Leaf-litter production and soil organic matter dynamics along a nitrogen-availability gradient in Southern Wisconsin (U.S.A.)

1983 ◽  
Vol 13 (1) ◽  
pp. 12-21 ◽  
Author(s):  
Knute J. Nadelhoffer ◽  
John D. Aber ◽  
Jerry M. Melillo
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Leaf Litter ◽  
N Mineralization ◽  
N Uptake ◽  
Mineral Soil ◽  
Litter Production ◽  
N Availability ◽  
Net N Mineralization ◽  
Mineral N

Annual net N mineralization in the 0–10 cm mineral soil zone of nine forest stands on silt–loam soils was measured using a series of insitu soil incubations from April 1980 through April 1981. Differences in soil organic matter (SOM) dynamics among sites were shown with net N mineralization ranging from 0.54 to 2.10 mg N mineralized•g SOM−1•year−1. This variation was not related to percent N in SOM. Net N mineralization varied seasonally with maximum rates in June and very low rates in winter. Nitrification rates were constant from May through September despite fluctuations in soil ammonium pools. Nitrification was greater than 50% of annual net N mineralization at all sites. N uptake by vegetation, as estimated by net N mineralization plus mineral N inputs via precipitation, with minor corrections for mineralization below the incubation depth and for mineral N losses to groundwater, ranged from 40.3 to 119.2 kg N•ha−1•year−1. Annual leaf and needle litter production ranged from 2.12 to 4.17 Mg•ha−1•year−1 and was strongly correlated with N uptake (r = 0.938, P < 0.01). N returned in leaf litter was also correlated with N uptake (r = 0.755, P < 0.05). Important feedbacks may exist between N availability and litter quality and quantity.

Improving nitrogen availability indicators by emphasizing correlations between gross nitrogen mineralization and the quality and quantity of labile soil organic matter fractions

2012 ◽  
Author(s):  
Mike J. Castellano ◽  
Abraham G. Shaviv ◽  
Raphael Linker ◽  
Matt Liebman
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
N Mineralization ◽  
Nitrogen Availability ◽  
N Availability ◽  
Net N Mineralization ◽  
N Dynamics ◽  
Organic Matter Fractions ◽  
N Fertility ◽  
Labile Soil Organic Matter

A major goal in Israeli and U.S. agroecosystems is to maximize nitrogen availability to crops while minimizing nitrogen losses to air and water resources. This goal has presented a significant challenge to global agronomists and scientists because crops require large inputs of nitrogen (N) fertilizer to maximize yield, but N fertilizers are easily lost to surrounding ecosystems where they contribute to water pollution and greenhouse gas concentrations. Determination of the optimum N fertilizer input is complex because the amount of N produced from soil organic matter varies with time, space and management. Indicators of soil N availability may help to guide requirements for N fertilizer inputs and are increasingly viewed as indicators of soil health To address these challenges and improve N availability indicators, project 4550 “Improving nitrogen availability indicators by emphasizing correlations between gross nitrogen mineralization and the quality and quantity of labile organic matter fractions” addressed the following objectives: Link the quantity and quality of labile soil organic matter fractions to indicators of soil fertility and environmental quality including: i) laboratory potential net N mineralization ii) in situ gross N mineralization iii) in situ N accumulation on ion exchange resins iv) crop uptake of N from mineralized soil organic matter sources (non-fertilizer N), and v) soil nitrate pool size. Evaluate and compare the potential for hot water extractable organic matter (HWEOM) and particulate organic matter quantity and quality to characterize soil N dynamics in biophysically variable Israeli and U.S. agroecosystems that are managed with different N fertility sources. Ultimately, we sought to determine if nitrogen availability indicators are the same for i) gross vs. potential net N mineralization processes, ii) diverse agroecosystems (Israel vs. US) and, iii) management strategies (organic vs. inorganic N fertility sources). Nitrogen availability indicators significantly differed for gross vs. potential N mineralization processes. These results highlight that different mechanisms control each process. Although most research on N availability indicators focuses on potential net N mineralization, new research highlights that gross N mineralization may better reflect plant N availability. Results from this project identify the use of ion exchange resin (IERs) beads as a potential technical advance to improve N mineralization assays and predictors of N availability. The IERs mimic the rhizosphere by protecting mineralized N from loss and immobilization. As a result, the IERs may save time and money by providing a measurement of N mineralization that is more similar to the costly and time consuming measurement of gross N mineralization. In further search of more accurate and cost-effective predictors of N dynamics, Excitation- Emission Matrix (EEM) spectroscopy analysis of HWEOM solution has the potential to provide reliable indicators for changes in HWEOM over time. These results demonstrated that conventional methods of labile soil organic matter quantity (HWEOM) coupled with new analyses (EEM) may be used to obtain more detailed information about N dynamics. Across Israeli and US soils with organic and inorganic based N fertility sources, multiple linear regression models were developed to predict gross and potential N mineralization. The use of N availability indicators is increasing as they are incorporated into soil health assessments and agroecosystem models that guide N inputs. Results from this project suggest that some soil variables can universally predict these important ecosystem process across diverse soils, climate and agronomic management. BARD Report - Project4550 Page 2 of 249 

