Herbicide Fate Under Conservation Tillage, Cover Crop, and Edge-of-Field Management Practices

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.


2019 ◽  
Vol 20 (3) ◽  
pp. 147-154
Author(s):  
Gabriela Inveninato Carmona ◽  
Jennifer Rees ◽  
Ron Seymour ◽  
Robert Wright ◽  
Anthony Justin McMechan

The wheat stem maggot (Meromyza americana Fitch) (WSM) is a minor pest of wheat, rye, and other grasses. In 2017, growers in Nebraska reported dead center whorls and excessive tillering in early-season cornfields that followed wheat or rye terminated after planting corn. A survey was conducted to evaluate the risk factors for this insect in cover crop to corn transition systems. In each field, management practices and the percentage of injured plants were recorded. Symptomatic corn plants were collected from each field and dissected to determine larval and plant characteristics. In a few cases, small patches of a field were planted to a cover crop to manage soil erosion, and injured plants were only found where the cover crop was present. From these observations, the hypothesis is that terminating a cover crop after planting corn allowed the WSM larva to move from the dying cover crop to corn to complete its development. Cornfields infested with WSM had a frequency of injured corn plants from 0 to 60% with yield losses estimated at 30 bushels/acre. This paper provides the first detailed documentation of WSM injury in corn and addresses important management practices that may have influenced this uncommon situation.


2021 ◽  
pp. 1-31
Author(s):  
Andrew J. Price ◽  
Robert L. Nichols ◽  
Trent A. Morton ◽  
Kipling S. Balkcom ◽  
Timothy L. Grey ◽  
...  

Conservation tillage adoption continues to be threatened by glyphosate and acetolactate synthase-resistant Palmer amaranth and other troublesome weeds. Field experiments were conducted from autumn 2010 through crop harvest in 2013 at two locations in Alabama to evaluate the effect of integrated management practices on weed control and seed cotton yield in glyphosate-resistant cotton. The effects of a cereal rye cover crop using high or low biomass residue, followed by wide or narrow within-row strip-tillage, and three PRE herbicide regimes were evaluated. The three PRE regimes were: 1) pendimethalin at 0.84 kg ae ha-1 plus fomesafen at 0.28 kg ai ha-1 applied broadcast, 2) pendimethalin plus fomesafen applied banded on the row, or 3) no PRE. Each PRE treatment was followed by (fb) glyphosate (1.12 kg ae ha-1) applied POST fb a LAYBY applications of diuron (1.12 kg ai ha-1) plus MSMA (2.24 kg ai ha-1). Low residue plots ranged in biomass from 85 to 464 kg ha-1, while high biomass plots ranged from 3119 to 6929 kg ha-1. In most comparisons, surface disturbance width, residue amount, and soil applied herbicide placement did not influence within-row weed control; however, broadcast PRE resulted in increased carpetweed, large crabgrass, Palmer amaranth, tall morningglory, and yellow nutsedge weed control in row middles compared to plots receiving banded PRE. In addition, high residue increased carpetweed, common purslane, large crabgrass, Palmer amaranth, sicklepod, and tall morningglory weed control between rows. Use of banded PRE herbicides resulted in equivalent yield and revenue in four of six comparisons compared to those with broadcast PRE herbicide application; however, this would likely result in many between row weed escapes. Thus, conservation tillage cotton would benefit from broadcast soil-applied herbicide applications regardless of residue amount and tillage width when infested with Palmer amaranth and other troublesome weed species.


Insects ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 220
Author(s):  
Jo Marie Reiff ◽  
Sebastian Kolb ◽  
Martin H. Entling ◽  
Thomas Herndl ◽  
Stefan Möth ◽  
...  

