scholarly journals Asymbiotic nitrogen fixation is greater in soils under long-term no-till versus conventional tillage

2018 ◽  
Author(s):  
David W. Franzen ◽  
Patrick W. Inglett ◽  
Caley K. Gasch
Keyword(s):  
Soil Microorganisms ◽  
Conventional Tillage ◽  
N Fixation ◽  
Reduction Procedure ◽  
Fixation Rate ◽  
No Till ◽  
Asymbiotic Nitrogen Fixation ◽  
Deep Sample ◽  
Similar Soil

A series of N-rate experiments was previously conducted in spring wheat, corn and sunflower in North Dakota indicated that less N was required when fields were in 6-years or more continuous no-till compared to conventional till. The objective of this study was to determine whether part of the reason for the decreased requirement for N was the greater activity of asymbiotic N-fixing organisms. Twelve paired-samplings were conducted in 2018. A surface 0-5cm deep sample was obtained in a long-term no-till field directly across the fence/road from a similar soil in conventional till. Samples were incubated in an acetylene-reduction procedure to estimate N fixation rate. Ten of twelve paired samplings had greater asymbiotic N fixation compared to the conventional till counterpart. This indicates that long-term no-till soils support greater N production from soil microorganisms than conventional till soils, which would result in lower input costs to no-till farmers.

Effect of long term no-till and conventional tillage practices on soil quality

2013 ◽  
Vol 131 ◽  
pp. 28-35 ◽  
Author(s):  
Irfan Aziz ◽  
Tariq Mahmood ◽  
K. Rafiq Islam
Keyword(s):  
Soil Quality ◽  
Conventional Tillage ◽  
Tillage Practices ◽  
No Till

scholarly journals Temporal Change of Soil Carbon on a Long-Term Experimental Site with Variable Crop Rotations and Tillage Systems

Agronomy ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 840 ◽  
Author(s):  
Ahmed Laamrani ◽  
Paul R. Voroney ◽  
Aaron A. Berg ◽  
Adam W. Gillespie ◽  
Michael March ◽  
...  
Keyword(s):  
Winter Wheat ◽  
Soil Carbon ◽  
Cover Crops ◽  
Cover Crop ◽  
Red Clover ◽  
Conventional Tillage ◽  
Crop Rotations ◽  
Tillage Practices ◽  
No Till

The impacts of tillage practices and crop rotations are fundamental factors influencing changes in the soil carbon, and thus the sustainability of agricultural systems. The objective of this study was to compare soil carbon status and temporal changes in topsoil from different 4 year rotations and tillage treatments (i.e., no-till and conventional tillage). Rotation systems were primarily corn and soy-based and included cereal and alfalfa phases along with red clover cover crops. In 2018, soil samples were collected from a silty-loam topsoil (0–15 cm) from the 36 year long-term experiment site in southern Ontario, Canada. Total carbon (TC) contents of each sample were determined in the laboratory using combustion methods and comparisons were made between treatments using current and archived samples (i.e., 20 year and 9 year change, respectively) for selected crop rotations. Overall, TC concentrations were significantly higher for no-till compared with conventional tillage practices, regardless of the crop rotations employed. With regard to crop rotation, the highest TC concentrations were recorded in corn–corn–oats–barley (CCOB) rotations with red clover cover crop in both cereal phases. TC contents were, in descending order, found in corn–corn–alfalfa–alfalfa (CCAA), corn–corn–soybean–winter wheat (CCSW) with 1 year of seeded red clover, and corn–corn–corn–corn (CCCC). The lowest TC concentrations were observed in the corn–corn–soybean–soybean (CCSS) and corn–corn–oats–barley (CCOB) rotations without use of cover crops, and corn–corn–soybean–winter wheat (CCSW). We found that (i) crop rotation varieties that include two consecutive years of soybean had consistently lower TC concentrations compared with the remaining rotations; (ii) TC for all the investigated plots (no-till and/or tilled) increased over the 9 year and 20 year period; (iii) the no-tilled CCOB rotation with 2 years of cover crop showed the highest increase of TC content over the 20 year change period time; and (iv) interestingly, the no-till continuous corn (CCCC) rotation had higher TC than the soybean–soybean–corn–corn (SSCC) and corn–corn–soybean–winter wheat (CCSW). We concluded that conservation tillage (i.e., no-till) and incorporation of a cover crop into crop rotations had a positive effect in the accumulation of TC topsoil concentrations and could be suitable management practices to promote soil fertility and sustainability in our agricultural soils.

