scholarly journals Wheat Straw Incorporation Affecting Soil Carbon and Nitrogen Fractions in Chinese Paddy Soil

Agriculture ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 803
Author(s):  
Wei Dai ◽  
Jun Wang ◽  
Kaikai Fang ◽  
Luqi Cao ◽  
Zhimin Sha ◽  
...  
Keyword(s):  
Microbial Biomass ◽  
Wheat Straw ◽  
Paddy Soil ◽  
Rice Paddy ◽  
Water Soluble ◽  
Microbial Biomass N ◽  
Rice Grain ◽  
Organic C ◽  
Straw Incorporation ◽  
N Fractions

Soil organic carbon (SOC) and nitrogen (N) fractions greatly affect soil health and quality. This study explored the effects of wheat straw incorporation on Chinese rice paddy fields with four treatments: (1) a control (CK), (2) a mineral NPK fertilizer (NPK), (3) the moderate wheat straw (3 t ha−1) plus NPK (MSNPK), and (4) the high wheat straw (6 t ha−1) plus NPK (HSNPK). In total, 0–5, 5–10, 10–20, and 20–30 cm soil depths were sampled from paddy soil in China. Compared with the CK, the HSNPK treatment (p < 0.05) increased the C fraction content (from 13.91 to 53.78%), mainly including SOC, microbial biomass C (MBC), water-soluble organic C (WSOC), and labile organic C (LOC) in the soil profile (0–30 cm), and it also (p < 0.05) increased the soil N fraction content (from 10.70 to 55.31%) such as the soil total N (TN) at 0–10 cm depth, microbial biomass N (MBN) at 0–20 cm depth, total water-soluble N (WSTN) at 0–5 and 20–30 cm depths, and total labile N (LTN) at 0–30 cm depth. The primary components of soil LOC and LTN are MBC and MBN. Various soil C and N fractions positively correlated with each other (p < 0.05). The HSNPK treatment promoted the soil MBC, WSOC, and LOC to SOC ratios, and also promoted MBN, WSTN, and LTN to soil TN ratios at a depth of 0–20 cm. To summarize, the application of HSNPK could maintain and improve rice paddy soil quality, which leads to increased rice grain yields.

EFFECT OF WHEAT STRAW INCORPORATION ON DENITRIFICATION OF N UNDER ANAEROBIC AND AEROBIC CONDITIONS

1987 ◽  
Vol 67 (4) ◽  
pp. 825-834 ◽  
Author(s):  
M. S. AULAKH ◽  
D. A. RENNIE
Keyword(s):  
Wheat Straw ◽  
Water Saturation ◽  
Initial Period ◽  
Fertilizer N ◽  
N Losses ◽  
Total Period ◽  
Organic C ◽  
Key Words Denitrification ◽  
Straw Incorporation ◽  
Water Saturated

The effects of wheat straw incorporation on denitrification, immobilization of N, and C mineralization were investigated at H2O contents of 60, 90 and 120% saturation. Incorporation of increasing levels of straw consistently increased the rate of denitrification for the first 4–8 d, followed by negligible N losses thereafter. In a total period of 96 d, the addition of 1.0% straw increased N losses from 2.5 to 10.1, and from 61.6 to 83.9 μg g−1 in the 60 and 120% water saturation treatments, respectively. The pattern of CO2-C evolved was practically identical to that of the denitrification rate for the initial period when sufficient [Formula: see text] was present. This study has confirmed that in flooded soils, high rates of denitrification will persist only when C is supplied by native or applied organic C sources, provided adequate [Formula: see text] is present. When [Formula: see text] was low, denitrification rates rapidly decreased, even with a sufficient supply of C. Immobilization of fertilizer N (50 μg N g−1 as K15NO3) was very rapid. Around 90% of the total immobilization of applied N occurred within 4 d. Incorporation of 1.0% straw increased the immobilization of fertilizer N from 8.4 to 42.8, and from 1.0 to 7.6% in the 60 and 120% water-saturated treatments, respectively. Remineralization of recently immobilized fertilizer N was observed after 32 d in the 60% saturation treatments only. Key words: Denitrification, wheat straw, mineralization of N

scholarly journals Fire Alters Soil Properties and Vegetation in a Coniferous–Broadleaf Mixed Forest in Central China

Forests ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 164 ◽  
Author(s):  
Mengjun Hu ◽  
Yanchun Liu ◽  
Tiantian Wang ◽  
Yuanfeng Hao ◽  
Zheng Li ◽  
...  
Keyword(s):  
Microbial Biomass ◽  
Soil Properties ◽  
Aboveground Biomass ◽  
Dead Wood ◽  
Mixed Forest ◽  
Central China ◽  
Biomass Combustion ◽  
Microbial Biomass N ◽  
Organic C ◽  
N Concentration

