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

Agronomy ◽  
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.

scholarly journals Responses of weed community, soil nutrients, and microbes to different weed management practices in a fallow field in Northern China

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7650 ◽  
Author(s):  
Xian Gu ◽  
Yu Cen ◽  
Liyue Guo ◽  
Caihong Li ◽  
Han Yuan ◽  
...  
Keyword(s):  
Soil Fertility ◽  
Soil Nutrients ◽  
Seed Bank ◽  
Weed Management ◽  
Seed Banks ◽  
Total Biomass ◽  
Weed Seed ◽  
Soil Biodiversity ◽  
Deep Tillage ◽  
Positive Effects

The long-term use of herbicides to remove weeds in fallow croplands can impair soil biodiversity, affect the quality of agricultural products, and threaten human health. Consequently, the identification of methods that can effectively limit the weed seed bank and maintain fallow soil fertility without causing soil pollution for the next planting is a critical task. In this study, four weeding treatments were established based on different degrees of disturbance to the topsoil: natural fallow (N), physical clearance (C), deep tillage (D), and sprayed herbicide (H). The changes in the soil weed seed banks, soil nutrients, and soil microbial biomass were carefully investigated. During the fallow period, the C treatment decreased the annual and biennial weed seed bank by 34% against pretreatment, whereas the H treatment did not effectively reduce the weed seed bank. The D treatment had positive effects on the soil fertility, increasing the available nitrogen 108% over that found in the N soil. In addition, a pre-winter deep tillage interfered with the rhizome propagation of perennial weeds. The total biomass of soil bacterial, fungal, and actinomycete in H treatment was the lowest among the four treatments. The biomass of arbuscular mycorrhizal fungi in the N treatment was respectively 42%, 35%, and 91%, higher than that in the C, D, and H treatments. An ecological weeding strategy was proposed based on our findings, which called for exhausting seed banks, blocking seed transmission, and taking advantage of natural opportunities to prevent weed growth for fallow lands. This study could provide a theoretical basis for weed management in fallow fields and organic farming systems.

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

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.

Residual Effect of Weed Management Practices Executed in Preceding Maize on Succeeding Greengram

2021 ◽  
Author(s):  
B. Sandhya Rani ◽  
V. Chandrika ◽  
G. Prabhakara Reddy ◽  
P. Sudhakar ◽  
K.V. Nagamadhuri ◽  
...  
Keyword(s):  
Weed Management ◽  
Management Practices ◽  
Block Design ◽  
Residual Effect ◽  
Cropping System ◽  
Dry Weight ◽  
Microbial Count ◽  
Yield Attributes ◽  
Randomized Block Design ◽  
Weed Infestation

Background: Maize followed by summer pulses is the emerging cropping system in many places in India. Herbicides are the efficient tools for checking weed infestation and their usage is increasing throughout the globe due to increased labour cost and quick weed control. Some herbicides do not degrade quickly and may remain in the soil for weeks, months or years after application and may inhibit the growth of succeeding crops. Methods: Field experiment was conducted in a randomized block design (RBD) during rabi and summer seasons of 2017-18 and 2018-19 to know the residual effect of different herbicides applied in maize on succeeding greengram. Result: The present study revealed that lower density and dry weight of total weeds and higher yield attributes and yield was recorded with the practice of adopting two hand weedings at 15 and 30 DAS, which was however, at par with atrazine 1.0 kg ha-1 as PE fb one HW at 30 DAS, atrazine 1.0 kg ha-1 as PE fb topramezone 30 g ha-1 as PoE and atrazine 1.0 kg ha-1 as PE fb tembotrione 120 g ha-1 as PoE, without any significant disparity among them. Herbicides applied in maize did not alter statistically the enzyme activity and microbial count in the soil at harvest of succeeding greeengram. 

scholarly journals A “Stressed” Alfalfa-Based Cropping System Leads to the Selection of Quizalofop-Resistant Italian Ryegrass (Lolium perennessp.multiflorum)

Weed Science ◽  
2016 ◽  
Vol 64 (4) ◽  
pp. 683-694 ◽  
Author(s):  
Alberto Collavo ◽  
Silvia Panozzo ◽  
Antonio Allegri ◽  
Maurizio Sattin
Keyword(s):  
Ethyl Ester ◽  
Seed Production ◽  
Weed Management ◽  
Cropping System ◽  
Italian Ryegrass ◽  
Integrated Weed Management ◽  
Forage Production ◽  
Weed Seed ◽  
Quizalofop Ethyl ◽  
Selection Of

Italian ryegrass populations investigated in this study were harvested in an alfalfa-based cropping system. In that system, the agronomic practices and chemical weed management, based on the use of aryloxyphenoxy-propionates herbicides (i.e., quizalofop ethyl ester), were optimized to obtain a dual seed–forage production. Five of seven populations tested were confirmed resistant to quizalofop ethyl ester with resistance indexes ranging from 4.5 to >209. Both target- and nontarget-site resistance mechanisms were most likely involved. Three allelic variants were detected (Ile-1781–Leu, Trp-2027–Cys, and Ile-2041–Asn) in four resistant populations, whereas no known mutations were found in one resistant population. The herbicide treatment on Italian ryegrass plants at different phenological stages suggested that to control regrowth, it is necessary to use two to fives times the herbicide dose suitable for younger plants. This situation is encountered in fields when Italian ryegrass plants need to be controlled to maximize the alfalfa seed production, and it is comparable to using a sublethal herbicide dose, leading to the selection of herbicide-resistant biotypes. In such a situation, the cropping system is not sustainable, and integrated weed management should be implemented to deplete the soil weed seed bank and prevent new weed seed production.

