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1.
Kazuto Ishikawa Takashi Ohmori Hirokuni Miyamoto Toshiyuki Ito Yoshifumi Kumagai Masatoshi Sonoda Jirou Matsumoto Hisashi Miyamoto Hiroaki Kodama 《Applied microbiology and biotechnology》2013,97(3):1349-1359
NO 3 ? is a major nitrogen source for plant nutrition, and plant cells store NO 3 ? in their vacuoles. Here, we report that a unique compost made from marine animal resources by thermophiles represses NO 3 ? accumulation in plants. A decrease in the leaf NO 3 ? content occurred in parallel with a decrease in the soil NO 3 ? level, and the degree of the soil NO 3 ? decrease was proportional to the compost concentration in the soil. The compost-induced reduction of the soil NO 3 ? level was blocked by incubation with chloramphenicol, indicating that the soil NO 3 ? was reduced by chloramphenicol-sensitive microbes. The compost-induced denitrification activity was assessed by the acetylene block method. To eliminate denitrification by the soil bacterial habitants, soil was sterilized with γ irradiation and then compost was amended. After the 24-h incubation, the N2O level in the compost soil with presence of acetylene was approximately fourfold higher than that in the compost soil with absence of acetylene. These results indicate that the low NO 3 ? levels that are often found in the leaves of organic vegetables can be explained by compost-mediated denitrification in the soil. 相似文献
2.
Background and Aims
The post-fire mineral N pool is relevant for plant regrowth. Depending on the plant regeneration strategies, this pool can be readily used or lost from the plant–soil system. Here we studied the retention of the post-fire mineral N pool in the system over a period of 12 years in three contrasted Mediterranean plant communities.Methods
Three types of vegetation (grassland, mixed shrub-grassland and shrubland) were subjected to experimental fires. We then monitored the fate of 15?N-tracer applied to the mineral N pool in soils and in plants over 12 years.Results
The plant community with legumes (mixed shrub-grasslands) showed the lowest soil retention of 15?N-tracer during the first 9 months after fire. Between years 6 and 12 post-fire, a drought promoted plant and litter deposition. Coinciding with this period, 15?N-recovery in the first 15 cm of the soil increased in all cases, except in mixed shrub-grassland. This lack of increase may be attributable to the input of impoverished 15?N plant residues and enhanced leaching and denitrification, possibly by N2-fixing shrubs. After the drought, the deepest soil layer showed large decreases in total N and 15?N-recovery, which were possibly caused by N mineralization.Conclusions
Twelve years after the fires, plant communities without N2-fixing shrubs recycled a significant part of the N derived from the post-fire mineral N and this pool continued to interact in the plant–soil system. 相似文献3.
Ch. Srinivasarao Sumanta Kundu B. K. Ramachandrappa Sharanbhoopal Reddy Rattan Lal B. Venkateswarlu K. L. Sahrawat R. Prakash Naik 《Plant and Soil》2014,374(1-2):315-330
Aims
In Alfisols, potassium (K) deficiency limits productivity, as these soils are poor in K-bearing minerals such as mica. As nutrient management practices greatly influence K nutrition of crops especially in the longer term, we evaluated the effects of 27 (1978–2004) years of cropping fingermillet (Eleusine coracana G.) under different manure and mineral fertilizer treatments on K release, balance and yield sustainability on K deficient Alfisols in the semi-arid tropical region of southern India.Methods
Fingermillet (variety: PR-202) was grown each year under rainfed conditions with 5 different nutrient management treatments: control (no amendment), 10 Mg ha?1 farm yard manure (FYM), 10 Mg ha?1 FYM +50 % NPK, 10 Mg ha?1 FYM +100 % NPK and 100 % NPK. Potassium release characteristics in the soil profile were determined using 1 N boiling HNO3 (strong extracting solution), 0.01 M HCl (medium extracting solution) and 0.01 M CaCl2 (mild extracting solution).Results
Continuous cropping of Alfisols for 27 years resulted in a decrease in K supplying capacity due to soil K depletion through crop K uptake. In soils without K addition, inherent soil supply could not meet the K requirement of fingermillet; thus, a negative K balance following 27 years of cropping affected K nutrition of the crop in all the treatments. As a result, the highest sustainable yield index (SYI) was observed using an integrated nutrient supply (combined application of nutrients from organic and inorganic sources), and the lowest index was obtained without K additions.Conclusion
For balanced nutrient management in cereal production systems, K nutrition needs urgent attention in the K deficient Alfisol region of southern India. Addition of any amount of organic manures available at field level offers an alternative strategy for maintaining soil K fertility to improve and sustain crop productivity. 相似文献4.