Fire is the predominant natural disturbance that influences the community structure as well as ecosystem function in forests. This study was conducted to examine the soil properties, loss of aboveground biomass, and understory plant community in response to an anthropogenic fire in a coniferous (Pinus massoniana Lamb.) and broadleaf (Quercus acutissima Carruth.) mixed forest in a subtropical–temperate climatic transition zone in Central China. The results showed that soil pH, NO3−-N concentration, and microbial biomass carbon (C) increased three months after the fire; however, there were no significant differences in soil organic C, total nitrogen (N), NH4+-N concentration, or microbial biomass N between the burned and unburned observed plots. The total aboveground biomass was 39.0% lower in the burned than unburned plots four weeks after fire. Direct biomass combustion (19.15 t ha−1, including understory shrubs and litters) was lower than dead wood biomass loss (23.69 t ha−1) caused by the fire. The declining trends of tree mortality with increasing diameter at breast height for both pine and oak trees suggest that small trees are more likely to die during and after fires due to the thinner bark of small trees and tree and branch fall. In addition, burning significantly stimulated the density of shrub (160.9%) and herb (88.0%), but it also affected the richness of shrub and herb compared with that in the unburned plots two months after the fire. The rapid recovery of understory plants after fires suggest that the diversity of understory species could benefit from low-severity fires. Our findings highlight that the decomposition of dead wood and understory community recovery should be considered for offsetting C emissions after fires for further research.

Seasonal trends in selected soil biochemical attributes: Effects of crop rotation in the semiarid prairie

1999 ◽  
Vol 79 (1) ◽  
pp. 73-84 ◽  
Author(s):  
C. A. Campbell ◽  
V. O. Biederbeck ◽  
G. Wen ◽  
R. P. Zentner ◽  
J. Schoenau ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Microbial Biomass ◽  
Microbial Biomass Carbon ◽  
Light Fraction ◽  
Water Soluble ◽  
Microbial Biomass C ◽  
Weather Variables ◽  
Total N ◽  
Organic C ◽  
C And N

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

Effects of Slope Aspect on Soil Chemical and Microbial Properties during Natural Recovery on Abandoned Cropland in the Loess Plateau, China

2011 ◽  
Vol 356-360 ◽  
pp. 2422-2429 ◽  
Author(s):  
Chao Zhang ◽  
Sha Xue ◽  
Guo Bin Liu ◽  
Chang Sheng Zhang
Keyword(s):  
Microbial Biomass ◽  
Loess Plateau ◽  
North Slope ◽  
Slope Aspect ◽  
Microbial Biomass N ◽  
The Loess Plateau ◽  
Organic C ◽  
Microbial Properties ◽  
South Slope ◽  
Abandoned Cropland

Abandoning cropland to enable recovery of the natural vegetation has been implemented during the past decade to restore the soil quality in the Loess Plateau, China. However, natural succession on cropland in the different slope aspect is different. The present study aimed at investigating the change in soil chemical and microbial properties abandoned farmland across time, and also to compare the difference of soil chemical and microbial properties in north slope and south slope on the Loess Plateau. The results showed that the slope aspect greatly affected the soil chemical and microbial properties after the cropland was abandoned, this could be attributed to the different precipitation and temperature in the two slopes. Compared with the north slope in which the organic C, total N and available N increased with the increase of abandonment years, that of south slope fluctuated significantly. Microbial biomass C and microbial biomass N in both slopes did not differ significantly in the first 10 years abandoned cropland, then decreased drastically in 15-year sites and thereafter tended to increase. Basal respiration in both slope fluctuated greatly in the sites with different abandonment years. Enzymes activities differed significantly in two slopes.

scholarly journals Effects of Organic Amendments on Soil Aggregate Stability and Microbial Biomass in a Long-Term Fertilization Experiment (IOSDV)

2021 ◽  
Vol 13 (17) ◽  
pp. 9769
Author(s):  
Gábor Csitári ◽  
Zoltán Tóth ◽  
Mónika Kökény
Keyword(s):  
Microbial Biomass ◽  
Grain Yield ◽  
Temporal Variability ◽  
Organic Amendments ◽  
Aggregate Stability ◽  
Microbial Biomass C ◽  
Organic C ◽  
Fertilization Experiment ◽  
Straw Incorporation

