scholarly journals Changes in Soil Labile Organic Matter as Affected by 50 Years of Fertilization with Increasing Amounts of Nitrogen

Agronomy ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2026
Author(s):  
Nikola Koković ◽  
Elmira Saljnikov ◽  
Frank Eulenstein ◽  
Dragan Čakmak ◽  
Aneta Buntić ◽  
...  
Keyword(s):  
Organic Matter ◽  
Microbial Biomass ◽  
Quality Parameters ◽  
Light Fraction ◽  
Microbial Biomass C ◽  
Microbial Biomass N ◽  
Sensitivity Index ◽  
Strong Impact ◽  
Labile Organic Matter ◽  
C And N

Microbially mediated soil organic matter is an extremely sensitive pool that indicates subtle changes in the quality parameters responsible for the soil’s ecological and productive functions. Fifty years of mineral fertilization of a wheat-corn cropping system has a strong impact on soil quality parameters. The goal of the research was to study the dynamics and quality of soil biological parameters affected by increasing amounts of mineral nitrogen. Soil respiration, potentially mineralizable C and N, microbial biomass C and N and light-fraction OM on Cambisol were analyzed in the following treatments: (1) Control (without fertilization); (2) NPK (60/51/67); (3) NPK (90/51/67); (4) NPK (120/51/67); (5) NPK (150/51/67 kg ha−1). The parameters studied were significantly affected by the long-term application of mineral fertilizer compared with both the control and the adjacent native soil. The highest amounts of nitrogen (N150) did not significantly differ from N120 and N90 for most of the parameters studied. Potentially mineralizable C represented the largest labile carbon pool, while microbial biomass N was the largest labile nitrogen pool. The mineralization rates for C and N were oppositely distributed over the seasons. The sensitivity index correlated with the amount of light-fraction OM. The results give a deeper insight into the behavior and distribution of different pools of labile SOM in the agro-landscapes and can serve as a reliable basis for further research focused on zero soil degradation.

scholarly journals Nitrogen Immobilisation and Microbial Biomass Build-Up Induced by Miscanthus x giganteus L. Based Fertilisers

Agronomy ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1386
Author(s):  
Michael Stotter ◽  
Florian Wichern ◽  
Ralf Pude ◽  
Martin Hamer
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Microbial Biomass ◽  
Triticum Aestivum L ◽  
Microbial Biomass C ◽  
Microbial Biomass N ◽  
Miscanthus X Giganteus ◽  
Organic Fertilisers ◽  
Biomass N ◽  
Set Up

Cultivation of Miscanthus x giganteus L. (Mis) with annual harvest of biomass could provide an additional C source for farmers. To test the potential of Mis-C for immobilizing inorganic N from slurry or manure and as a C source for soil organic matter build-up in comparison to wheat (Triticum aestivum L.) straw (WS), a greenhouse experiment was performed. Pot experiments with ryegrass (Lolium perenne L.) were set up to investigate the N dynamics of two organic fertilisers based on Mis at Campus Klein-Altendorf, Germany. The two fertilisers, a mixture of cattle slurry and Mis as well as cattle manure from Mis-bedding material resulted in a slightly higher N immobilisation. Especially at the 1st and 2nd harvest, they were partly significantly different compared with the WS treatments. The fertilisers based on Mis resulted in a slightly higher microbial biomass C and microbial biomass N and thus can be identified as an additional C source to prevent nitrogen losses and for the build-up of soil organic matter (SOM) in the long-term.

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

Long-term effects of NPK fertiliser and manure on soil fertility and a sorghum - wheat farming system

2007 ◽  
Vol 47 (6) ◽  
pp. 700 ◽  
Author(s):  
M. C. Manna ◽  
A. Swarup ◽  
R. H. Wanjari ◽  
H. N. Ravankar
Keyword(s):  
Organic Matter ◽  
Humic Acid ◽  
Soil Organic Matter ◽  
Microbial Biomass ◽  
Aggregate Size ◽  
Microbial Biomass C ◽  
Continuous Cropping ◽  
C And N ◽  
Organic Matter Fractions

