Dissolved soil organic carbon and nitrogen were affected by conversion of native forests to plantations in subtropical China

2010 ◽  
Vol 90 (1) ◽  
pp. 27-36 ◽  
Author(s):  
J -S Wu ◽  
P -K Jiang ◽  
S X Chang ◽  
Q -F Xu ◽  
Y. Lin

To better understand the impact of converting native forests to intensively managed plantations on soil carbon (C) and nitrogen (N) dynamics in subtropical China, we examined the seasonal patterns of water-soluble organic C (WSOC) and N (WSON) concentrations in soils in Chinese chestnut (Castanea mollissima Blume) (CF) and bamboo (Phyllostachys praecox C.D. Chu & C.S. Chou) plantation forests (BF) and adjacent native evergreen broadleaf forests (NF) in Ling-long Mountain, Zhejiang Province, China. The plantations were disturbed through surface soil removal and were fertilized and/or mulched, from which economic products (such as nuts and bamboo shoots) were annually harvested. We found that WSOC and WSON had large seasonal variations and were lower in the warmer than in the colder season. Average WSOC concentrations followed the order of BF (58.6) > NF (35.1) > CF (18.1 mg C kg-1), a pattern mainly caused by mulching in BF in winter and the removal of surface soil in CF. Soil total C and N followed the order of BF > NF > CF. The extensive inorganic and organic fertilizer application in BF caused WSON concentrations to be 21 and 14 times higher than those in NF and CF, respectively. Conversion of native forests to plantations lowered soil WSOC:WSON and soil C:N ratios. The seasonal dynamics of WSOC:SOC (soil organic C) and WSON/TN ratios followed the same patterns of WSOC and WSON, respectively. The impacts of forest types on WSOC/SOC ratio, which is a measure of the quality of organic matter, were dependent on seasonal changes of management practices and/or tree growth. Nevertheless mean annual WSON/TN ratios of BF and CF were 2 and 12 times that of NF, indicating that a greater proportion of the total soil N pool became solubilized in the intensively managed plantations. We conclude that land-use conversion and associated management practices had a profound impact on WSOC, WSON, and total C and N concentrations in the studied forest soils in subtropical China.Key words: Forest management, water-soluble organic C, water-soluble organic N, WSOC/WSON ratio

1999 ◽  
Vol 79 (1) ◽  
pp. 73-84 ◽  
Author(s):  
C. A. Campbell ◽  
V. O. Biederbeck ◽  
G. Wen ◽  
R. P. Zentner ◽  
J. Schoenau ◽  
...  

Measurements of seasonal changes in soil biochemical attributes can provide valuable information on how crop management and weather variables influence soil quality. We sampled soil from the 0- to 7.5-cm depth of two long-term crop rotations [continuous wheat (Cont W) and both phases of fallow-wheat (F–W)] at Swift Current, Saskatchewan, from early May to mid-October, 11 times in 1995 and 9 times in 1996. The soil is a silt loam, Orthic Brown Chernozem with pH 6.0, in dilute CaCl2. We monitored changes in organic C (OC) and total N (TN), microbial biomass C (MBC), light fraction C and N (LFC and LFN), mineralizable C (Cmin) and N (Nmin), and water-soluble organic C (WSOC). All biochemical attributes, except MBC, showed higher values for Cont W than for F–W, reflecting the historically higher crop residue inputs, less frequent tillage, and drier conditions of Cont W. Based on the seasonal mean values for 1996, we concluded that, after 29 yr, F–W has degraded soil organic C and total N by about 15% compared to Cont W. In the same period it has degraded the labile attributes, except MBC, much more. For example, WSOC is degraded by 22%, Cmin and Nmin by 45% and LFC and LFN by 60–75%. Organic C and TN were constant during the season because one year's C and N inputs are small compared to the total soil C or N. All the labile attributes varied markedly throughout the seasons. We explained most of the seasonal variability in soil biochemical attributes in terms of C and N inputs from crop residues and rhizodeposition, and the influences of soil moisture, precipitation and temperature. Using multiple regression, we related the biochemical attributes to soil moisture and the weather variables, accounting for 20% of the variability in MBC, 27% of that of Nmin, 29% for LFC, 52% for Cmin, and 66% for WSOC. In all cases the biochemical attributes were negatively related to precipitation, soil moisture, temperature and their interactions. We interpreted this to mean that conditions favouring decomposition of organic matter in situ result in decreases in these attributes when they are measured subsequently under laboratory conditions. We concluded that when assessing changes in OC or TN over years, measurements can be made at any time during a year. However, if assessing changes in the labile soil attributes, several measurements should be made during a season or, measurements be made near the same time each year. Key words: Microbial biomass, carbon, nitrogen, mineralization, water-soluble-C, light fraction, weather variables


