Comparative effects of subterranean clover, medic, lucerne, and chickpea in wheat rotations, on nitrogen, organic carbon, and moisture in two contrasting soils

Soil Research ◽  
1998 ◽  
Vol 36 (1) ◽  
pp. 57 ◽  
Author(s):  
I. C. R. Holford ◽  
B. E. Schweitzer ◽  
G. J. Crocker
Keyword(s):  
Organic Carbon ◽  
Subterranean Clover ◽  
Field Capacity ◽  
Residual Effects ◽  
Organic N ◽  
Wheat Crop ◽  
First Year ◽  
Red Clay ◽  
Total N ◽  
Organic C

The effects of subterranean clover, medic, and lucerne, grown simultaneously from 1988 to 1990, followed by wheat from 1991 to 1993, and of chickpea and long fallow in alternate years with wheat, on soil total nitrogen (N), nitrate-N (NO-3-N), organic carbon (C), and moisture were measured over 6 years in 2 long-term experiments on a black earth (pellic vertisol) and red clay (chromic vertisol) in northern New South Wales. The accretion of soil total N in the black earth and NO-3-N in both soils was higher after lucerne than after other legumes, and NO-3 in the black earth remained high after lucerne to the full depth (120 cm) of measurement during the following 3 years of wheat growing. Clover had the next largest effect on total N and NO-3 accretion, and chickpea had the smallest effect except in the red clay where chickpea increased NO-3 more than medic in 1990. However, none of the annual legumes had much effect on NO-3 after the first year of cropping and their small residual effects, if any, were confined to the top 30 cm of soil. Levels of total N accretion after lucerne were higher than previously measured, because of the greater depth of measurement, but were similar on a per unit depth basis. High levels of NO-3 -N after long fallow, especially in the black earth, which tended to be higher than after medic or chickpea, were probably caused by accelerated mineralisation of organic N which has declined more in this rotation than in any other. There was no accumulation of organic C during the legume growing period in any rotation, and C tended to be lower after chickpea than after other legumes. Organic C was almost always lowest in the long fallow treatment. Summer-growing grasses, which occurred in all treatments to varying degrees, may have caused the organic C accumulation during the 3 years of cropping. In the first year of wheat growing, soil water was lower after lucerne than after other treatments and highest after long fallow, continuous wheat, and chickpea. It was replenished in the red clay to field capacity in all treatments by high rainfall during the fallow before the first wheat crop but not in the black earth, which failed to reach field capacity in any treatment even 2.5 years after the pasture legume phase.

Nitrogen nutrition of cereals in a short-term rotation. I. Single season treatments as a source of nitrogen for subsequent cereal crops

1981 ◽  
Vol 32 (5) ◽  
pp. 703 ◽  
Author(s):  
I Papastylianou ◽  
DW Puckridge ◽  
ED Carter
Keyword(s):  
Soil Nitrogen ◽  
Nitrogen Availability ◽  
Subterranean Clover ◽  
Residual Effects ◽  
Yield Response ◽  
Wheat Crop ◽  
First Year ◽  
Fertilizer Nitrogen ◽  
The Third ◽  
Second Year

The residual effects of one season of five cultural treatments common in southern Australian dryland farming were examined with respect to soil water and nitrogen, and the production of cereals in the next two years. The initial treatments were medic or subterranean clover pasture, faba beans, oats or bare fallow. In the second year barley, wheat and triticale were grown on the same plots, with 0,30,60 or 90 kg ha-1 of fertilizer nitrogen. Wheat was sown over the whole area for the third season. The medic and subterranean clover pastures contributed approximately 100 kg ha-1 of nitrogen in top growth, but this remained on the surface until cultivation. Oats and fallow plots declined in total soil nitrogen by about 70 kg ha-1. The nitrogen content of the faba bean stubble showed that this crop has the potential of providing equivalent nitrogen to a good legume pasture. At the beginning of the second season the previous plots of fallow, beans, subterranean clover and medic had 36,27, 14 and 12 mm more water in the top metre of soil than oat plots. Cereals after oats apparently did not respond to fertilizer nitrogen because of the dry conditions, but on other plots the yield response was not proportional to the additional water. Although first year treatments affected growth of the three cereals in the second season, the new cereal, triticale, showed no evidence of different adaptation to growing conditions than wheat or barley. The effects of first and second year treatments carried through to the wheat crop in the third season. There were marked differences in nitrogen availability, but evidence that the second crop was depleting soil nitrogen reserves. Nitrogen from first year legume residues was available earlier in the season than second year fertilizer nitrogen which had been leached from the surface soil.

