Impact of weed management practices on soil biological activity in corn and soybean field crops in Québec (Canada)

2020 ◽  
pp. 1-10
Author(s):  
Émile Samson-Brais ◽  
Marc Lucotte ◽  
Matthieu Moingt ◽  
Gilles Tremblay ◽  
Serge Paquet

Repeated applications and combination of glyphosate-containing herbicides (GCH) with other herbicides are two weed management practices (WMP) used to compensate for GCH decreasing efficiency impacts in field crops. These practices may have serious impacts on soil functions because GCH affect soil biota and soil biological activity (SBA). Two field experiments, one with corn and one with soybean crops, were conducted during one growing season. SBA indicators, soil respiration (SR) and fluorescein diacetate (FDA) hydrolysis, were measured at two sampling times following six WMP. These WMP included one or two GCH applications (GCH alone or combined with other herbicides), applications of other herbicides only and mechanical weeding. WMP did not affect FDA neither for corn or soybean at either sampling times. In contrast, WMP affected SR in corn fields at both sampling times and SR in soybean field at the first sampling time. Repeating GCH applications and combining different herbicides led to lower SR, suggesting that these practices decreased SBA, whilst one single GCH application presented higher SR, suggesting that this practice stimulated SBA. Our study demonstrates that using GCH in combination with other herbicides or in multiple applications affects SBA in field conditions. Affecting soil functions and carbon cycle do bear serious weed management implications, and the choice of WMP should be taken into consideration to minimize their impacts on SBA for field crops sustainability.

2008 ◽  
Vol 88 (4) ◽  
pp. 451-460 ◽  
Author(s):  
M A Bolinder ◽  
O. Andrén ◽  
T. Kätterer ◽  
L -E Parent

The potential for storage of atmospheric CO2-C as soil organic C (SOC) in agroecosystems depends largely on soil biological activity and the quantity and quality of annual C inputs to soil. In this study we used the Introductory Carbon Balance Model (ICBM) approach driven by daily standard weather station data, specific soil properties and crop characteristics at the scale of Canadian agricultural ecoregions. The objectives were to calculate a climate-dependent soil biological activity parameter representative for annual agricultural crop production systems (re_crop) and to estimate the effect of fallow (re_fallow). These parameters are based on the daily product of soil temperature and stored water that influence biological activity in the arable layer, and are used to adjust the decomposition rates of the ICBM SOC pools. We also tested re_crop and re_fallow on SOC stock change data for different site and treatment combinations from long-term field experiments located in some of the ecoregions. An re_crop value of 0.95 for western ecoregions was on average 0.23 units lower than that of the eastern ecoregions, indicating a lower decomposition rate of SOC. Although the estimated annual C inputs to soil for small-grain cereals were on average ≈7.5% higher in the eastern ecoregions (305 vs. 285 g C m-2 yr-1), the overall results suggest that the western ecoregions would have a greater potential to maintain high SOC levels in the long term. However, these parameters varied between ecoregions and, consequently, the SOC sequestration potential was not always higher for the western ecoregions. The effect of fallow was on average ≈0.04, i.e., SOC decomposed slightly faster under fallow. Predictions for 24 out of 33 site and treatment combinations across Canada were significantly improved (P = 0.003), compared with a previous application with the ICBM that did not differentiate between crops and fallow. The methodology used here enabled us to examine regional differences in the potential for SOC sequestration as a balance between annual C inputs to soil and soil biological activity. Key words: Annual C inputs, climate, fallow, soil biological activity, agroecosystems


Plants ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 96 ◽  
Author(s):  
Hugh J. Beckie ◽  
Ken C. Flower ◽  
Michael B. Ashworth

Recent statements from scientific organisations and court decisions have resulted in widespread public interest and concern over the safety of glyphosate, the most popular and effective herbicide used worldwide. Consequently, glyphosate-based products are under intense scrutiny from governments at all levels. Some jurisdictions have already banned or restricted its use, which will adversely impact international trade in bulk grain commmodities if glyphosate residues are detected. The possibility of farming without glyphosate is becoming an important issue facing the agri-food research and development sector. Contingency plans need to be formulated if that scenario becomes a reality. In this review, we briefly summarize international events that have led to this possible situation, describe current glyphosate usage in major agronomic field crops worldwide, outline possible alternatives to glyphosate in two agroregions and perform bioeconomic model scenarios of southern Australian broadacre cropping systems without the herbicide. Model predictions suggest that we can farm profitably without glyphosate by consistently utilizing key non-herbicidal weed management practices combined with robust pre-emergence soil residual herbicide treatments. However, maintaining low weed seed banks will be challenging. If the social license to use glyphosate is revoked, what other pesticides will soon follow?