Influence of sampling date and substrate on nitrogen mineralization: comparison of laboratory-incubation and buried-bag methods for two Massachusetts forest soils

1992 ◽  
Vol 22 (12) ◽  
pp. 1895-1900 ◽  
Author(s):  
Richard D. Boone
Keyword(s):  
Organic Matter ◽  
N Mineralization ◽  
Unit Area ◽  
Seasonal Pattern ◽  
Mineral Soil ◽  
Net N Mineralization ◽  
Laboratory Incubation ◽  
Mineralization Potential ◽  
Organic Horizons ◽  
N Mineralization Potential

Nitrogen (N) mineralization potential and net N mineralization insitu were measured monthly over 7 months for the forest floor horizons (Oi, Oe, Oa) and mineral soil (0–15 cm) of a pine stand and the mineral soil (0–15 cm) of a maple stand in Massachusetts, United States. In all cases, N mineralization potential per unit organic matter (anaerobic laboratory incubation) varied significantly by sampling month but was unrelated to the seasonal pattern for net N mineralization (buried-bag method). The organic horizons in the pine stand exhibited the most variable N mineralization potential, with the Oe horizon having more than a fourfold seasonal range. For the pine stand the Oe horizon also had the highest N mineralization potential (per unit organic matter) and the highest net N mineralization insitu (per unit area). In general, temporal and depth-wise variability should be considered when sites are assessed with respect to the pool of mineralizable N.

Empirical relationships between temperature and nitrogen availability across North American forests

1992 ◽  
Vol 22 (5) ◽  
pp. 707-712 ◽  
Author(s):  
Xiwei Yin
Keyword(s):  
N Mineralization ◽  
Regional Scale ◽  
Mineral Soil ◽  
Published Data ◽  
N Availability ◽  
Net N Mineralization ◽  
Soil N ◽  
Litter Fall ◽  
Available N ◽  
N Pool

Published data were analyzed to examine whether nitrogen (N) availability varies along macroclimatic gradients in North America. Extractable N produced during 8-week aerobic laboratory incubation was used as an index of potential net N mineralization. Mean extractable N during the growing season in the forest floor plus top mineral soil was used as an index of the available N pool. Using multiple regression, potential net N mineralization was shown to increase with available N and with litter-fall N (R2 = 0.722). Available N increased with increasing total soil N and with decreasing mean January and July air temperatures (R2 = 0.770). These relationships appeared to hold also for deciduous and coniferous forests separately across regions. Results suggest that net N mineralization output under uniform temperature and moisture conditions can be generally expressed by variations of N input (litter fall) and the available soil N pool, and that the available soil N pool is predictable along a temperature gradient at a regional scale.