Nitrogen nutrition of cereals in a short-term rotation. II. Stem nitrate as an indicator of nitrogen availability

1981 ◽  
Vol 32 (5) ◽  
pp. 713 ◽  
Author(s):  
I Papastylianou ◽  
DW Puckridge
Keyword(s):  
Nitrate Nitrogen ◽  
Nitrogen Concentration ◽  
Subterranean Clover ◽  
Residual Effects ◽  
Wheat Crop ◽  
First Year ◽  
Growth Stages ◽  
Fertilizer Nitrogen ◽  
The Third ◽  
Second Year

The effect of cultural treatments and fertilizer nitrogen on nitrate nitrogen concentration of cereal steins and the relation between nitrate nitrogen and cereal production were examined in a three-year experiment. Five cultural treatments in the first year were medic or subterranean clover pasture, field beans, oats or bare fallow. These were oversown in the second year with barley, wheat and triticale, with 0, 30, 60 or 90 kg ha-1 of fertilizer nitrogen. Wheat was sown over the whole area in the third season. There were marked differences in nitrate nitrogen concentrations in the second year cereals as a result of the previous cultural treatments and the current application of fertilizer nitrogen. For cultural treatments the concentrations were highest after fallow, intermediate after legumes, and lowest after oats. There was an asymptotic increase in nitrate nitrogen as fertilizer nitrogen increased. The second year had low rainfall, and there was little correlation between nitrate nitrogen concentration and production, but measurements of nitrate nitrogen clearly indicated relative availability of nitrogen. In the third season's wheat crop the residual effects of first year subterranean clover gave highest nitrate nitrogen, but effects of fallow were almost as high. Second year fertilizer had less effect than first year cultural treatments. Grain yield of wheat in the third year was closely related to nitrate nitrogen concentration during early growth stages. This was a year with good rainfall. Measurement of nitrate concentration in plant stems could be useful for determining the need for fertilizer nitrogen.

Decline in soil organic carbon and total nitrogen in relation to tillage, stubble management, and rotation

1995 ◽  
Vol 35 (7) ◽  
pp. 877 ◽  
Author(s):  
DP Heenan ◽  
WJ McGhie ◽  
FM Thomson ◽  
KY Chan
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Total Nitrogen ◽  
Subterranean Clover ◽  
Wagga Wagga ◽  
Soil Organic C ◽  
Total N ◽  
Organic C ◽  
Stubble Retention ◽  
C And N

The influence of rotation, tillage, stubble management, and nitrogen (N) fertiliser on soil organic carbon (C) and total nitrogen (N) was studied between 1979 and 1993 in a field experiment at Wagga Wagga, New South Wales, on a red earth. The rotations included lupin-wheat (LW), subterranean clover-wheat (SW), and continuous wheat (WW) with and without N fertiliser (100 kg N/ha). At the start of the experiment the soil organic C and N in the surface 10 cm were high following many years of subterranean clover based pasture. The trends in soil organic C varied considerably between treatments from near equilibrium levels for SW direct-drilled and stubble-retained to annual losses of 400 kg/ha for WW conventionally cultivated and stubble burnt. Similarly, total soil N content over time varied from equilibrium levels to highly significant declines of 53 kg/ha. year for WW conventionally cultivated and stubble burnt. Both direct drilling and stubble retention reduced the losses of organic C and N compared with conventional cultivation and burning, with greatest loss occurring when cultivation and stubble burning were combined. SW and LW produced a similar contribution of fixed N to total N product removal, but greater benefits to following wheat crops were provided by SW rotations. Where losses of organic C and N were recorded there was no evidence of equilibrium levels being reached after 14 years.

scholarly journals Nitrogen fertilizer value of animal slurries with different proportions of liquid and solid fractions: A 3-year study under field conditions

2021 ◽  
pp. 1-11
Author(s):  
Betina Nørgaard Pedersen ◽  
Bent T. Christensen ◽  
Luca Bechini ◽  
Daniele Cavalli ◽  
Jørgen Eriksen ◽  
...  
Keyword(s):  
Solid Fraction ◽  
Liquid Fraction ◽  
N Fertilizer ◽  
Organic N ◽  
First Year ◽  
Net N Mineralization ◽  
Pig Slurry ◽  
Total N ◽  
Plant Availability ◽  
Loamy Sand Soil