Arbuscular mycorrhizas and their role in plant growth, nitrogen interception and soil gas efflux in an organic production system 总被引:2,自引:0,他引:2
Background and aims
Roots and mycorrhizas play an important role in not only plant nutrient acquisition, but also ecosystem nutrient cycling.Methods
A field experiment was undertaken in which the role of arbuscular mycorrhizas (AM) in the growth and nutrient acquisition of tomato plants was investigated. A mycorrhiza defective mutant of tomato (Solanum lycopersicum L.) (named rmc) and its mycorrhizal wild type progenitor (named 76R) were used to control for the formation of AM. The role of roots and AM in soil N cycling was studied by injecting a 15N-labelled nitrate solution into surface soil at different distances from the 76R and rmc genotypes of tomato, or in plant free soil. The impacts of mycorrhizal and non-mycorrhizal root systems on soil greenhouse gas (CO2 and 14+15N2O and 15N2O) emissions, relative to root free soils, were also studied.Results
The formation of AM significantly enhanced plant growth and nutrient acquisition, including interception of recently applied NO 3 ? . Whereas roots caused a small but significant decrease in 15N2O emissions from soils at 23?h after labeling, compared to the root-free treatment, arbuscular mycorrhizal fungi (AMF) had little effect on N2O emissions. In contrast soil CO2 emissions were higher in plots containing mycorrhizal root systems, where root biomass was also greater.Conclusions
Taken together, these data indicate that roots and AMF have an important role to play in plant nutrient acquisition and ecosystem N cycling. 相似文献5.
Aims
Effects of different soil amendments were investigated on methane (CH4) emission, soil quality parameters and rice productivity in irrigated paddy field of Bangladesh.Methods
The experiment was laid out in a randomized complete block design with five treatments and three replications. The experimental treatments were urea (220 kg ha?1) + rice straw compost (2 t ha?1) as a control, urea (170 kg ha?1) + rice straw compost (2 t ha?1) + silicate fertilizer, urea (170 kg ha?1) + sesbania biomass (2 t ha?1 ) + silicate fertilizer, urea (170 kg ha?1) + azolla biomass (2 t ha?1) + cyanobacterial mixture 15 kg ha?1 silicate fertilizer, urea (170 kg ha?1) + cattle manure compost (2 t ha?1) + silicate fertilizer.Results
The average of two growing seasons CH4 flux 132 kg ha?1 was recorded from the conventional urea (220 kg ha?1) with rice straw compost incorporated field plot followed by 126.7 (4 % reduction), 130.7 (1.5 % reduction), 116 (12 % reduction) and 126 (5 % reduction) kg CH4 flux ha?1 respectively, with rice straw compost, sesbania biomass, azolla anabaena and cattle manure compost in combination urea and silicate fertilizer applied plots. Rice grain yield was increased by 15 % and 10 % over the control (4.95 Mg ha?1) with silicate plus composted cattle manure and silicate plus azolla anabaena, respectively. Soil quality parameters such as soil organic carbon, total nitrogen, microbial biomass carbon, soil redox status and cations exchange capacity were improved with the added organic materials and azolla biofertilizer amendments with silicate slag and optimum urea application (170 kg ha?1) in paddy field.Conclusion
Integrated application of silicate fertilizer, well composted organic manures and azolla biofertilizer could be an effective strategy to minimize the use of conventional urea fertilizer, reducing CH4 emissions, improving soil quality parameters and increasing rice productivity in subtropical countries like Bangladesh. 相似文献6.
