ scale, errors were observed that could be explained either by secondary growth that was not incorporated or by uncertainties in morphological parameters (durations of expansion and life). Ecophysiological outputs highlighted the dramatic negative impact of ramification on the source-sink ratio, as well as the decrease in this ratio during seed filling despite pod envelope photosynthesis that allowed significant biomass production to be maintained. This work is a promising first step in the construction of a structure-function model for a plant as complex as WOSR. Once tested for other environments and/or genotypes, the model can be used for studies on WOSR architectural plasticity.

Cropping systems and crop residue management in the Trans-Gangetic Plains: Issues and challenges for conservation agriculture from village surveys

Conservation agriculture practices are being advocated to help sustain crop productivity gains and secure environmental sustainability in the Trans-Gangetic Plains, India’s Green Revolution heartland. The paper illustrates the use of village surveys as a quasi-quantitative system analysis tool to derive implications for agricultural research and development. Drawing from village surveys in 170 communities, the paper assesses current crop residue management practices in Punjab and Haryana’s rice–wheat, basmati–wheat and non-rice–wheat cropping systems. The prevalence of wheat as the winter crop implies an intensive collection, trading and use of wheat straw as basal feed for dairy livestock; which contrasts with the diverse crop residue management of the monsoon crops. The increased use of combine harvesters has spurred the rapid advent of mechanical wheat straw reapers whereas the bulk of combine harvested rice straw is burned in situ. Present crop residue management practices are largely incompatible with year-round mulch retention despite significant biomass production. The research and development community faces the challenge of evening out straw use and management over seasons to ensure at least partial residue retention if its calls for conservation agriculture in this important sub-region are to succeed. The paper also reiterates the worrying decline of groundwater tables associated with the rice–wheat system.

PRODUÇÃO DE BIOMASSA E ACÚMULO DE NUTRIENTES PELA VEGETAÇÃO ESPONTÂNEA EM CULTIVO DE CAFÉ ORGÂNICO

To evaluate biomass production and nutrient accumulation by the spontaneous vegetation in organic coffee crops and the phytosociology of these species, an experiment was set up at Fazendinha Agroecologica, in Seropedica, Rio de Janeiro state, in Brazil. The experiment consisted of three treatments, corresponding to systems of cultivation of conilon coffee ( Coffea canephora Pierre ex A. Froehner) in association with the tree legumes Gliricidia sepium (Jacq.) Kunth ex Walp. and Erythrina variegata L. (treatments 1 and 2), and a full sun cultivation system (treatment 3), distributed in a random block design with six replicates. Although six hoeings were performed over the course of one year, the aerial biomass produced by the spontaneous vegetation and the N, P, K, Ca, Mg and micronutrient contents accumulated in it were measured in only five periods4, to estimate the amount of nutrients that could be recycled after decomposition. The phytosociology of the spontaneous vegetation was evaluated in October 2006 and June 2007. Based on the species found, richness, abundance, relative frequency of species and Shannon’s diversity index were determined. The most significant biomass production values were obtained between October and December 2006, the highest results being found in coffee grown with gliricidia. No differences regarding the N, K, and Ca contents in the biomass were observed between the different treatments; however, the highest P content was registered in coffee grown in the full sun system, while the highest Mg content was found in coffee grown with gliricidia. The diversity of plant species is small and no differences can be observed among the systems. The most frequent invasive plant species in the systems, in both periods evaluated, were Commelina diffusa Burm. f. and Paspalum conjugatum L.

Yarrowia lipolytica: A model microorganism used for the production of tailor‐made lipids

AbstractThis paper presents a review of studies related with the production of specialty lipids by the yeast Yarrowia lipolytica during growth on various fatty agro‐industrial residues utilized as substrates. In a first approach, the potential for growth on stearin (a low‐cost industrial derivative of tallow composed of saturated free fatty acids) was assessed; significant biomass production was obtained, accompanied by notable intracellular accumulation of lipid which occurred as a primary anabolic activity regardless of the extracellular nitrogen availability in the medium. Y. lipolytica consumed its own storage lipids in the stationary growth phase. The secretion of extracellular lipase in non‐negligible quantities was also observed in cultures performed on stearin. Although Y. lipolytica tended to increase the intracellular level of stearic acid, its reserve lipid could be used as a cocoa butter substitute, provided that an oleic acid donor, such as chemically hydrolyzed rapeseed oil, is used as co‐substrate together with stearin. Accordingly, predetermined lipids with composition similarities to cocoa butter were synthesized using low‐cost substrates. Other strategies related with the production of microbial cocoa butter substitutes are also presented and comprehensively discussed.

