Effects of land-use change and management on soil carbon and nitrogen in the Brigalow Belt, Australia: I. Overview and inventory

2016 ◽  
Vol 38 (5) ◽  
pp. 443 ◽  
Author(s):  
D. E. Allen ◽  
M. J. Pringle ◽  
D. W. Butler ◽  
B. K. Henry ◽  
T. F. A. Bishop ◽  
...  

Soil and land-management interactions in Australian native-forest regrowth remain a major source of uncertainty in the context of the global carbon economy. We sampled soil total organic C (TOC) and soil total N (TN) stocks at 45 sites within the Brigalow ecological community of the Brigalow Belt bioregion, Queensland, Australia. The sites were matched as triplets representing three land uses, specifically: uncleared native brigalow forest (‘Remnant’); grassland pasture (‘Pasture’), derived by clearing native vegetation and maintained as pasture for a minimum of 10 years, and; regrowing native brigalow forest (‘Regrowth’, stand ages ranging from 10 to 58 years) that had developed spontaneously after past vegetation clearing for pasture establishment. Soil TOC fractions and natural abundance of soil C and N isotopes were examined to obtain insight into C and N dynamics. An updated above- and belowground carbon budget for the bioregions was generated. Average soil TOC stocks at 0–0.3-m depth ranged from 19 to 79 Mg ha–1 and soil TN stocks from 1.8 to 7.1 Mg ha–1 (2.5th and 97.5th percentiles, respectively). A trend in stocks was apparent with land use: Remnant > Regrowth ≅ Pasture sites. Soil δ13C ranged from –14 to –27‰, and soil δ15N ranged from 4‰ to 17‰, in general reflecting the difference between Pasture (C4-dominated) land use and N2-fixing (C3-dominated) Remnant and Regrowth. Mid-infrared spectroscopy predicted C fractions as a percentage of soil TOC stock, which ranged from 5% to 60% (particulate), 20–80% (humus) and 9–30% (resistant/inert). The geo-referenced soil and management information we collected is important for the calibration of C models, for the estimation of national C accounts, and to inform policy developments in relation to land-resource management undertaken within the Brigalow Belt bioregions of Australia.

2018 ◽  
Author(s):  
Natalia Andrea Osinaga ◽  
Carina Rosa Álvarez ◽  
Miguel Angel Taboada

Abstract. Abstract. The sub-humid Chaco region of Argentina, originally covered by dry sclerophyll forest, has been subjected to clearing since the end of the '70 and replacement of the forest by no till farming. Land use changes produced a decrease in aboveground carbon stored in forests, but little is known about the impact on soil organic C stocks. The aim of this study was to evaluate soil C stocks and C fractions up to 1 m depth in soils under different land use:  20 yr continuous cropping, warm season grass pasture and native forest in 32 sites distributed over the Chaco region. The organic C stock content up to 1 m depth expressed as equivalent mass varied as follows: forest (119.3 Mg ha−1) > pasture (87.9 Mg ha−1) > continuous cropping (71.9 and 77.3 Mg ha−1), with no impact of the number of years under cropping. The most sensitive organic carbon fraction was the coarse particle fraction (2000 μm–212 μm) at 0–5 cm and 5–20 cm depth layers. Resistant carbon (


2002 ◽  
Vol 82 (2) ◽  
pp. 211-217 ◽  
Author(s):  
S S Malhi ◽  
J T Harapiak ◽  
M. Nyborg ◽  
K S Gill ◽  
N A Flore

An adequate level of organic matter is needed to sustain the productivity, improve the quality of soils and increase soil C. Grassland improvement is considered to be one of the best ways to achieve these goals. A field experiment, in which bromegrass (Bromus inermis Leyss) was grown for hay, was conducted from 1974 to 1996 on a thin Black Chernozemic soil near Crossfield, Alberta. Total organic C (TOC) and total N (TN), and light fraction organic C (LFOC) and light fraction N (LFN) of soil for the treatments receiving 23 annual applications of 112 kg N ha-1 as ammonium nitrate (AN) or urea in early autumn, late autumn, early spring or late spring were compared to zero-N check. Soil samples from 0- to 5- cm (layer 1), 5- to 10- cm (layer 2), 10- to 15- cm (layer 3) and 15- to 30-cm depths were taken in October 1996. Mass of TOC, TN, LFOC and LFN was calculated using equivalent mass technique. The concentration and mass of TOC and LFOC, TN and LFN in the soil were increased by N fertilization compared to the zero-N check. The majority of this increase in C and N occurred in the surface 5-cm depth and predominantly occurred in the light fraction material. In layer 1, the average increase from N fertilization was 3.1 Mg C ha-1 for TOC, 1.82 Mg C ha-1 for LFOC, 0.20 Mg N ha-1 for TN and 0.12 Mg N ha-1 for LFN. The LFOC and LFN were more responsive to N fertilization compared to the TOC and TN. Averaged across application times, more TOC, LFOC, TN and LFN were stored under AN than under urea in layer 1, by 1.50, 1.21, 0.06 and 0.08 Mg ha-1, respectively. Lower volatilization loss and higher plant uptake of surfaced-broadcast N were probable reasons from more soil C and N storage under AN source. Time of N application had no effect on the soil characteristics studied. In conclusion, most of the N-induced increase in soil C and N occurred in the 0- to 5-cm depth (layer 1) and in the light fraction material, with the increases being greater under AN than urea. Key words: Bromegrass, light fraction C and N, N source, soil, total organic C and N