Background and aims
Plant physiological traits and their relation to soil N availability was investigated as regulators of the distribution of understory shrub species along a slope in a Japanese cedar (Cryptomeria japonica) plantation in central Japan.Methods
At the study site, previous studies demonstrated that both net and gross soil nitrification rates are high on the lower slope and there are dramatic declines in different sections of the slope gradient. We examined the distributions of understory plant species and their nitrate (NO 3 ? -N) use traits, and compared the results with the soil traits.Results
Our results show that boundaries between different dominant understory species correspond to boundaries between different soil types. Leucosceptrum stellipilum occurs on soil with high net and gross nitrification rates. Hydrangea hirta is dominant on soil with high net and low gross nitrification rates. Pieris japonica occurs on soil with very low net and gross nitrification rates. Dominant understory species have species-specific physiological traits in their use of NO 3 ? -N. Pieris japonica lacks the capacity to use NO 3 ? -N as a N source, but other species do use NO 3 ? -N. Lindera triloba, whose distribution is unrelated to soil NO 3 ? -N availability, changes the extent to which it uses NO 3 ? -N in response to soil NO 3 ? -N availability.Conclusions
Our results indicate that differences in the physiological capabilities and adaptabilities of plant species in using NO 3 ? -N as a N source regulate their distribution ranges. The identity of the major form of available soil N is therefore an environmental factor that influences plant distributions. 相似文献7.
Aims
A pot study spanning four consecutive crop seasons was conducted to compare the effects of successive rice straw biochar/rice straw amendments on C sequestration and soil fertility in rice/wheat rotated paddy soil.Methods
We adopted 4.5 t ha?1, 9.0 t ha?1 biochar and 3.75 t ha?1 straw for each crop season with an identical dose of NPK fertilizers.Results
We found no major losses of biochar-C over the 2-year experimental period. Obvious reductions in CH4 emission were observed from rice seasons under the biochar application, despite the fact that the biochar brought more C into the soil than the straw. N2O emissions with biochar were similar to the controls without additives over the 2-year experimental period. Biochar application had positive effects on crop growth, along with positive effects on nutrient (N, P, K, Ca and Mg) uptake by crop plants and the availability of soil P, K, Ca and Mg. High levels of biochar application over the course of the crop rotation suppressed NH3 volatilization in the rice season, but stimulated it in the wheat season.Conclusions
Converting straw to biochar followed by successive application to soil is viable for soil C sequestration, CH4 mitigation, improvements of soil and crop productivity. Biochar soil amendment influences NH3 volatilization differently in the flooded rice and upland wheat seasons, respectively. 相似文献8.
Effect of biochar amendment on maize yield and greenhouse gas emissions from a soil organic carbon poor calcareous loamy soil from Central China Plain 总被引:30,自引:0,他引:30
Afeng Zhang Yuming Liu Genxing Pan Qaiser Hussain Lianqing Li Jinwei Zheng Xuhui Zhang 《Plant and Soil》2012,351(1-2):263-275
Aims
A field experiment was conducted to investigate the effect of biochar on maize yield and greenhouse gases (GHGs) in a calcareous loamy soil poor in organic carbon from Henan, central great plain, China.Methods
Biochar was applied at rates of 0, 20 and 40?t?ha?1 with or without N fertilization. With N fertilization, urea was applied at 300?kg?N ha?1, of which 60% was applied as basal fertilizer and 40% as supplementary fertilizer during crop growth. Soil emissions of CO2, CH4 and N2O were monitored using closed chambers at 7?days intervals throughout the whole maize growing season (WMGS).Results
Biochar amendments significantly increased maize production but decreased GHGs. Maize yield was increased by 15.8% and 7.3% without N fertilization, and by 8.8% and 12.1% with N fertilization under biochar amendment at 20?t?ha?1 and 40?t?ha?1, respectively. Total N2O emission was decreased by 10.7% and by 41.8% under biochar amendment at 20?t?ha?1 and 40?t?ha?1 compared to no biochar amendment with N fertilization. The high rate of biochar (40?t?ha?1) increased the total CO2 emission by 12% without N fertilization. Overall, biochar amendments of 20?t?ha?1 and 40?t?ha?1 decreased the total global warming potential (GWP) of CH4 and N2O by 9.8% and by 41.5% without N fertilization, and by 23.8% and 47.6% with N fertilization, respectively. Biochar amendments also decreased soil bulk density and increased soil total N contents but had no effect on soil mineral N.Conclusions
These results suggest that application of biochar to calcareous and infertile dry croplands poor in soil organic carbon will enhance crop productivity and reduce GHGs emissions. 相似文献9.
