Secondary seed dormancy prolongs persistence of volunteer canola in western Canada

Weed Science ◽  
2003 ◽  
Vol 51 (6) ◽  
pp. 904-913 ◽  
Author(s):  
Robert H. Gulden ◽  
Steven J. Shirtliffe ◽  
A. Gordon Thomas
Keyword(s):  
Seed Dormancy ◽  
Seedling Recruitment ◽  
Seedling Emergence ◽  
Conventional Tillage ◽  
Western Canada ◽  
Tillage Systems ◽  
Spring Canola ◽  
Typical Summer ◽  
Different Soils

In western Canada, little is known about the seedbank ecology of volunteer canola. Therefore, integrated recommendations for the management of this weed are limited. In this study, we investigated the seedbank persistence and seedling recruitment of two spring canola genotype groups with different secondary seed dormancy potentials under contrasting tillage systems. The study was conducted at two locations with different soils in the Mixed Moist Grassland ecoregion of Saskatchewan. A single cohort seedbank was established in 1999 and was followed for 3 yr in successive wheat crops. In a separate laboratory study, the six canola genotypes examined were classified as those with high and those with medium potentials for the development of secondary seed dormancy (HD and MD, respectively). After one, two, and three winters, maximum persistence of 44, 1.4, and 0.2% of the original seedbank was observed among the treatments, respectively. In 2001, HD canola genotypes tended to exhibit 6- to 12-fold greater persistence than MD canola genotypes, indicating lower seedbank mortality in HD canola. Seedling recruitment of HD canola also was higher than MD canola when differences were observed between these genotype groups. Therefore, long-term seedbank persistence of canola can be reduced by growing genotypes with low inherent potential for the development of secondary seed dormancy. The proportion of persisting seeds tended to be higher under conventional tillage than under zero tillage because of lower seedbank mortality, but no clear distinction in seedbank persistence in terms of absolute time could be made between these two tillage systems. Volunteer canola seedling recruitment followed the pattern of a typical summer-annual weed, where seedling emergence was observed only during May and June.

Seed Dormancy and Seedling Recruitment in Smooth Barley (Hordeum murinum ssp. glaucum) Populations in Southern Australia

Weed Science ◽  
2012 ◽  
Vol 60 (3) ◽  
pp. 394-400 ◽  
Author(s):  
Benjamin Fleet ◽  
Gurjeet Gill
Keyword(s):  
Seed Dormancy ◽  
Seedling Recruitment ◽  
Seedling Emergence ◽  
South Australia ◽  
Conventional Tillage ◽  
The Other ◽  
Barley Plant ◽  
Weed Species ◽  
Time Interaction ◽  
Recruitment Behavior

Weedy barley species have emerged as important weeds in southern Australia, where they can be particularly difficult to control in cereal crops. Knowledge of seed dormancy mechanisms, germination ecology, and recruitment behavior in the field would facilitate development of effective weed-control programs for these weed species. Based on somatic chromosome number, smooth barley was identified as the species infesting all the sites sampled in South Australia. Smooth barley populations from cropping fields and noncrop habitats showed large differences in their pattern of dormancy loss. Noncrop populations (EP2, EP3, and MN2) rapidly lost dormancy during dry after-ripening and showed 70 to 95% germination at 3 mo after maturity. Five populations collected from cropping fields (EP1, EP4, EP5, MN1, and MN3), on the other hand, showed < 30% germination, even at 8 mo after maturity, when germination was assessed at 20/12 C day/night temperatures. These dormant, smooth barley populations from cropping fields were found to be highly responsive to cold stratification, with germination increasing in response to the duration of the treatment. Germination of dormant, smooth barley populations increased with the addition of gibberellic acid (0.001 M GA3), but only when lemma and palea had been removed. Recruitment behavior of smooth barley in the field was influenced by the population and the tillage system. A nondormant population, collected from a long-term pasture (MN2), showed high seedling emergence (> 90%) during autumn, which was well before planting of the winter crop (lentil). In contrast, the other three populations sampled from cropping fields showed very little seedling establishment (< 10%) before crop planting, which would make them difficult to control in cereals because there are no selective herbicides available for the control of weedy barley species. There was a significant seeding system by emergence time interaction (P < 0.001), which was reflected in greater in-crop, smooth barley plant densities under zero-till than under conventional tillage and no-till systems.

