scholarly journals WEEDS IN SOYBEAN CULTIVATION WITH DIFFERENT PREDECESSOR COVER CROPS

2021 ◽  
Vol 8 (2) ◽  
pp. e5890
Author(s):  
Pedro Henrique Gomes Pinto ◽  
Sebastião Ferreira Lima ◽  
Maria Gabriela Oliveira Andrade ◽  
Lucymara Merquides Contardi ◽  
Jorgiani Ávila ◽  
...  

The competition between soybean and weeds affects crop development due to reduced resources such as water, light, and nutrients, leading to yield losses. Thus, the study aimed to evaluate quantitatively and qualitatively, through phytosociology and seed bank, the weed presence in a soybean cultivation area with different predecessor cover crops. The experiment was installed under no-till system conditions using a randomized block design with nine treatments and three replications. The treatments were composed of the following cover crops, sorghum (Sorghum bicolor), crotalaria (Crotalaria ochroleuca), millet (Pennisetum americanum), Urochloa ruziziensis, U. brizantha cv. Piatã, fodder radish (Raphanus sativus L.), U. brizantha cv. Xaraés, millet + fodder radish, and fallow. The soybean crop was established on the cover crops in the 2019/20 harvest. Soybean characteristics, the seed bank, and weed phytosociology were evaluated. The highest soybean yield was obtained with U. ruziziensis as predecessor cover crop, reaching 4530 kg ha-1. It was concluded that the following cover crops, sorghum, crotalaria, and millet, were the ones that most suppressed the soil weed seed bank. Contrarily, the fallow provided the greatest viable seed number. The weed species Eleusine indica, Digitaria insularis, and Cenchrus echinatus had higher phytosociological values in all treatments.

2014 ◽  
Vol 47 (2) ◽  
pp. 29-40 ◽  
Author(s):  
S. Hassannejad ◽  
A.R. Mobli

Abstract In order to evaluate the effects of some cover crops on extinction coefficient and weed cover percentage in sunflower, a field experiment was conducted based on a randomized complete block design with nine treatments and three replicates at the Agricultural Research Station, Tabriz University of Iran, during growing season 2012-2013. Treatments were triticale, hairy vetch, rapeseed, triticale + hairy vetch, triticale + rapeseed, hairy vetch + rapeseed, application of trifluralin herbicide, and controls (weed infested and weed free without planting cover crop). Result indicated than once established, living mulches can rapidly occupy the open space between the rows of the main crop and use the light that would otherwise be available to weeds. In the all cover crops treatments, the light extinction coefficient was increased and weed cover percentage was reduced. Highest reduction in total weed species was observed in hairy vetch + rapeseed and triticale + rapeseed cover crop 61.92% and 61.43 %, respectively, compared to weed infested, so this treatment was better than trifluralin application. It concluded that cover crops could be considered as integrated strategies for weed sustainable management.


Author(s):  
G. C. Michael ◽  
H. Tijani-Eniola ◽  
F. A. Nwagwu ◽  
O. W. Olaniyi

Aim: Competition from weeds is an obstacle to profitable maize production. Knowledge of weed species limiting productivity is essential for sustainable management. A two years field experiment was conducted to evaluate the effect of a leguminous cover crop, akidi (Vigna unquiculata sub-sp sequipedalis) and two non-leguminous cover crops (melon and sweet potato) planted at three densities on weed flora composition and shift in maize at Jalingo, North-eastern Nigeria. Study Design: There were 11 treatments replicated three times in a randomized complete block design. Methodology: Low, moderate and high densities (20,000, 30,000 and 40,000 stands/ha respectively) of Akidi, Melon and Sweet potato (A1, A2, A3, M1, M2, M3, S1, S2, S3) with weeded (C1) and unweeded (C2) checks constituted the treatments laid out in a randomized complete block design replicated three times. Weed flora abundance, percentage density, percentage frequency, frequency index and percentage contributions were determined from a 50cm x 50cm quadrat thrown twice per plot at various phases of maize growth. Results: Thirteen weed families made up of 11 broad leaves, one grass and one sedge were identified. The abundance was in the order Broad leaf > Grass > Sedges. The most abundant weed species were: Imperata cylindrica L (3.8), Mucuna utilis (3.0), Oldenlandia herbacea L. (2.6) Sida acuta Burm F, Tridax procumbens L. (2.5 each), Leucas martinicensis, Pennisetum pedicellatum (2.3 each). Commelina benghalensis, Cyperus difformis (3.5), Digitaria horizontalis, Fimbristylis littoralis (2.8 each). The influence of selected cover crops on individual weed percentage the contribution shows: Commelina benghalensis ( C2<C1 < M <S< A), Euphorbia hyssopifolia (C2<M/S < A<C1), Euphorbia heterophylla (M<S<A), Leucasmartinicensis (C1<C2<M<A<S), Mucunautilis (S<M<C1<C2<A) and Sida acuta (M<S<A<C2<C1) while grassy weeds, Imperata cylindrical (A<C2<S<M), Pennisetum pedicellatum (A<C2), Digitaria horizontalis (C1/ C2< A < M <S), Kyllinga squamulata (M/S <C2<A <C1). Commelina spp. increased in status from an accessory (21.2%) to abundance (66.7%) while others increased from rare to accessory (from 0.0 to 20-40%). Conclusion: Akidi was more effective on broad-leaved weeds while melon and sweet potato were more effective on grasses and Commelina benghalensis need to be monitored.