Abstract The plant availability of manure nitrogen (N) is influenced by manure composition in the year of application whereas some studies indicate that the legacy effect in following years is independent of the composition. The plant availability of N in pig and cattle slurries with variable contents of particulate matter was determined in a 3-year field study. We separated cattle and a pig slurry into liquid and solid fractions by centrifugation. Slurry mixtures with varying proportions of solid and liquid fraction were applied to a loamy sand soil at similar NH4+-N rates in the first year. Yields and N offtake of spring barley and undersown perennial ryegrass were compared to plots receiving mineral N fertilizer. The first year N fertilizer replacement value (NFRV) of total N in slurry mixtures decreased with increasing proportion of solid fraction. The second and third season NFRV averaged 6.5% and 3.8% of total N, respectively, for cattle slurries, and 18% and 7.5% for pig slurries and was not related to the proportion of solid fraction. The estimated net N mineralization of residual organic N increased nearly linearly with growing degree days (GDD) with a rate of 0.0058%/GDD for cattle and 0.0116%/GDD for pig slurries at 2000–5000 GDD after application. In conclusion NFRV of slurry decreased with increasing proportion of solid fraction in the first year. In the second year, NFRV of pig slurry N was significantly higher than that of cattle slurry N and unaffected by proportion between solid and liquid fraction.

scholarly journals Soil Organic Carbon and Nitrogen Decomposition in Fecal Manure of Cattle Fed Browse/Maize Silages

2014 ◽  
Vol 3 (3) ◽  
pp. 50
Author(s):  
Habib Kato ◽  
Robert Mulebeke ◽  
Felix Budara Bareeba ◽  
Elly Nyambobo Sabiiti
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
The Other ◽  
Organic N ◽  
Calliandra Calothyrsus ◽  
Maize Silage ◽  
Protein Nitrogen ◽  
Microbial Decomposition ◽  
Organic C ◽  
Soil Microbial

<p>Soil organic carbon (C) and nitrogen (N) decomposition in fecal manure of cattle fed browses of Calliandra (<em>Calliandra calothyrsus</em>), Gliricidia (<em>Gliricidia sepium</em>) and Leucaena (<em>Leucaena leucocephala</em>) browse/maize silage mixtures and maize (<em>Zea mays</em>) silage alone when applied to the soil were investigated in a pot experiment in comparison to the corresponding silages fed. Maize silage alone had the lowest N and a larger C: N ratio, making it a poor quality compost when applied to the soil, but compared to the browse/maize silage mixtures it had the highest level of soluble N as non-protein nitrogen (NPN) which makes much of its N available for soil microbial decomposition of its organic C. Calliandra browse/maize silage mixture had the highest level of fiber-bound N (ADFN), which reduces N availability for soil microbial decomposition of its organic C in spite of its high N content and a narrower C: N ratio. Fecal manure from maize silage alone had a lower level of N and a wider C: N ratio than fecal manure from the other silages fed which would affect its decomposition in the soil, but it had the lowest level of ADFN and much of its N is made available for soil microbial decomposition of its organic C. Soil samples after 12 weeks of the experiment showed that Calliandra browse/maize silage mixture maintained the highest level of C in the soil, while maize silage alone maintained the lowest level. Also soils treated with fecal manure from the other browse/maize silage mixtures maintained higher levels of C than fecal manure from maize silage alone. Organic C levels were lowest at 8 weeks of the experiment for all treatments and rose to the original levels at 12 weeks which could have been as a result of biotic and hydrologic factors coupled with soil aggregation. Decomposition of organic N followed a similar trend as organic C. The two elements are linked in both plant inputs in the soil and in the eventual soil humic substances. The soils treated with browse/maize silage mixtures maintained C: N ratios that were similar to that of the control soil and higher than those of the fecal manure treatments. Thus, in spite of the added silage materials to the soil, rapid decomposition of organic C could not occur to reflect benefits of adding the silage materials to the soil. Thus, fecal manure, particularly from feeding animals on browse/forage diets is more beneficial in the soil as it would decompose more readily releasing the plant nutrients they contain.</p>

Determination of soil organic carbon and nitrogen at the field level using near-infrared spectroscopy

2002 ◽  
Vol 82 (4) ◽  
pp. 413-422 ◽  
Author(s):  
P D Martin ◽  
D F Malley ◽  
G. Manning ◽  
L. Fuller
Keyword(s):  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Analytical Data ◽  
Principal Component ◽  
Soil Samples ◽  
Organic N ◽  
Least Squares Regression ◽  
Total N ◽  
Organic C