scholarly journals Modeling the effects of litter stoichiometry and soil mineral N availability on soil organic matter formation using CENTURY-CUE (v1.0)

2018 ◽  
Vol 11 (12) ◽  
pp. 4779-4796 ◽  
Author(s):  
Haicheng Zhang ◽  
Daniel S. Goll ◽  
Stefano Manzoni ◽  
Philippe Ciais ◽  
Bertrand Guenet ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Litter Quality ◽  
Plant Litter ◽  
Climate Mitigation ◽  
N Availability ◽  
Mineral N ◽  
Microbial Decomposition ◽  
Soil C ◽  
C Cycle

Abstract. Microbial decomposition of plant litter is a crucial process for the land carbon (C) cycle, as it directly controls the partitioning of litter C between CO2 released to the atmosphere versus the formation of new soil organic matter (SOM). Land surface models used to study the C cycle rarely considered flexibility in the decomposer C use efficiency (CUEd) defined by the fraction of decomposed litter C that is retained as SOM (as opposed to be respired). In this study, we adapted a conceptual formulation of CUEd based on assumption that litter decomposers optimally adjust their CUEd as a function of litter substrate C to nitrogen (N) stoichiometry to maximize their growth rates. This formulation was incorporated into the widely used CENTURY soil biogeochemical model and evaluated based on data from laboratory litter incubation experiments. Results indicated that the CENTURY model with new CUEd formulation was able to reproduce differences in respiration rate of litter with contrasting C : N ratios and under different levels of mineral N availability, whereas the default model with fixed CUEd could not. Using the model with flexible CUEd, we also illustrated that litter quality affected the long-term SOM formation. Litter with a small C : N ratio tended to form a larger SOM pool than litter with larger C : N ratios, as it could be more efficiently incorporated into SOM by microorganisms. This study provided a simple but effective formulation to quantify the effect of varying litter quality (N content) on SOM formation across temporal scales. Optimality theory appears to be suitable to predict complex processes of litter decomposition into soil C and to quantify how plant residues and manure can be harnessed to improve soil C sequestration for climate mitigation.

scholarly journals Nitrogen Availability in Biochar-Amended Soils with Excessive Compost Application

Agronomy ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 444 ◽  
Author(s):  
Chen-Chi Tsai ◽  
Yu-Fang Chang
Keyword(s):  
N Mineralization ◽  
Nitrogen Availability ◽  
Agricultural Soils ◽  
Inorganic Nitrogen ◽  
Clay Content ◽  
N Availability ◽  
Net N Mineralization ◽  
Mineral N ◽  
Mineralization Potential ◽  
The Impact

Adding biochar to excessive compost amendments may affect compost mineralization rate and nitrogen (N) availability. The objective of this 371-day incubation study was to evaluate the effects of four proportions of woody biochar (0%, 0.5%, 1.0%, and 2.0%) from lead tree (Leucaena leucocephala (Lam.) de. Wit) biochar produced at 750 °C through dynamic mineral N and N mineralization rates in three rural soils (one Oxisol and two Inceptisols). In each treatment, 5% poultry–livestock manure compost was added to serve as an excessive application. The results indicated that the biochar decreased available total inorganic nitrogen (TIN) (NO3−-N+NH4+-N) by on average 6%, 9% and 19% for 0.5%, 1.0% and 2.0% treatments, respectively. The soil type strongly influenced the impact of the biochar addition on the soil nitrogen mineralization potential, especially the soil pH and clay content. This study showed that the co-application of biochar and excessive compost benefited the agricultural soils by improving NO3−-N retention in agroecosystems. The application of biochar to these soils to combine it with excessive compost appeared to be an effective method of utilizing these soil amendments, as it diminished the net N mineralization potential and reduced the nitrate loss of the excessive added compost.

scholarly journals Effect of compaction on microbial activity and carbon and nitrogen transformations in two oxisols with different mineralogy