Comparison of porosity in a Chernozemic clay loam soil under long-term conventional tillage and no-till

1998 ◽  
Vol 78 (4) ◽  
pp. 619-629 ◽  
Author(s):  
J. J. Miller ◽  
E. G. Kokko ◽  
G. C. Kozub
Keyword(s):  
Image Analysis ◽  
Root Growth ◽  
Surface Soil ◽  
Conventional Tillage ◽  
Clay Loam ◽  
Clay Loam Soil ◽  
Seedling Root ◽  
No Till ◽  
Loam Soil

Tillage practice can alter soil structure, porosity and the size distribution of pores. Consequently, this study was conducted to compare the long-term (since 1968) effects of conventional tillage (CT) using a heavy-duty cultivator and no-till (NT) on structure and porosity of a Dark Brown Chernozem (clay loam) soil in southern Alberta. Number and porosity of total, round, intermediate and elongated pores, maximum equivalent circular diameter (MECD), and mean circularity of pore sizes 50–500 µm (P-150), 500–1000 µm (P-500) and >1000 µm (P-1000) diameter were quantified. These parameters were determined for three depths (0–10, 10–20 and 20–30 cm) and two orientations (vertical, horizontal) using UV-dye impregnated soil sections and image analysis. The surface soil (0–10 cm) of CT was dominantly granular-spongy, but for NT it was dominantly crack to massive. Since tillage treatments were not replicated, only general trends on the effect of tillage and its interaction with depth and orientation are given and probability levels are not reported. Tillage treatment had an influence on P-150 and P-500 pores but little or no influence on P-1000 pores. Mean number and porosity of total and intermediate P-500 pores, which are the most important pore size class for seedling root growth in these soils, were higher for CT than NT for the surface soil, but were higher for NT than CT for the subsoil. For example, the total porosity of P-500 pores was 2.21% for CT and 1.95% for NT at the 0- to10-cm depth, 3.80% for NT and 2.27% for CT at the 10- to 20-cm depth, and 3.18% for NT and 2.80% for CT at the 20- to 30-cm depth. These results suggested a higher potential for seedling root growth in the surface soil of CT, but a greater potential for root growth in the subsoil of NT. Key words: structure, porosity, image analysis, tillage

Preferential Leaching in Large Undisturbed Soil Blocks from Conventional Tillage and No-Till Fields in Southern Alberta

1999 ◽  
Vol 34 (2) ◽  
pp. 249-266 ◽  
Author(s):  
J.J. Miller ◽  
B.J. Lamond ◽  
N.J. Sweetland ◽  
F.J. Larney
Keyword(s):  
Surface Soil ◽  
Conventional Tillage ◽  
Breakthrough Curves ◽  
Short Term ◽  
Water Fraction ◽  
No Till ◽  
Southern Alberta ◽  
Region Model ◽  
Earthworm Burrows

Abstract There is a concern that adoption of conservation tillage practices such as no-till may increase preferential leaching of water and chemicals to the groundwater. Evidence from previous studies of long-term (since 1968) conventional tillage (CT) and no-till (NT) fields in southern Alberta suggests that tillage practice has the potential to influence preferential leaching. However, no studies have been done to test this hypothesis. Our objective was to utilize the two-region (mobile/immobile water) model of solute transport to compare preferential leaching in CT and NT fields of clay loam texture. Four large (46 × 46 × 51 cm) undisturbed blocks of soil were excavated from each tillage field (unreplicated) during the fallow phase of a wheat-fallow rotation. The soil blocks were transported to the laboratory, stored under drying conditions (32 months), and miscible displacement experiments conducted under saturated, steady-state conditions. Because of the long storage period, the focus of our study was on long-term (e.g., structure, earthworm burrows, old root channels) rather than short-term (e.g., tillage of surface soil) tillage effects on preferential leaching. Breakthrough curves (BTCs) for chloride were derived, and the modified convection-dispersion equation fitted to the experimental data using a two-region model (CXTFIT-Version 2.0 ) to allow estimation of the mobile water fraction (B) or extent of preferential leaching. Breakthrough curves for both tillage fields exhibited early initial breakthrough, a rapid rise in tracer concentration, a shift of the BTC peak to the left of one pore volume, and a slow decline (“tailing”) toward zero concentration for the descending limb of the curve. Reasonably good fits were obtained for fitting of the two-region model to the BTCs, as indicated by correlation coefficients ranging from 0.60 to 0.84. Mean values for the mobile water fraction were similar for the CT field (0.78) and NT field (0.80), suggesting no difference in preferential leaching of chloride. We hypothesize that the extent of preferential leaching in earthworm burrows (Aporrectodea caliginosa) in the NT field and leaching in old root channels in the CT field may have been similar. Further research on replicated plots is needed to examine short-term effects of tillage practice (e.g., tillage of surface soil) as well as the individual contribution of earthworm burrows and old root channels, to preferential leaching under CT and NT.