Responses of CO2 efflux from an alpine meadow soil on the Qinghai Tibetan Plateau to multi-form and low-level N addition 总被引:1,自引:0,他引:1
Huajun Fang Shulan Cheng Guirui Yu Jiaojiao Zheng Peilei Zhang Minjie Xu Yingnian Li Xueming Yang 《Plant and Soil》2012,351(1-2):177-190
Aims
To assess the effects of atmospheric N deposition on the C budget of an alpine meadow ecosystem on the Qinghai–Tibetan Plateau, it is necessary to explore the responses of soil-atmosphere carbon dioxide (CO2) exchange to N addition.Methods
Based on a multi-form, low-level N addition experiment, soil CO2 effluxes were monitored weekly using the static chamber and gas chromatograph technique. Soil variables and aboveground biomass were measured monthly to examine the key driving factors of soil CO2 efflux.Results
The results showed that low-level N input tended to decrease soil moisture, whereas medium-level N input maintained soil moisture. Three-year N additions slightly increased soil inorganic N pools, especially the soil NH 4 + -N pool. N applications significantly increased aboveground biomass and soil CO2 efflux; moreover, this effect was more significant from NH 4 + -N than from NO 3 ? -N fertilizer. In addition, the soil CO2 efflux was mainly driven by soil temperature, followed by aboveground biomass and NH 4 + -N pool.Conclusions
These results suggest that chronic atmospheric N deposition will stimulate soil CO2 efflux in the alpine meadow on the Qinghai–Tibetan Plateau by increasing available N content and promoting plant growth. 相似文献10.
Aliaksandr Kolbas Lilian Marchand Rolf Herzig Erika Nehnevajova Michel Mench 《Plant and Soil》2014,376(1-2):377-397
Background and aims
The potential use of a metal-tolerant sunflower mutant line for both biomonitoring and phytoremediating a Cu-contaminated soil series was investigated.Methods
The soil series (21–1,170 mg Cu kg?1) was sampled in field plots at control and wood preservation sites. Sunflowers were cultivated 1 month in potted soils under controlled conditions.Results
pH and dissolved organic matter influenced Cu concentration in the soil pore water. Leaf chlorophyll content and root growth decreased as Cu exposure rose. Their EC10 values corresponded to 104 and 118 μg Cu L?1 in the soil pore water, 138 and 155 mg Cu kg?1 for total soil Cu, and 16–18 mg Cu kg?1 DW shoot. Biomass of plant organs as well as leaf area, length and asymmetry were well correlated with Cu exposure, contrary to the maximum stem height and leaf water content.Conclusions
Physiological parameters were more sensitive to soil Cu exposure than the morphological ones. Bioconcentration and translocation factors and distribution of mineral masses for Cu highlighted this mutant as a secondary Cu accumulator. Free Cu2+ concentration in soil pore water best predicted Cu phytoavailability. The usefulness of this sunflower mutant line for biomonitoring and Cu phytoextraction was discussed. 相似文献11.
Zubin Xie Yanping Xu Gang Liu Qi Liu Jianguo Zhu Cong Tu James E. Amonette Georg Cadisch Jean W. H. Yong Shuijin Hu 《Plant and Soil》2013,370(1-2):527-540
Aims
Two field microcosm experiments and 15N labeling techniques were used to investigate the effects of biochar addition on rice N nutrition and GHG emissions in an Inceptisol and an Ultisol.Methods
Biochar N bioavailability and effect of biochar on fertilizer nitrogen-use efficiency (NUE) were studied by 15N-enriched wheat biochar (7.8803 atom% 15N) and fertilizer urea (5.0026 atom% 15N) (Experiment I). Corn biochar and corn stalks were applied at 12 Mg?ha?1 to study their effects on GHG emissions (Experiment II).Results
Biochar had no significant impact on rice production and less than 2 % of the biochar N was available to plants in the first season. Biochar addition increased soil C and N contents and decreased urea NUE. Seasonal cumulative CH4 emissions with biochar were similar to the controls, but significantly lower than the local practice of straw amendment. N2O emissions with biochar were similar to the control in the acidic Ultisol, but significantly higher in the slightly alkaline Inceptisol. Carbon-balance calculations found no major losses of biochar-C.Conclusion
Low bio-availability of biochar N did not make a significantly impact on rice production or N nutrition during the first year. Replacement of straw amendments with biochar could decrease CH4 emissions and increase SOC stocks. 相似文献12.
