scholarly journals Measured and Modeled (DNDC) Nitrous Oxide Emissions (N2O) under Different Crop Management Practices in the Nitra Region, Slovakia

2016 ◽  
Vol 19 (2) ◽  
pp. 54-57
Author(s):  
Ján Horák ◽  
Irina Mukhina

Abstract An important method of investigating N2O emissions from cropland is model simulation. The measured data of N2O emissions under conventional tillage (CT) and reduced tillage (RT) with (N1) and without (N0) N fertilizer application were used to test the DNDC model during the year 2012 (April-December) in Slovakia. There was found a good agreement with seasonal N2O emissions only for CTN0 treatment, but in case of other treatments DNDC overestimated the emissions. The relative deviation between observed and simulated total seasonal N2O emissions (kg N ha−1) from four treatments were 46%, 164%, 346% and 321% for CTN0, CTN1, RTN0 and RTN1, respectively. Also, some discrepancies were found between observed and simulated emissions when evaluating the daily N2O emissions, especially when looking at the magnitude of N2O emissions peaks. The correlation between observed and simulated daily N2O emissions (N = 38) in case of conventional tillage was quite high and significant with r = 0.48 (P <0.01), r = 0.45 (P <0.01) for CTN0 and CTN1 treatment, respectively. On the other hand, there was found poor correlation in reduced tillage treatment with r = 0.22 (P >0.01) and r = 0.39 (P >0.01), for RTN0, RTN1, respectively.

2018 ◽  
Vol 32 (1) ◽  
pp. 81-91 ◽  
Author(s):  
Anna M. Gajda ◽  
Ewa A. Czyż ◽  
Anthony R. Dexter ◽  
Karolina M. Furtak ◽  
Jarosław Grządziel ◽  
...  

AbstractThe effects of different tillage systems on the properties and microbial diversity of an agricultural soil was investigated. In doing so, soil physical, chemical and biological properties were analysed in 2013-2015, on a long-term field experiment on a loamy sand at the IUNG-PIB Experimental Station in Grabów, Poland. Winter wheat was grown under two tillage treatments: conventional tillage using a mouldboard plough and traditional soil tillage equipment, and reduced tillage based on soil crushing-loosening equipment and a rigid-tine cultivator. Chopped wheat straw was used as a mulch on both treatments. Reduced tillage resulted in increased water content throughout the whole soil profile, in comparison with conventional tillage. Under reduced tillage, the content of readily dispersible clay was also reduced, and, therefore, soil stability was increased in the toplayers, compared with conventional tillage. In addition, the beneficial effects of reduced tillage were reflected in higher soil microbial activity as measured with dehydrogenases and hydrolysis of fluorescein diacetate, compared with conventional tillage. Moreover, the polimerase chain reaction – denaturing gradient gel electrophoresis analysis showed that soil under reduced till-age had greater diversity of microbial communities, compared with conventionally-tilled soil. Finally, reduced tillage increased organic matter content, stability in water and microbial diversity in the top layer of the soil.


2021 ◽  
Author(s):  
Margot Peluchon ◽  
Didier Michot ◽  
Blandine Lemercier ◽  
Sylvain Busnot ◽  
Thierry Morvan ◽  
...  

&lt;p&gt;The measurement of aggregate stability is an important indicator of soil quality and is widely used for monitoring soil condition. The SLAKES mobile app is an alternative tool to laboratory-based methods to measure soil aggregate stability. It provides aggregate stability measurements through Slaking Index (SI) with SI close to 0 suggesting high stability and values above 7 suggesting minimum stability. As the duration of this low-cost experiment is only 10 minutes, SLAKES is very attractive for scientists and no-scientists. SLAKES was implemented in Australia and has proven its efficiency in several studies.&lt;/p&gt;&lt;p&gt;This study was conducted to determine whether the SLAKES mobile app could be adapted to French soils and then could be an alternative to the Mean Weight Diameter (MWD) method, normalized in France (ISO 10390). More specifically, the three main objectives were: (i) determining whether the aggregate stability measurements depend on the phones used for the experiment, (ii) estimating the number of measurements necessary to get reliable results, (iii) determining whether the app has the ability to detect the effect of contrasting soil managements previously shown using the MWD method.&lt;/p&gt;&lt;p&gt;The study was performed on silty loam soils from EFELE (Effluents d&amp;#8217;Elevage et Environnement) experimental site at le Rheu (Brittany, France) which is part of the French &amp;#8220;Organic Residues&amp;#8221; research observatory (SOERE PRO). The experimental design combines two different tillage practices (conventional tillage and shallow tillage) with two fertilizer treatments (mineral and organic (cattle manure)) randomly replicated three times. Soil samples were collected in March 2017 at both 0-15 cm and 15-25 cm depth from the 12 plots.&amp;#160;&lt;/p&gt;&lt;p&gt;The SI was measured on three aggregates simultaneously and this measurement was repeated 15 times for each sample which provided 45 SI per sample. Outliers above SI=11 were removed before statistical treatments. Four different phones of the same brand and generation were used to measure SI.&lt;/p&gt;&lt;p&gt;An analysis of variance showed that the effect of the smartphone on SI measurements was not significant (p-value = 0.73, 0.88, 0.067 for 3 different samples).&amp;#160;The SLAKES results showed comparable significant separation of means (p &lt; 0.0001) between each soil management than the MWD method. According to the results of an analysis of variance, SI was significantly lower in reduced tillage than in conventional tillage condition (p-value = 2.10&lt;sup&gt;-16&lt;/sup&gt;). These results indicate a higher soil stability in reduced tillage. Yet, the analysis of variance did not underline any effect of fertilization on the SI (p-value = 0.28), as previously found with the MWD method.&lt;/p&gt;&lt;p&gt;This study proved that a relatively simple mobile app can detect the effect of soil management practices on aggregate stability with a similar performance than the MWD method. This conclusion was reinforced by the existing correlation between the SI and the MWD index (p-value = 0.00059, R&lt;sup&gt;2&lt;/sup&gt; = 0.39). We recommend to perform similar experiments on other sampling campaigns or in other pedological and soil management contexts taking at least 15 measures per sample.&lt;/p&gt;


