Strip Tillage and Crop Residue Retention Decrease the Size but Increase the Diversity of the Weed Seed Bank under Intensive Rice-Based Crop Rotations in Bangladesh

Cropping under conservation agriculture (CA) has become increasingly attractive among farmers in recent years. However, weed control may be more difficult during the transition to CA from conventional establishment methods due to the reduction in tillage intensity. Conversely, CA changes to weed dynamics can alter the weed seed bank in the longer run. In Bangladesh’s intensively cropped rice-based rotations, the nature of weed seed bank shifts over time after adopting CA are poorly known. Two 2-year studies were sampled from on-farm CA experiments under wheat-mungbean-winter rice and monsoon rice-mustard-winter rice rotations. We investigated the effects of reduced soil disruption in the form of strip-tillage (ST) combined with increased deposition of standing reside from previous crops (0 vs. 50%). The weed seed bank in 0–5, 5–10, and 10–15 cm depths of soil were quantified in a shade-house experiment by measuring weed emergence over 12 months in seedling trays. After 2 years of field study, the year-round count of emerged weeds from the seed bank showed that ST plus 50% mulch had a lower weed abundance and biomass and fewer weed species than that of conventional tillage (CT) without residue. The perennial weeds Ageratum conyzoides L., Alternanthera philoxeroides L., Cynodon dactylon L., Cyperus rotundus L., Jussia decurrence Walt., Leersia hexandra L., Scirpus mucronatus (L.) Palla., and Solanum torvum Sw. were enriched in the smaller-sized ST seed banks in terms of both density and biomass. The CT, on the other hand, was dominated by annual weeds: Cyperus difformis L., Cyanotis axillaris Roem., Echinochloa crus-galli (L.) Beauv., Eleusine indica L., Fimbristylis miliacea (L.) Vahl., and Rotala ramosior L. Overall, ST plus 50% residue had a more diverse seed bank than CT without mulch. The majority of weed seeds were amassed in the 0–5 cm soil depth of the ST, while most of them were accumulated in the 10–15 cm layer of the CT. The wheat-mungbean-winter rice rotation had a more diverse floristic composition with many more weed species than the monsoon rice-mustard-winter rice rotation.

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Continuous Practice of Conservation Agriculture for 3–5 Years in Intensive Rice-Based Cropping Patterns Reduces Soil Weed Seedbank

Agriculture ◽

10.3390/agriculture11090895 ◽

2021 ◽

Vol 11 (9) ◽

pp. 895

Author(s):

Mohammad Mobarak Hossain ◽

Mahfuza Begum ◽

Abul Hashem ◽

Md. Moshiur Rahman ◽

Md. Enamul Haque ◽

...

Keyword(s):

Species Diversity ◽

Seed Bank ◽

Conservation Agriculture ◽

Conventional Tillage ◽

Cyperus Rotundus ◽

Control Treatment ◽

Weed Seed ◽

Solanum Torvum ◽

Gangetic Plain ◽

Density And Biomass

When farmers first shift from conventional tillage (CT) to conservation agriculture (CA) practices, the control of weeds may be more difficult, due to the absence of tillage. However, continuous CA, over several years, may alter the weed seedbank. The nature of the weed seedbank changes over time, in intensively cropped rice-based rotations that are typical of the Eastern Gangetic Plain, are not well understood. Two on-farm CA experiments were sampled (in Beluapara after 3 years and Digram after 5 years) in Bangladesh for the effects of strip planting (SP) and bed planting (BP) at both the sites, plus no-tillage (NT) in Beluapara, and increased retention of the residue of previous crops (20% vs. 50%). The conventional tillage (CT) and 20% residue was the control treatment. The weed seedbank in 0–15 cm soil was quantified by assessing the emergence of weeds from soils collected from the field after irrigation, (Boro) rice in Digram and wheat in Beluapara, and they were allowed to emerge in trays in a shade-house experiment. The year-round count of emerged weeds at both the locations revealed the fewest number of weed species (especially broadleaf weeds), and the lowest weed density and biomass in SP, followed by CT, BP, and NT, with 50% crop residue mulch. Relative to CT, the SP, BP, and NT produced relatively more perennials weeds, as follows: Alternanthera denticulata ((R.) Brown.), Cyperus rotundus (L.), Dentella repens (L.), Jussia deccurence (Walt.), Leersia hexandra (L.), and Solanum torvum (Sw.), which was the opposite of CT that was enriched with the following annual weeds: Cyperus iria (L.), Digitaria sanguinalis (L.), Euphorbia parviflora (L.), Fimbristylis miliacea (L.), Lindernia antipoda (L.), L. hyssopifolia (L.), and Monochoria hastata (L.). The soil weed seed bank reduced by 13% in SP, while it increased by 19% and 76% in BP and NT, respectively, compared with CT. The species diversity reduced in SP and NT, by 24% and 11%, respectively, but increased by 2% in BP. In 50% residue, the soil weed seed bank and species diversity reduced by 16% and 14%, respectively, relative to that of 20% residue. The continuous practice of CA, for 3 or more years, in two rice-based crop rotations, decreased the size of the weed seedbank, but increased the relative proliferation of specific perennial weeds.

