scholarly journals Perennial Trees Associating with Nitrogen-Fixing Symbionts Differ in Leaf After-Life Nitrogen and Carbon Release

Nitrogen ◽  
2020 ◽  
Vol 1 (2) ◽  
pp. 111-124 ◽  
Author(s):  
Thomas E. Marler

Plants that enter symbiotic relationships with nitrogen (N)-fixing microbes contribute some of their N to the community through leaf litter decomposition and mineralization processes. The speed of these processes varies greatly among tree species. Mesocosm methods were used to determine the speed of N and carbon (C) release from Cycas micronesica, Intsia bijuga, and Serianthes nelsonii leaf litter. Microcosm methods were used to determine soil respiration traits in soils containing the leaf litter. The speed of leaf litter N and C release during decomposition occurred in the order C. micronesica < I. bijuga < S. nelsonii. Soil carbon dioxide efflux was increased by adding leaf litter to incubation soils, and the increase was greatest for S. nelsonii and least for C. micronesica litter. Ammonium, nitrate, total N, organic C, and total C were increased by adding litter to incubation soils, and the differences among the species converged with incubation duration. The rate of increases in available N and decreases in organic C were greatest for S. nelsonii and least for C. micronesica litter. These findings indicate that S. nelsonii litter released N and C rapidly, C. micronesica litter released N and C slowly, and the leaf economic spectrum accurately predicted the differences.

Author(s):  
Željko S. Dželetović ◽  
Nevena Lj. Mihailović

Based on a greenhouse experiment, we evaluated nitrogen availability in the surface mineral layer of soil under various natural meadow stands by analyzing the following soil characteristics: total organic C, total N, initial content of easily available N inorganic forms, mineralized N content obtained by aerobic and anaerobic incubations and A-value. The experiment was performed on a test plant and through the application of urea enriched with 5.4 % 15N. The investigated soils under natural meadows are characterized with comparatively high mineralization intensity and high N availability indices. Contents of mineral N produced by aerobic incubation and the intensity of the mineralization correlate with the total organic C in the soil and the total N in the soil. Correlation of the availability index of the soil N produced by aerobic incubation with the total organic C and the total N in the soil under natural meadows is almost linear (r = 0.9981 and r = 0.9997, respectively). Contents of mineral N produced by anaerobic incubation, as well as the corresponding N availability and mineralization intensity indices correlate poorly with the mentioned parameters. Efficiency of nitrogen utilization from the applied N-fertilizer by the test crop varies within a wide range of values and correlates with the biomass yields of the test crop.


Soil Research ◽  
1998 ◽  
Vol 36 (1) ◽  
pp. 17 ◽  
Author(s):  
X. J. Wang ◽  
P. J. Smethurst ◽  
G. K. Holz

To improve our understanding of nitrogen (N) supply in eucalypt plantations in Tasmania, N fluxes were determined in surface soils (0–10 cm) at 4 sites supporting 1–2-year-old plantations of E. nitens. Net N mineralisation, nitrification, leaching, and uptake were measured by an in situ soil-core technique. Soils were derived from basalt (3 sites) or mudstone (1 site). Average rates of net N mineralisation ranged from 18 to 91 kg N/ha·year, and most mineralised N was nitrified and leached. There were significant linear relationships among net N mineralisation, nitrification, and leaching (r = 0·61–0·83). Annual rates of net N mineralisation varied as much within sites as between them, and rates in individual plots were significantly correlated with anaerobically mineralisable N (r = 0·82) or total N (r = 0·66), but were not correlated or only weakly correlated with C: N ratio, loss-on-ignition, organic C, water content, or temperature. Leaching was weakly correlated with effective rainfall (rainfall minus evaporation, r = 0·39). Soil contained most mineral N during February–April (i.e. late summer–early autumn) and least during October–November (i.e. late spring). We concluded that available N at these sites was highly variable spatially and temporally, and at a plot scale was closely related to concentrations of mineralisable substrate and not to soil water or temperature.