Aims
Rice fields are an important source for the greenhouse gas methane. Plants play an essential role in carbon supply for soil microbiota, but the influence of the microbial community on carbon cycling is not well understood.Methods
Microcosms were prepared using sand-vermiculite amended with different soils and sediments, and planted with rice. The microcosms at different growth stages were pulse-labeled with 13CO2 followed by tracing 13C in plant, soil and atmospheric carbon pools and quantifying the abundance of methanogenic archaea in rhizosphere soil.Results
Overall,?>85 % of the freshly assimilated carbon was allocated in aboveground plant biomass, approximately 10 % was translocated into the roots and?2 % was recovered in soil organic matter, independently from soil type. Only about 0.3 % was transformed to CH4, but emission of 13C-labeled CH4 started immediately and 13C enrichment revealed that plant-derived carbon was an important source for methanogenesis. The results further demonstrated that carbon assimilation and translocation processes, microbial abundance and gas emission were not only affected by the plant growth stage, but also by the content and type of soil in which the rice plants grew.Conclusions
The study illustrates the close ties between plant physiology, soil properties and microbial communities for carbon turnover and ecosystem functioning. 相似文献13.
Simeon J. Smaill Peter W. Clinton Robert B. Allen Murray R. Davis 《Plant and Soil》2014,374(1-2):371-379
Background and aims
Plant nutrient uptake from coarse soil (2–4 mm diameter) has been demonstrated for only a limited number of nutrients, and the nutritional contribution of coarse soil when present with fine soil (material <2 mm diameter) in realistic ratios is unknown. We conducted a seedling pot trial to investigate the functional relevance of this soil fraction to plant nutrition.Methods
Fine soil was mixed with either coarse soil, or the equivalent volume of inert glass chips, in ratios identical to those occurring naturally in soil sampled from two depths at each of two sites. Seedlings of Nothofagus solandri var. cliffortioides and Weinmannia racemosa were planted in the soil mixtures and harvested after 9 months.Results
The content of nitrogen, phosphorous, potassium, magnesium and other elements in the above ground seedling tissue was significantly increased by the presence of coarse soil. The coarse soil fraction also contributed proportionally much more to plant nutrient uptake than fine soil on a mass per mass basis.Conclusions
Coarse soil is excluded from conventional soil analysis, so is possible that soil nutrient capital is systematically underestimated. This has implications for land management and studies of plant dynamics in relation to nutrient supply. 相似文献14.
Chanjuan Guo Judy Simon Rainer Gasche Pascale Sarah Naumann Carolin Bimüller Rodica Pena Andrea Polle Ingrid Kögel-Knabner Bernd Zeller Heinz Rennenberg Michael Dannenmann 《Plant and Soil》2013,369(1-2):657-668
Aims
Our aims were to characterize the fate of leaf-litter-derived nitrogen in the plant-soil-microbe system of a temperate beech forest of Southern Germany and to identify its importance for N nutrition of beech seedlings.Methods
15N-labelled leaf litter was traced in situ into abiotic and biotic N pools in mineral soil as well as into beech seedlings and mycorrhizal root tips over three growing seasons.Results
There was a rapid transfer of 15N into the mineral soil already 21 days after tracer application with soil microbial biomass initially representing the dominant litter-N sink. However, 15N recovery in non-extractable soil N pools strongly increased over time and subsequently became the dominant 15N sink. Recovery in plant biomass accounted for only 0.025 % of 15N excess after 876 days. After three growing seasons, 15N excess recovery was characterized by the following sequence: non-extractable soil N?>>?extractable soil N including microbial biomass?>>?plant biomass?>?ectomycorrhizal root tips.Conclusions
After quick vertical dislocation and cycling through microbial N pools, there was a rapid stabilization of leaf-litter-derived N in non-extractable N pools of the mineral soil. Very low 15N recovery in beech seedlings suggests a high importance of other N sources such as root litter for N nutrition of beech understorey. 相似文献15.