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Diversities of soil weed seed bank and rice yield performance in response to tillage method and weeding regime

Progressive Agriculture ◽

10.3329/pa.v27i1.27533 ◽

2016 ◽

Vol 27 (1) ◽

pp. 39-47

Author(s):

MM Hossain ◽

MO Faruk ◽

M Begum ◽

MA Salam

Keyword(s):

Seed Bank ◽

Rice Field ◽

Cynodon Dactylon ◽

Conventional Tillage ◽

Cyperus Rotundus ◽

Azolla Pinnata ◽

Weed Seed ◽

Weed Species ◽

Broad Leaf ◽

Paspalum Distichum

Rice field was infested with eight weed species. Among the species found in conventionally tilled plots, the five dominant species ranked in order of importance value were Cynodon dactylon (L.), Paspalum distichum (L.), Cyperus rotundus (L.), Azolla pinnata (L.) and Cyanotis axillaris (L.) while in stale seedbed the rank was Paspalum distichum (L.), Cynodon dactylon (L.), Cyanotis axillaris (L.), Leersia hexandra (L.) and Cyperus rotundus (L.). There were 15 weed species found in the soil weed seed bank studied at the net house. Among them five species were common of rice field. Ten new species were found in the seed bank. Azolla pinnata (L.), Cyperus difformis (L.) and Paspalum commersonii (L.) of field rice were not found in net house seed bank. In the field, Cynodon dactylon (L.) was the dominant over Paspalum distichum (L.) but at the net house Paspalum distichum (L.) was dominant over Cynodon dactylon (L.). In seed bank under conventional tillage, 11 species were found consisting of 3559 heads count and in stale seedbed 12 species consisting 3826 heads were counted. Among the identified species, nine were common in both tillage practice. Parapholis strigose (Dumort.) and Phyllanthus niruri (L.) were present in the soil of conventional tillage but not in stale bed while Echinochloa colonum (L.), Fimbristylis miliaceae (L.) and Eragrotis gangetica (Roxb.) were found in stale bed but not in conventional tillage. At the rice field grass weeds were dominant over sedges and broad leaf under the both types of tillage. At the seed bank of net house, grass weeds were dominant over sedges and broadleaf under conventional tillage while under stale seedbed, sedges were dominant over broad leaf and grass. Around 7% higher grain was recorded from stale seedbed compared to conventional tillage which attributed from higher number of effective tillers hill-1, higher number of fertile grains panicle-1, and lower number of sterile grains panicle-1. Weed free condition yield the highest grains followed by the combination of pre and post-emergence herbicides and unweeded control yielded the lowest. Stale seedbed kept weed free yielded the highest followed by stale seedbed sprayed the two herbicides. Conventional tillage remained unweeded yielded the lowest grain.Progressive Agriculture 27 (1): 39-47, 2016

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Evaluation of Different Weed Management Practices on Growth Variables and Yield of Wheat Varieties

Asian Plant Research Journal ◽

10.9734/aprj/2020/v5i430112 ◽

2020 ◽

pp. 7-30

Author(s):

Md. Golam Mostafa ◽

Syed Arvin Hassan ◽

Md. Ehsanul Haq ◽

Md. Ahasan Habib ◽

Kaniz Fatema ◽

...