Yield decline or stagnation under long-term cultivation and its relationship with soil organic matter fractions are rarely considered. To understand this phenomenon, soil organic matter fractions and soil aggregate size distribution were studied in a long-term experiment at Akola, in a Vertisol in a semiarid tropical environment. For 14 years, the following fertiliser treatments were compared with undisturbed fallow plots: unfertilised (control), 100% recommended rates of N, NP, NPK (N : P : K ratios of 100 : 21.8 : 18.2 and 120 : 26.2 : 50 kg/ha for sorghum and wheat, respectively) and 100% NPK plus farmyard manure (FYM) and continuous cropping with a sorghum (Sorghum bicolor L. Moench) and wheat (Triticum aestivum L.) system during 1988–2001. The significant negative yield trend was observed in unbalanced use of inorganic N application for both crops. However, yields were maintained when NPK and NPK + FYM were applied. Results showed that soil organic C and total N in the unfertilised plot decreased by 21.7 and 18.2%, compared to the initial value, at a depth of 0–15 cm. Depletion of large macroaggregates (>2 mm) accounted for 22–81% of the total mass of aggregates in N, NP and unfertilised control plots compared to fallow plots. Irrespective of treatments, small macroaggregates (0.25–2 mm) dominated aggregate size distribution (56–71%), followed by microaggregates (0.053–0.25 mm, 18–37%). Active fractions, such as microbial biomass C, microbial biomass N, hot water soluble C and N, and acid hydrolysable carbohydrates were greater in NPK and NPK + FYM treatments than in the control. Carbon and N mineralisation were greater in small macroaggregates than microaggregates. Particulate organic matter C (POMC) and N (POMN) were significantly correlated (P < 0.01) with water-stable aggregate C and N (0.25–2 mm size classes), respectively. It was further observed that POMC and POMN were significantly greater in NPK and NPK + FYM plots than N and NP treated plots. Microbial biomass C was positively correlated with acid-hydrolysable carbohydrates (r = 0.79, P < 0.05). Continuous cropping and fertiliser use also influenced humic acid C and fulvic acid C fractions of the soil organic matter. Acid-hydrolysable N proportion in humic acid was greater than fulvic acid and it was greatest in NPK + FYM treatments. Continuous application of 100% NPK + FYM could restore soil organic carbon (SOC) to a new equilibrium level much earlier (t = 1/k, 2.4 years) than N (t = 1/k, 25.7 years), NP (t = 1/k, 8.1 years) and NPK (t = 1/k, 5.02 years). In conclusion, integrated use of NPK with FYM would be vital to obtain sustainable yields without deteriorating soil quality.

Straw removal increases the light fraction and mineralizable C and N compared with moldboard ploughing

2007 ◽  
Vol 87 (1) ◽  
pp. 113-115 ◽  
Author(s):  
Y K Soon
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Microbial Biomass ◽  
Crop Production ◽  
Light Fraction ◽  
Straw Management ◽  
N Retention ◽  
Cereal Straw ◽  
C And N ◽  
Straw Incorporation

An earlier study indicated that cereal straw may be removed after harvest without affecting crop production, soil organic matter and microbial biomass. Further measurements of early indicators of changes in soil organic matter, viz., the light fraction and mineralizable C and N, confirm that straw removal is superior to straw incorporation with moldboard ploughing, and comparable to straw incorporation by disking, in C and N retention and turnover. Key words: Carbon, light fraction, mineralization, nitrogen, straw management

scholarly journals Repeated short-term organic amendments effects on physical and biological properties of a San Antón soil

1969 ◽  
Vol 100 (2) ◽  
pp. 123-140
Author(s):  
Ian C. Pagán-Roig ◽  
Joaquín A. Chong ◽  
José A. Dumas ◽  
Consuelo Estévez de Jensen
Keyword(s):  
Organic Matter ◽  
Humic Acid ◽  
Soil Organic Matter ◽  
Microbial Biomass ◽  
Organic Amendments ◽  
Biological Properties ◽  
Microbial Biomass C ◽  
Microbial Biomass N ◽  
Short Term ◽  
Biomass N

The objective of this work was to measure the effects of repeated short-term organic amendments that we termed soil treatment management cycles (STMC) on physical and biological properties of a San Antón series soil. Each STMC lasted 60 days and consisted of incorporating 5% organic matter from coffee pulp compost; the planting, growth and incorporation of an intercrop of four green manure species; and the application of mycorrhizae and compost tea. The treatments were labeled: CL0, CL1, CL2 and CL3; where CL0 was the control, CL1 received one STMC, CL2 and CL3 received two and three STMC, respectively. The STMC intended to mimic the overall effect of a sustainable agricultural system, not to measure the individual effects of the practices. All treatments (CL1, CL2, CL3) showed an increase in soil organic matter (p≤0.05). When compared to the CL0 control, saturated hydraulic conductivity increased and bulk density decreased in all soils. Soil macroporosity was significantly increased by CL2 and CL3. Soil aggregate stability increased in CL1, CL2 and CL3 plots. Microbial biomass C increased in treatment CL3, and microbial biomass N increased in CL2 and CL3. The production of stable aggregates was correlated to humic acid content and positively influenced all other physical parameters assessed in this study. The STMC had a positive impact on soil properties by increasing the soil organic matter as well as the humic acid fraction. Soil macroporosity, defined as porosity with radius > 38 µm, was significantly increased by treatments CL2 and CL3. All of the organic matter fractions, including total organic matter, humic acid content, microbial biomass C and microbial biomass N were significantly increased by one or more STMC.

