Weed seedbank response to crop rotation and tillage in semiarid agroecosystems

Weed Science ◽  
1999 ◽  
Vol 47 (1) ◽  
pp. 67-73 ◽  
Author(s):  
J. Dorado ◽  
J. P. Del Monte ◽  
C. López-Fando

In a semiarid Mediterranean site in central Spain, field experiments were conducted on a Calcic Haploxeralf (noncalcic brown soil), which had been managed with three crop rotations and two tillage systems (no-tillage and conventional tillage) since 1987. The crop rotations consisted of barley→vetch, barley→sunflower, and a barley monoculture. The study took place in two growing seasons (1992–1994) to assess the effects of management practices on the weed seedbank. During this period, spring weed control was not carried out in winter crops. In the no-tillage system, there was a significant increase in the number of seeds of different weed species: anacyclus, common purslane, corn poppy, knotted hedge-parsley, mouse-ear cress, spring whitlowgrass, tumble pigweed, venus-comb, andVeronica triphyllos.Conversely, the presence of prostrate knotweed and wild radish was highest in plots under conventional tillage. These results suggest large differences in the weed seedbank as a consequence of different soil conditions among tillage systems, but also the necessity of spring weed control when a no-tillage system is used. With regard to crop rotations, the number of seeds of knotted hedge-parsley, mouse-ear cress, and spring whitlowgrass was greater in the plots under the barley→vetch rotation. Common lambsquarters dominated in the plots under the barley→sunflower rotation, whereas venus-comb was the most frequent weed in the barley monoculture. Larger and more diverse weed populations developed in the barley→vetch rotation rather than in the barley→sunflower rotation or the barley monoculture.

Weed Science ◽  
1989 ◽  
Vol 37 (2) ◽  
pp. 233-238 ◽  
Author(s):  
J. Anthony Mills ◽  
William W. Witt

Field experiments were conducted to evaluate the interactions of tillage systems with imazaquin and imazethapyr on weed control and soybean injury and yield. Control of jimsonweed, common cocklebur, ivyleaf morningglory, velvetleaf, and giant foxtail from imazaquin and imazethapyr in conventional tillage was generally equal to or greater than control in no-tillage. However, under limited rainfall, weed control in no-tillage was generally equal to or greater than control in conventional tillage. Reductions in soybean heights due to herbicide treatment were evident in both tillage systems in 1985 and 1986 but not in. Soybean yields were reduced in 1985 from imazaquin at 140, 210, and 250 g/ha and imazethapyr at 105 and 140 g/ha. Yields were not reduced in 1986 and. Imazaquin and imazethapyr appear to provide adequate control of jimsonweed, common cocklebur, ivyleaf morningglory, velvetleaf, and giant foxtail in conventional and no-till systems.


Land ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 386
Author(s):  
Liliana Mureșan ◽  
Doina Clapa ◽  
Orsolya Borsai ◽  
Teodor Rusu ◽  
Thomas T. Y. Wang ◽  
...  

Soybean is an important natural source of isoflavones, but their concentration is likely to be influenced by external factors, such as climatic conditions and soil tillage systems. However, there is minimal information about the effects of such external factors on the isoflavone concentration in soybeans grown in Europe. Therefore, in this study, field experiments were established in Romania to investigate the potential impacts of three different soil tillage systems—conventional, minimum tillage and no-tillage—on crop yields and the isoflavone concentration of soybeans for three experimental years, 2014–2016. Our experimental results indicated that the soil tillage systems had little impact on the soybean yields each year. However, the 2016 yield was found to be higher than the 2014 and 2015 yields under all three soil systems. For every experimental year, the higher yield was recorded by the conventional system, followed by the minimum tillage system and no-tillage system under first weed control (weed control two (wct2): S-metolaclor 960 g/L, imazamox 40 g/L and propaquizafop 100 g/L). Likewise, the soil tillage system did not have a significant influence on the total isoflavone concentrations. Nevertheless, we noticed some variations in the individual isoflavone concentration (daidzin, genistin, glycitin, daidzein, genistein) in each year. Altogether, the minimum tillage and no-tillage systems may be employed as a suitable soil tillage system in soybean farming without an impact on the total isoflavone.