Keyword(s):

Grain Yield ◽

Weed Management ◽

Management Practices ◽

Cynodon Dactylon ◽

Chenopodium Album ◽

Cyperus Rotundus ◽

Alternanthera Philoxeroides ◽

Weed Species ◽

Wheat Varieties ◽

Hand Weeding

A field experiment was conducted in medium fertile soil at Sher-e-Bangla Agricultural University, Dhaka, Bangladesh during November 2017 to April 2018 in Rabi season with a view to evaluate the performance of wheat varieties under different weed control methods. The experiment was carried out with three varieties i.e. BARI Gom-28, BARI Gom-29 and BARI Gom-30 in the main plot and five weed management methods viz. control (no weeding), two hand weeding at 20 and 40 DAS, Panida 33EC (Pendimethalin) @ 2000 ml ha-1 at 5 DAS pre-emergence, Afinity 50.75WP (Isoproturon) 1500 g ha-1 at 25 DAS as post-emergence herbicide and Panida 33EC (Pendimethalin) @ 2000 ml ha-1 at 5 DAS + Afinity 50.75WP (Isoproturon)1500 g ha-1 at 25 DAS in the sub plot in split plot design. Nine different major weed species were found in the field such as Cynodon dactylon, Cyperus rotundus, Echinochloa colonum, Eleusine indica, Chenopodium album, Alternanthera philoxeroides, Brassica kaber, Leliotropium indicum, Vicia sativa. Results reveled that BARI Gom-30 contributed the highest grain yield 3.01 tha-1. Pre-emergence application of Panida 33EC controlled weeds significantly which showed highest growth followed by yield achieved in wheat. BARI Gom-30 in combination with Panida 33EC produced the highest grain yield 3.52 tha-1 while the lowest grain yield 2.09 t ha-1 was obtained from BARI Gom-28 with no weeding treatment. Results reveled that Panida 33EC (pre-emergence) was found more effective to controlling weeds in wheat. Results of the study finally reveled that Panida 33EC might be considered as a feasible option for combating weed and ensuring higher yield in wheat cultivation.

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Relation between Soil Weed Seedbank and Weed Management Practises and Diversity in Farms in Kisii Central Sub County, Nyanza

Journal of Horticulture and Plant Research ◽

10.18052/www.scipress.com/jhpr.10.1 ◽

2020 ◽

Vol 10 ◽

pp. 1-14

Author(s):

Charles N. Nyamwamu ◽

Rebecca Karanja ◽

Peter Mwangi

Keyword(s):

Seed Bank ◽

Weed Management ◽

Management Practices ◽

Soil Seed Bank ◽

Shannon Index ◽

Weed Seed ◽

Weed Species ◽

Western Kenya ◽

Weed Diversity ◽

Hand Weeding

This study sought to determine the relation between soil weed seed bank and weed management practices and diversity in farms in Kisii Central Sub County, Western Kenya. Eight administrative sub-locations were randomly selected. Ten farms were selected at equal distance along transect laid across each sub-location. Weed soil seed bank was assessed from soil samples collected from each of the farms; a sub-sample was taken from a composite sample of ten soil cores of 5cm diameter and 15cm deep and placed in germination trays in a greenhouse. Weed diversity in soil weed seedbank was calculated using the Shannon index (H’). Twelve weed species from 12 genera of nine families were recorded. Diversity of the weed species in soil weed seed bank was (H'=1.48). Weed management practises significantly affected weed species soil weed seedbank reserves. Use of inefficient and ineffective hand-weeding techniques resulted in high weed species diversity and abundance.

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Solar Heating of the Soil: Involvement of Environmental Factors in the Weed Control Process

Weed Science ◽

10.1017/s0043174500058653 ◽

1984 ◽

Vol 32 (1) ◽

pp. 138-142 ◽

Cited By ~ 47

Author(s):

Baruch Rubin ◽

Abraham Benjamin

Keyword(s):