2011 ◽  
Vol 35 (4) ◽  
pp. 1141-1149 ◽  
Author(s):  
Sérgio Ricardo Silva ◽  
Ivo Ribeiro da Silva ◽  
Nairam Félix de Barros ◽  
Eduardo de Sá Mendonça
Keyword(s):  
Organic Matter ◽  
Microbial Activity ◽  
Soil Compaction ◽  
N Mineralization ◽  
Organic N ◽  
Net N Mineralization ◽  
Mineral N ◽  
Organic C ◽  
Soil Microbial ◽  
Controlled Conditions

The use of machinery in agricultural and forest management activities frequently increases soil compaction, resulting in greater soil density and microporosity, which in turn reduces hydraulic conductivity and O2 and CO2 diffusion rates, among other negative effects. Thus, soil compaction has the potential to affect soil microbial activity and the processes involved in organic matter decomposition and nutrient cycling. This study was carried out under controlled conditions to evaluate the effect of soil compaction on microbial activity and carbon (C) and nitrogen (N) mineralization. Two Oxisols with different mineralogy were utilized: a clayey oxidic-gibbsitic Typic Acrustox and a clayey kaolinitic Xantic Haplustox (Latossolo Vermelho-Amarelo ácrico - LVA, and Latossolo Amarelo distrófico - LA, respectively, in the Brazil Soil Classification System). Eight treatments (compaction levels) were assessed for each soil type in a complete block design, with six repetitions. The experimental unit consisted of PVC rings (height 6 cm, internal diameter 4.55 cm, volume 97.6 cm³). The PVC rings were filled with enough soil mass to reach a final density of 1.05 and 1.10 kg dm-3, respectively, in the LVA and LA. Then the soil samples were wetted (0.20 kg kg-1 = 80 % of field capacity) and compacted by a hydraulic press at pressures of 0, 60, 120, 240, 360, 540, 720 and 900 kPa. After soil compression the new bulk density was calculated according to the new volume occupied by the soil. Subsequently each PVC ring was placed within a 1 L plastic pot which was then tightly closed. The soils were incubated under aerobic conditions for 35 days and the basal respiration rate (CO2-C production) was estimated in the last two weeks. After the incubation period, the following soil chemical and microbiological properties were detremined: soil microbial biomass C (C MIC), total soil organic C (TOC), total N, and mineral N (NH4+-N and NO3--N). After that, mineral N, organic N and the rate of net N mineralization was calculated. Soil compaction increased NH4+-N and net N mineralization in both, LVA and LA, and NO3--N in the LVA; diminished the rate of TOC loss in both soils and the concentration of NO3--N in the LA and CO2-C in the LVA. It also decreased the C MIC at higher compaction levels in the LA. Thus, soil compaction decreases the TOC turnover probably due to increased physical protection of soil organic matter and lower aerobic microbial activity. Therefore, it is possible to conclude that under controlled conditions, the oxidic-gibbsitic Oxisol (LVA) was more susceptible to the effects of high compaction than the kaolinitic (LA) as far as organic matter cycling is concerned; and compaction pressures above 540 kPa reduced the total and organic nitrogen in the kaolinitic soil (LA), which was attributed to gaseous N losses.

scholarly journals Nitrogen mineralization of legume residues: interactions between species, temperature and placement in soil

2020 ◽  
Vol 18 (1) ◽  
pp. e1101
Author(s):  
Miguel Oliveira ◽  
Dragan Rebac ◽  
João Coutinho ◽  
Luís Ferreira ◽  
Henrique Trindade
Keyword(s):  
Faba Bean ◽  
N Mineralization ◽  
Sandy Loam ◽  
Soil Surface ◽  
Interactive Effects ◽  
N Availability ◽  
Net N Mineralization ◽  
Legume Species ◽  
Mineral N ◽  
Lower Carbon