2019 ◽  
Vol 17 (3) ◽  
pp. e1102
Author(s):  
Lixia Zhu ◽  
Jutian Chen ◽  
Yufang Shen ◽  
Shiqing Li

Aim of study: A field study was conducted to assess responses of soil organic C (SOC) and total N (TN) to film mulching and manure, which were important in identifying the changes of SOC and TN.Area of study: A semiarid area in northwestern China.Material and methods: The field (soil classified as CumuliUstic Isohumosol) has been planted with spring maize (Zea mays L.) for years. Three treatments were: 1) NPK fertilization and no film mulching (CK), 2) NPK fertilization and film mulching (PF) and 3) film mulching and NPK fertilization combined with cow manure (OMF).Main results: Compared with CK, OMF significantly increased SOC and TN, while no significant effect was observed under PF. The average increases of SOC storage in OMF were 39.2% in 0-10 cm layer and 34.3% in 10-20 cm layer. The average increases of TN storage were 37.6% in 0-10 cm layer and 31.3% in 10-20 cm layer, relative to CK. Compared with the initial SOC (8.86 g/kg) and TN (0.99 g/kg), CK and PF decreased 1.4% and 6.9% of SOC, and 9.1% and 17.2% of TN, whereas OMF increased SOC and TN. The SOC/TN was not affected by treatments but slight increase was observed since the beginning of experiment. Both PF and OMF significantly increased maize grain yields (on average 45.8% and 75.7%, respectively) compared with CK.Research highlights: Manure combined with film mulching significantly increased soil C and N, ameliorating harmful effects of plastic film mulching, improving soil fertility in the long term and increasing crop yields.


2020 ◽  
Vol 8 (1) ◽  
pp. 1-8
Author(s):  
Refki Aulia Wiwaha ◽  
Syahrul Kurniawan

The Kali Kungkuk micro watershed which is located in the upper area of Brantas watershed, had experienced forest conversion to horticulture during the last fourth decades. Since the physiographic of Kali Kungkuk micro watershed is hilly, forest conversion to horticulture may result in soil nutrient stock changes. The research aimed to analyze soil nutrient stock from forest to horticulture land uses (i.e. apple orchard and vegetables) in the Kali Kungkuk micro watershed. The field research was conducted on three different land uses (i.e. vegetable land (PK), apple orchard (PA), and forest (PH)) and four land slope classes (i.e. slope 0-8% (K1), 8-15% (K2), 15-25% (K3), and > 25% (K4)), with three, replicates plots of each. Soil samples were collected at three different depths (0-10, 10-30, and 30- 50 cm) from each plot. The parameters measured included soil texture, bulk density, standing litter mass, canopy cover, basal area, soil organic carbon and total nitrogen. Data analysis was conducted with Linear Mixed Effect Models with a level of 5% and a further analysis of LSD test level of 5% as well as a correlation test between observational parameters. The results showed that differences in land use and slope affected to significant differences in the content of soil organic C and total N. In general, forests had higher soil C and N stocks as compared to other land uses (i.e. apple orchard and vegetables). Furthermore, soil organic C and total N was higher in the low slopes (i.e. 0-8%) and (8-15%) as compared to the high slopes (i.e. 15-25%) and (> 25%). The study found a positive correlation between soil nutrient stocks (i.e. C and N) and clay content. In contrast, soil C and N stock was negatively correlated with soil bulk density. Soil fertility degradation that occurs in the Kali Kungkuk micro watershed (i.e. apple orchard and vegetables) requires serious attention in soil management in order to ensure the sustainability of apple and vegetable production.


2013 ◽  
Vol 37 (3) ◽  
pp. 784-795 ◽  
Author(s):  
José Augusto Amorim Silva do Sacramento ◽  
Ana Caroline de Moraes Araújo ◽  
Maria Eugenia Ortiz Escobar ◽  
Francisco Alisson da Silva Xavier ◽  
Ana Clara Rodrigues Cavalcante ◽  
...  