Cynodon Dactylon ◽

Soil Depth ◽

Control Process ◽

Solar Heating ◽

Cyperus Rotundus ◽

Weed Species ◽

Purple Nutsedge ◽

Deep Layers ◽

Hot Season ◽

Vegetative Propagules

Solar heating (SH) of wet soil by mulching it with transparent polyethylene (PE) during the hot season increased soil temperature in a typical daily course which varied with soil depth. Annual weed species responded to soil heating in the laboratory with the same pattern as under SH conditions in the field. Rhizomes of bermudagrass (Cynodon dactylonL. Pers. ♯3CYNDA) and johnsongrass (Sorghum halepenseL. Pers. ♯ SORHA) were very sensitive to heat treatment, but purple nutsedge (Cyperus rotundusL. ♯ CYPRO) tubers were able to survive temperatures as high as 80 C for 30 min. Species having big and heavy seeds or vegetative propagules were able to emerge from deep layers of soil, thus practically escaping the lethal temperature prevailing in the upper layer. Transparent and black PE mulching effectively prevented water loss from soil, as compared with perforated PE and nonmulched control. CO2concentration in the soil atmosphere under transparent PE mulching increased rapidly during the first week and reached a maximal level which was 20-fold higher than that formed in nonmulched soil. Ethylene at 0.2 ppm was detected only in a mulched soil environment. No differences in levels of CH4or CO were detected.

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Effect of tillage method and weeding regime on soil weed seed bank status and yield performance of wheat

Progressive Agriculture ◽

10.3329/pa.v27i1.27528 ◽

2016 ◽

Vol 27 (1) ◽

pp. 9-19

Author(s):

MJ Khatun ◽

M Begum ◽

MM Hossain

Keyword(s):

Grain Yield ◽

Seed Bank ◽

Cynodon Dactylon ◽

Chenopodium Album ◽

Conventional Tillage ◽

Weed Seed ◽

Weed Species ◽

Sonchus Arvensis ◽

Tillage Method ◽

Tillage Methods

An experiment was conducted at the Agronomy Field Laboratory and net house of the Department of Agronomy, Bangladesh Agricultural University, Mymensingh from November 2012 to March 2014. Wheat (cv. BARI Gom-26) was sown with two tillage methods viz., (i) conventional tillage and (ii) stale seedbed technique and nine weeding regimes viz., (i) Unweeded (Control), (ii) Weed free, (iii) Hand weeding (HW) at 15 Days after sowing (DAS), (iv) HW at 15 and 45 DAS, (v) HW at 25 and 45 DAS (vi) HW at 25 DAS (vii) HW at 25 and 60 DAS (viii) 2,4-D amine at 15 DAS and (ix) 2,4-D amine at 15 DAS + HW at 60 DAS. The design was split-plot with three replications where tillage method was assigned to the main plots and weeding regime to the sub plots. Conventionally tilled plots were infested with 12 weed species of which the five most dominant weed species in descent order were Polygonum coccineum L, Chenopodium album L, Cynodon dactylon L., Sonchus arvensis L. and Cyperus rotundus L. In stale seedbed out of 15 weed species Digitaria sanguinalis L. and Hedyotis corymbosa (L.) Lamk. was dominant instead of Chenopodium album L. and Sonchus arvensis L. identified in conventional tillage. In soil weed seed bank study, 28 species were identified in conventional tillage and 30 in stale seedbed. Among them annuals were dominant over perennials and broadleaves over grasses and sedges. In conventional tillage, the five most dominant weed species in descent order were Chenopodium album L., Hedyotis corymbosa L., Sonchus arvensis L., Polygonum coccineum L. and Rotala ramosior L. while in stale seedbed, five dominant weeds were Polygonum coccineum L., Chenopodium album L., Cynodon dactylon L., Lindernia procumbens Krock. and L. hyssopifolia L. Except the number of spikelets spike-1, rest of all other yield attributes and yield of wheat were affected significantly by the tillage methods. Stale seedbed technique yielded the higher grain (3.54 t ha-1) and the conventional tillage yielded the lower (3.13 t ha-1). The effect of weeding regime was significant on wheat except plant height and 1000-grain weight. The highest grain yield (3.85 t ha-1) was recorded from weed free treatment followed by 2,4-D amine at 15 DAS and lowest (3.22 t ha-1) from control. Interaction between the treatments was also. The highest grain yield (4.09 t ha-1) was recorded from the stale seedbed technique kept weed free followed by 2,4-D amine at 15 DAS and lowest grain yield (3.04 t ha-1) recorded from the conventional tillage retained unweeded.Progressive Agriculture 27 (1): 9-19, 2016