Weed Science ◽  
1992 ◽  
Vol 40 (2) ◽  
pp. 255-263 ◽  
Author(s):  
Barry D. Sims ◽  
David R. Guethle

Postemergence and commonly used preemergence plus postemergence herbicide programs were evaluated for weed control in conventional and no-tillage soybeans double cropped after winter wheat in the northern Mississippi River Delta. Broadleaf weed species present varied with tillage, location, and year. Large crabgrass was present in both tillage systems for all locations and years. Conventional tillage usually resulted in higher densities of large crabgrass, common cocklebur, and smooth pigweed. Soil-applied preemergence herbicides alone did not provide season-long ivyleaf and entireleaf morningglory or common cocklebur control in either tillage system. For weed control and soybean yields comparable to weed-free controls, postemergence broadleaf herbicides were required in both tillage systems following the soil-applied herbicide programs, alachlor plus linuron and alachlor plus metribuzin. Postemergence herbicide programs provided excellent season-long annual grass and broadleaf weed control when sethoxydim was applied separately from the broadleaf herbicides. Antagonism of large crabgrass control resulted when sethoxydim was tank mixed with postemergence broadleaf herbicides, compared to separate applications of the postemergence grass and broadleaf herbicides. In three out of four studies, soybean yields in handweeded controls were similar between tillage systems.


Weed Science ◽  
1990 ◽  
Vol 38 (3) ◽  
pp. 243-248 ◽  
Author(s):  
John W. Wilcut ◽  
Glenn R. Wehtje ◽  
T. Vint Hicks

Field experiments were conducted from 1985 to 1987 to evaluate herbicide systems for minimum-tillage and conventional-tillage peanut production. While acceptable weed control could be achieved in both tillage systems, minimum-tillage systems generally had to be more herbicide intensive. Preemergence or preplant-incorporated within-the-row applications of either ethalfluralin or pendimethalin plus postemergence applications of paraquat and sethoxydim provided Texas panicum control equivalent to preplant-incorporated applications of ethalfluralin or pendimethalin. Early-postemergence paraquat applications improved Florida beggarweed and pitted morningglory control in conventional-tillage systems at least 15% compared to the same systems without paraquat Control of bristly starbur and sicklepod in conventional-tillage systems did not increase with paraquat application. Broadleaf weed control did not differ between tillage systems, except pitted morningglory control was lower in the minimum-tillage system. Conventional-tillage peanuts produced yields 800 to 1900 kg/ha higher, depending on herbicide system, and also provided greater net returns than minimum-tillage peanuts. The greater yield and net returns in conventional- versus minimum-tillage systems were not attributed to weed control or disease problems.


2006 ◽  
Vol 20 (3) ◽  
pp. 622-626 ◽  
Author(s):  
Patrick W. Geier ◽  
Phillip W. Stahlman ◽  
John C. Frihauf

Field experiments were conducted during 2003 and 2004 to compare the effectiveness of KIH-485 and S-metolachlor for PRE weed control in no-tillage and conventional-tillage corn. Longspine sandbur control increased as KIH-485 or S-metolachlor rates increased in conventional-tillage corn, but control did not exceed 75% when averaged over experiments. Both herbicides controlled at least 87% of green foxtail with the exception of no-tillage corn in 2004, when KIH-485 was more effective than S-metolachlor at lower rates. Palmer amaranth control ranged from 85 to 100% in 2003 and 80 to 100% in 2004, with the exception of only 57 to 76% control at the lowest two S-metolachlor rates in 2004. Puncturevine control exceeded 94% with all treatments in 2003. In 2004, KIH-485 controlled 86 to 96% of the puncturevine, whereas S-metolachlor controlled only 70 to 81%. Mixtures of atrazine with KIH-485 or S-metolachlor generally provided the most effective control of broadleaf weeds studied.


2010 ◽  
Vol 45 (12) ◽  
pp. 1331-1341 ◽  
Author(s):  
Homero Bergamaschi ◽  
Genei Antonio Dalmago ◽  
João Ito Bergonci ◽  
Cleusa Adriane Menegassi Bianchi Krüger ◽  
Bruna Maria Machado Heckler ◽  
...  

The objective of this work was to evaluate changes in the photosynthetic photon flux density (PPFD) interception efficiency and PPFD extinction coefficient for maize crop subjected to different soil tillage systems and water availability levels. Crops were subjected to no-tillage and conventional tillage systems combined with full irrigation and non-irrigation treatments. Continuous measurements of transmitted PPFD on the soil surface and incoming PPFD over the canopy were taken throughout the crop cycle. Leaf area index and soil water potential were also measured during the whole period. Considering a mean value over the maize cycle, intercepted PPFD was higher in the conventional tillage than in the no-tillage system. During the initial stages of plants, intercepted PPFD in the conventional tillage was double the PPFD interception in the no-tillage treatment. However, those differences were reduced up to the maximum leaf area index, close to tasseling stage. The lowest interception of PPFD occurred in the conventional tillage during the reproductive period, as leaf senescence progressed. Over the entire crop cycle, the interception of PPFD by the non-irrigated plants was about 20% lower than by the irrigated plants. The no-tillage system reduced the extinction coefficient for PPFD, which may have allowed a higher penetration of solar radiation into the canopy


Weed Science ◽  
1980 ◽  
Vol 28 (1) ◽  
pp. 101-104 ◽  
Author(s):  
J. J. Kells ◽  
C. E. Rieck ◽  
R. L. Blevins ◽  
W. M. Muir

