• Authors:
    • Meca, A. V.
    • Popescu, N.
  • Source: Annals of the University of Craiova - Agriculture, Montanology, Cadastre Series
  • Volume: 40
  • Issue: 2
  • Year: 2010
  • Summary: Within our country conditions the wheat, rye, barley, oilseed rape and pea-oat fodder are sown in autumn. They may be grown after crops that are harvested during summer or perennial crops or pastures that are included is crop rotation schemes. In the conditions of our country, crops that are harvested during the summer are: pea-oat fodder, pea, early potato, barley and wheat. After harvesting these crops, there must be done, immediately, the summer plowing because the soil is still moist, resulting a good quality plowing. Any delay conducts to diminishing the yields. Usually, the summer plow is made at 18-20 cm depth. Deeper plow are not necessary on most soil types from our country. Twenty cm deeper plow is need only on clayey soil that easily compacts, when the soil is highly infested by weeds, covered by high straw or when in the last year there was made a shallow plow. Summer plow, no matter the depth must be done along with harrow after plow. During the fall, till drilling, the soil has to be harrowed in order to destroy weeds and to maintain soil loosened.
  • Authors:
    • Helmers, M. J.
    • Qi, Z.
  • Source: Vadose Zone Journal
  • Volume: 9
  • Issue: 1
  • Year: 2010
  • Summary: Utilization of cereal rye (Secale cereale L. ssp. cereal) as a winter cover crop has potential benefits for subsurface drainage and NO(3) loss reduction. The objective of this study was to quantify the soil water balance components and impacts of a rye cover crop on subsurface drainage in central Iowa. Rye was planted in lysimeters in mid-October and terminated in early June in 3 yr and the lysimeters were left fallow during the summer months. Subsurface drainage water was generally pumped out weekly along with taking soil moisture measurements; however, multiple appreciable rain events in a given week required more frequent pumping. During May through July of the 3 yr, monthly subsurface drainage was significantly reduced by 21% when comparing the rye system to bare soil (P
  • Authors:
    • Thorup-Kristensen, K.
    • Dresboll, D. B.
  • Source: Soil Use and Management
  • Volume: 26
  • Issue: 1
  • Year: 2010
  • Summary: The significance of incorporation date of a catch crop on the nitrogen supply for the subsequent crop, the N effect (N(eff)), was examined. Winter rye was grown as a catch crop for 3 years during the autumn, and incorporated on five dates, two in the autumn and three in the spring. Two of the winters had high precipitation, and the N(eff) was small at the early autumn incorporation date, but increased when incorporation was delayed into late autumn and further increased by early spring incorporation. In the third winter, which was very dry, the N(eff) was negative at all incorporation dates, with the negative effect gradually increasing in value the later the incorporation date. In all 3 years the N(eff) was reduced when incorporation was delayed from early spring until later in the spring. The main processes determining this pattern were found to be (1) the risk of leaching of N mineralized after catch crop incorporation, which can reduce the N(eff) at early incorporation under wet conditions, (2) pre-emptive competition which can reduce the N(eff) when incorporation is delayed until later in the spring, and in dry conditions is already apparent during the autumn, and (3) catch crop growth leading to carbon gain and increased C/N ratio which decreases mineralization and thus the N(eff) after delayed incorporation in the spring. Lack of time for catch crop N uptake prior to early incorporation, or lack of time for N mineralization after late incorporation which might also reduce the N(eff) did not appear to be important in our experiment. The results show that catch crops grown in high rainfall areas on sandy soils should be incorporated later than those in low rainfall areas on nitrate retentive soils.
  • Authors:
    • Shimi, P.
    • Fereidoonpoor, M.
    • Jamali, M.
  • Source: Proceedings of 3rd Iranian Weed Science Congress, Volume 2: Key papers, weed management and herbicides, Babolsar, Iran, 17-18 February 2010
  • Year: 2010
  • Summary: In order to compare efficacy of Pantera (quizalofop-P-tefuryl 4%EC) with other graminicides in canola fields of Fars province, an experiment was carried out in randomized complete block design with 4 replication and 11 treatments in Darab research station in 2008-2009. Treatments included Pantera at 1, 1.5 and 2 lha -1, Galant super (haloxyfop-R-methyl aster) at 0.75 lha -1, Focus (cycloxydim) at 2 lha -1, Treflan, (trifluralin 48% EC) at 2 lha -1, Butisan star (metazachlor 33.33%+quinmerac 8.8%) at 2.5 lha -1, Treflan at 2 lha -1+Pantera at 1.5 lha -1, Treflan at 2 lha -1+Galant super at 0.75 lha -1, Treflan at 2 lha -1+Focus 2 lha -1 and full season weed control as check. Results showed that 2 lha -1 Pantera in compare with Treflan+other graminicides as super gallant, focus and Pantera and full season weed control treatment had no significant difference and increased canola yield by 39.5-41.7%. Also, 2 lha -1 Pantera controlled wheat, barley, wild oat and ryegrass. In 100, 100, 90.97 and 92.92 percent respectively and 75.4 percent in decreasing of dry weight of grasses.