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Effects of Initial Seed-Bank Density on Weed Seedling Emergence during the Transition to an Organic Feed-Grain Crop Rotation

Weed Science ◽

10.1614/ws-09-031.1 ◽

2009 ◽

Vol 57 (5) ◽

pp. 533-540 ◽

Cited By ~ 10

Author(s):

Richard G. Smith ◽

Randa Jabbour ◽

Andrew G. Hulting ◽

Mary E. Barbercheck ◽

David A. Mortensen

Keyword(s):

Seed Bank ◽

Weed Management ◽

Cover Crop ◽

Management Practices ◽

Transition Period ◽

Red Clover ◽

Weed Seed ◽

Weed Species ◽

Organic Certification ◽

Weed Seeds

The transition period to certified organic production can present a significant weed management challenge for growers. Organic certification requires that prohibited fertilizers and pesticides must not have been used for 36 mo before harvest of the first organic crop. Understanding how organic management practices and initial weed seed-bank densities affect weed population dynamics during the transition period may improve weed management efficacy and adoption of organic practices. We examined how tillage systems (full or reduced) and cover crop species planted during the first transition year (rye or a mixture of timothy and red clover) affect the seedling densities of three common annual weed species, common lambsquarters, velvetleaf, and foxtail spp., during the 3-yr transition period. Weed seeds were applied in a one-time pulse at the beginning of the study at three densities, low, medium, and high (60, 460, and 2,100 seeds m−2, respectively), and cumulative seedling densities of each species were assessed annually. Treatment factors had variable and species-specific effects on weed seedling densities. In general, the full-tillage system, with an initial cover crop of timothy and red clover, resulted in the lowest density of weed seedlings following seed-bank augmentation. There was little consistent association between the initial densities of applied weed seeds in the weed seed bank at the start of the transition and weed seedling densities at the end of the transition period. This suggests that when multiple crop and weed cultural management practices are employed during the organic transition period, initial failures in weed management may not necessarily lead to persistent and intractable annual weed species management problems following organic certification.

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REVIEW OF THE INFLUENCE OF CROP ROTATION AND PRIMARY TILLAGE OPERATIONS ON WEED SEED BANK

International Journal of Research -GRANTHAALAYAH ◽

10.29121/granthaalayah.v9.i7.2021.4131 ◽

2021 ◽

Vol 9 (7) ◽

pp. 407-421

Author(s):

Nawal Al-Hajaj

Keyword(s):

Seed Production ◽

Crop Rotation ◽

Seed Bank ◽

Seedling Recruitment ◽

Crop Productivity ◽

Crop Rotations ◽

Weed Seed ◽

Weed Species ◽

Primary Tillage ◽

Weed Emergence

In this study, we reviewed weed seed bank dynamic and main agriculture operations to come up with the weed seed management modeling designed to increase crop productivity by removing weed competition. Weed contributing with 10% loss of total global grain production. Weed seed bank regulate by five demographic processes seedling recruitment and survival, seed production, dispersal and seed survival in soil. The main agriculture operations that interference with weed seed bank are crop rotation and primary tillage. Tillage systems affect weed emergence, management, and seed production; therefore, changing tillage practices changes the composition, vertical distribution, and density of weed seed bank in agricultural soils. Weed species vary in their response to various crop rotations, due to the variability of weed-crop competition in their relative capacity to capture growth–limiting resources. Crop rotations affect weed emergence, management, composition, and density of weed seed bank. Finally, the study suggests elevating crop competitiveness against weeds, through a combination of crop rotation and reduce_ zero tillage, has strong potential to reduce weed-induced yield losses in crop.