Habitat simplification and intensive use of pesticides are main drivers of global arthropod declines and are, thus, decreasing natural pest control. Organic farming, complex landscapes, and local vineyard management practices such as implementation of flower-rich cover-crop mixtures may be a promising approach to enhance predator abundance and, therefore, natural pest control. We examined the effect of organic versus integrated management, cover-crop diversity in the vineyard inter-rows, and landscape composition on the natural pest control of Lobesia botrana eggs and pupae. Predation of L. botrana pupae was reduced by organic farming and species-poor cover-crops by about 10%. Predation rates of L. botrana eggs did not differ significantly in any of the studied management options. Dominant predators were earwigs (Forficulidae), bush crickets (Tettigoniidae), and ants (Formicidae). Negative effects of organic viticulture are most likely related to the negative nontarget effects on arthropods related to the frequent sulfur and copper applications in combination with the avoidance of strongly damaging insecticides by integrated winegrowers. While a 10% difference in predation rates on a single pest stage is unlikely to have strong practical implications, our results show that the assumed effectiveness of environmentally friendly agriculture needs to be evaluated for specific crops and regions.


Weed Science ◽  
2015 ◽  
Vol 63 (2) ◽  
pp. 477-490 ◽  
Author(s):  
John R. Teasdale ◽  
Steven B. Mirsky

Insufficient weed control is a major constraint to adoption of reduced-tillage practices for organic grain production. Tillage, cover crop management, and crop planting date are factors that influence emergence periodicity and growth potential of important weed species in these systems. We assessed two hairy vetch cover crop management practices, disk-kill and roll-kill, across a range of corn planting dates from early May to late June in three experiments in Beltsville, MD. Patterns of seed dormancy, emergence, and early weed growth were determined for overseeded populations of common ragweed, giant foxtail, and smooth pigweed, three important species in the Mid-Atlantic states that represent early to late emergence. Common ragweed emergence was lowest and dormancy was highest of the three species across all planting dates. Giant foxtail emergence was higher than the other species in roll-killed hairy vetch and included a significant number of seeds that germinated before rolling operations in late June. Smooth pigweed had the highest emergence and lowest dormancy in disk-killed hairy vetch in June. Individual giant foxtail plant weight was higher in roll-killed than disk-killed hairy vetch in 2 of 3 yr, whereas that of smooth pigweed plants was higher in disk-killed than roll-killed vetch in 2 of 3 yr. Giant foxtail was the dominant species in roll-killed hairy vetch (averaged 79% of total weed biomass at corn silking), probably because of early germination and establishment before rolling operations. Smooth pigweed was the dominant species in disk-killed hairy vetch at June planting dates (averaged 77% of total weed biomass), probably because of high growth rates under warm conditions in tilled soil. This research demonstrated that cover crop management practices and the timing of planting operations can shift the dominant species of weed communities in organic farming systems and must be considered in long-term weed management planning.


1988 ◽  
Vol 34 (3) ◽  
pp. 201-206 ◽  
Author(s):  
C. S. Rothrock ◽  
W. L. Hargrove

The influence of winter legume cover crops and of tillage on soil populations of fungal genera containing plant pathogenic species in the subsequent summer sorghum crop were examined in field studies. Legume cover crops significantly increased populations of Pythium spp. throughout the sorghum crop compared with a rye cover crop or no cover crop. This stimulation of the populations of Pythium spp. was not solely due to colonization of cover-crop residue, as populations were significantly greater at the time the legume cover crop was desiccated. Removal of aboveground residue generally decreased populations of Pythium spp. in soil. Incorporation of residue by tillage increased populations of Pythium spp. at some sampling dates. Legumes differed in the magnitude of stimulation, with hairy vetch stimulating Pythium spp. more than crimson clover. Cover crop treatments did not consistently influence soil populations of Fusarium spp., Rhizoctonia solani, Rhizoctonia-like binucleate fungi, or Macrophomina phaseolina. Macrophomina phaseolina populations were significantly greater under no tillage.


2019 ◽  
Vol 10 ◽  
Author(s):  
Sana Romdhane ◽  
Aymé Spor ◽  
Hugues Busset ◽  
Laurent Falchetto ◽  
Juliette Martin ◽  
...  