Yield-scaled greenhouse gas emissions from flood irrigated rice under long-term conventional tillage and no-till systems in a Humid Subtropical climate

2014 ◽  
Vol 162 ◽  
pp. 60-69 ◽  
Author(s):  
Cimélio Bayer ◽  
Falberni de Souza Costa ◽  
Gabriel Munhoz Pedroso ◽  
Tiago Zschornack ◽  
Estefania S. Camargo ◽  
...  
Keyword(s):  
Greenhouse Gas Emissions ◽  
Greenhouse Gas ◽  
Conventional Tillage ◽  
Subtropical Climate ◽  
Irrigated Rice ◽  
Gas Emissions ◽  
No Till

Effect of Tillage Systems on Distribution of Aggregates and Organic Carbon in a Long-Term No-Tillage Paddy Field

2011 ◽  
Vol 183-185 ◽  
pp. 1185-1189
Author(s):  
Qi Wen Tang ◽  
Chang Sheng Jiang ◽  
Qing Ju Hao ◽  
Yan Wu
Keyword(s):  
Organic Carbon ◽  
Soil Layer ◽  
Bottom Layer ◽  
Conventional Tillage ◽  
Organic Carbon Content ◽  
Diameter Class ◽  
Tillage Systems ◽  
No Till ◽  
Long Term Experiment

The effect of different tillage systems on the size distribution of aggregates and organic carbon distribution and storage in different size aggregates in a Hydragric Anthrosol were studied in a long-term experiment in Chongqing, China. The experiment included five tillage treatments, which are conventional tillage with rice only system (DP), conventional tillage with rotation of rice and rape system (SH), no-till and ridge culture with rotation of rice and rape system (LM), no-till and plain culture with rotation of rice and rape system (XM) and tillage and ridge culture with rotation of rice and rape system (LF), respectively. The results showed that the aggregates 0.25-0.05 mm in diameter accounted for the largest proportion in each soil layer under all treatments. The organic carbon mainly exist in aggregates in the 0.25-2 mm and 0.05-0.25 mm diameter in the plough layer, which mainly exist in the 0.25-2 mm in diameter in the bottom layer. Distribution of organic carbon in aggregates in the 0.05-0.25 mm diameter class was highest, followed by the aggregates in the 0.25-2mm diameter class. The organic carbon in aggregates under different tillage systems was in a decreasing order of LM (21.05 g·kg-1)> DP (14.13 g·kg-1)> XM (13.29 g·kg-1)> LF (12.54 g·kg-1) > SH (11.41 g·kg-1). The total organic carbon content showed a significant correlation with the amount of aggregates with diameter >0.005 mm. The results showed that the accumulation of soil organic carbon was mainly affected by aggregates in the >0.005mm diameter class.

scholarly journals Alachlor Movement Through Intact Soil Columns Taken From Two Tillage Systems

1991 ◽  
Vol 5 (3) ◽  
pp. 485-489 ◽  
Author(s):  
Sharon A. Clay ◽  
William C. Koskinen ◽  
Paul Carlson
Keyword(s):  
Chemical Properties ◽  
Conventional Tillage ◽  
Rapid Screening ◽  
Soil Columns ◽  
Screening Technique ◽  
No Till ◽  
Intact Surface ◽  
Physical And Chemical ◽  
Intact Soil

Intact soil columns were evaluated as a screening technique to determine the effect of tillage on herbicide movement through soil. Alachlor was applied at 3.3 kg ai ha-1to intact surface 0- to 10-cm and subsurface 10- to 20-cm soil columns (15-cm diam) taken from long-term no-till and conventional tillage plots and leached with 11.6 pore volumes (7 L; 39 cm) of water at a rate that did not create ponding. Leachate was collected in 0.07 pore volume fractions. Twice as much alachlor leached from surface no-till than from surface conventional tillage columns. The differences in leaching patterns from the surface soil can be attributed to the effect of tillage on soil physical and chemical properties. Using intact soil columns in the laboratory can be a useful rapid screening technique to evaluate tillage impacts on herbicide movement.

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