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Changes in the Weed Seed Bank in Long-Term Establishment Methods Trials under Rice-Wheat Cropping System

Agronomy ◽

10.3390/agronomy10020292 ◽

2020 ◽

Vol 10 (2) ◽

pp. 292

Author(s):

Prashant Sharma ◽

Manoj Kumar Singh ◽

Kamlesh Verma ◽

Saroj Kumar Prasad

Keyword(s):

Species Richness ◽

Seed Bank ◽

Weed Management ◽

Soil Depth ◽

Block Design ◽

Cropping System ◽

Field Trials ◽

Management Program ◽

Weed Seed ◽

Design Factor

The rice–wheat cropping system in the Indo-Gangetic Plains is the backbone of food security in India. In the 1990s, due to the scarcity of resources, the traditional Crop Establishment (CE) method shifted from Conventional Till Puddle Transplanted Rice (CTPTR) to CT Direct Seeded Rice (CTDSR) and Zero-Till DSR (ZTDSR) in paddy; and in wheat, from Conventional Till Wheat (CTW) to Zero Till Wheat (ZTW), with residue retention in rice (RRR) or in both rice and wheat (RRRW). Shift in CE methods led to change in Weed Seed Bank (WSB) dynamics and ultimately affected the weed management program. After five years of field trials, soil samples were drawn as per 2-factors factorial randomized block design. Factor-I comprised 4-CE methods, whereas factor-II consisted of 3-soil depths (0–10, 10–20 and 20–30 cm). Results showed CTPTR-CTW and ZTDSR-ZTW (RRRW) record the highest seed bank (SB) of grasses, sedges and BLWs as total weeds, in general; and predominant weeds like Echinochloa spp., Ammania baccifera, Commelina benghalensis and Digitaria sanguinalis, in particular. It also showed the higher species richness (DMg) and Shannon–Weaver (H’) indices. CTDSR-CTW and CTDSR-ZTW (RRR) show the lowest WSB and at par with Shannon–Weaver (H’) index; further, lowest species richness (DMg) under CTDSR-CTW. Species Evenness (J’) and Simpson index (λ) vary non-significantly with CE methods. Furthermore, 0–10 cm soil depth showed the highest SB of different category of total weed, predominant weeds as well as higher values of DMg, H’, and λ; whereas reverse trend was observed in Whittaker Statistic (βW). Interaction between CE methods and soil depth revealed most of WSB lying on the top layer in case of ZTDSR-ZTW (RRRW) and CTDSR-ZTW (RRR); while CTPTR-CTW showed almost uniform WSB distribution, and in case of CTDSR-CTW, a gradual decrease in WSB with soil depth.

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Seed bank characterization and emergence of a weed community in a moldboard plow system

Weed Science ◽

10.1017/s004317450009247x ◽

1997 ◽

Vol 45 (1) ◽

pp. 54-60 ◽

Cited By ~ 20

Author(s):

Dawit Mulugeta ◽

David E. Stoltenberg

Keyword(s):

Seed Bank ◽

Field Experiments ◽

Negative Binomial ◽

Soil Disturbance ◽

Weed Seed ◽

Weed Species ◽

Common Lambsquarters ◽

Redroot Pigweed ◽

Viable Seeds ◽

Moldboard Plow

Field experiments were conducted in 1992 and 1993 to characterize the weed seed bank, to determine the influence of moldboard plowing and secondary soil disturbance on the emergence pattern of weeds, and to measure weed seed bank depletion by emergence in a long-term moldboard plow corn cropping system. Viable seeds of common lambsquarters, redroot pigweed, and each of 10 other species accounted for about 85, about 9, and less than 1%, respectively, of the total weed species in the seed bank. A negative binomial distribution described the spatial distribution of viable seeds of 10 species, but not of common lambsquarters or of redroot pigweed. Decreased density of seeds among species was associated with increased aggregation. Secondary soil disturbance increased the rate and magnitude of common lambs quarters emergence in 1992 but did not influence emergence in 1993. Secondary soil disturbance did not influence the magnitude and rate of emergence of redroot pigweed or velvetleaf. Whereas cumulative growing degree days from April through July were similar between years, the amount of rainfall was about 50% less in 1992 than in 1993. Secondary soil disturbance may have increased common lambsquarters emergence by increasing the availability of soil moisture and improving conditions for seed germination during the dry year. Even though seed bank depletion by seedling emergence was relatively low for all species, secondary soil disturbance in creased seed bank depletion of common lambsquarters and redroot pigweed about 7- and 3-fold, respectively, in 1992. Seasonal variation in the amount of rainfall may have influenced the effect of soil disturbance on emergence and seed bank depletion of common lambsquarters, which is the most abundant species in the weed community.

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