Yellow Nutsedge (Cyperus esculentus) Interference in Soybean

Field research was conducted in 2000 and 2001 to determine the effect of yellow nutsedge emergence timing and plant density on soybean yield and on yellow nutsedge propagation the following year. Yellow nutsedge tubers were planted at 0-, 7.5- (13/m2), 15- (8.6/m2), 30- (4.3/m2), 60- (2.2/m2), and 90-cm (1.5/m2) in-row spacings with soybean. Yellow nutsedge densities from 2.2 to 13 plants/m2in a high-yield year (2000) and 4.3 to 13 plants/m2in a low-yield year (2001) reduced grain yields 9 to 34%. In a separate experiment, tubers were planted 0, 2, 4, 6, and 8 wk after planting at a 15-cm (8.6/m2) in-row spacing. Seedlings that emerged with the crop and until 2 wk after planting reduced yield 9 to 11%. Yellow nutsedge densities from 1.5 to 13 plants/m2contributed to significant aboveground biomass production, even with a competitive crop, such as soybean. For every gram of aboveground yellow nutsedge biomass produced in the fall, there were more than four shoots present the following spring.

Studies on Biomass Production in Auricularia polytricha Collected from Wilberforce Island, Bayelsa State, Nigeria

Auricularia polytricha (Mont) Saccardo, were found growing on decaying logs of wood in their large numbers within the marshy riverine ecosystem area of Wilberforce Island, Bayelsa State, Nigeria. The sporophores of this edible mushroom were tissue cultured and biomass production in submerged liquid medium was assessed. This fungus produced best mycelial biomass (340 mg cm-3) at 25°C after 15 days of incubation while no biomass was produced at 5, 45 and 50°C after 20 days. Likewise, very good biomass was produced at pH 6.5 after 10 days of incubation. Among the carbohydrate sources tested, glucose stimulated highest biomass yield of 375 mg cm-3 at 1.6% concentration closely followed by fructose (350 mg cm-3) at 1.8% concentration. All the nitrogen compounds investigated enhanced significant biomass production (p≤0.05). However, 0.8% of peptone stimulated the best biomass yield (320 mg cm-3) followed by tryptophan (300 mg cm-3) at 0.9% concentration. The volume of inoculum of A. polytricha that produced highest biomass of this fungus in liquid culture was 7.0 cm3. The implications of these findings were discussed.

Influence of ectomycorrhizal inoculation on Afzelia quanzensis Welw. seedlings in a nutrient-deficient soil

The growth and mineral nutrition of seedlings of one provenance of Afzelia quanzensis Welw. from Kenya, inoculated with two ectomycorrhizal fungi (ECM), one isolate of Scleroderma dictyosporum IR.408 and one isolate of Thelephora sp. ORS.XM002 from Burkina Faso and Senegal, respectively, were assessed in a ECM propagules-free soil at a deficient supply of NPK in a pot experiment. Thelephora sp. ORS.XM002 colonized A. quanzensis seedlings better than S. dictyosporum IR.408. Thus, root dry weight of A. quanzensis was stimulated with Thelephora sp. ORS.XM002, but did not improve any significant total biomass production. P, N, Ca and Mg concentrations in inoculated and non-inoculated A. quanzensis seedlings did not vary significantly. The increase of leaf K concentrations in A. quanzensis seedlings due to ECM inoculation with Thelephora sp. ORS.XM002 or S. dictyosporum IR.408 was not related to plant biomass production. However, the height increments of inoculated plants with S. dictyosporum IR.408 may be nutritional effects, but they are not expressed in terms of dry weight. The hypothesis that non-nutritional effects (e.g. hormonal effects) could explain our experimental results (e.g. stimulation of root dry weight) should also be taken into account.

Effect of organic enrichments on hydrolytic potentials and growth of bacteria in deep-sea sediments

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 140:239-250 (1996) - doi:10.3354/meps140239 Effect of organic enrichments on hydrolytic potentials and growth of bacteria in deep-sea sediments Boetius A, Lochte K To test the response of a natural benthic microbial assemblage to differences in the composition of organic matter supply, surface sediments from the Arctic continental slope (1000 m water depth) were enriched with a variety of organic compounds. Glycine and glucose represent substrates which can be directly utilized by bacteria; protein, chitin, cellulose, starch and the lipid Tween require extracellular hydrolysis by peptidase, chitobiase, beta-glucosidase, alpha-glucosidase and lipase, respectively. The effect of these enrichments on hydrolytic activity potentials and on several parameters of microbial biomass was observed over a period of 63 d. Within 10 d, specific activities of beta-glucosidase and chitobiase were enhanced by their respective substrates by a factor of 10 to 20. alpha-Glucosidase and peptidase were greatly inhibited in the presence of glucose and glycine, respectively. Peptidase, alpha-glucosidase and lipase activities were not induced by their respective substrates. The supply of starch, lipid and cellulose did not cause detectable growth of the bacterial assemblage for the whole period of the experiment. Enrichment with glycine, albumin, chitin and glucose resulted in significant biomass production of the bacterial populations with similar growth rates of 0.1 d-1 after a lag phase of up to 10 d. However, the supply of amino acid sources resulted in a 60% higher bacterial biomass yield after 63 d compared to chitin and glucose. Extracellular enzymes · Bacterial growth · Benthic bacteria · Organic matter supply · Deep-sea sediments Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 140. Publication date: September 12, 1996 Print ISSN:0171-8630; Online ISSN:1616-1599 Copyright © 1996 Inter-Research.