Field studies and laboratory analyses were conducted to examine factors affecting degradation of14C-atrazine [2-chloro-4-(ethylamine)-6-(isopropylamino)-s-triazine] under field conditions. The effects of these factors on weed control under no-tillage and conventional tillage systems were also examined. The amount of radioactivity which was unextractable in 90% methanol increased with time following treatment with14C-atrazine. The rate of formation of unextractable14C compounds was greater under no-tillage and increased with decreasing pH. After 14 to 18 days, a greater amount of extractable atrazine was present in areas receiving lime. The degradation of atrazine occurred more rapidly when surface pH was less than 5.0 compared with a pH greater than 6.5. The effect of lime on the amount of parent atrazine present in the soil was directly correlated to its effect on soil pH. Extractable atrazine in the soil 45 days after treatment was significantly correlated with weed control with the greatest effect under no-tillage.


1989 ◽  
Vol 69 (4) ◽  
pp. 1101-1111 ◽  
Author(s):  
E. J. DEIBERT ◽  
R. A. UTTER

A field study was conducted during 1985–1987 on a Fargo clay soil to evaluate growth, and NPK content at beginning flowering, pod fill, and mature seed at harvest of an early- (McCall) and a late-maturity (Dawson) soybean (Glycine max (L.) Merr.) cultivar as influenced by conventional (plow) or reduced (sweep, intertill, no-till) tillage systems and weed control methods. Excellent seed emergence was obtained on all tillage systems. Fall application of granular herbicide provided excellent weed control but herbicide plus cultivation caused reduced plant growth. Tillage system did not significantly affect plant and seed dry matter production. Yearly differences in dry matter production between early- and late-maturity cultivars depended on precipitation distribution. N and P uptake at pod fill was equal to seed uptake while K in the seed was one-half that measured at pod fill. Stratification of P and K in the surface soil profile of the reduced tillage systems was not detrimental and possibly enhanced early growth when root development was not extensive. Plants exhibited chlorosis on only the plow system under wet soil conditions indicating improved internal drainage under the reduced tillage systems. Interactions of climate with tillage system and cultivar maturity were more pronounced in this soybean study than previously reported which may be related to the cool, dry northern area.Key words: Soybean, no-till, zero-till, weed control, plant nutrients, cultivars, soil nutrient stratification


2008 ◽  
Vol 23 (2) ◽  
pp. 107-114
Author(s):  
Milena Simic ◽  
Nebojsa Momirovic ◽  
Zeljko Dolijanovic ◽  
Zeljko Radosevic

The effects of different herbicide combinations: control (1), alachlor+linuron (2), and alachlor+linuron+imazethapyr (3) were investigated in double-cropped soybean grown in two row spacing variants, 38 cm and 76 cm, under conventional tillage (CT) or no-tillage (NT). In trials conducted on a sandy loam soil at Zemun Polje, high weediness had a negative effect of on the yield of double-cropped soybean, especially at the higher row spacing tested and with no-tillage. Regression and correlation data revealed a dependence of weediness in double-cropped soybean on tillage system and herbicide combination, and dependence of soybean yield on tillage system.


Weed Science ◽  
1989 ◽  
Vol 37 (2) ◽  
pp. 239-249 ◽  
Author(s):  
Michael D. Johnson ◽  
Donald L. Wyse ◽  
William E. Lueschen

The objectives of this research were to compare the weed control efficacy of liquid, granular, and microencapsulated formulations of preemergence herbicides in moldboard plow, chisel plow, ridge tillage, and no-tillage corn and soybean production systems, and to determine whether herbicide formulation can influence herbicide interception and retention on surface corn residue. Common lambsquarters populations were threefold higher in corn than in soybeans. A mixed population of giant foxtail and green foxtail was highest in the chisel plow and lowest in the ridge tillage system as were total weed numbers. Percent weed control was not influenced by tillage when considered across all herbicide treatments. Weed control was not influenced by herbicide formulation in the moldboard plow, chisel plow, or ridge tillage systems, but granular herbicide applications provided better weed control than liquid applications in the no-tillage system and across various rates of corn residue in an experiment with no tillage variables. Two- to threefold less granular-applied herbicide was intercepted by surface corn residue at the time of application compared to liquid-applied herbicide. Increasing amounts of postapplication rainfall decreased the difference among formulations with regard to both total soil reception of the herbicide and resultant weed control. There was no consistent advantage for the microencapsulated formulation over the other herbicide formulations. Surface corn residue controlled many weeds without the aid of a herbicide and actually contributed to overall weed control even where herbicides were applied. This suggests that the binding of preemergence herbicides on surface crop residue may not be the cause of weed control failures in reduced-tillage systems as is often assumed to be the case.


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