Effect of crop rotations and cultural practices on soil organic matter, microbial biomass and respiration in a thin Black Chernozem

1991 ◽  
Vol 71 (3) ◽  
pp. 363-376 ◽  
Author(s):  
C. A. Campbell ◽  
V. O. Biederbeck ◽  
R. P. Zentner ◽  
G. P. Lafond
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Microbial Biomass ◽  
Cultural Practices ◽  
Respiratory Activity ◽  
Crop Rotations ◽  
Microbial Biomass C ◽  
Soil Organic C ◽  
Organic C ◽  
C And N

The effects of crop rotations and various cultural practices on soil organic matter quantity and quality in a Rego, Black Chernozem with a thin A horizon were determined in a long-term study at Indian Head, Saskatchewan. Variables examined included: fertilization, cropping frequency, green manuring, and inclusion of grass-legume hay crop in predominantly spring wheat (Triticum aestivum L.) production systems. Generally, fertilizer increased soil organic C and microbial biomass in continuous wheat cropping but not in fallow-wheat or fallow-wheat-wheat rotations. Soil organic C, C mineralization (respiration) and microbial biomass C and N increased (especially in the 7.5- to 15-cm depth) with increasing frequency of cropping and with the inclusion of legumes as green manure or hay crop in the rotation. The influence of treatments on soil microbial biomass C (BC) was less pronounced than on microbial biomass N. Carbon mineralization was a good index for delineating treatment effects. Analysis of the microbial biomass C/N ratio indicated that the microbial suite may have been modified by the treatments that increased soil organic matter significantly. The treatments had no effect on specific respiratory activity (CO2-C/BC). However, it appeared that the microbial activity, in terms of respiration, was greater for systems with smaller microbial biomass. Changes in amount and quality of the soil organic matter were associated with estimated amount and C and N content of plant residues returned to the soil. Key words: Specific respiratory activity, crop residues, soil quality, crop rotations

scholarly journals ORGANIC C DYNAMICS IN GRASSLAND SOILS. 2. MODEL VALIDATION AND SIMULATION OF THE LONG-TERM EFFECTS OF CULTIVATION AND RAINFALL EROSION

1981 ◽  
Vol 61 (2) ◽  
pp. 211-224 ◽  
Author(s):  
R. P. VORONEY ◽  
J. A. VAN VEEN ◽  
E. A. PAUL
Keyword(s):  
Organic Matter ◽  
Microbial Biomass ◽  
Management Practices ◽  
State Level ◽  
Microbial Biomass C ◽  
Organic C ◽  
Native Prairie ◽  
Cropping Sequence ◽  
C And N ◽  
Rainfall Erosion

The amounts of organic matter in native prairie and in an adjacent cultivated field were compared with the output from a simulation model describing organic matter dynamics. The effects of past and possible future soil management practices, and the loss of organic C through rainfall erosion were incorporated into the simulation study. Seventy years of cultivation increased the bulk density of the A horizon by an average of 16% along the catena of a Black Chernozemic soil. Organic C had decreased by 36% in the soil profile at the mid-slope position. Losses of organic N were 5–10% less. Depletion of organic C and N from the Ah horizon accounted for > 90% of the total loss from the soil profile. Therefore, extrapolation of data from surface soil, based solely on changes in the concentration of organic C and N, could result in an overestimation of organic matter losses from soils. Microbial biomass in the Ap horizon of the crop-summer-fallow site was 30% less than in the Ah horizon of the native prairie. The model predicted an immediate rise in microbial biomass C upon cultivation of the native prairie due to a large initial input of grassland litter and roots. Subsequently, the microbial biomass C decreased and approached a steady-state level which was 25% less than in the native prairie. The model indicates that large quantities of N released during the initial years of cultivation would not have been totally utilized by the cultivated crops, therefore resulting in major losses to the environment. However, now the organic matter is reaching a steady-state level and only small net release of N can be expected; external N sources are required for optimum crop production. Management practices such as straw removal and cropping sequence have short-term effects on the rate of depletion of soil organic C. Similar equilibrium levels of soil organic matter were predicted after 100 yr of cultivation in simulation studies that did not consider erosion losses. The inclusion of rainfall erosion losses indicated that major organic C and other nutrient losses will occur in management practices that include significant portions of fallow in the cropping sequence.

Effects of land use on soil total and light fraction organic, and microbial biomass C and N in a semi-arid ecosystem of northwest China

Geoderma ◽  
2009 ◽  
Vol 153 (1-2) ◽  
pp. 285-290 ◽  
Author(s):  
Xiao-Ling Wang ◽  
Yu Jia ◽  
Xiao-Gang Li ◽  
Rui-Jun Long ◽  
Qifu Ma ◽  
...  
Keyword(s):  
Land Use ◽  
Microbial Biomass ◽  
Northwest China ◽  
Light Fraction ◽  
Microbial Biomass C ◽  
Arid Ecosystem ◽  
C And N ◽  
Effects Of Land Use ◽  
Semi Arid
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