In the semiarid region of Brazil, inadequate management of cropping systems and low plant biomass production can contribute to reduce soil carbon (C) and nitrogen (N) stocks; therefore, management systems that preserve C and N must be adopted. This study aimed to evaluate the changes in soil C and N stocks that were promoted by agroforestry (agrosilvopastoral and silvopastoral) and traditional agricultural systems (slash-and-burn clearing and cultivation for two and three years) and to compare these systems with the natural Caatinga vegetation after 13 years of cultivation. The experiment was carried out on a typical Ortic Chromic Luvisol in the municipality of Sobral, Ceará, Brazil. Soil samples were collected (layers 0-6, 6-12, 12-20, 20-40 and 40-60 cm) with four replications. The plain, convex and concave landforms in each study situation were analyzed, and the total organic C, total N and densities of the soil samples were assessed. The silvopastoral system promoted the greatest long-term reductions in C and N stocks, while the agrosilvopastoral system promoted the smallest losses and therefore represents a sustainable alternative for soil C and N sequestration in these semiarid conditions. The traditional agricultural system produced reductions of 58.87 and 9.57 Mg ha-1 in the organic C and total N stocks, respectively, which suggests that this system is inadequate for these semiarid conditions. The organic C stocks were largest in the concave landform in the agrosilvopastoral system and in the plain landform in the silvopastoral system, while the total N values were highest in the concave landform in the native, agrosilvopastoral and silvopastoral systems.


PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8384
Author(s):  
Junyong Ma ◽  
Hairong Han ◽  
Xiaoqin Cheng

Forest soils sequester a large amount of carbon (C) and have a significant effect on the global C balance. Forests are commonly managed to maintain certain age structures but the effects of this management on soil C pools (kg C m−2) is still uncertain. We compared 40-year-old (1GF) and 24-year-old (2GF) plantations of Larix principis-rupprechtii in North China. Specifically, we measured environmental factors (e.g., soil temperature, moisture, and pH), the active C and nitrogen (N) pools (e.g., soil organic C, soil total N, dissolved organic C and N, microbial biomass C and N), and soil processes (e.g., C mineralization and microbial activity in different seasons) in five soil layers (0–50 cm, 10 cm for each soil layer) across the growing seasons in three 25 m × 25 m plots in each age class (1GF and 2GF). Findings indicated that the soil organic C pool in the older 1GF forest (12.43 kg C m−2) was significantly higher than 2GF forests (9.56 kg C m−2), and that soil temperature in 1GF forests was 9.8 °C, on average, 2.9% warmer than temperature in 2GF forests. The C lost as carbon dioxide (CO2) as a result of mineralization in the 2GF plots may partly explain the lower soil organic C pool in these younger forests; microorganisms likely drive this process.


2008 ◽  
Vol 32 (3) ◽  
pp. 1253-1260 ◽  
Author(s):  
Fabiano de Carvalho Balieiro ◽  
Marcos Gervasio Pereira ◽  
Bruno José Rodrigues Alves ◽  
Alexander Silva de Resende ◽  
Avílio Antonio Franco

In spite of the normally low content of organic matter found in sandy soils, it is responsible for almost the totality of cation exchange capacity (CEC), water storage and availability of plant nutrients. It is therefore important to evaluate the impact of alternative forest exploitation on the improvement of soil C and N accumulation on these soils. This study compared pure and mixed plantations of Eucalyptus grandis and Pseudosamanea guachapele, a N2-fixing leguminous tree, in relation to their effects on soil C and N stocks. The studied Planosol area had formerly been covered by Panicum maximum pasture for at least ten years without any fertilizer addition. To estimate C and N contents, the soil was sampled (at depths of 0-2.5; 2.5-5.0; 5.0-7.5; 7.5-10.0; 10.0-20.0 and 20.0-40.0 cm), in pure and mixed five-year-old tree plantations, as well as on adjacent pasture. The natural abundance 13C technique was used to estimate the contribution of the soil organic C originated from the trees in the 0-10 cm soil layer. Soil C and N stocks under mixed plantation were 23.83 and 1.74 Mg ha-1, respectively. Under guachapele, eucalyptus and pasture areas C stocks were 14.20, 17.19 and 24.24 Mg ha-1, respectively. For these same treatments, total N contents were 0.83; 0.99 and 1.71 Mg ha-1, respectively. Up to 40 % of the soil organic C in the mixed plantation was estimated to be derived from trees, while in pure eucalyptus and guachapele plantations these same estimates were only 19 and 27 %, respectively. Our results revealed the benefits of intercropped leguminous trees in eucalyptus plantations on soil C and N stocks.