The effect of two types of organic amendment (manure and straw incorporation) and various doses (0–200 kg N*ha−1) of mineral N fertilization on microbial biomass C (MBC), aggregate stability (AS), soil organic C (SOC) and grain yield were investigated in an IOSDV long-term fertilization experiment (Keszthely, Hungary). This study was conducted during years 2015–2016 in a sandy loam Ramann-type brown forest soil (Eutric Cambisol according to WRB). Organic amendments had a significant effect on AS, MBC and SOC, increased their values compared to the unamended control. The organic amendments showed different effects on AS and MBC. AS was increased the most by straw incorporation and MBC by manure application. The magnitude of temporal variability of AS and MBC differed. Presumably, the different effects of organic amendments and the different degrees of temporal variability explain why there was only a weak (0.173) correlation between AS and MBC. AS did not correlate with SOC or grain yield. MBC correlated (0.339) with SOC but not with the grain yield. The N fertilizer dose did not have a significant effect on AS and MBC, but had a significant effect on SOC and grain yield.

scholarly journals Different root exudates C/N ratios accelerate CO2 emission from paddy soil

2021 ◽  
Author(s):  
Guan Cai ◽  
Muhammad Shahbaz ◽  
Tida Ge ◽  
yajun Hu ◽  
Baozhen Li ◽  
...  
Keyword(s):  
Microbial Biomass ◽  
Root Exudates ◽  
Paddy Soil ◽  
Co2 Emission ◽  
Extracellular Enzymes ◽  
High Energy ◽  
Organic N ◽  
C Mineralization ◽  
Organic C ◽  
Stoichiometric Ratios

Root exudates can greatly modify microbial activity and soil organic matter (SOM) mineralization. However, the mechanism of root exudation and its stoichiometric ratio of C/N controlling upon paddy soil C mineralization are poorly understand. In this study, we used a mixture of glucose, oxalic acid, and alanine as root exudate mimics, employing three C/N stoichiometric ratios (CN6, CN10, and CN80) to explore the underlying mechanisms involved in C mineralization. The input of root exudates enhanced CO2 emission by 1.8–2.3-fold than that of the control. Artificial root exudates with low C/N ratios (CN6 and CN10) increased the metabolic quotient (qCO2) by 12% over those obtained at higher stoichiometric ratios (CN80 and C-only), suggesting a relatively high energy demand for microorganisms to acquire organic N from SOM by increasing N-hydrolase production. The stoichiometric ratios of enzymes (β-1,4-glucosidase to β-1,4-N-acetyl glucosaminidase) promoting organic C degradation compared to those involved in organic N degradation showed a significant positive correlation with qCO2; the stoichiometric ratios of microbial biomass (MBC/MBN) were positively correlated with carbon use efficiency. This suggests that root exudates with higher C/N ratios entail an undersupply of N for microorganisms, triggering the release of N-degrading extracellular enzymes. This in turn decreases SOM mineralization, implying the C/N ratio of root exudates to be a controlling factor. Our findings show that the C/N stoichiometry of root exudates controls C mineralization by the specific response of the microbial biomass through the release of C- and N-releasing extracellular enzymes to adjust for the microbial C/N ratio.

ALLOCATION AND MICROBIAL UTILIZATION OF C IN TWO SOILS CROPPED TO BARLEY

1988 ◽  
Vol 68 (3) ◽  
pp. 495-505 ◽  
Author(s):  
G. D. DINWOODIE ◽  
N. G. JUMA
Keyword(s):  
Microbial Biomass ◽  
Black Soil ◽  
Water Soluble ◽  
Microbial Biomass C ◽  
Organic C ◽  
Soil C ◽  
Microbial Utilization ◽  
Below Ground ◽  
Microbial C ◽  
Soluble C

This study was undertaken to compare some aspects of carbon cycling in a Gray Luvisol at Breton and a Black soil at Ellerslie, Alberta cropped to barley. Comparisons of the above and below-ground allocation of carbon, distribution of carbon in soil, and microbial use of carbon were made between sites. Shoot C, root C, microbial biomass C, soil organic C, water soluble organic C, and polysaccharide C were measured on four dates between 31 July and 20 Oct. 1986. The total quantity of carbon in the soil-plant system at Ellerslie (17.2 kg C m−2) was greater than at Breton (6.6 kg C m−2). On average shoot C at Ellerslie (247 g C m−2) was greater than at Breton (147 g m−2). The quantity of root C (avg. 21 g C m−2) was the same at both sites resulting in higher shoot C:root C ratios at Ellerslie than Breton. Microbial biomass (expressed as g C m−2 or g C g−1 root C) was one to two times lower at Breton than at Ellerslie but respiration (g CO2-C g−1 microbial biomass C) during a 10-d laboratory incubation was two to four times greater. Microbial biomass C, soluble C and polysaccharide C expressed as mg C g−1 of soil were less at Breton than Ellerslie. However when these data were compared on a relative basis in terms of soil C (g C g−1 soil C), microbial biomass C and soluble C were higher at Breton than Ellerslie. Polysaccharide C was the same at both sites. Although the microbial biomass was smaller at Breton than at Ellerslie, more carbon was lost from the system by microbial respiration and a greater proportion of the carbon in the soil was in microbial and soluble C pools. Soil characteristics, and cropping history affected the amount of carbon stabilized in soil. Key words: Chernozemic, Luvisolic, microbial C, soluble C, polysaccharide C, soil organic matter, barley

scholarly journals Dynamics in Stoichiometric Traits and Carbon, Nitrogen, and Phosphorus Pools across Three Different-Aged Picea asperata Mast. Plantations on the Eastern Tibet Plateau