Water and bromide movement in a Vertosol under four fallow management systems

Soil Research ◽  
1999 ◽  
Vol 37 (1) ◽  
pp. 75 ◽  
Author(s):  
J. E. Turpin ◽  
J. P. Thompson ◽  
B. J. Bridge ◽  
D. Orange
Keyword(s):  
Water Movement ◽  
Conventional Tillage ◽  
Management Systems ◽  
Zero Tillage ◽  
Tillage Systems ◽  
Fallow Management ◽  
Stubble Retention ◽  
Tracer Solution ◽  
Stubble Burning

Recent work on the Hermitage long-term fallow management found increased rates of anion movement under zero tillage systems compared with conventional tillage. Four separate experiments have been used to determine relative rates of water movement through different fallow management treatments on the Hermitage long-term fallow management trial and the causes of any differences. Photography of the aggregation patterns at the depth of tillage (approx. 15 cm) showed that conventional tillage combined with stubble burning has led to the formation of large massive peds up to 20 cm across below the tillage layer, whereas zero-tillage with stubble retention has maintained much smaller aggregates in this zone. Measurements of hydraulic conductivity at 15 cm under both dry and moist conditions indicated that, when the soil is dry and cracked, all tillage treatments have similar conductivities, but when the soil swells and cracks close, zero tillage–stubble retention maintains a greater volume of large pores and thereby greater conductivity. This effect was further demonstrated when a bromide tracer solution was applied to a relatively wet soil by ring infiltrometer, where only 15% of the solution moved below 15 cm in conventional tillage–stubble burning compared with 26% and 38% in zero tillage{stubble retention. In the final experiment, which followed the movement of surface applied bromide over a 6-month fallow, there were no significant differences in rates of leaching between management treatments.

Determinants of annual fluxes of CO2 and N2O in long-term no-tillage and conventional tillage systems in northern France

2007 ◽  
Vol 95 (1-2) ◽  
pp. 133-148 ◽  
Author(s):  
Katrien Oorts ◽  
Roel Merckx ◽  
Eric Gréhan ◽  
Jérôme Labreuche ◽  
Bernard Nicolardot
Keyword(s):  
Conventional Tillage ◽  
No Tillage ◽  
Tillage Systems ◽  
Northern France

Tillage and crop rotations enhance populations of earthworms, termites, dung beetles and centipedes: evidence from a long-term trial in Zambia

2019 ◽  
Vol 157 (6) ◽  
pp. 504-514
Author(s):  
T. Muoni ◽  
B. Mhlanga ◽  
J. Forkman ◽  
M. Sitali ◽  
C. Thierfelder
Keyword(s):  
Biological Activity ◽  
Soil Fertility ◽  
Conservation Agriculture ◽  
Conventional Tillage ◽  
Dung Beetles ◽  
Coptotermes Formosanus ◽  
Crop Rotations ◽  
Tillage Systems ◽  
Term Trial

AbstractMacro-organisms contribute significantly to soil fertility improvement. The influence of conservation agriculture (CA) in southern Africa on their populations has not yet been fully understood. Thus, the objective of the current study was to evaluate the effects of CA and conventional tillage on below ground biological activity in a CA long-term trial in Monze, Zambia from 2011 to 2013. The study had ten treatments which differed by tillage systems (conventional ploughing, planting basins and direct seeding) and crop diversification intensity (sole cropping, 2- or 3-year crop rotations) involving maize, cotton and sunn hemp. These factors were combined to create rotation-tillage (RotTill) treatments. Sampling of macrofauna was done once per year using a metal frame measuring 0.25 m2, hand-sorted to 30-cm depth. RotTill treatments had a significant effect on earthworms (Lumbricus terrestris), termites (Coptotermes formosanus), dung beetles (Scarabaeus viettei) and centipedes (Lithobius forficatus). Earthworms and termites were more abundant in CA treatments than in conventionally ploughed (CP) treatments. Biota diversity was generally higher in CA treatments than in CP controls. Conventional mouldboard ploughing generally reduced macrofauna, thus affecting biological soil fertility and the beneficial effect of the interactions of these organisms with the soil. CA treatments had the highest maize grain yields throughout the study period. Based on the results, reduced tillage systems and crop rotations increase biological activity shown by increased densities of termites and earthworms.