1995 ◽  
Vol 25 (8) ◽  
pp. 1385-1396 ◽  
Author(s):  
T.A. Black ◽  
J.W. Harden

Four plots from a mixed conifer forest were similarly cleared, burned, and replanted at various times over 17 years; a plot logged 79 years before sampling was used as a control. The plots had similar slope (2 to 15%, midslope position), aspect (south to southeast), and soil type (Holland series: mesic Haploxeralf; a Gray Brown Luvisol in the Canadian classification system). Twenty sites at each plot were sampled volumetrically by horizon to 20 cm below the organic–mineral soil boundary. Samples were analyzed for bulk density, organic C, and total N. There was an initial loss (15%) of organic C from the soil within 1 to 7 years, likely the result of oxidation (burning and decomposition) and erosion. For 17 years of forest regrowth, the soil continued to lose C (another 15%), probably owing to decomposition of slash material and possibly erosion, despite the slight accumulation of new litter and roots. After 80 years of regrowth, rates of carbon accumulation exceeded rates of loss, but carbon storage had declined and was not likely to recover to preharvest levels. Timber harvest and site preparation dramatically altered soil C and N distribution, in which C/N ratios after site preparation were initially high throughout the upper 20 cm. Subsequently, C/N ratios became lower with depth and with recovery age. Although stocks of C and N varied considerably among the plots and did not change consistently as a function of recovery age, the C/N ratios did vary systematically with recovery age. We hypothesize that the amount of C ultimately stored in the soil at steady state depends largely on N reserves and potentials, which appear to vary with erosion, intensity of burning, and site treatment.


2008 ◽  
Vol 65 (3) ◽  
pp. 290-297 ◽  
Author(s):  
Gabriel Agustín Piccolo ◽  
Adrián Enrique Andriulo ◽  
Bruno Mary

Highly weathered tropical soils rapidly loose soil organic matter (SOM) and may be affected by water erosion and soil compaction after deforestation and intensive cultivation. With the main objective to estimate the SOM balances in a subtropical soil we determined the dynamics of SOM in a degraded yerba mate (Ilex paraguaiensis Saint Hil.) plantation introduced after deforestation and with elephant grass (Pennisetum purpureum L.) as a cover crop. The study site was in Misiones, Argentina, and we use the natural 13C abundance methodology and a descriptive model. The study was conducted on three contiguous 50 x 100 m plots of a typic Kandihumult soil with: (i) native forest, (ii) 50 years of continuous yerba mate monoculture with intensive tillage, and (iii) yerba mate associated with elephant grass as a cover crop and no tillage. We determined bulk density, carbon (C), nitrogen (N) and 13C content of the soil (0 - 0.05, 0.05 - 0.15 m layers) and the grass biomass. Yerba mate monoculture reduced soil C and N content as well as porosity at 0 - 0.15 m depth by 43 and 23%, respectively, as compared to the native forest. After ten years of yerba mate - elephant grass association soil C and N contents at the same depth increased by 19 and 12%, respectively, compared to the yerba mate monoculture, while soil porosity remained similar. Total C input,13C, and soil organic C were incorporated into a three compartment model to evaluate elephant grass C dynamics. Through the natural 13C abundance methodology we tracked the elephant grass C incorporation and the "old" soil C loss, and determined the model parameters - humification (k1) and mineralization (k) coefficients and stable C (Cs)- unambiguously. The high k1 and k predicted by the model are probably explained by elephant grass root system incorporation under no tillage and humid subtropical climate, respectively. In soil under yerba mate monoculture, Cs was counted as 91% of the total soil organic C.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Francisco J. Matus

AbstractWhen studying carbon (C) sequestration in soil, it is necessary to recognize the maximal storage potential and the main influencing factors, including the climate, land use, and soil properties. Here, we hypothesized that the silt and clay contents in soils as well as the clay mineralogy are the main factors affecting the maximal C and N storage levels of soils. This hypothesis was evaluated using a database containing the organic C contents of topsoils separated by ultrasonic dispersion to determine the particle size fractions. The slopes of the linear regressions between the C contents in silt and clay to the soil organic C (SOC) and between the N contents in silt and clay to the total N content were independent of the clay mineralogy (2:1, 1:1, calcareous soil, amorphous clays), climate type (tropical, temperate, and Mediterranean), and land use type (cropland, grassland, and forest). This clearly shows that the silt and clay content is the main factor defining an upper SOC level, which allowed us to propose a generalized linear regression (R2 > 0.95) model with a common slope, independent of the land use and climate type, to estimate the soil C sequestration potential. The implications of these findings are as follows: (1) a common slope regression was accurately calculated (0.83 ± 0.02 for C-silt + clay < 63 μm and 0.81 ± 0.02 for C-silt + clay < 20 μm) and (2) there was no asymptotic pattern found to support the existence of an SOC saturation pool.


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