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

Weed Science ◽  
2009 ◽  
Vol 57 (5) ◽  
pp. 533-540 ◽  
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.

scholarly journals Yield response and economic implications of soybean (Glycine max (L.). Merrill) – lowland-upland rice sequential cropping in the rainforest/savanna transitory ecosystem

2017 ◽  
Vol 109 (3) ◽  
pp. 529
Author(s):  
Paul Abayomi Sobowale SOREMI ◽  
Olalekan Sulaimon SAKARIYAWO ◽  
Kehinde Adebayo OKELEYE ◽  
Victor Idowu O. OLOWE ◽  
Jamiu Oladipupo AZEEZ ◽  
...  
Keyword(s):  
Upland Rice ◽  
Block Design ◽  
Cropping System ◽  
Field Trials ◽  
Yield Response ◽  
Economic Implications ◽  
Glycine Max L ◽  
Main Plot ◽  
Conventional Ct ◽  
Sequential Cropping

<p>A sequential cropping system of soybean-lowland (NERICA L-42)-upland (NERICA 2) rice was established at Abeokuta and Ibadan (Nigeria) to evaluate the performance of the cropping system. Field trials were in split-split plot arrangement fitted into randomised complete block design and replicated three times. The first sequence had in the main plot tillage [minimum (MT) and conventional (CT)]. Soybean varieties TGx 1448-2E (V1) and TGx 1740-2F (V2) in sub-plot and spacing in sub-sub plot were 60 cm × 5 cm (R1), 60 cm × 10 (R2) and 60 cm × 15 cm (R3). Individual rice plots were established by dry dibble (DD) seeding and transplanting and sub-sub plot spacing were 15 cm × 15 cm (S1), 20 cm × 20 and 25 cm (S2) × 25 cm (S3). The sequence soybean (V1 CT R3); lowland and upland rice (S3 CT DD) was the most economically efficient (N 1,754 ha<sup>-1</sup> day<sup>-1</sup>) in Abeokuta, while soybean (V1 MT R1) and lowland and upland rice (S1 DD MT) was the most economically efficient (N 1,858 ha<sup>-1</sup> day<sup>-1</sup>) in Ibadan.</p>

scholarly journals Chemical Weed Management in Transplanted Rice (Oryza sativa L.) under Rice – Mustard Cropping System

2020 ◽  
pp. 63-72
Author(s):  
Rupen Sharma ◽  
Jaladhar Gorain ◽  
Parthendu Poddar ◽  
Sagar Maitra ◽  
Manjil Pandey
Keyword(s):  
Sodium Salt ◽  
Weed Management ◽  
Oryza Sativa L ◽  
Management Practice ◽  
Block Design ◽  
Rice Variety ◽  
Cropping System ◽  
Transplanted Rice ◽  
Randomized Block Design ◽  
Stover Yield

An experiment was conducted at instructional farm Uttar Banga Krishi Viswavidyalaya during kharif season, 2017 to find out a suitable chemical weed management practice in transplanted rice. The experiment was laid out in randomized block design having 12 treatments replicated thrice. The treatments were T1: Weedy check, T2: Weed free, T3: Bispyribac sodium 10% SC @ 20 g a.i ha-1 at 14 DAT, T4: Bispyribac sodium 10% SC @ 30 g a.i  ha-1 at 14 DAT, T5: Butachlor 1.5 kg a.i ha-1 at 3 DAT, T6: Pendimethalin 1.0 kg a.i. ha-1 at 3 DAT, T7: Pretilachlor 0.60 kg a.i ha-1 at 3 DAT + 2,4-D sodium salt 0.50 kg a.i ha-1 at 30 DAT, T8: Butachlor 1.5 kg a.i ha-1 at 3 DAT + 2,4-D sodium salt 0.50 kg a.i ha-1 at 30 DAT, T9: Metsulfuron methyl 20% WP @ 8 g a.i ha-1 at 14 DAT, T10: Pretilachlor 0.60 kg a.i ha-1 at 3 DAT + Almix @ 20 g a.i. ha-1 at 21 DAT, T11: Butachlor 1.5 kg a.i. ha-1 at 3 DAT + Bispyribac sodium 10% SC @ 20 g a.i  ha-1 at 21 DAT and T12: Almix @ 20 g a.i ha-1 at 21 DAT. The rice variety used in the experiment was MTU 1075. It was observed that different herbicides treatments influenced weed control efficiency, weed index and yield components in transplanted rice. The highest number of filled grains (113.12 panicle-1), 1000 grain weight (22.90 g), grain yield (5.07 t ha-1) and straw yield (7.15 t ha-1) of rice was recorded with weed free (T2) treatment being at par with T11, T4, T3 and T10. In mustard, plots under weed free i.e. T2 treatment in rice performed the best in terms of every yield attribute viz. number of siliqua (77.00 plant-1), number of seeds (20.41siliqua-1), 1000 seed weight (3.14 g) as well as seed yield (1067.46 kg ha-1) and stover yield (2157.40 kg ha-1) being statistically at par with the plots under treatment T11 & plots under treatment T4. It can be concluded that the treatment comprising combination of pre-emergence & post-emergence herbicide like T11 i.e. Butachlor 1.5 kg a.i. ha-1 at 3 DAT + Bispyribac sodium 10% SC @ 20 g a.i. ha-1 at 21 DAT or application of higher dose of efficient & highly effective post-emergent herbicide molecule like T4 i.e. Bispyribac sodium 10% SC @ 30 g a.i  ha-1 at 14 DAT can be opted for sufficient control of weeds in transplanted kharif paddy in terai zone of West Bengal to maximize the economic return.