Soil Research ◽  
2003 ◽  
Vol 41 (4) ◽  
pp. 717 ◽  
Author(s):  
L. F. C. Leite ◽  
E. S. Mendonça ◽  
P. L. O. A. Machado ◽  
E. S. Matos

A 15-year experiment in a clayey Red-Yellow Podzolic in the tropical highlands of Viçosa, Brazil, was studied in 2000, aiming to evaluate the impact of different management systems (no tillage, disk plowing, heavy scratcher + disk plowing, and heavy scratched) on the total organic carbon (TOC), total nitrogen (TN), and several organic carbon pools. A natural forest, adjacent to the experimental area, was used as reference. The greatest TOC and TN as well as microbial biomass C (CMB), light fraction C (CFL), and labile organic carbon (CL) stocks were observed in the Atlantic Forest, compared with all other systems. The long-term cultivation (±70 years) of this area, prior to the installation of the experiment, has led to soil degradation, slowing the C recovery. No tillage had the higher C and N stocks and greater CL pool at the surface (0–10 cm), indicating improvement in soil nutrient status, although none of the systems presented potential to sequester C-CO2. Sustainable tropical agricultural systems should involve high residue input and conservative soil management in order to act as a C-CO2 sink. The C stocks in the CMB, CFL, and CL compartments were more reduced in relation to the natural vegetation with higher intensity management than the TOC stocks. This result indicates that these C compartments are more sensitive to changes in the soil management.


2003 ◽  
Vol 128 (2) ◽  
pp. 277-284 ◽  
Author(s):  
Jose E. Sanchez ◽  
Charles E. Edson ◽  
George W. Bird ◽  
Mark E. Whalon ◽  
Thomas C. Willson ◽  
...  

Designing and implementing more productive, nutrient-efficient, and environmentally sound orchard management systems requires a better understanding of plant and soil responses to more biologically driven management practices. This study explored the effect of orchard floor and N management on soil organic C and N, populations of nematodes, NO3 leaching, and yields in tart cherry (Prunus cerasus L. `Montmorency') production. A baseline conventional orchard system consisting of an herbicide-treated tree row and a full rate of N fertilizer was compared to two modified-conventional and ten alternative orchard floor and N management systems. Living ground cover and the use of mulch with or without composted manure increased total C and the active C and N pools in the soil. For instance, supplemental mulch or mulch applied using a side-delivery mower increased soil C by >20% above the conventional baseline. The size of the active C pool increased 45% and 60% with the use of the species mix 2 ground cover and compost, respectively. Increases in the active N pool ranged from a low of 25% in the soils using mulch or a ground cover mix to a high of 60% when compost was used. As a result, the ability of these soils to provide N to growing plants was enhanced. Total soil N increased in the treatment using natural weeds as ground cover and the full rate of N fertilizer. It is likely that weeds were able to convert significant amounts of fertilizer N into organic forms. Increasing the active C and N pools stimulates microbial activity, and may favor populations of nonplant parasitic nematodes over plant parasitic species. Using a trunk-to-trunk cover crop mix under the cherry trees reduced NO3 leaching by >90% compared to a conventional, herbicide treated soil, even when N fertilizer was used at full rate. Nitrate leaching also dramatically diminished when N fertilizer was fertigated at a reduced rate or when compost was used as N source. Alternative orchard floor and N management did not reduce yields when compared to the baseline conventional treatment.


2021 ◽  
Vol 13 (22) ◽  
pp. 12740
Author(s):  
Jian Li ◽  
Zhanrui Leng ◽  
Yueming Wu ◽  
Guanlin Li ◽  
Guangqian Ren ◽  
...  