Soil Research ◽  
1990 ◽  
Vol 28 (4) ◽  
pp. 563 ◽  
Author(s):  
RC Dalal ◽  
RJ Mayer

Six major soil series of southern Queensland were studied for the changes in the levels of available N indices (determined by both biological and chemical methods) and nitrate-N, with continuous cultivation and cereal cropping for up to 70 years. The biological N indices, measured in soil collected at planting of winter cereals, were anaerobic mineralizable N, aerobic mineralizable N and nitrate-N down to 1.2 m depth. The chemical indices were autoclave N and oven N. The predictive capabilities of various available N indices, and total N and organic C, were assessed from dry matter and N uptake of winter cereals in the field in 1983 as well as in the glasshouse. Anaerobic mineralizable N levels increased with mean annual rainfall but decreased with mean annual temperatures of the sampling sites of the six soil series. Therefore, it was possible to predict closely anaerobic mineralizable N from soil total N, and mean annual rainfall and temperature. Autoclave N showed no such trends. Anaerobic mineralizable N declined with period of cultivation, exponentially in Waco, Langlands-Logie and Cecilvale soils (0.112, 0.111 and 0.247 year-1, respectively) and linearly in the other three soil series. No consistent trends were discerned in autoclave N and oven N in four of the soil series with period of cultivation. Generally, nitrate-N (measured at planting) declined with period of cultivation. However, in Billa Billa soil, it increased in the soil profile (0-1.2 m) during the initial 7 years of cultivation and declined rapidly after 12 years. Although a number of available N indices, including total N and organic C, were significantly correlated with crop dry matter yield and N uptake, the best prediction of crop performance was provided by a combination of anaerobic mineralizable N (0-0.3 m) and nitrate-N (0-0 6 m) in the six soil series.


2011 ◽  
Vol 57 (No. 4) ◽  
pp. 131-140 ◽  
Author(s):  
S. Dželetović Ž ◽  
N. Pivić R ◽  
L. Djurović N J

Based on a greenhouse experiment, we evaluated nitrogen availability in the surface mineral layer of soil under various deciduous forest stands by analysing the following soil characteristics: total organic C, total N, initial content of easily available N inorganic forms, mineralized N content obtained by aerobic and anaerobic incubations and A-value. The experiment was performed on a test plant and through the application of urea enriched with 5.4% 15N.<br />The studied forest soils are characterized by high mineralization intensity and high N availability indices. Aerobic incubation appears to be the most appropriate method for evaluating the available N content. The amounts of mineralized and nitrified N, obtained by aerobic incubation, with subtraction of the initial content of available mineral N forms are in correlation (P &le; 0.05) with total organic C content (r = 0.916) and total soil N (r = 0.903) while the correlation with the C/N ratio is poor (r = 0.645).


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ningguang Dong ◽  
Guanglong Hu ◽  
Yunqi Zhang ◽  
Jianxun Qi ◽  
Yonghao Chen ◽  
...  

AbstractThis study characterized the effect of green manures (February orchid, hairy vetch, rattail fescue and a no-green-manure control) and the termination method (flail or disk) on nutrient contents, enzyme activities, microbial biomass, microbial community structure of rhizosphere soil and vegetative growth of walnut tree. All three selected green manures significantly enhanced the water content, organic C, total N and available P. The rattail fescue significantly decreased the mineral N. Total organic C, total N, mineral N and available P were significantly greater under flail than under disk. Hairy vetch and February orchid significantly improved levels of soil β-glucosidase, N-acetyl-glucosaminidase and acid phosphatase activity, whereas rattail fescue improved only β-glucosidase activity. All of the green manures significantly decreased phenoloxidase activity. β-glucosidase, N-acetyl-glucosaminidase and acid phosphatase activities were significantly greater under flail relative to disk. The termination method had no significant effect on phenoloxidase activity. The different types of green manures and termination methods significantly altered the soil microbial biomass and microbial community structure. The green-manure treatments were characterized by a significantly greater abundance of Gram-positive (Gram +) bacteria, total bacteria and saprophytic fungi compared to the control. Hairy vetch significantly decreased the abundance of arbuscular mycorrhizal fungi (AMF) while February orchid and rattail fescue increased their abundance compared to the no-green-manure treatment. The abundance rates of Gram+ bacteria, actinomycetes, saprophytic fungi and AMF were significantly greater in soils under flail than under disk. In terms of vegetative growth of walnut tree, hairy vetch showed the greatest positive effects. The growth of walnut tree was significantly greater under flail relative to disk. Our results indicate that green-manure application benefits the rhizosphere soil micro-ecology, rhizosphere soil nutrient contents and tree growth. Overall, the hairy vetch and flail combined treatment is recommended for walnut orchards in northern China.