2009 ◽  
Vol 33 (5) ◽  
pp. 1147-1152 ◽  
Author(s):  
Rodrigo Nogueira Olendzki ◽  
Andréia Christina Ignácio ◽  
Antonio Salvio Mangrich

In the Earth's carbon cycle, C stocks in the soil are higher than in vegetation and atmosphere. Maintaining and conserving organic C concentrations in the soil by specific management practices can improve soil fertility and productivity. The aim of this study was to evaluate the impact of agricultural management techniques and influence of water regime (flooded or drained) on the structure of humic substances by excitation/emission matrix fluorescence. Six samples of a Planosol (Planossolo by the Brazilian System of Soil Classification) were collected from a rice field. Humic substances (HS) were extracted from flooded and drained soil under different agricultural management techniques: conventional tillage, reduced tillage and grassland. Two peaks at a long emission wavelength were observed in the EEM spectra of HA whereas those of the corresponding FA contained a unique fluorophore at an intermediate excitation/emission wavelength pair (EEWP) value. The fluorescence intensity measured by total luminescence (FI TL) of HA was lower than that of the corresponding FA. A comparison of all samples (i.e., the HA values compared to each other) revealed only slight differences in the EEWP position, but the FI TL values were significantly different. In this soil, anoxic conditions and reduced tillage (little plowing) seem to favor a higher degree of humification of the soil organic matter compared with aerated conditions and conventional tillage.


Plants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2431
Author(s):  
Salwinder Singh Dhaliwal ◽  
Sandeep Sharma ◽  
Arvind Kumar Shukla ◽  
Vivek Sharma ◽  
Makhan Singh Bhullar ◽  
...  

The escalating scarcity of irrigation water, transplantation of rice on light-textured soils and labour cost acted as major drivers for the transition towards direct-seeded rice (DSR) cultivation from the conventionally flooded transplanting system. Despite these advantages, DSR is a challenge in light texture soil due to heavy weed infestation and a slight decline in crop yield. The weeds compete for nutrients and have an adverse effect on the growth and yield of crops. Hence, to assess the removal of macro and micronutrients by weeds and direct-seeded rice, a field experiment was carried out on sandy loam soil for two consecutive Kharif seasons (2018 and 2019). Three treatments from rice, namely: DSR under zero tillage (DSR-ZT), DSR under conventional tillage (DSR-CT) and DSR under reduced tillage (DSR-RT) were taken as main plots with three tillage treatments in wheat, namely: Conventional tillage without rice straw (CTW-R), Zero tillage without rice straw (ZTW-R) and Zero tillage with straw as mulch using Happy Seeder (ZTW+R) as subplots, replicated thrice. Among the rice establishment methods, DSR-RT showed an edge in terms of rice grain and straw yield (6.18 and 8.14 Mg ha−1, respectively) as well as macro- and micronutrient uptake by rice. Under management practices, ZTW+R proved as an efficient strategy in terms of yield and nutrient uptake by crops. The contribution of weeds towards biomass production was maximum under the ZTW-R (9.44%) treatment followed by DSR-ZT (7.72%). The nutrient budgeting showed that macro- and micronutrient removal by weeds was minimum under reduced tillage (24.51 and 50.35%, respectively), whereas it was 21.88 and 44.87% when wheat was grown under conventional tillage without rice straw. In overall, the research study concluded that weeds on an average remove 25.65 % macronutrients (N, P, K) and 51.47% of micronutrients (Zn, Cu, Fe and Mn) in DSR under rice-wheat cropping system.