Aim of study: To assess the interactive effects of legume species, residue placement and temperature on the net nitrogen (N) mineralization dynamics in a sandy loam soil.Area of study: Northern PortugalMaterial and methods: Cowpea (Vigna unguiculata L. Walp), faba bean (Vicia faba L.) and pea (Pisum sativum L.) residues were incorporated or applied to the soil surface at typical field yields in Europe and incubated in aerobic conditions for up to 240 days, either at 10ºC or 20ºC. Initial chemical characteristics of the soil and residues were determined. Net N mineralization was estimated at eight time intervals.Main results: Cowpea residues caused no negative changes in soil mineral N contents and were able to release the equivalent of 21-45 kg N ha-1 in 240 days. Net N immobilization (up to 17 kg N ha-1) was observed throughout most of the trial in soil with faba bean and pea residues. Differences in mineralization patterns could be attributed to the higher quality (lower carbon to nitrogen (C:N) ratios) of cowpea. Surface placement increased net N mineralized by as much as 18 kg N ha-1. The sensitivity of N mineralization to changes in temperature and residue placement varied with legume species, likely due to effects associated with differences in C:N ratios.Research highlights: Adding cowpea residues to soil is suitable when high N availability is immediately required. Faba bean or pea residues are better suited for conservation of soil N for later release.

Effects of modifying plant carbon inputs on nitrogen distribution in intact cores of a perennial grass pasture

Soil Research ◽  
1995 ◽  
Vol 33 (2) ◽  
pp. 297 ◽  
Author(s):  
FA Robertson ◽  
RJK Myers ◽  
PG Saffigna
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Microbial Biomass ◽  
N Uptake ◽  
Organic N ◽  
Root Pruning ◽  
Panicum Maximum ◽  
15N Recovery ◽  
N Availability ◽  
Plant Shoots

Perennial pastures can accumulate large quantities of roots and surface litter of high C:N ratio, which may reduce N availability to the plant by stimulating microbial immobilization. We studied the effects of modifying carbon inputs from roots and litter on the distribution of nitrogen (N) in plant and soil fractions of an old N-deficient green panic (Panicum maximum var. trichoglume) pasture. Intact pasture cores were taken from the field to a glasshouse, and the surface litter was removed before applying the following treatments: (i) surface litter added, (ii) roots pruned to kill approximately 60% of roots, and (iii) plant shoots removed. A small pulse of 15N as ammonium sulfate was added to the soil surface, and the cores were destructively sampled on several occasions over the following 4 months. Litter addition had little effect on N uptake by uncut plants. When plant shoots were removed, litter markedly reduced plant N uptake. Litter increased N and 15N in microbial biomass and N and 15N stabilized in non-biomass soil organic matter, and reduced loss of N from the cores. Root pruning had little effect on N distribution, except for an initial reduction in plant uptake. Removal of pasture shoots markedly increased soil nitrate and loss of 15N, and decreased non-biomass organic N and 15N. Recovery of 15N in non-biomass organic matter was around three times greater than 15N in microbial biomass, and was closely associated with microbial CO2 production. There was evidence that 15N entered the non-biomass organic matter by both abiotic and microbially mediated processes. In these pastures, the non-biomass soil organic matter may be a more important sink for N than the microbial biomass.

Nitrogen benefits from four green-manure legumes in dryland cropping systems

1996 ◽  
Vol 76 (2) ◽  
pp. 307-315 ◽  
Author(s):  
V. O. Biederbeck ◽  
O. T. Bouman ◽  
C. A. Campbell ◽  
G. E. Winkleman ◽  
L. D. Bailey
Keyword(s):  
Green Manure ◽  
N Mineralization ◽  
Nitrogen Concentration ◽  
N Uptake ◽  
Partial Replacement ◽  
N Availability ◽  
Net N Mineralization ◽  
N Content ◽  
Annual Legumes ◽  
Cereal Grain