The introduction of embankment seawalls to limit the expansion of the exotic C4 perennial grass Spartina alteniflora Loisel in eastern China’s coastal wetlands has more than doubled in the past decades. Previous research focused on the impact of sea embankment reclamation on the soil organic carbon (C) and nitrogen (N) stocks in salt marshes, whereas no study attempted to assess the impact of sea embankment reclamation on greenhouse gas (GHG) fluxes in such marshes. Here we examined the impact of sea embankment reclamation on GHG stocks and fluxes of an invasive Spartina alterniflora and native Phragmites australis dominated salt marsh in the Dongtai wetlands of China’s Jiangsu province. Sea embankment reclamation significantly decreased soil total organic C by 54.0% and total organic N by 73.2%, decreasing plant biomass, soil moisture, and soil salinity in both plants’ marsh. It increased CO2 emissions by 38.2% and 13.5%, and reduced CH4 emissions by 34.5% and 37.1%, respectively, in the Spartina alterniflora and Phragmites australis marshes. The coastal embankment wall also significantly increased N2O emission by 48.9% in the Phragmites australis salt marsh and reduced emissions by 17.2% in the Spartina alterniflora marsh. The fluxes of methane CH4 and carbon dioxide CO2 were similar in both restored and unrestored sections, whereas the fluxes of nitrous oxide N2O were substantially different owing to increased nitrate as a result of N-loading. Our findings show that sea embankment reclamation significantly alters coastal marsh potential to sequester C and N, particularly in native Phragmites australis salt marshes. As a result, sea embankment reclamation essentially weakens native and invasive saltmarshes’ C and N sinks, potentially depleting C and N sinks in coastal China’s wetlands. Stakeholders and policymakers can utilize this scientific evidence to strike a balance between seawall reclamation and invasive plant expansion in coastal wetlands.


EDIS ◽  
1969 ◽  
Vol 2004 (2) ◽  
Author(s):  
Craig D. Stanley ◽  
Brent K. Harbaugh

There is no more essential component for the poinsettia production system than water, yet it is often less intensively managed than other production inputs. Perhaps the tendency to overlook the importance of water occurs because its use is linked so closely to other components of production which are intensively managed. Water management is a critical consideration for many aspects of production such as fertility control, media selection, and disease and insect control. In addition, because water conservation and protection have become important issues to society as a whole, poinsettia producers must consider management practices which minimize the impact that production has on the environment and water resources. This paper will discuss the uses of water in poinsettia production, the advantages and disadvantages of the use of different irrigationsystems (management, maintenance, water conservation, and economics) available for poinsettia production, irrigation water requirements and scheduling, and plant and environmental water quality concerns. This is document SL-212, a publication of the Soil and Water Science Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL. Published January 2004.


Author(s):  
Enzhu Hu ◽  
Zhimin Ren ◽  
Xiaoke Wang ◽  
Hongxing Zhang ◽  
Weiwei Zhang

Abstract Elevated tropospheric ozone concentration ([O3]) may substantially influence the belowground processes of the terrestrial ecosystem. Nevertheless, a comprehensive and quantitative understanding of the responses of soil C and N dynamics to elevated [O3] remains elusive. In this study, the results of 41 peer-reviewed studies were synthesized using meta-analytic techniques, to quantify the impact of O3 on ten variables associated with soil C and N, i.e., total C (TC, including soil organic C), total N (TN), dissolved organic C (DOC), ammonia N (NH4 +), nitrate N (NO3 -), microbial biomass C (MBC) and N (MBN), rates of nitrification (NTF) and denitrification (DNF), as well as C/N ratio. The results depicted that all these variables showed significant changes (P < 0.05) with [O3] increased by 27.6 ± 18.7 nL/L (mean ± SD), including decreases in TC, DOC, TN, NH4 +, MBC, MBN and NTF, and increases in C/N, NO3 - and DNF. The effect sizes of TN, NTF, and DNF were significantly correlated with O3 fumigation level and experimental duration (P < 0.05). Soil pH and climate were essential in analyses of O3 impacts on soil C and N. However, the responses of most variables to elevated [O3] were generally independent of O3 fumigation method, terrestrial ecosystem type, and additional [CO2] exposure. The altered soil C and N dynamics under elevated [O3] may reduce its C sink capacity, and change soil N availability thus impact plant growth and enhance soil N losses.