2017 ◽  
Vol 7 (4) ◽  
pp. 18-24 ◽  
Author(s):  
P. V. Lykhovyd ◽  
S. O. Lavrenko

<p>The article is devoted to study of the biological activity of soil under sweet corn crops depending on tillage depth, mineral fertilizers application rate with drip irrigation in the soil-ecological conditions of the Dry Steppe Zone of Ukraine. The plan of the experiment foresaw study of such factors: A — tillage depth (moldboard plowing on 20-22 and 28-30 cm); B — mineral fertilizers application rate (no fertilizers, N<sub>60</sub>P<sub>60</sub>, N<sub>120</sub>P<sub>120</sub>); C — plants density (35, 50, 65, 80 plants ha<sup>-1</sup>). We used water of the Ingulets irrigation system for irrigation. The water belongs to II quality class by agronomical criteria of the DSTU 2730-94 and its suitability for irrigation is limited. We studied the soil biological activity on variants with 65 plants ha<sup>-1 </sup>by the indicies of its respiration rate (method of V.I. Shtatnov) and linen decomposition degree (“application” method). At the same time we have made monitoring of the soil meliorative state  depending on the moldboard plowing depth by the toxic salts content, anionic-cationic composition of the aqueous soil extract. The results of the laboratory-field experiments prove that the moldboard plowing depth , mineral fertilizers application rates and soil meliorative state have an influence on its biological activity. The maximum respiration rate, which is used to characterize an activity of the aerobic microflora of the upper soil layers, was at moldboard plowing on depth of 20-22 cm at non-fertilized experimental variant — 250.0 mg СО<sub>2</sub>/m<sup>2</sup>×hour. Increase of the tillage depth and mineral fertilizers application rate significantly decreased carbonic acid emission to the athmosphere, which was the minimum of 178.3 mg СО<sub>2</sub>/m<sup>2</sup>×h. The maximum linen decomposition degree, which is used to characterize an activity of the cellulose-decomposing soil microflora, was at moldboard plowing depth of 28-30 cm at non-fertilized experimental variant — 58.3%. The tillage depth changed cellulose-decomposing soil microflora activity insignificantly. Mineral fertilizers application at the maximum rate of N<sub>120</sub>P<sub>120</sub>decreased cellulose-decomposing soil biota activity 1.7 times comparatively to non-fertilized variant. Higher toxic salts concentration (at 0.006-0.019 %), sodium ions content (at 0.15-0.38 mg-eq/100 g of soil) in the 0-50 cm layer led to decrease of the soil biological activity. We consider, that the best from the agroecological point of view is the variant with moldboard plowing depth of 28-30 cm, mineral fertilizers application rate N<sub>120</sub>P<sub>120</sub>.</p>


2021 ◽  
Vol 212 ◽  
pp. 60-67
Author(s):  
V. Yu. Skorokhodov ◽  

This article is devoted to the study of the effect of nitrate nitrogen content in the soil on its biological activity on crops cultivated in the system of six-field crop rotation and mono-crops, as well as the effect of nitrate nitrogen and soil bioactivity on the yield of field crops (corn for silage, peas, millet and barley) in crop rotations and mono-crops. Field experiments were carried out on a long-term plot and the results are objective from the point of view of the data on the yield of field crops, soil bioactivity and the content of nitrate nitrogen on the crops were obtained in various weather conditions, including suitable and very dry years. Very dry years are considered when the hydrothermal index is 0.6 or less, they accounted for 68% of the total number of research years. The question of the forecrop influence and the nutritional background on the field crop yield, the content of nitrate nitrogen and the biological activity of the soil is considered. The lowest biological activity of the soil is noted in the variant with permanent barley sowing on unfertilized background - 6.0 %, on fertilized background - 6.1%. As a result of the research, it was found that the yield of corn for silage is higher in mono-crops compared to crop rotation. Millet slightly reacts to application of mineral fertilizers, and when cultivated in monoculture, it reduces yield. The usage of mineral fertilizers increases the content of nitrate nitrogen and the biological activity of the soil in all variants of the experiment.