Forests ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1346
Author(s):  
Jixin Cao ◽  
Hong Pan ◽  
Zhan Chen ◽  
He Shang
Keyword(s):  
Microbial Biomass ◽  
Forest Floor ◽  
Soil Microbes ◽  
Mineral Soil ◽  
Tibet Plateau ◽  
Stand Age ◽  
Microbial Biomass N ◽  
Organic C ◽  
Picea Asperata ◽  
Stoichiometric Traits

Understanding the variations in soil and plants with stand aging is important for improving management measures to promote the sustainable development of plantations. However, few studies have been conducted on the dynamics of stoichiometric traits and carbon (C), nitrogen (N), and phosphorus (P) pools across Picea asperata Mast plantations of different ages in subalpine regions. In the present study, we examined the stoichiometric traits and C, N, and P stocks in different components of three different aged (22-, 32-, and 42-year-old) P. asperata plantations by plot-level inventories. We hypothesized that the stoichiometric traits in mineral soil could shape the corresponding stoichiometric traits in soil microbes, tree roots and foliage, and the C, N, and P stocks of the total P. asperata plantation ecosystem would increase with increasing stand age. Our results show that the N:P ratio in mineral soil was significantly correlated with that in tree foliage and herbs. Additionally, the C:N ratio and C:P ratio in mineral soil only correlated with the corresponding stoichiometric traits in soil microbes and forest floor, respectively. Both the fractions of microbial biomass C in soil organic C and microbial biomass N in soil total N decreased with increasing stand age. The C, N, and P stocks of the total ecosystem did not continuously increase across stand development. In particular, the P stock of the total ecosystem exhibited a trend of increasing first and then decreasing. The aboveground tree biomass C accounted for more than 55% of the total ecosystem C stock regardless of stand age. In contrast, mineral soil and forest floor were the major contributors to the total ecosystem N and P stocks in all stands. This study suggested that all three different stands were N limited, and the stoichiometric homeostasis in the roots of P. asperata was more stable than that in the foliage. In addition, the soil microbial community assembly may change with increasing stand age for P. asperata plantations in the subalpine region.

scholarly journals Responses of Soil and Microbial C:N:P Stoichiometry to Vegetation Succession in a Karst Region of Southwest China

Forests ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 755 ◽  
Author(s):  
Min Song ◽  
Wanxia Peng ◽  
Hu Du ◽  
Qingguo Xu
Keyword(s):  
Microbial Biomass ◽  
Vegetation Succession ◽  
Karst Region ◽  
Microbial Biomass N ◽  
Agricultural Abandonment ◽  
Total N ◽  
C:N:P Stoichiometry ◽  
Organic C ◽  
Successional Stages ◽  
Time Substitution

Spontaneous vegetation succession after agricultural abandonment is a general phenomenon in many areas of the world. As important indicators of nutrient status and biogeochemical cycling in ecosystems, the stoichiometry of key elements such as carbon (C), nitrogen (N) and phosphorous (P) in soil and microbial biomass, and their responses to vegetation recolonization and succession after agricultural abandonment remain poorly understood. Here, based on a space-for-time substitution approach, surface soil samples (0–15 cm) were collected from four vegetation types, e.g., tussock grassland, shrubland, secondary forest, and primary forest, which represent four successional stages across this region. All samples were examined C, N and P concentrations and their ratios in soil and microbial biomass. The results showed that soil organic C and total N content increased synchronously but total soil P did not remarkably change along a progressive vegetation succession. Consequently, soil C:P and N:P ratios increased while C:N ratio stayed almost unchanged during vegetation succession. Soil microbial biomass C (SMBC) and microbial biomass N (SMBN) concentrations elevated while SMBP did not significantly change during vegetation succession. Unlike the soil C:N:P stoichiometry, however, microbial C:N and C:P ratios were significantly or marginally significantly greater in grassland than in the other three successional stages, while microbial N:P did not significantly vary across the four successional stages. Overall, the present study demonstrated that soil and microbial stoichiometry responded differently to secondary vegetation succession in a karst region of subtropical China.

Sign in / Sign up

Export Citation Format

Share Document