This study explored the use of near-infrared spectroscopy (NIRS) for the rapid analysis of organic C (Corg) and organic N (Norg) in the A horizon of soil within a single field. Soil was sampled throughout a field in Manitoba, Canada to capture soil variability associated with topography. The soil samples were oven-dried and treated with acid to remove carbonates, after which C and N were determined by dry combustion. In this study, portions of the dried soil samples not treated with acid were scanned with a near-infrared scanning spectrophotometer between 1100 and 2500 nm. Correlating the spectral and the chemical analytical data using multiple linear regression or principal component analysis/partial least squares regression gave useful correlations for Corg. Over the range of 0–40 mg g-1 Corg, NIR-predicted values explained 75–78% of the variance in the chemical results. Results were improved to 80% for calibrations developed for the 0–20 mg g-1 organic C range. Useful results were not obtained for Norg although the literature shows that total N in soil is predictable using NIRS. It is likely that the acid treatment altered the composition of the samples in an inconsistent manner such that the chemically analyzed samples and those scanned by NIRS were different from each other in Norg concentration or composition. Extrapolation of these Corg results to the landscape scale implies that NIRS has potential to be a suitable method for mapping C for the purposes of monitoring C sequestration. Key words: Near-infrared spectroscopy, soil, carbon, nitrogen, topography, soil monitoring

Wheat response after temperate crop legumes in south-eastern Australia

1991 ◽  
Vol 42 (1) ◽  
pp. 31 ◽  
Author(s):  
J Evans ◽  
NA Fettell ◽  
DR Coventry ◽  
GE O'Connor ◽  
DN Walsgott ◽  
...  
Keyword(s):  
New South ◽  
Wheat Yield ◽  
Wheat Crop ◽  
First Year ◽  
Mineral N ◽  
Total N ◽  
Available N ◽  
Relative Contribution ◽  
South Wales ◽  
Eastern Australia

At 15 sites in the cereal belt of New South Wales and Victoria, wheat after lupin or pea produced more biomass and had a greater nitrogen (N) content than wheat after wheat or barley; on average these crops assimilated 36 kg N/ha more. The improved wheat yield after lupin averaged 0 . 9 t/ha and after pea 0.7 t/ha, increases of 44 and 32% respectively. The responses were variable with site, year and legume. Soil available N was increased by both lupin and pea and the levels of surface inorganic N measured at the maturity of first year crops was often related to N in wheat grown in the following year. Of two possible sources of additional N for wheat after legumes, namely mineral N conserved in soil by lupin or pea (up to 60 kg N/ha) and the total N added in the residues of these legumes (up to 152 kg N/ha), both were considered significant to the growth of a following wheat crop. Their relative contribution to explaining variance in wheat N is analysed, and it is suggested wheat may acquire up to 40 kg N/ha from legume stubbles. Non-legume break crops also increased subsequent wheat yield but this effect was not as great as the combined effect of added N and disease break attained with crop legumes.

scholarly journals Perubahan Sifat Kimia Tanah Vertik KambisolAkibat Pemberian Jenis Pupuk dan Varietas Kacang Tanah (Arachis hypogaea L.) Di Muara Tiga Di Kabupaten Pidie

2020 ◽  
Vol 4 (2) ◽  
pp. 81-90
Author(s):  
Wardia Rahmi ◽  
Zainabun Zainabun ◽  
Teuku Alvisyahrin
Keyword(s):  
Arachis Hypogaea ◽  
Block Design ◽  
Chemical Properties ◽  
Organic N ◽  
Total N ◽  
Organic C ◽  
Randomized Block Design ◽  
Arachis Hypogaea L ◽  
Implementation Time ◽  
Treatment Analysis