2002 ◽  
Vol 82 (3) ◽  
pp. 365-374 ◽  
Author(s):  
W N Smith ◽  
R L Desjardins ◽  
B. Grant ◽  
C. Li ◽  
R. Lemke ◽  
...  

Measured data from two experimental sites in Canada were used to test the ability of the DeNitrification and DeComposition model (DNDC) to predict N2O emissions from agricultural soils. The two sites, one from eastern Canada, and one from western Canada, provided a variety of crops, management practices, soils, and climates for testing the model. At the site in eastern Canada, the magnitude of total seasonal N2O flux from the seven treatments was accurately predicted with a slight average over-prediction (ARE) of 3% and a coefficient of variation of 41%. Nitrous oxide emissions based on International Panel for Climate Change (IPCC) methodology had a relative error of 62% for the seven treatments. The DNDC estimates of total yearly emissions of N2O from the field site in western Canada showed an underestimation of 8% for the footslope landscape position and an overestimation of 46% for the shoulder position. The data input for the DNDC model were not of sufficient detail to characterize the moisture difference between the landscape positions. The estimates from IPCC guidelines showed an underestimation of 54% for the footslope and an overestimation of 161% for the shoulder. The results indicate that the DNDC model was more accurate than IPCC methodology at estimating N2O emissions at both sites. Key words: Nitrous oxide, DNDC, soil model, greenhouse gas, testing


Soil Research ◽  
2019 ◽  
Vol 57 (2) ◽  
pp. 200 ◽  
Author(s):  
J. Somasundaram ◽  
M. Salikram ◽  
N. K. Sinha ◽  
M. Mohanty ◽  
R. S. Chaudhary ◽  
...  

Conservation agriculture (CA) including reduced or no-tillage and crop residue retention, is known to be a self–sustainable system as well as an alternative to residue burning. The present study evaluated the effect of reduced tillage coupled with residue retention under different cropping systems on soil properties and crop yields in a Vertisol of a semiarid region of central India. Two tillage systems – conventional tillage (CT) with residue removed, and reduced tillage (RT) with residue retained – and six major cropping systems of this region were examined after 3 years of experimentation. Results demonstrated that soil moisture content, mean weight diameter, percent water stable aggregates (&gt;0.25mm) for the 0–15cm soil layer were significantly (Pmoderately labile&gt;less labile. At the 0–15cm depth, the contributions of moderately labile, less labile and non-labile C fractions to total organic C were 39.3%, 10.3% and 50.4% respectively in RT and corresponding values for CT were 38.9%, 11.7% and 49.4%. Significant differences in different C fractions were observed between RT and CT. Soil microbial biomass C concentration was significantly higher in RT than CT at 0–15cm depth. The maize–chickpea cropping system had significantly (P–1 followed by soybean+pigeon pea (2:1) intercropping (3.50 t ha–1) and soybean–wheat cropping systems (2.97 t ha–1). Thus, CA practices could be sustainable management practices for improving soil health and crop yields of rainfed Vertisols in these semiarid regions.


2019 ◽  
Vol 446 (1-2) ◽  
pp. 163-177 ◽  
Author(s):  
Arlete S. Barneze ◽  
Jeanette Whitaker ◽  
Niall P. McNamara ◽  
Nicholas J. Ostle

Abstract Aims Grasslands are important agricultural production systems, where ecosystem functioning is affected by land management practices. Grass-legume mixtures are commonly cultivated to increase grassland productivity while reducing the need for nitrogen (N) fertiliser. However, little is known about the effect of this increase in productivity on greenhouse gas (GHG) emissions in grass-legume mixtures. The aim of this study was to investigate interactions between the proportion of legumes in grass-legume mixtures and N-fertiliser addition on productivity and GHG emissions. We tested the hypotheses that an increase in the relative proportion of legumes would increase plant productivity and decrease GHG emissions, and the magnitude of these effects would be reduced by N-fertiliser addition. Methods This was tested in a controlled environment mesocosm experiment with one grass and one legume species grown in mixtures in different proportions, with or without N-fertiliser. The effects on N cycling processes were assessed by measurement of above- and below-ground biomass, shoot N uptake, soil physico-chemical properties and GHG emissions. Results Above-ground productivity and shoot N uptake were greater in legume-grass mixtures compared to grass or legume monocultures, in fertilised and unfertilised soils. However, we found no effect of legume proportion on N2O emissions, total soil N or mineral-N in fertilised or unfertilised soils. Conclusions This study shows that the inclusion of legumes in grass-legume mixtures positively affected productivity, however N cycle were in the short-term unaffected and mainly affected by nitrogen fertilisation. Legumes can be used in grassland management strategies to mitigate climate change by reducing crop demand for N-fertilisers.


