scholarly journals Impact of Residue Incorporation on Soil Carbon Storage, Soil Organic Fractions, Microbial Community Composition and Carbon Mineralization in Rice-wheat Rotation – A Review

Author(s):  
R. K. Naresh ◽  
M. Sharath Chandra ◽  
Aryan Baliyan ◽  
Shakti Om Pathak ◽  
Pradeep Kumar Kanaujiya ◽  
...  

In agroecosystems, straw return is a useful management strategy for increasing soil fertility and crop productivity. The total organic carbon (TOC), dissolved organic C (DOC), and microbial biomass C (MBC) contents all increased significantly when compared to the no straw return (N) and straw return (S) treatments, while the easily oxidizable C content remained same. The S treatment resulted in a 28–52 percent increase in soil light fraction, light fraction organic C, and particle organic C over the N treatment. When compared to the N treatment, crop straw return increased total phospholipid fatty acid (PLFA), bacterial biomass, and actinomycete biomass by 52, 75, and 56 percent, respectively. Under short-term crop straw return, MBC and TOC were the two key determinants determining microbial populations. In comparison to residue removal, residue retention (RR) enhanced SOC storage by 11.3 percent. SOC content and contribution of macro-aggregates in the 0-20 cm depth and micro-aggregates in the 20-40 cm depth rose significantly when no-tillage and straw returns were used together. When no-tillage with straw returning (NTS) was used instead of CT, SOC content, mean weight diameter (MWD), geometric mean diameter (GMD), and fractal dimensions (FD) rose by 25%, 21%, 19%, and 12%, respectively, in the 0-20 cm depth. Soil micro-aggregates were greater in the 20-40 cm depth after CTS treatment. In the 0-20 cm depth, the percentages of macro- and micro-aggregates increased by 60% and 40%, respectively, under NTS. MWD, GMD, > 5, 2-5, 1-2, and 0.25-0.5 mm aggregates all had a positive linear relationship with the SOC. Microbial biomass C (MBC) was considerably enhanced by 20.0 percent when compared to conventional tillage (CT) and no-tillage (NT), but total organic C (TOC), dissolved organic C (DOC), readily oxidizable C (EOC), and SOC of aggregates were not affected. MBC increased by 18.3% and SOC content of 2–1-mm aggregate increased by 9.4% when residue was returned. Total PLFAs grew by 9.8%, while fungal biomass increased by 40.8 percent, thanks to NT. Total PLFAs, bacterial biomass, fungal biomass, F/B, and MUFA/STFA were all increased by 31.1, 36.0, 95.9, 42.5, and 58.8 percent, respectively, while microbial stress was reduced by 45.9%. Wheat straw return had a considerable impact on the bacterial community in the soil, but not on the fungus community. It increased the relative abundance of the bacteria phylum Proteobacteria and the fungal phylum Zygomycota, while decreasing the relative richness of the bacterial phylum Acidobacteria and the fungal phylum Ascomycota. It increased the relative abundance of nitrogen-cycling bacterial taxa including Bradyrhizobium and Rhizobium, among others. This diversity includes bacteria, cyanobacteria, archaea, planctomycetes, and -proteobacteria, as well as endophytes. The system's intricacy and dynamic nature necessitate in-depth research on the three-part interactions between plants, microorganisms, and the soil-water environment.

1998 ◽  
Vol 78 (2) ◽  
pp. 283-290 ◽  
Author(s):  
P. Rochette ◽  
E. G. Gregorich

Application of manure and fertilizer affects the rate and extent of mineralization and sequestration of C in soil. The objective of this study was to determine the effects of 3 yr of application of N fertilizer and different manure amendments on CO2 evolution and the dynamics of soil microbial biomass and soluble C in the field. Soil respiration, soluble organic C and microbial biomass C were measured at intervals over the growing season in maize soils amended with stockpiled or rotted manure, N fertilizer (200 kg N ha−1) and with no amendments (control). Manure amendments increased soil respiration and levels of soluble organic C and microbial biomass C by a factor of 2 to 3 compared with the control, whereas the N fertilizer had little effect on any parameter. Soil temperature explained most of the variations in CO2 flux (78 to 95%) in each treatment, but data from all treatments could not be fitted to a unique relationship. Increases in CO2 emission and soluble C resulting from manure amendments were strongly correlated (r2 = 0.75) with soil temperature. This observation confirms that soluble C is an active C pool affected by biological activity. The positive correlation between soluble organic C and soil temperature also suggests that production of soluble C increases more than mineralization of soluble C as temperature increases. The total manure-derived CO2-C was equivalent to 52% of the applied stockpiled-manure C and 67% of the applied rotted-manure C. Estimates of average turnover rates of microbial biomass ranged between 0.72 and 1.22 yr−1 and were lowest in manured soils. Manured soils also had large quantities of soluble C with a slower turnover rate than that in either fertilized or unamended soils. Key words: Soil respiration, greenhouse gas, soil carbon


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.


Geoderma ◽  
2019 ◽  
Vol 345 ◽  
pp. 93-103 ◽  
Author(s):  
Parag Bhople ◽  
Ika Djukic ◽  
Katharina Keiblinger ◽  
Franz Zehetner ◽  
Dong Liu ◽  
...  