scholarly journals Do Tillage Methods Affect Germination and Species Similarity of Soil Weed Seeds Bank?

2015 ◽  
Vol 18 (4) ◽  
pp. 97-101
Author(s):  
Hassan Shahgholi ◽  
Hassan Makarian ◽  
Behzad Shokati ◽  
Ghassem Hossein Talaei ◽  
Mohammad Reza Asgharipour
Keyword(s):  
Seed Bank ◽  
Dominant Species ◽  
Block Design ◽  
Chenopodium Album ◽  
Similarity Index ◽  
Amaranthus Retroflexus ◽  
Weed Seed ◽  
Weed Seeds ◽  
Species Similarity ◽  
Tillage Methods

AbstractCultural practices such as tillage used for crop production influence the composition of the weed seed bank in the soil. In order to investigate the effects of different tillage methods on seed bank properties, species diversity and similarity, two laboratory and greenhouse experiments were carried out as randomized complete block design with four replications in 2011. Treatments included: once tillage per year (T1), twice tillage per year (T2), more than twice tillage (T3) and no tillage (T4). Laboratory results showed that the T3 and T4 treatments had the highest and the lowest observed seeds numbers, respectively. Between the laboratory observed weed seeds, the maximum weed seed numbers were Echinochloa crus-galli and Amaranthus retroflexus in the T3 treatment, while Chenopodium album, Polygonum aviculare and Cuscuta campestris had the highest seed numbers in the T2 treatment. At the greenhouse study, Chenopodium album, Amaranthus retroflexus and Hordeum morinum in the T2 treatment were dominant species. The highest diversity was observed in the T2 treatment, and Chenopodium album and Echinochloa crus-galli were dominant species in the T2 and T3 treatments. Maximum species similarity index was achieved from the T1 and T3 treatments. Thereby this study concluded that increasing of tillage number could affect the similarity index of weed seeds and subsequently alters the weed community composition.

Impact of forest fire on soil seed bank composition in Himalayan Chir pine forest

2019 ◽  
Vol 13 (2) ◽  
pp. 177-184
Author(s):  
Bobbymoore Konsam ◽  
Shyam S Phartyal ◽  
Nagendra P Todaria
Keyword(s):  
Species Richness ◽  
Forest Fire ◽  
Seed Bank ◽  
Soil Depth ◽  
Soil Seed Bank ◽  
Pine Forest ◽  
Seed Density ◽  
Postfire Regeneration ◽  
Standing Vegetation ◽  
Chir Pine

Abstract Aims To explain how plant community copes with a recurring anthropogenic forest fire in Himalayan Chir pine forest, it is important to understand their postfire regeneration strategies. The primary aim of the study was to know: (i) how fire impact soil seed bank composition and (ii) how much soil seed bank composition differs with standing vegetation after the forest fire. Methods Soil samples were collected from burned and adjoining unburned sites in blocks using three layers down to 9 cm depth immediately after a forest fire and incubated in the net-house for seedling emergence. Same sites were revisited during late monsoon/early autumn season to know the species composition of standing vegetation recovered after a forest fire. Important Findings Soil contained viable seeds of &gt;70 species. The average seed bank density was 8417 and 14 217 seeds/m2 in the burned and unburned site, respectively. In both sites, it decreased with increasing soil depth. Overall fire had no significant impact on seed density; however, taking individual layers into consideration, fire had a significant impact on seed density only in the uppermost soil layer. The species richness of soil seed bank and standing vegetation was 73 and 100, respectively (with 35 shared species), resulting in a similarity of about 40%. In contrast, &gt;80% species in soil seed bank was found similar between burned and unburned sites. Further, there were no significant differences in species richness of standing vegetation in burned (87 spp.) and unburned (78 spp.) sites. Our results showed that fire had an insignificant impact on soil seed bank composition and restoration potential of a plant species from seeds. The understory herb and shrub plant community’s ability to form a fire-resistant viable soil seed bank and capable to recover in the postfire rainy season, explains how they reduce the risk of recurring fire damage in maintaining their population.

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