Biotreatment of swine manure by intensive lagooning during winter

The intent of the proposed system was to develop an in situ biotreatment system for swine manure that should involved minimum handling by the farmer. A demonstration plant has been installed in the Paris region. The intensive lagooning system consists of algal ponds, daphnid ponds and a polishing fish pond working in series with a total area of 2100 m 2 and a total volume of 3600 m 3. The performance of the system was evaluated under winter conditions with raw decanted swine manure by measuring N-NH 4 + and P-PO 4 3− removal, pH, temperature, water oxygen, algal biomass and daphnid productions. Results showed that low temperatures (<5° C) did not allow any significant biomass production (0·41–0·68 g dry mass/m 2 d). Ammonia-nitrogen, mostly stripped (98% lost by stripping), and phosphate removals were small. However, as soon as the temperature increased in spring (March), ammonia-nitrogen removal was improved with a large contribution (71%) due to stripping and the algal productivity increased to ≈ 3·5 g dry mass/m 2 d; CO 2 appeared to be a limiting factor. Ammonia-nitrogen, nitrate, nitrite and orthophosphate showed marked variations that could be correlated with manure overdoses.

Growth Response of Mediterranean Herbaceous Swards to Inoculation with Azospirillum Brasilense

A study was conducted on the effect of the rhizobacterium Azospirillum brasilense strain Cd on the production of herbaceous swards growing at 2 rangeland habitats in Israel. One habitat was the semiarid zone (< 300 mm annual rainfall, calcareous soil on rocky slopes) while the other was a typical Mediterranean zone (approximately-600 mm annual rainfall, karstic rock covered with terra rossa soil). The inoculum was applied in water suspension at a concentration of 109 colony forming units (CFU) ml-1. The effect of inoculation was compared with P-fertilizer application at a rate of 5 g/M2. The same treatments were also applied on potted soil from the 2 sites. The semiarid ecosystem showed a strong response to Azospirillum inoculation, to P-fertilizer and to the combination of these 2 treatments, with aerial biomass production increasing by approximately fourfold in the treatments as compared with the control. The response to inoculation or P-fertilization was similar, with no interaction or additive effect noted for the combined treatment. At the Mediterranean site, the response to inoculation or P-fertilization alone was variable, with only a moderate effect on biomass production as compared with the control; however, the inoculation-fertilization interaction was highly significant and doubled biomass production. In the greenhouse experiment, the response to inoculation or fertilization was significant and the biomass production at the end of the growing season was approximately 50% higher than in the control. At both sites, standing biomass was greater in the treated plots already at early stages of growth, thereby potentially lengthening the effective grazing season. It is suggested that inoculation with Azospirillum brasilense on a commercial scale may offer a means of increasing rangeland production without resorting to costly and ecologically unfavorable fertilizer application.

Aerobic treatment of silage effluent — Laboratory experiments

Laboratory-scale reactors were used to study the aerobic treatment of silage effluent. Raw silage effluent was characterised and shown to contain high concentrations of soluble organic matter. Aerobic treatment markedly reduced the soluble organic matter in the effluent, thus decreasing its pollution potential. A large increase in TSS, VSS and organic nitrogen in the solids fraction of the effluent was observed after treatment, suggesting significant biomass production.

Investigation ofJuniperus species of the United States for new Sources of Cedarwood Oil

The 11 taxa of Juniperus with widespread distribution in the United States and with significant biomass production were investigated to determine their yields of cedarwood oil and the major components of commercial interest: alpha-cedrene, beta-cedrene, thujopsene, cuparene, cedrol, and widdrol. Taxa examined wereJ. ashei, J. californica, J. erythrocarpa, J. deppeana, J. monosperma, J. occidentalis var.occidentalis, J. o. var.australis, J. osteosperma, J. pinchotii, J. scopulorum, andJ. virginiana. The volatile heartwood oils were removed by steam distillation and analyzed by gas chromatography-mass spectroscopy to determine their yields and composition. Cedarwood oil yields inJ. erythrocarpa andJ. scopulorum were comparable to those of the two species currently being utilized (J. ashei, J. virginiana).