Soil Research ◽  
2018 ◽  
Vol 56 (6) ◽  
pp. 623 ◽  
Author(s):  
Roberto Cardelli ◽  
Gabriele Giussani ◽  
Fausto Marchini ◽  
Alessandro Saviozzi

The use of the residual material from waste aerobic digestion and biochar as amendments is currently discussed in the literature concerning the positive and negative effects on soil quality. We assessed the suitability of digestate (D) from biogas production and green biochar (B) to improve soil biological activity and antioxidant capacity and investigated whether there is an interaction between digestate and biochar applied to soil in combination. In a short-term (100-days) laboratory incubation, we monitored soil chemical and biological parameters. We compared soil amendments with 1% D (D1), 5% D (D5), 1% B (B), digestate–biochar combinations (D1+B and D5+B), and soil with no amendment. In D5, CO2 production, antioxidant capacity (TEAC), and dehydrogenase activity (DH-ase) and the contents of microbial biomass C, DOC and alkali-soluble phenols increased to the highest level. The biochar increased the total organic C (TOC) and TEAC of soil but decreased DOC, CO2 production, microbial biomass C, and DH-ase. The addition of biochar to digestate reduced soluble compounds (DOC and phenols), thus limiting the amount and activity of the soil microbial biomass (CO2 production and DH-ase). After 100 days of incubation D5+B showed the highest TOC content (82.8% of the initial amount). Both applied alone and in combination with digestate, the biochar appears to enrich the soil C sink by reducing CO2 emissions into the atmosphere.


1996 ◽  
Vol 26 (10) ◽  
pp. 1799-1804 ◽  
Author(s):  
F. Eivazi ◽  
M.R. Bayan

In low-input or unmanaged ecosystems, the relationship between soil enzyme activity and plant biomass is expected and may be used as an early and sensitive indicator of soil productivity. This study was designed to (1) examine the long-term effects of burning on the activities of arylsulfatase, acid phosphatase, α- and β-glucosidase, and urease; (2) determine the relationship between microbial biomass C and enzyme activities as affected by long-term prescribed burning; and (3) study the seasonal variations in activities of the above-mentioned enzymes. Soil samples (Typic Fragiudalf) were collected from southeastern Missouri where a long-term burning experiment was established in 1949. Treatments consisted of (1) annual burning; (2) periodic burning, every 4 years; and (3) control, unburned. Soil samples (0–15 cm) were collected before and after annual and periodic burning during 1992 and seasonally in 1993. Long-term burning treatments significantly reduced the activities of enzymes studied but did not affect the pH and organic C. The microbial biomass C, total N, available P, and available S content of soil samples from both annual and periodic burning plots were significantly reduced. A significant positive correlation between soil enzyme activities and the microbial biomass was established. The treatment effects were apparent over the background seasonal variability, with reduced enzyme activity for the annual and periodic burning plots as compared with the unburned plots.


2019 ◽  
Vol 13 ◽  
pp. 04009 ◽  
Author(s):  
Claudio Mondini ◽  
Giovanni Bigot ◽  
Tania Sinicco ◽  
Davide Mosetti

Biochemical parameters are particularly suited to evaluate soil fertility because soil microorganisms play a pivotal role in determining soil quality and functionand are very sensitive to changes in soil management and environmental conditions. For such reasons, in this work, we used several biochemical indexes to assess the effect on soil fertility of 3 different conservative management systems of vineyards. The managements compared were chemical weed control vs permanent grass (CWC/MWC), land levelling vs undisturbed soil (LL/US), conventional farming vs organic farming (CON/ORG). The following parameters were determined in 2014 and 2015 on soil samples: total organic C (TOC), extractable N (EN), soil basal respiration (SBR), microbial biomass C (BC), microbial quotient (BC/TOC) and metabolic quotient (qCO2 = SBR/BC). Results showed that biochemical indicators were effective in detecting changes in soil fertility between compared systems. In particular, conservative systems (MWC, US and ORG) showed a larger and more efficient microbial biomass and enhanced EN content in comparison to the relative conventional systems. Furthermore BC/TOC and qCO2 indicated higher C use efficiency in conservative systems. Results as a whole indicate that conservative management systems aimed to maintain and enhance soil organic matter displayed a higher level of soil fertility.


2006 ◽  
Vol 57 (8) ◽  
pp. 837 ◽  
Author(s):  
G. M. Lodge ◽  
K. L. King

Studies were conducted at 3 pasture sites in northern New South Wales to examine the effects of grazing treatments over 4 years (spring 1997 to spring 2001) on soil microbial biomass carbon (C), labile C, total C, and total nitrogen (N). These data were collected (0–0.05 m soil depth) at 9 sampling times in 2 replicates of 5 (native pastures) or 4 (a sown pasture) grazing treatments and examined for differences over time using cubic spline analyses. For each site, differences among grazing treatments were also examined in spring 2001 for herbage, litter, and root mass (kg DM/ha), ground cover (%), and perennial grass basal cover (%). Indices were also calculated for the C pool index (CPI), lability index (LI), a carbon management index (CMI), and the microbial quotient. Relationships among microbial biomass C, labile C, total organic C, CPI, LI, CMI, microbial quotient, herbage mass, litter mass, and ground cover were examined by linear regression and correlation analyses. For each of the sites, treatment differences in the linear trend over time for soil microbial biomass C, labile C, total organic C, or total N were not significantly different (P > 0.05). In spring 2001, (4 years after treatments commenced) there were also no significant effects of treatments within sites on soil total organic C and none of the indices (lability of C, CPI, LI, CMI, or the microbial quotient) indicated any distinct trends among treatments. However, in spring 2001, there were significant (P < 0.05) treatment effects at both native pasture sites for herbage mass, litter mass, and ground cover. Similarly, in autumn 2001, herbage mass, root mass, and perennial grass basal cover were lowest (P < 0.05) in the continuously grazed high-stocking rate treatment at the sown pasture site. For all data, microbial biomass C was 10.35% of labile C and labile C was 21.60% of total C. From autumn 1998 to spring 2001, labile C was positively correlated (P < 0.05) with total C (r = 0.72) and in spring 2001, these 2 variables were also highly correlated (r = 0.98).


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