Author(s):  
Yadwinder Singh ◽  
Kanwaljit Singh

Background: To study effect of various spacing and weed management practices on weed control, growth parameter, yield and yield attributes of pigeon pea variety Pusa Arhar-16, field experiments were conducted at Student’s Research Farm, Khalsa College Amritsar, Punjab, India during kharif season of 2019-20.Methods: The experiment was laid out in Split plot design with three replications. The treatments comprised of four different spacing i.e. S1 (30×10 cm), S2 (30×15 cm), S3 (40×15 cm) and S4 (50×25 cm) which were considered as main plot treatments and three weed management practices W1 (weedy check), W2 (pendimethalin @ 1.5 kg a.i. ha-1 at 1DAS) and W3 (rice straw mulch) as sub-plot treatments.Result: It was found that maximum plant height (218.2 cm) and highest leaf area index (2.104) was recorded in treatment S1 (30×10 cm) whereas treatment S4 (50×25 cm) was superior in rest of growth parameters viz. maximum crop growth rate (0.85 gram per plant per day), number of primary branches (18.2 per plant) and number of secondary branches (13.8 per plant). Among yield and yield attributes, spacing S1 (30×10 cm) showed maximum grain yield (16.29 q ha-1) and stover yield (49.29 q ha-1) whereas, maximum number of pods per plant (154.6), pod length (4.83 cm), number of seeds per pod (3.90) and 100-seed weight (7.14 grams) were recorded in spacing S4 (50×25 cm). The weed management treatments showed non-significant effect on growth and yield parameters due to weed suppressing ability of the crop. which might be due to weed suppressing ability of the crop. It may be concluded that pigeon pea cultivar Pusa Arhar-16 performed better in narrower spacing of 30×10 cm due to its dwarf nature and it also showed good smothering effect on the weeds due to its smothering effect.


2012 ◽  
Vol 26 (3) ◽  
pp. 490-498 ◽  
Author(s):  
Andrew J. Price ◽  
Kip S. Balkcom ◽  
Leah M. Duzy ◽  
Jessica A. Kelton

Conservation agriculture (CA) practices are threatened by glyphosate-resistant Palmer amaranth. Integrated control practices including PRE herbicides and high-residue CA systems can decreaseAmaranthusemergence. Field experiments were conducted from autumn 2006 through crop harvest in 2009 at two sites in Alabama to evaluate the effect of integrated weed management practices onAmaranthuspopulation density and biomass, cotton yield, and economics in glyphosate-resistant cotton. Horizontal strips included four CA systems with three cereal rye cover crop seeding dates and a winter fallow (WF) CA system compared to a conventional tillage (CT) system. Additionally, vertical strips of four herbicide regimes consisted of: broadcast, banded, or no PRE applications ofS-metolachlor (1.12 kg ai ha−1) followed by (fb) glyphosate (1.12 kg ae ha−1) applied POST fb layby applications of diuron (1.12 kg ai ha−1) plus MSMA (2.24 kg ai ha−1) or the LAYBY application alone. Early-seasonAmaranthusdensity was reduced in high-residue CA in comparison to the CA WF systems in 2 of 3 yr.Amaranthusdensities in herbicide treatments that included a broadcast PRE application were lower at three of five sampling dates compared to banding early-season PRE applications; however, the differences were not significant during the late season and cotton yields were not affected by PRE placement. High-residue conservation tillage yields were 577 to 899 kg ha−1more than CT, except at one site in 1 yr when CT treatment yields were higher. CA utilizing high-residue cover crops increased net returns over CT by $100 ha−1or more 2 out of 3 yr at both locations. High-residue cover crop integration into a CA system reducedAmaranthusdensity and increased yield over WF systems; the inclusion of a broadcast PRE application can increase early-seasonAmaranthuscontrol and might provide additional control when glyphosate-resistantAmaranthuspopulations are present.