scholarly journals Effect of Tillage Systems on Physical Properties of a Clay Loam Soil under Oats

Agriculture ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 62 ◽  
Author(s):  
Karen Ordoñez-Morales ◽  
Martin Cadena-Zapata ◽  
Alejandro Zermeño-González ◽  
Santos Campos-Magaña
Keyword(s):  
Soil Properties ◽  
Environmental Conditions ◽  
Conservation Tillage ◽  
Pore Space ◽  
Conventional Tillage ◽  
Clay Loam ◽  
Clay Loam Soil ◽  
Tillage Systems ◽  
Loam Soil

In many regions, conservation tillage has been shown to contribute to preserving soil properties. However, in order to promote this practice in new areas, it is necessary to generate information about its results in local environmental conditions. Our objective was to study the effect of No Tillage (NT), Vertical Tillage (VT) and Conventional Tillage (CT) on physical soil properties of a clay loam soil and on yields (Avena sativa L.), in a semiarid area of Mexico. From 2013 to 2016 an experiment was conducted in random blocks, with the three tillage systems as treatments. Four variables were measured; bulk density (Bd), pore space (P), hydraulic conductivity (Ks) and crop yield. Our results did show scarce differences between the tillage systems. Values ranged between 1.21 g cm−3 to 1.39 g cm−3 for Bd, 45% to 55% for P, and 4.29 mm h−1 to 13.61 mm h−1 for Ks. Although differences were not significant among treatments, Bd decreased 6.7% for CT, 5.6% for NT and 0.7% for VT. P increased 6% for CT, 5% for NT and 0.5% for VT. Ks for CT decreased 6% more than for NT and VT. Average yield was 13% less in NT compared to CT and VT. A long-term investigation is needed in order to determine the effects of tillage methods, in our particular environmental conditions.

Tillage systems and seed dormancy effects on common waterhemp (Amaranthus tuberculatus) seedling emergence

Weed Science ◽  
2006 ◽  
Vol 54 (6) ◽  
pp. 1037-1044 ◽  
Author(s):  
Ramon G. Leon ◽  
Micheal D. K. Owen
Keyword(s):  
Seed Dormancy ◽  
Seedling Emergence ◽  
Tillage Systems ◽  
Common Waterhemp ◽  
Amaranthus Tuberculatus

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 Long term effects of different soil tillage systems on maize (Zea mays L.) yields

2011 ◽  
Vol 57 (No. 4) ◽  
pp. 186-192 ◽  
Author(s):  
Ž. Videnović ◽  
M. Simić ◽  
J. Srdić ◽  
Z. Dumanović
Keyword(s):  
Zea Mays L ◽  
Maize Yield ◽  
Conventional Tillage ◽  
Soil Tillage ◽  
Reduced Tillage ◽  
No Tillage ◽  
Long Term Effects ◽  
Tillage Systems ◽  
Maize Production

The effects of three tillage systems: no-tillage (NT), reduced tillage (RT) and conventional tillage (CT), and three levels of fertilization (0, 258 and 516 kg/ha NPK (58:18:24)), on the maize yield during ten years (1999&ndash;2008) were analyzed on the chernozem soil type in Zemun Polje, Serbia. Statistical analyses showed significant effects of all three factors i.e., year, soil tillage and amount of fertilizers, and their interactions on the maize yield. The ten-year averages showed that the highest yields were observed with CT (10.61 t/ha), while the averages with RT and NT were lower (8.99 t/ha and 6.85 t/ha, respectively). The results of the influence of the amount of the applied fertilizers on maize yield showed that the lowest yield was in the zero level of fertilization 7.71 t/ha, while the yield was raised when the 258 kg/ha and 516 kg/ha NPK were applied (9.18 t/ha and 9.56 t/ha, respectively). Analyzing the influence of the soil tillage systems on maize production with respect to the amounts of applied fertilizers, this research revealed the benefits of CT under the presented agroecological conditions, irrespective of the level of applied fertilizer.

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