2021 ◽  
Vol 13 (4) ◽  
pp. 1991
Author(s):  
Silvia Stanchi ◽  
Odoardo Zecca ◽  
Csilla Hudek ◽  
Emanuele Pintaldi ◽  
Davide Viglietti ◽  
...  

We studied the effects of three soil management approaches (permanent grassing, chemical weeding, and buffer strips), and the additional impact of tractor passage on soil erosion in a sloping vineyard located in the inner part of Aosta Valley (N-W Italian Alps). The vineyard rows were equipped with a sediment collection system with channels and barrel tanks. A total of 12 events with sediment production were observed across 6 years, and the collected sediments were weighted and analyzed. Average erosion rates ranged from negligible (mainly in grassed rows) to 1.1 t ha−1 per event (after weeding). The most erosive event occurred in July 2015, with a total rainfall of 32.2 mm, of which 20.1 were recorded in 1 h. Despite the limited number of erosive events observed, and the low measured erosion rates, permanent grassing reduced soil erosion considerably with respect to weeding; buffering had a comparable effect to grassing. The tractor passage, independent of the soil management approaches adopted, visibly accelerated the erosion process. The collected sediments were highly enriched in organic C, total N, and fine size fractions, indicating a potential loss of fertility over time. Despite the measured erosion rates being low over the experiment’s duration, more severe events are well documented in the recent past, and the number of intense storms is likely to increase due to climate change. Thus, the potential effects of erosion in the medium and long term need to be limited to a minimum rate of soil loss. Our experiment helped to compare soil losses by erosion under different soil management practices, including permanent grassing, i.e., a nature-based erosion mitigation measure. The results of the research can provide useful indications for planners and practitioners in similar regions, for sustainable, cross-sectoral soil management, and the enhancement of soil ecosystem services.


2021 ◽  
Vol 11 (2) ◽  
pp. 750
Author(s):  
Roberta Pastorelli ◽  
Giuseppe Valboa ◽  
Alessandra Lagomarsino ◽  
Arturo Fabiani ◽  
Stefania Simoncini ◽  
...  

Digestate from biogas production can be recycled to the soil as conditioner/fertilizer improving the environmental sustainability of the energy supply chain. In a three-year maize-triticale rotation, we investigated the short-term effects of digestate on soil physical, chemical, and microbiological properties and evaluated its effectiveness in complementing the mineral fertilizers. Digestate soil treatments consisted of combined applications of the whole digestate and its mechanically separated solid fraction. Digestate increased soil total organic C, total N and K contents. Soil bulk density was not affected by treatments, while aggregate stability showed a transient improvement due to digestate treatments. A decrement of the transmission pores proportion and an increment of fissures was observed in digestate treated soils. Soil microbial community was only transiently affected by digestate treatments and no soil contamination from Clostridiaceae-related bacteria were observed. Digestate can significantly impair seed germination when applied at low dilution ratios. Crop yield under digestate treatment was similar to ordinary mineral-based fertilization. Overall, our experiment proved that the agronomic recycling of digestate from biogas production maintained a fair crop yield and soil quality. Digestate was confirmed as a valid resource for sustainable management of soil fertility under energy-crop farming, by combining a good attitude as a fertilizer with the ability to compensate for soil organic C loss.