Agronomy ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 291
Author(s):  
Ramón Bienes ◽  
Maria Jose Marques ◽  
Blanca Sastre ◽  
Andrés García-Díaz ◽  
Iris Esparza ◽  
...  

Long-term field trials are essential for monitoring the effects of sustainable land management strategies for adaptation and mitigation to climate change. The influence of more than thirty years of different management is analyzed on extensive crops under three tillage systems, conventional tillage (CT), minimum tillage (MT), and no-tillage (NT), and with two crop rotations, monoculture winter-wheat (Triticum aestivum L.) and wheat-vetch (Triticum aestivum L.-Vicia sativa L.), widely present in the center of Spain. The soil under NT experienced the largest change in organic carbon (SOC) sequestration, macroaggregate stability, and bulk density. In the MT and NT treatments, SOC content was still increasing after 32 years, being 26.5 and 32.2 Mg ha−1, respectively, compared to 20.8 Mg ha−1 in CT. The SOC stratification (ratio of SOC at the topsoil/SOC at the layer underneath), an indicator of soil conservation, increased with decreasing tillage intensity (2.32, 1.36, and 1.01 for NT, MT, and CT respectively). Tillage intensity affected the majority of soil parameters, except the water stable aggregates, infiltration, and porosity. The NT treatment increased available water, but only in monocropping. More water was retained at the permanent wilting point in NT treatments, which can be a disadvantage in dry periods of these edaphoclimatic conditions.


Land ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 200
Author(s):  
Felicia Chețan ◽  
Cornel Chețan ◽  
Ileana Bogdan ◽  
Adrian Ioan Pop ◽  
Paula Ioana Moraru ◽  
...  

The regional agroecological conditions, specific to the Transylvanian Plain, are favorable to soybean crops, but microclimate changes related to global warming have imposed the need for agrotechnical adaptive measures in order to maintain the level of soybean yield. In this study, we consider the effect of two soil tillage systems, the seeding rate, as well as the fertilizer dosage and time of application on the yield and quality of soybean crops. A multifactorial experiment was carried out through the A × B × C × D − R: 3 × 2 × 3 × 3 − 2 formula, where A represents the year (a1, 2017; a2, 2018; and a3, 2019); B represents the soil tillage system (b1, conventional tillage with mouldboard plough; b2, reduced tillage with chisel cultivator); C represents the fertilizer variants (c1, unfertilized; c2, one single rate of fertilization: 40 kg ha−1 of nitrogen + 40 kg ha−1 of phosphorus; and c3, two rates of fertilization: 40 kg ha−1 of nitrogen + 40 kg ha−1 of phosphorus (at sowing) + 46 kg ha−1 of nitrogen at V3 stage); D represents the seeding rate (1 = 45 germinating grains (gg) m−2; d2 = 55 gg m−2; and d3 = 65 gg m−2); and R represents the replicates (r1 = the first and r2 = the second). Tillage had no effect, the climate specific of the years and fertilization affected the yield and the quality parameters. Regarding the soybean yield, it reacted favorably to a higher seeding rate (55–65 gg m−2) and two rates of fertilization. The qualitative characteristics of soybeans are affected by the fertilization rates applied to the crop, which influence the protein and fiber content in the soybean grains. Higher values of protein content were recorded with a reduced tillage system, i.e., 38.90 g kg−1 DM in the variant with one single rate of fertilization at a seeding rate of 45 gg per m−2 and 38.72 g kg−1 DM in the variant with two fertilizations at a seeding rate of 65 gg m−2.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yang Su ◽  
Benoit Gabrielle ◽  
Damien Beillouin ◽  
David Makowski

AbstractConservation agriculture (CA) has been promoted to mitigate climate change, reduce soil erosion, and provide a variety of ecosystem services. Yet, its impacts on crop yields remains controversial. To gain further insight, we mapped the probability of yield gain when switching from conventional tillage systems (CT) to CA worldwide. Relative yield changes were estimated with machine learning algorithms trained by 4403 paired yield observations on 8 crop species extracted from 413 publications. CA has better productive performance than no-till system (NT), and it stands a more than 50% chance to outperform CT in dryer regions of the world, especially with proper agricultural management practices. Residue retention has the largest positive impact on CA productivity comparing to other management practices. The variations in the productivity of CA and NT across geographical and climatical regions were illustrated on global maps. CA appears as a sustainable agricultural practice if targeted at specific climatic regions and crop species.


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