2013 ◽  
Vol 27 (2) ◽  
pp. 133-141 ◽  
Author(s):  
A.M. Gajda ◽  
B. Przewłoka ◽  
K. Gawryjołek

Abstract The aim of this research was to evaluate changes in soil quality associated with the tillage system applied with chosen parameters of soil biological properties. The long-term field experiments were located at a private farm in Rogów (Zamooeć region, E Poland) on a silt soil and at the Experimental Station in Laskowice (Wrocław region, S-W Poland) on a sandy loam soil. Soil samples were collected from 0-15 and 15-30 cm layers. Winter wheat was grown under traditional, reduced and no-tillage systems. The analyses included estimations of microbial biomass C and N content, microbial respiration rate, activity of dehydrogenase and arylsulfatase, and fluorescein diacetate hydrolysis. After eight years the effects of tillage on both soils were clearly noticed. In general, the less disturbing tillage systems enhanced the increase of soil biological activity by 15-40%, on average, than conventional tillage system. The significant correlations between microbial biomass, and/or enzyme activities with total organic C content indicate that concentration of organic C in soil environment plays an extremely important role in enhancing the stabilization and activity of soil microorganisms, and protection of an extracellular enzymes. The studied parameters of soil biological activity showed their sensitivity to tillage applied and may be considered as an useful indicators of soil quality in monitoring all conditions alter soil environment.


2003 ◽  
Vol 51 (4) ◽  
pp. 461-464
Author(s):  
◽  
B. J. Pandian ◽  
P. Thukkaiyannan ◽  
N. Thavaprakash

Field experiments were conducted at the Agricultural College and Research Institute, Tamil Nadu Agricultural University, Killikulam, India during the kharif (July to November) and summer (December to April) seasons of 1999 and 2000 in a randomized block design. The treatment consisted of three pre-emergence herbicides (pretilachlor + safener 0.3 kg ha-1 4 days after sowing [DAS], butachlor 1.0 kg ha-1 8 DAS and pendimethalin 1.0 kg ha-1 8 DAS) and one early post-emergence herbicide (butanil 3.0 ha-1 15 DAS), each in combination with mechanical or hand weeding 30 and 45 DAS. In addition, green manure (Daincha) intercropping and incorporation, mechanical and hand weeding twice alone (25 and 50 DAS) were compared with the unweeded check. The results revealed that the pre-emergence application of pretilachlor + safener 0.3 kg ha-1 + hand weeding twice (30 and 45 DAS) promoted higher yield attributes and maximum yield in wet-seeded rice.


1996 ◽  
Vol 10 (2) ◽  
pp. 258-262 ◽  
Author(s):  
Robert E. Blackshaw ◽  
John T. O'Donovan ◽  
M. Paul Sharma ◽  
K. Neil Harker ◽  
Denise Maurice

Wild oat populations resistant to triallate have been identified in Alberta. Dose response experiments were conducted in the greenhouse to determine if triallate-resistant wild oat was controlled by other selective wild oat herbicides. Triallate-resistant wild oat populations were effectively controlled by atrazine, ethalfluralin, fenoxaprop-P, flamprop, imazamethabenz, and tralkoxydim. EPTC and cycloate, which are chemically related to triallate, differed in their efficacy on triallate-resistant wild oats. EPTC at the 0.25x field use rate was more efficacious on triallate-resistant than triallate-susceptible wild oat. In contrast, cycloate at the 0.25 to 0.5x field use rate was less efficacious on triallate-resistant than susceptible wild oats. At higher rates, both EPTC and cycloate killed triallate-resistant wild oat populations. Growers have several herbicide choices to selectively control triallate-resistant wild oat in prairie field crops but should plan to rotate herbicides among different chemical families and adopt integrated weed management practices to reduce the risk of these wild oat populations developing resistance to other wild oat herbicides.


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