Selenium accumulation in durum wheat and spring canola as a function of amending soils with selenite, selenate and or sulphate 总被引:3,自引:0,他引:3
Aims
A comparison was performed between plant species to determine if extractable, rather than total soil Se, is more effective at predicting plant Se accumulation over a full growing season.Methods
Durum wheat (Triticum turgidum L.) and spring canola (Brassica napus L.) were sown in potted soil amended with 0, 0.1, 1.0, or 5.0 mg kg?1 Se as SeO4 2? or SeO3 2?. In addition, SeO4 2?-amended soils were amended with 0 or 50 mg kg?1 S as SO4 2?. Soils were analyzed for extractable and total concentration of Se ([Se]). Twice during the growing season plants were harvested and tissue [Se] was determined.Results
Plants exposed to SeO3 2? accumulated the least Se. Fitted predictive models for whole plant accumulation based on extractable soil [Se] were similar to models based on total [Se] in soil (R2?=?0.73 or 0.74, respectively) and selenium speciation and soil [S] were important soil parameters to consider. As well, soil S amendments limited Se toxicity.Conclusions
Soil quality guidelines (SQGs) based on extractable Se should be considered for risk assessment, particularly when Se speciation is unknown. Predictive models to estimate plant Se uptake should include soil S, a modifier of Se accumulation. 相似文献16.
Background and aims
Biochar is produced from the pyrolysis of organic materials, and when buried in soil can act as a long term soil carbon (C) store. Evidence suggests that biochar can also increase crop yields, reduce nutrient leaching and increase biological nitrogen fixation in leguminous plants. However, the potential for increasing biological N2 fixation in agroecosystems is poorly understood, with inconsistent reports of root nodulation following biochar application. Therefore, the aim of this study was to determine the effect of biochar application rate and time since application on nodulation and nitrogenase activity in nodules of clover grown in a temperate agricultural soil.Methods
We used replicated field plots with three biochar application rates (0, 25 and 50 t ha?1). Three years after biochar amendment, the plots were further split and fresh biochar added at two different rates (25 and 50 t ha?1) resulting in double-loaded reapplications of 25?+?25 and 50?+?50 t ha?1.Results
Three years after biochar application, there was no significant difference in the total number of root nodules between biochar-amended and unamended soil, regardless of the application rate. However, despite clover root nodules being of a similar number and size the level of nitrogenase activity of individual nodules in biochar-amended soil was significantly higher than in unamended soil. Reapplication of biochar resulted in decreased nodulation, although the rate of nitrogenase activity per nodule remained unaffected.Conclusion
In the short term, biochar influences root nodule number and localised N2 fixation per nodule; however, total nitrogenase activity for the whole root system remained unaffected by the application rate of biochar or time since its application. These results emphasise the importance of long-term field studies, with a variety of applications rates for determining the influence of biochar applications on N2-fixing organisms and in providing data that can meaningfully inform agronomic management decisions and climate change mitigation strategies. 相似文献17.