2011 ◽  
Vol 59 (7) ◽  
pp. 654 ◽  
Author(s):  
K. L. Page ◽  
R. C. Dalal ◽  
R. J. Raison

Australia’s harvested native forests are extremely diverse in terms of species-mix, disturbance history and ecology, forest productivity and C storage. Our understanding of the effects of harvesting on C storage and greenhouse gas (GHG) emissions from these systems is incomplete, and this paper consolidates current Australian knowledge, places this in a global context, and identifies areas requiring further study. The uptake of CO2 and the re-accumulation of forest C stocks after harvesting or other disturbance is largely dependent on forest primary production. However, in Australian native forests, knowledge of rates of primary production for the diverse range of species and management practices present is poor. Soil respiration rates following harvest have also been largely unquantified for Australian systems. It is essential that both these parameters are quantified if estimates of net ecosystem production (NEP) are to be made. It is generally acknowledged that harvested forests have a negative NEP, and thus are sources of C, immediately following harvest, but attain a positive NEP as the forest regrows and photosynthetic capacity increases. The magnitude and time course of these changes are largely unknown for most Australian forest systems. In addition, little data are available to quantify the effect on soil C storage, and where estimates have been made these are often subject to methodological uncertainty and are thus highly contentious. Following harvest, the changes that occur to soil structure, moisture content, and N cycling may also influence CH4 and N2O flux, although these fluxes also remain largely unquantified in harvested Australian forests. Given the significant changes to NEP, CH4 and N2O fluxes observed after forest harvest in international studies, it is expected that GHG fluxes would typically increase from Australian native forests following harvest, and then slowly decrease over time as biomass accumulates, and N2O and CH4 fluxes return to background levels. However, it is currently difficult to quantify the magnitude and time course of these changes due to a lack of both gas flux and primary production measurements. Clearly, further research effort to quantify these parameters throughout Australia is required in order to obtain a more reliable picture of the effects of harvesting and other disturbances on forest GHG balance.


2013 ◽  
Vol 93 (3) ◽  
pp. 319-328 ◽  
Author(s):  
Noura Ziadi ◽  
Bernard Gagnon ◽  
Judith Nyiraneza

Ziadi, N., Gagnon, B. and Nyiraneza, J. 2013. Crop yield and soil fertility as affected by papermill biosolids and liming by-products. Can. J. Soil Sci. 93: 319–328. Papermill biosolids (PB) in combination with alkaline industrial residuals could benefit agricultural soils while diverting these biosolids from landfill. A greenhouse study was conducted to evaluate the effect of three types of PB at rates of 0, 30, and 60 wet Mg ha−1, as well as five liming by-products at 3 wet Mg ha−1 along with 30 Mg PB ha−1 on crop yield, nutrient accumulation, and soil properties. De-inking paper biosolids (DB, C/N of 65) were applied to soybean [Glycine max (L.) Merr.], and two combined PB (PB1, C/N of 31; and PB2, C/N of 14) were applied to dry bean (Phaseolus vulgaris L.) and barley (Hordeum vulgare L.), respectively. The liming by-products included lime mud (LM), wood ash (WA) from paper mills, commercial calcitic lime (CL), Mg dissolution by-product (MgD), and Mg smelting and electrolysis work (MgSE). Compared with the control, PB2 increased barley yield and total Mg and Na accumulation, and both PB increased plant N, P, and Ca accumulation in barley and dry bean. The impact of DB on soybean was limited. The addition of liming by-products to PB or DB did not affect crop attributes except the combination with MgSE, which severely reduced the growth of dry bean and, to a lesser extent, soybean. Soil NO3-N was immobilized following DB application, whereas there was a net release with both PB. Combining PB and liming by-products produced the greatest changes in soil properties at harvest. Generally, LM and CL raised pH and Mehlich-3 Ca, and MgSE caused a strong increase in Mehlich-3 Mg and Na and water-soluble Cl. When used with appropriate crops, biosolids from paper mills and alkaline residuals other than MgSE can efficiently enhance soil fertility by providing organic C and macronutrients for balanced crop fertilization.