Abstrak. Tujuan penelitin yaitu untuk mengetahui perubahan sifat kimia tanah akibat pemberian jenis pupuk dan penggunaan varietas kacang tanah serta interaksi antara perlakuan jenis pupuk dan varietas kacang tanah pada tanah Vertik Kambisol.. Penelitian ini telah dilaksanakan di Muara Tiga dan di Laboratorium Penelitian Tanah dan Tanaman Fakultas Pertanian Universitas Syiah Kuala. Waktu pelaksanaan dimulai dari bulan juli 2016-oktober 2016. Rancangan percobaan yang digunakan dalam penelitian ini adalah Rancangan Acak Kelompok (RAK) pola faktorial 4 x 5 dengan 3 ulangan. Adapun faktor yang diteliti yaitu jenis pupuk (j) varietas kacang tanah (V). Peubah yang diamati meliputi pH H2O, C-organik, N-total. Hasil penelitian menunjukkan aplikasi jenis pupuk berpengaruh nyata terhadap % C-organik tanah umur 45 hari setelah tanah (HST) kacang tanah. Hasil penelitian menunjukkan bahwa beberapa jenis pupuk berpengaruh untuk meningkatkan kesuburan tanah Vertik Kambisol. Nilai tertinggi untuk C-organik adalah 1,74% (pupuk kandang 4,68 kg plot-1+ NPK 0,117 kg plot-1 + kompos 4,68 kg plot-1) pada umur 45 HST kacang tanah. Hasil analisis perlakuan beberapa varietas kacang tanah tidak berpengaruh nyata terhadap pemberian perlakuan jenis pupuk serta tidak terdapat interaksi antara perlakuan jenis pupuk dan varietas kacang tanah terhadap pH H2O,    C-organik,  N total, pada tanah Vertik Kambisol.Changes in Soil Vertical Chemistry of Cambisol Due to the Provision of Peanut Fertilizers and Varieties (Arachis hypogaea L.) in Muara Tiga in District PidieAbstrack. The aim of the research was to determine changes in soil chemical properties due to the application of fertilizer types and the use of peanut varieties as well as interactions between fertilizer type treatment and peanut varieties on Vertical Cambisol soil. This research has been carried out in the Laweung area of Pidie Regency and at the Soil and Plant Research Laboratory of the Faculty of Agriculture, Syiah Kuala University. The implementation time starts from July 2016 to October 2016. The experimental design used in this study was a Randomized Block Design (RBD) 4 x 5 factorial pattern with 3 replications. The factors studied were the type of fertilizer (j) variety of peanut (V). The variables observed included pH H2O, C-organic, N-total. The results showed that the application of fertilizer types significantly affected% C soil organic age 45 days after soil (HST) peanuts. The results showed that several types of fertilizers had an effect on increasing Vertical soil fertility of cambisol. The highest value for C-organic is 1.74% (manure 4.68 kg plot-1 + NPK 0.117 kg plot-1 + compost 4.68 kg plot-1) at 45 HST of peanut. The results of the treatment analysis of several peanut varieties did not significantly affect the administration of fertilizer type and there was no interaction between the treatment of fertilizer types and peanut varieties on pH H2O, organic C, total N, on cambisol Vertical soil

The potential for sown tropical perennial grass pastures to improve soil organic carbon in the North-West Slopes and Plains of New South Wales

Soil Research ◽  
2013 ◽  
Vol 51 (8) ◽  
pp. 726 ◽  
Author(s):  
G. D. Schwenke ◽  
M. K. McLeod ◽  
S. R. Murphy ◽  
S. Harden ◽  
A. L. Cowie ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Total Organic Carbon ◽  
New South ◽  
Conventional Tillage ◽  
Tropical Pastures ◽  
Total N ◽  
Organic C ◽  
North West ◽  
South Wales ◽  
Native Pastures

Sown tropical perennial grass pastures may be a means to restore soil organic carbon (C) lost by cropping with conventional tillage to the levels originally present in native grass pastures. To assess this, total organic carbon and related soil properties were measured under sown tropical pastures, conventionally cultivated cropping, and native pastures on 75 Chromosols and 70 Vertosols to 0.3 m depth in the New South Wales North-West Slopes and Plains region of Australia. The impact of several perennial pasture species on soil organic carbon was also assessed in a 6-year-old, sown pasture experiment on a previously cropped Chromosol. Soil cores in 0.1-m segments to 0.3 m were analysed for total organic carbon, total nitrogen (N), pH, and phosphorus (Colwell-P). Mid-infrared scans were used to predict the particulate, humus, and resistant fractions of the total organic carbon. Bulk density was used to calculate stocks of C, N, and C fractions. In Chromosols, total organic carbon in the surface 0–0.1 m was greater under sown tropical pastures (23.1 Mg ha–1) than conventional tillage cropping (17.7 Mg ha–1), but still less than under native pastures (26.3 Mg ha–1). Similar land-use differences were seen for particulate and resistant organic C, and total N. The proportional differences between land uses were much greater for particulate organic C than other measures, and were also significant at 0.1–0.2 and 0.2–0.3 m. Subsurface bulk density (0.1–0.2 m) was lower under sown tropical pastures (1.42 Mg m–3) than conventionally tilled cropping (1.52 Mg m–3). For Vertosols, total organic carbon in the surface 0–0.1 m was greater under sown tropical pastures (19.0 Mg ha–1) and native pastures (20.5 Mg ha–1) than conventional tillage cropping (14.0 Mg ha–1). Similar land-use effects were seen for the particulate and humus organic C fractions, and total N. In the sown pasture species experiment, there was no significant difference in total N, total organic carbon, or any C fraction between soils under a native-grass species mixture, two improved tropical grass species, or a perennial pasture legume. Regular monitoring is required to better discern whether gradual changes are being masked by spatial and temporal variation. The survey results support previous research on Vertosols within the New South Wales North-West Slopes and Plains that show sown tropical grass pastures can improve total organic carbon. Improvements in total organic carbon on Chromosols have not previously been documented, so further targeted soil monitoring and experimentation is warranted for the region.