Soil Research ◽  
1990 ◽  
Vol 28 (6) ◽  
pp. 841 ◽  
Author(s):  
AA Webb ◽  
AJ Dowling

Morphological, chemical and physical properties of basaltic clay soils (Vertisols-Usterts and Torrerts) from the Oxford Land System in central Queensland are described and compared over their geographical range of occurrence and also their position in the landscape. These soils are derived from undifferentiated basic lavas and interbedded pyroclastics of Tertiary age. Black earths are the dominant soil group. Position on slope had the biggest influence on depth of soil, with crest and mid-upper slope positions having more shallow (<0.9 m) soils than mid-lower and footslope positions. Soils have very high CEC and clay contents throughout the profile, are mildly alkaline at the surface and strongly so at depth, are non-saline and non-sodic (except in some footslope positions), and have an exchange complex dominated by calcium and magnesium. In the surface 0.1 m, extractable P and Zn, and total N and S levels are low and crop responses to fertilizer are probable. In comparison of 26 paired sites, where areas of native pasture and cultivation occur in close proximity, cultivated soils have lower organic C and total N, P, K and S levels than native pasture soils. This reflects a general decline in soil fertility under cultivation, and has implications for soil management and long-term soil stability.


2021 ◽  
Vol 8 (4) ◽  
pp. 2995-3005
Author(s):  
Hasbullah Syaf ◽  
Muhammad Albar Pattah ◽  
Laode Muhammad Harjoni Kilowasid

Earthworms (Pheretima sp.) could survive under abiotic stress soil conditions. Furthermore, their activities as ecosystem engineers allow for the creation of soil biostructures with new characteristics. Therefore, this study aimed to investigate the effect of the abundance of Pheretima sp. on the aggregate size, physicochemistry, and biology of the topsoil from the nickel mining area of Southeast Sulawesi, Indonesia. It was carried out by first grouping their abundance into zero, two, four, six, and eight individuals per pot and then carrying out tests. The Pheretima sp. were then released onto the surface of the topsoil and mixed with biochar that was saturated with tap water in the pot overnight. The results showed that the abundance of the species had a significant effect on the size class distribution, and aggregate stability of the soil. Furthermore, the size of the soil aggregates formed was dominated by the size class 2.83 - 4.75 mm under both dry and wet conditions. Under dry conditions, three size classes were found, while under wet conditions, there were five size classes. The results also showed that the highest and lowest stability indexes occurred with zero and eight Pheretima sp., respectively. Furthermore, the abundance had a significant effect on pH, organic C, total N, CEC, and total nematodes. However, it had no significant effect on the total P, C/N ratio, total AMF spores, and flagellate. The highest soil pH occurred with zero Pheretima sp., while with six and two members of the species, the total nematode was at its highest and lowest populations, respectively. Therefore, it could be concluded that the species was able to create novel conditions in the topsoils at the nickel mining area that were suitable for various soil biota.


2010 ◽  
pp. 41-49
Author(s):  
Md Abiar Rahman ◽  
Md Giashuddin Miah ◽  
Hisashi Yahata

Productivity of maize and soil properties change under alley cropping system consisting of four woody species (Gliricidia sepium, Leucaena leucocephala, Cajanus cajan and Senna siamea) at different nitrogen levels (0, 25, 50, 75 and 100% of recommended rate) were studied in the floodplain ecosystem of Bangladesh. Comparative growth performance of four woody species after pruning showed that L. leucocephala attained the highest height, while C. cajan produced the maximum number of branches. Higher and almost similar amount of pruned materials (PM) were obtained from S. siamea, G. sepium and C. cajan species. In general, maize yield increased with the increase in N level irrespective of added PM. However, 100% N plus PM, 75% N plus PM and 100% N without PM (control) produced similar yields. The grain yield of maize obtained from G. sepium alley was 2.82, 4.13 and 5.81% higher over those of L. leucocephala, C. cajan and S. siamea, respectively. Across the alley, only one row of maize in the vicinity of the woody species was affected significantly. There was an increasing trend in soil properties in terms of organic C, total N and CEC in alley cropping treatments especially in G. sepium and L. leucocephala alleys compared to the initial and control soils. Therefore, one fourth chemical N fertilizer can be saved without significant yield loss in maize production in alley cropping system.


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