Amending soils of different texture with six compost types: impact on soil nutrient availability, plant growth and nutrient uptake 总被引:1,自引:0,他引:1
Background
Composts with different feedstocks may have differential effects on soil properties and plant growth which, may be further modulated by soil texture.Materials and methods
In a 77-day pot experiment in the glasshouse, we investigated the effect of a single application as mulch of six types of composts derived from different starting feedstocks in two soils (13% and 46% clay, referred to as S13 and S46) on soil physical, chemical and biological properties, plant growth and nutrient uptake. Composts were placed as 2.5?cm thick mulch layer on the soil surface and wheat plants were grown and harvested at 42?days and at 77?days (grain filling).Results
Composts differed in total and available N and P and particle size with C1, C3, C4 and C5 being fine-textured, whereas C2 and C6 were coarse-textured. Compost addition as mulch increased soil total organic C and EC, but had no effect on pH. In all treatments, cumulative soil respiration was higher in S13 than in S46 and was increased by compost addition with the greatest increase with C2 and C6. Compared to the unamended soil, most compost mulches (except C2) increased macroaggregate stability. Compost mulches significantly increased available P and N in both soils, except for C2. Compost mulches increased available N up to 6-fold in both soils with the strongest increase by C5. Most composts also increased wheat growth and shoot P and N concentrations with the greatest effect on plant N concentration by C5 and on plant P concentration by C4. However, C2 decreased shoot N and P concentrations compared to the unamended soil. Most compost mulches (except C2) increased mycorrhizal colonization by up to 50% compared to the unamended soil.Conclusions
Fine-textured compost mulches generally had a greater effect on soil properties and plant growth than coarse-textured composts. Despite distinct differences between the soils with respect to clay content, TOC and available P, the effect of the compost mulches on soil and plant properties was quite similar. 相似文献18.
Nitrogen deposition promotes ecosystem carbon accumulation by reducing soil carbon emission in a subtropical forest 总被引:1,自引:0,他引:1
Houbao Fan Jianping Wu Wenfei Liu Yinghong Yuan Rongzhen Huang Yingchun Liao Yanyan Li 《Plant and Soil》2014,379(1-2):361-371
Background and aims
Tropical and subtropical forests are experiencing high levels of atmospheric nitrogen (N) deposition, but the responses of such forests ecosystems to N deposition remain poorly understood.Methods
We conducted an 8-year field experiment examining the effect of experimental N deposition on plant growth, soil carbon dioxide efflux, and net ecosystem production (NEP) in a subtropical Chinese fir forest. The quantities of N added were 0 (control), 60, 120, and 240 kg ha?1 year?1.Results
NEP was lowest under ambient conditions and highest with 240 kg of N ha?1 year?1 treatment. The net increase in ecosystem carbon (C) storage ranged from 9.2 to 16.4 kg C per kg N added in comparison with control. In addition, N deposition treatments significantly decreased heterotrophic respiration (by 0.69–1.85 t C ha?1 year?1) and did not affect plant biomass. The nitrogen concentrations were higher in needles than that in fine roots.Conclusions
Our findings suggest that the young Chinese fir forest is carbon source and N deposition would sequester additional atmospheric CO2 at high levels N input, mainly due to reduced soil CO2 emission rather than increased plant growth, and the amount of sequestered C depended on the rate of N deposition. 相似文献19.
Contrasting effects of manure and green waste biochars on the properties of an acidic ferralsol and productivity of a subtropical pasture 总被引:1,自引:0,他引:1
P. G. Slavich K. Sinclair S. G. Morris S. W. L. Kimber A. Downie L. Van Zwieten 《Plant and Soil》2013,366(1-2):213-227
Background and Aim
We hypothesised that amending an acidic ferralsol with biochar would improve the productivity of a subtropical dairy pasture via reducing soil acidity related constraints and result in improved nitrogen use efficiency. We examined two contrasting biochars with different carbon, nutrient content and acid neutralising values.Methods
Field plots were amended with one of three biochar treatments (Nil, feedlot manure biochar [FM], green waste biochar [GW]) in combination with presence or absence of NPK fertiliser and presence or absence of liming. The FM and GW biochars had a carbon content of 44 and 76 %, available phosphorous of 5,960 and 93 mg kg?1, and liming values of 13 and 5.6 %, respectively. The pasture was managed to supply year round high quality feed for dairy production.Results
The FM biochar increased total pasture productivity by 11 % and improved the agronomic nitrogen use efficiency by 23 %. It also reduced soil acidity but did not significantly affect the pH dependent soil cation exchange capacity. The GW biochar did not improve pasture productivity. Both biochars resulted in an increase in the soil carbon density.Conclusions
The high available phosphorous content of FM biochar makes it an effective amendment for acidic ferralsols. Greenwaste biochar did not have sufficient acid neutralising capacity or phosphorous content to reduce soil acidity constraints. Both biochars enhance soil carbon storage in pasture systems on ferralsol. 相似文献20.