Assessment of nitrogen and organic carbon stocks in agricultural soils: uncertainties and significance of temporal evolution

2021 ◽  
Author(s):  
Lucas Tabaud ◽  
Christian Walter ◽  
Clotilde Blancfene ◽  
Chantal Gascuel ◽  
Blandine Lemercier ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Total Nitrogen ◽  
Agricultural Soils ◽  
Sampling Site ◽  
Stochastic Approach ◽  
Measurement Procedure ◽  
Soil Sampling ◽  
Organic Matter Quality ◽  
Total N ◽  
Organic C

&lt;p&gt;Soils are crossroads of carbon and nitrogen geochemical cycles and were consequently identified as a potential sink for carbon (C) and a compartment storage for nitrogen (N). Monitoring the joint evolution over time of organic C and total N stocks in soils appears interesting because of the C/N ratio is an indicator of changes in the organic matter quality. Nevertheless, the temporal evolutions detected in most of the existing studies are in the order of a few gC.m&lt;sup&gt;-2&lt;/sup&gt;.yr&lt;sup&gt;-1&lt;/sup&gt; (C) and mgN.m&lt;sup&gt;-2&lt;/sup&gt;.yr&lt;sup&gt;-1 &lt;/sup&gt;(N). This study aims to assess uncertainties of soil organic carbon (SSOC) and soil total nitrogen (SSTN) stocks in the topsoil layer (0-25 cm) using three different methods (stochastic, deterministic and experimental), in order to identify the main sources of uncertainty and to evaluate the significance of SSOC and SSTN evolutions over the time. This study was based on a 1200 ha agricultural catchment area in Brittany (France) where systematic soil sampling was repeated at 108 sites in 2013 and 2018. Moreover, soil sampling was repeated three times in 2020 at the same sites by 3 different teams of experienced samplers. Comparing the three methods of uncertainty assessment, we found they provided equivalent results with a SSOC standard deviation of 0.85, 0.74 and 0.68 kgC.m&lt;sup&gt;-2&lt;/sup&gt; respectively for stochastic, deterministic and experimental approaches and 0.08, 0.07 and 0.06 kgN.m&lt;sup&gt;-2&lt;/sup&gt; for SSTN. Variance decomposition identified variations of fine earth mass as the main source of uncertainty (77 % of total variance) and attributed at least 16% of the uncertainties due to the operator procedure and were therefore reducible. Using the stochastic approach, the width of the 90 % confidence interval was estimated at each sampling site for C, N and C/N temporal changes. Changes were considered significant at respectively 59, 77 et 99 sites for SSOC, SSTN and C/N: a majority of sites lost organic carbon (-0.03 &amp;#177; 0.07 kgC.m&lt;sup&gt;-2&lt;/sup&gt;.yr&lt;sup&gt;-1&lt;/sup&gt;), gained total nitrogen (0.006 &amp;#177; 0.005 kgN.m&lt;sup&gt;-2&lt;/sup&gt;.yr&lt;sup&gt;-1&lt;/sup&gt;) and the C.N&lt;sup&gt;-1&lt;/sup&gt; (-0.17 &amp;#177; 0.09 yr&lt;sup&gt;-1&lt;/sup&gt;) ratio decreased. Finally, stock measurements uncertainty was mainly explained by soil natural variability but may still be reduced by a better control of the measurement procedure. In the agricultural context of the study area, the accuracy of the direct measurement appeared sufficient to detect SSOC and SSTN evolution over a time span of 5 years.&lt;/p&gt;

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