  • Authors:
    • Frederick, J. R.
    • Fortnum, B. A.
    • Bauer, P. J.
  • Source: Agronomy Journal
  • Volume: 102
  • Issue: 4
  • Year: 2010
  • Summary: Longer rain-free periods are predicted to occur more often in the southeastern United States as a result of global climate change. This nonirrigated field study was conducted from 1997 through 2002, which coincided with the 1998-2002 drought that affected most of the United States. The objective was to determine the effect of rotation and tillage on cotton (Gossypium hirsutum L.) productivity. Treatments in the study were rotation [cotton rotated with corn (Zea mays L.), cotton planted after a rye (Secale cereale L.) winter cover crop, and continuous cotton with no cover crop] and tillage system (conventional tillage and conservation tillage). Two levels of aldicarb [2-methyl-2-(methylthio)propanal O-{(methylamino)carbonyl}oxime] (0 and 1.18 kg a.i. ha(-1)) were also included because of known soil management effects on thrips (Frankliniella sp.) and root-knot nematodes (Meloidigyne incognita). The predominant soil types were Bonneau loamy sand (loamy, siliceous, subactive, thermic Arenic Paleudult) and Norfolk loamy sand (fine-loamy, kaolinitic, thermic Typic Kandiudult). Rotation did not affect cotton yield in any year. Tillage did not affect cotton yield in 1997. Conservation tillage resulted in an average 25% yield increase in cotton lint yield over conventional tillage during the 5-yr drought. Tillage and aldicarb affected both thrips and root-knot nematodes, but lack of interaction among these factors for lint yield suggested that management of these pests was not the predominant cause for the cotton yield increase with conservation tillage. Conservation tillage for cotton production could be an important method to help mitigate the effects of climate change in the region if change occurs as predicted.
  • Authors:
    • Kaul, H. -P
    • Loiskandl, W.
    • Himmelbauer, M.
    • Bodner, G.
  • Source: Agronomy for Sustainable Development
  • Volume: 30
  • Issue: 2
  • Year: 2010
  • Summary: Cover crops are plants that are integrated in the crop rotation between two cash crops. The main objectives of cover cropping are organic matter input, mitigation of nitrate leaching and reduction of soil erosion. These benefits will only be achieved efficiently if the selected cover crop species are adapted to local environmental conditions and appropriate for the defined agro-ecological target. Therefore, a main limitation in cover cropping is the lack of a comprehensive species description. An improved cover crop characterization could be achieved with quantitative parameters derived from growth functions. Here, we show the use of this approach to assess plant traits relevant for erosion control by cover cropping. An experiment with four cover crop species (phacelia, vetch, rye and mustard) was performed over two years at a semi-arid site in Eastern Austria. Canopy cover was measured four times over the vegetation period. Root length density measurements were made to 40 cm soil depth before winter. Canopy dynamics were characterized by parameters from the asymptotic Gompertz function and from an extended logistic model that includes a parameter for decay after maximum coverage. Our results show that vetch had the lowest early vigor after dry conditions at sowing, with +45% longer time to attain maximum growth rate (parameter t(max)) than the other species. Drought during the later autumn growing period led to the highest reduction in maximum canopy cover (parameter y(max)) for phacelia (-41%). The rooting pattern was assessed by parameters from the exponential distribution function of Gerwitz and Page. The most intense rooting near the soil surface (parameter L(0)) was found for phacelia (9.7 cm cm(-3)). Vetch had the lowest L(0) (4.6 cm cm(-3)) but highest root allocation to deeper soil layers. Mustard combined high average values in y(max) (76%) and L(0) (6.3 cm cm(-3)) with a stable growth over both years. The potential strengths of phacelia and vetch were more dependent on the particular year. Rye showed a stably high L(0) (8.6 cm cm(-3)), but had only a low average value of y(max) (55.1%). The quantitative parameter sets we derived for plant traits required for erosion control improved cover crop comparison and analysis of their local adaptation. Based on this extended species description our approach allows a better evaluation of cover crops and can be used for the optimization of management and decision support.
  • Authors:
    • Comin, J. J.
    • Lovato, P. E.
    • Bittencourt, H. von H.
    • Lana, M. A.
    • Altieri, M. A.
  • Source: ACTA SCIENTIARUM-AGRONOMY
  • Volume: 31
  • Issue: 4
  • Year: 2009
  • Summary: The effect of the winter cover crops rye, oat, ryegrass, vetch and fodder radish (and their mixtures) in no-tillage systems was investigated on soil cover, cover crop biomass and summer weed biomass during the critical competition stage with common bean. Bean yield was also evaluated. The experimental design was randomized complete blocks and four repetitions. The highest soil cover during winter was observed in the treatments rye+vetch, rye+vetch+fodder radish and oat+vetch. The highest values of cover crops biomass production were observed in the treatments rye+vetch+fodder radish. Weed suppression was higher in the ryegrass monoculture and in the rye+vetch+fodder radish association, and there was no correlation between cover crop biomass and summer weed suppression; the best bean yields were achieved with the following treatments: ryegrass in monoculture, oat in monoculture and rye+vetch, producing 1,950, 1,730 e 1,790 kg ha -1 respectively. The monocultures of ryegrass and oat showed the lowest costs with seeds and the highest economic returns.