Partial replacement of fallow with legume green manures has the potential to improve cereal production and agricultural sustainability in the northern Great Plains. This is possible if N gains by annual legumes and enhancement of soil N availability are optimized. The objectives of the study were to (i) determine the N distribution in different vegetative components of four annual legumes; (ii) estimate their ability to accumulate N through fixation; and (iii) compare the N uptake of the cereal crop that follows legume green manure with that of cereal grown on fallow or of cereal receiving N fertilizer. Black lentil (Lens culinaris Medik.), Tangier flatpea (Lathyrus tingitanus L.), chickling vetch (Lathyrus sativus L.), and feedpea (Pisum sativum L.) were grown in rotation with spring wheat (Tnticum aestivum L.). Nitrogen concentration in legume nodules was several times greater than in any other plant part. However, N concentration in legume shoots was, on average, 27% greater than in legume roots. Total legume N content (% × mass) ranged from 41 to 126 kg ha−1 in years of low weediness. In those years, below-ground legume N content ranged between 2 and 29 kg ha−1 and averaged 7, 8, 17 and 6 kg ha−1 for black lentil, Tangier flatpea, chickling vetch and feedpea, respectively. Estimates of N2 fixation varied between 6 and 69 kg ha−1 and averaged 18 kg ha−1 for black lentil, 16 for Tangier flatpea, 49 for chickling vetch and 40 for feedpea. Within 3 mo of green-manure incorporation, average net N mineralization across years was greatest after black lentil and chickling vetch (38 kg N ha−1). The average 49 kg N ha−1 lost through cereal grain harvest was balanced by gains through symbiotic N2 fixation when chickling vetch and feedpea were used as green manure, but black lentil and Tangier flatpea replaced only about 35% of the N removed in the grain. Key words: Symbiotic N2 fixation, N mineralization, Tangier flatpea, black lentil, chickling vetch, feedpea

scholarly journals Implications of the Thermodynamic Response of Soil Mineralization, Respiration, and Nitrification on Soil Organic Matter Retention

2021 ◽  
Vol 12 ◽  
Author(s):  
Anne E. Taylor ◽  
Camille Ottoman ◽  
Frank Chaplen
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Soil Respiration ◽  
N Mineralization ◽  
Time Course ◽  
Net N Mineralization ◽  
Willamette Valley ◽  
Temperature Regimes ◽  
Pool Model ◽  
The Difference

Considerable research has shown that modifications in global temperature regimes can lead to changes in the interactions between soil respiration and the sequestration of C and N into soil organic matter (SOM). We hypothesized that despite the interconnected nature of respiration, net N mineralization, and nitrification processes, there would be differences in their thermodynamic responses that would affect the composition of inorganic soil N and the potential for retention of N in SOM. To test this hypothesis, soil respiration, N mineralization and nitrification responses were evaluated during constant temperature incubations at seven temperatures (4–42°C) in tilled and no-till soils from two major agroecological zones in Oregon; Willamette Valley, and Pendleton located in the Columbia River Basin. We observed (1) significant thermodynamic differences between the three processes in all soils, (2) a distinctly different thermodynamic profile in Willamette vs. Pendleton, and (3) a dynamic response of Topt (optimal temperature for activity), and Tsmax (temperature of greatest rate response to temperature), and temperature sensitivity (ΔCp‡) over the incubation time course, resulting in shifts in the thermodynamic profiles that could not be adequately explained by changes in process rates. We found that differences in contributions of ammonia oxidizing archaea and bacteria to nitrification activity across temperature helped to explain the thermodynamic differences of this process between Willamette and Pendleton soils. A two-pool model of SOM utilization demonstrated that the dynamic thermodynamic response of respiration in the soils was due to shifts in utilization of labile and less-labile pools of C; and that the respiration response by Pendleton soils was more dependent upon contributions from the less-labile C pool resulting in higher Topt and Tsmax than Willamette soils. Interestingly, modeling of N mineralization using the two-pool model suggested that only the less-labile pool of SOM was contributing to N mineralization at most temperatures in all soils. The difference in labile and less-labile SOM pool utilization between respiration and N mineralization may suggest that these processes may not be as interconnected as previously thought.

Sign in / Sign up

Export Citation Format

Share Document