2019 ◽  
Vol 16 (14) ◽  
pp. 2905-2922 ◽  
Author(s):  
Wei Zhang ◽  
Chunyan Liu ◽  
Xunhua Zheng ◽  
Kai Wang ◽  
Feng Cui ◽  
...  

Abstract. It is still a severe challenge to optimize the field management practices for a multi-crop system when simultaneously aiming at yield sustainability and minimum negative impacts on climate as well as atmosphere and water quality. This site-scale case study was devoted to developing a biogeochemical process model-based approach as a solution to this challenge. The best management practices (BMPs) of a three-crop system growing cotton and winter wheat–summer maize (W–M) in rotation, which is widely adopted in northern China, were identified. The BMPs referred to the management alternatives with the lowest negative impact potentials (NIPs) among the scenarios satisfying all given constraints. The independent variables used to determine the NIPs and those utilized as constrained criteria were simulated by the DeNitrification-DeComposition model, which was modified in this study. Due to the unsatisfactory performance of the model in daily simulations of nitric oxide (NO) emission and net ecosystem exchange of carbon dioxide (NEE), the model was modified to (i) newly parameterize the soil moisture effects on NO production during nitrification, and (ii) replace the original NEE calculation approach with an algorithm based on gross primary production. Validation of the modified model showed statistically meaningful agreements between the simulations and observations in the cotton and W–M fields. Three BMP alternatives with overlapping uncertainties of simulated NIPs were screened from 6000 management scenarios randomly generated by Latin hypercube sampling. All of these BMP alternatives adopted the baseline (currently applied) practices of crop rotation (3 consecutive years of cotton rotating with 3 years of W–M in each 6-year cycle), the fraction of crop residue incorporation (100 %), and deep tillage (30 cm) for cotton. At the same time, these BMP alternatives would use 18 % less fertilizer nitrogen and sprinkle or flood-irrigate ∼23 % less water than the baseline while adopting reduced tillage (5 cm) for W–M. Compared with the baseline practices, these BMP alternatives could simultaneously sustain crop yields, annually enlarge the soil organic carbon stock by 4 ‰ or more, mitigate the aggregate emission of greenhouse gases, NO release, ammonia volatilization, and nitrate leaching by ∼7 %, ∼25 %, ∼2 %, and ∼43 %, respectively, despite a ∼5 % increase in N2O emission. However, further study is still necessary for field confirmation of these BMP alternatives. Nevertheless, this case study proposed a practical approach to optimize multi-crop system management to simultaneously achieve multiple United Nations Sustainable Development Goals.


2019 ◽  
Vol 11 (17) ◽  
pp. 4522 ◽  
Author(s):  
Magdalena Ruiz ◽  
Encarna Zambrana ◽  
Rosario Fite ◽  
Aida Sole ◽  
Jose Luis Tenorio ◽  
...  

The increasing spread of conservation agriculture demands that the next generation of wheat varieties includes cultivars capable of maintaining satisfactory yields with lower inputs and under uncertain climate scenarios. On the basis of the genetic gains achieved during decades of selection oriented to yield improvements under conventional crop management, it is important that novel breeding targets are defined and addressed. Grain yield, yield-related traits, and phenological and morphological characteristics, as well as functional quality parameters have been analyzed for six varieties each of bread and durum wheat, under minimum tillage and no-tillage. During the three-year experiment, the climatic conditions at the field trial site were characterized by low rainfall, although different degrees of aridity—from moderate to severe—were experienced. Differences were found between these two soil management practices in regard to the varieties’ yield stability. A positive influence of no-tillage on traits related to grain and biomass yield was also evidenced, and some traits among the examined seemed involved in varietal adaptation to a particular non-conventional tillage system. The study also confirmed some breeding targets for improved performance of wheat genotypes in conservation agroecosystems. These traits were represented in the small set of traditional varieties analysed.


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