2001 ◽  
Vol 81 (5) ◽  
pp. 545-551 ◽  
Author(s):  
Nicole Bissonnette ◽  
Denis A. Angers ◽  
Régis R. Simard ◽  
Jean Lafond

In many soils, the content and quality of organic matter (OM) control water-stable aggregation, which in turn preserves soil surface integrity. The effects of management practices on soil OM and aggregation remain to be determined for certain soils and climatic conditions. We assessed the effects of eight management systems involving two crop sequences: [barley ( Hordeum vulgare L.) monoculture (M) and barley in rotation (R) with a forage mix of red clover ( Trifolium pratense L.) and timothy ( Phleum pratense L. ‘Champ’)], two fall tillage [moldboard plowing (MP) and chisel plowing (CP)] and two nutrient sources [liquid dairy manure (LDM) and mineral fertilizers (MIN)] on soil aggregation and OM fractions of a silty clay Humic Gleysol. Soil samples from the 0–7.5 cm layer were taken periodically during 7 yr, and the total C and N, microbial biomass C (MBC) and carbohydrate (AHC) contents, alkaline phosphatase activity (APA), and water-stable aggregation were determined. By the 7th yr, initial total C and N contents of the surface soil had increased by 35 and 45%, respectively, in R-CP-LDM. They were slightly increased in R-CP-MIN an d R-MP-LDM, whereas they decreased by an average of 19% in R-MP-MIN and all monoculture plots. Increases in C contents were attributed to higher annual C inputs from forage residues and LDM, less frequent tillage in the rotation, and shallower tillage with CP. The MBC, APA, AHC and aggregation generally responded faster and to a greater degree to conservation management practices than total C and N. Overall, conservation tillage and manure applications resulted in greater improvement in surface soil conditions when used in a rotation system rather than in a monoculture. The rapid rate of changes in soil properties suggests that the surface quality of this cold silty clay soil can be improved relatively quickly with selected management combinations. Key Words: Cropping systems, total soil C, microbial biomass, carbohydrate, alkaline phosphatase, soil aggregation, liquid dairy manure, reducted tillage, rotations


2021 ◽  
Vol 5 ◽  
Author(s):  
Pauline Sophie Rummel ◽  
Lukas Beule ◽  
Michael Hemkemeyer ◽  
Sanja Annabell Schwalb ◽  
Florian Wichern

Increased global production of animal-based protein results in high greenhouse gas (GHG) emissions and other adverse consequences for human and planetary health. Recently, commercial insect rearing has been claimed a more sustainable source of animal protein. However, this system also leaves residues called frass, which—depending on the insect diet—is rich in carbon (C) and nitrogen (N), and could thus be used as fertilizer in agriculture. The impact of this kind of fertilizer on soil GHG emissions is yet unknown. Therefore, we investigated the effect of black soldier fly (Hermetia illucens L.) frass derived from a carbohydrate (Carb-) or a protein (Prot-) based diet applied at two different application rates to an arable soil on C and N fluxes and microbial properties in a 40-day incubation experiment. CO2, N2O, NO, N2, CH4, water extractable organic C (WEOC), and inorganic N were continuously measured quantitatively. At the end of the incubation, microbial biomass (MB), stoichiometry, community composition, and abundance of functional genes were assessed. Along with a strong increase in WEOC and CO2, Carb-frass caused strong initial N2O emissions associated with high N and C availability. In contrast, Prot-frass showed lower CO2 emissions and N2O release, although soil nitrate levels were higher. At the end of incubation, MB was significantly increased, which was more pronounced following Carb-frass as compared to Prot-frass application, and at higher amendment rates. Fungal abundance increased most from both frass types with an even stronger response at higher application rates, whereas bacterial abundance rose following Carb-frass as compared to Prot-application. Abundance of functional genes related to ammonia-oxidizing bacteria and archaea were enhanced by high frass application but did not clearly differ between frass types. C use efficiency of microorganisms, as revealed by the metabolic quotient, was most strongly reduced in the high Prot-frass application rate. Overall, insect diet influenced available C and N in frass and thus affected mineralization dynamics, GHG emissions, and microbial growth. Overall, emissions were very high undermining the potential environmental benefit of insect based protein production and calling for more detailed analyses before frass is widely applied in agriculture.


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