  • Authors:
    • Eastridge, M. L.
    • Dick, R. P.
    • Barker, D. J.
    • Sulc, R. M.
    • Fae, G. S.
    • Lorenz, N.
  • Source: Agronomy Journal
  • Volume: 101
  • Issue: 5
  • Year: 2009
  • Summary: The benefits of cover crops within crop rotations are well documented, but information is limited on using cover crops for forage within midwestern United States cropping systems, especially under no-tillage management. Our objective was to evaluate plant, animal, and soil responses when integrating winter cover crop forages into no-till corn ( Zea mays L.) silage production. Three cover crop treatments were established no-till after corn silage in September 2006 and 2007 at Columbus, OH: annual ryegrass ( Lolium multiflorum L.), a mixture of winter rye ( Secale cereale L.) and oat ( Avena sativa L.), and no cover crop. Total forage yield over autumn and spring seasons was 38 to 73% greater ( P≤0.05) for oat+winter rye than for annual ryegrass. Soil penetration resistance (SPR) in May 2007 was 7 to 15% greater ( P≤0.10) in the grazed cover crops than in the nongrazed no cover crop treatment; however, subsequent silage corn yield did not differ among treatments, averaging 10.4 Mg ha -1 in August 2007. Compared with the no cover crop treatment, cover crops had three- to fivefold greater root yield, threefold greater soil microbial biomass (MB) in spring 2008, and 23% more particulate organic carbon (POC) concentrations in the 0- to 15-cm soil depth. Integration of forage cover crops into no-till corn silage production in Ohio can provide supplemental forage for animal feed without detrimental effects on subsequent corn silage productivity, with the added benefit of increasing labile soil C.
  • Authors:
    • Sattler, A.
    • Faganello, A.
    • Fontaneli, R. S.
    • Vargas, L.
  • Source: Ciencia Rural
  • Volume: 39
  • Issue: 7
  • Year: 2009
  • Summary: Black oat ( Avena strigosa [ Avena nuda]), an important winter cover crop in south Brazil, is a weed problem in cool season grain crops as well as ryegrass. Two trials in a randomized complete block design were conducted in Passo Fundo, Rio Grande do Sul, Brazil, to study different oat management methods applied on black oat at anthesis and milk stages to avoid it from becoming a weed plant in wheat cropped after soyabean. The plot area was 60 m 2. Nine treatments were tested in both trials: spray herbicide; roll plus herbicide; hay harvest; silage harvest; mowing; grinding, silage; rolling; disking; and grain harvesting. The average total biomass at anthesis was 5016 kg DM/ha and at milk stage was 6050 kg DM/ha. Soyabean cropped in the summer season yield 2080 kg/ha and it was not affected by black oat treatments. During the second year, the wheat plots sprayed herbicide before planting yielded 2472 kg/ha and spike density of 355/m 2, however, plots without herbicide yielded 836 kg/ha and had 225 spikes/m 2. On black oat milk stage managements, the yield average was 1733 kg/ha and 334 spikes/m 2, on sprayed herbicide plots before planting. In opposite, the plots without herbicide, wheat plants were completely dominated by resurgent black oat plants, due to managements applied during the previous winter. Mechanical management methods applied only in black oat development stages allowed seed germination during winter crops cycle. This problem is avoided by spraying herbicide before oat anthesis, because after that any management method tested was unsuccessful to control oat after the following winter crops, so it is necessary to spray herbicide before seeding winter cash crops.
  • Authors:
    • Denardin, R. B. N.
    • Wildner, L. do P.
    • Coimbra, J. L. M.
    • Gatiboni, L. C.
  • Source: Biotemas
  • Volume: 22
  • Issue: 2
  • Year: 2009
  • Summary: The present study was carried out with the aim of monitoring the edaphic fauna modifications during the decomposition of cover crops straw. The experiment was carried out in the 2005/2006 spring-summer season in Chapeco/SC, Brazil. The treatments were: (1) Straw of black oat ( Avena strigosa Scrheb.); (2) Straw of black oat cultivated with addition of 50 kg ha -1 of nitrogen; (3) Straw of rye ( Secale cereale L.); (4) Straw of rye cultivated with addition of 50 kg ha -1 of nitrogen; (5) Uncovered soil. The cover crops were cultivated until flowering, when they were handled with a roll-knife. Ten evaluations of the edaphic fauna were made during the straw decomposition process (from 23/09/2005 to 03/02/2006) using pitfall traps. The first sampling was taken six days before the handling of cover crops, and the others were taken at 4, 18, 32, 46, 67, 83, 98, 112 and 127 days after handling. The results showed that the evaluated edaphic fauna groups were sensitive to the remaining amount of straw covering the soil under no tillage, and that the straw decomposition induced a decrease in fauna diversity because of the relative increase of the Collembola group.