2013 ◽  
Vol 31 (4) ◽  
pp. 939-946
Author(s):  
P. Oliveira ◽  
A.S. Nascente ◽  
J. Kluthcouski ◽  
T.A.P. Castro

To achieve better results in the no-tillage system (NTS), it is important to properly manage the cover crop prior to planting by using herbicides, usually glyphosate. The effect of glyphosate on plant coverage is slow, and plants take a few days to die completely. Thus, when applying the herbicide on the same day of planting soybean or corn, cover crops are still alive and standing, causing initial shading on seedlings of the crop and delaying its establishment. Therefore, this study aimed to evaluate the effect of distinct cover crops and their timing of desiccation prior to planting soybean or corn, on crop yield and yield components. Two experiments were installed, one for soybean and another for corn. Each experiment consisted in combining three cover crops (Brachiaria brizantha, common bean or millet) chemically desiccated at two timings before planting the crop (15 or 0 days before planting) under no-tillage system (NTS). Experiments were installed in a completely randomized block design with five replications. Brachiaria brizantha produced the highest amount of biomass; common bean and millet as cover crops allowed higher soybean grain yields; herbicide application under common bean, millet and Brachiaria brizantha 15 days before planting soybean allowed higher crop grain yields; desiccation timing of common bean did not affect corn grain yield; Brachiaria brizantha should be desiccated 15 days before planting corn to allow maximum grain yield; when millet was used as a cover crop, glyphosate application at planting of corn allowed the highest grain yield.


2012 ◽  
Vol 42 (4) ◽  
pp. 614-620 ◽  
Author(s):  
Luciane Almeri Tabaldi ◽  
Maria do Carmo Vieira ◽  
Nestor Antonio Heredia Zárate ◽  
Luan Ramos da Silva ◽  
Wander Luiz Farias Gonçalves ◽  
...  

The use of cover crops can reduce or even eliminate the use of nitrogenous fertilizers, contributing to a more sustainable agriculture and ensuring the conservation of natural resources. Thus, the aim of this research was to evaluate the use of cover crops to improve the biomass yield of Serjania marginata plants. The experiment was carried out at the Federal University of Grande Dourados, in Dourados-MS, from December 2009 to February 2011. A split plot design was used in a randomized block design with four replications, being evaluated in plots three species of tropical legumes (Stizolobium aterrimum, Crotalaria spectabilis and Canavalia ensiformes, and one control plot (without cover crops), and in subplots the addition or not of nitrogen (N) (at 150 days after transplant (DAT)). Plants of S. marginata in each subplot were harvested at 240 and 350 DAT. S. aterrimum and C. ensiformes showed higher accumulation of fresh (average of 37.61t ha-1) and dry (average of 6.39t ha-1) biomass of shoot in flowering, compared with the C. spectabilis (21.92 and 4.63t ha-1, respectively). The contribution of cover crops as a likely source of N only was observed for S. aterrimum and C. ensiforme, which promoted an increase in chlorophyll index, leaf area, fresh and dry weight of leaves and stem of S. marginata plants, in absence of N. In leaves of S. marginata, only C. ensiformes contributed significantly to an increase in N levels, while an increase in K levels was observed with all cover crop treatments, when compared to control. Pre-cultivation with S. aterrimum and C. ensiformes provided an increase in P levels in leaves of S. marginata. Therefore, S. aterrimum and C. ensiformes were the most promising cover crops for growing of S. marginata, improving the biomass yield and probably the N economy.


Weed Science ◽  
2017 ◽  
Vol 65 (3) ◽  
pp. 426-439 ◽  
Author(s):  
Jeffrey A. Liebert ◽  
Antonio DiTommaso ◽  
Matthew R. Ryan

Maximizing cereal rye biomass has been recommended for weed suppression in cover crop–based organic no-till planted soybean; however, achieving high biomass can be challenging, and thick mulch can interfere with soybean seed placement. An experiment was conducted from 2012 to 2014 in New York to test whether mixing barley and cereal rye would (1) increase weed suppression via enhanced shading prior to termination and (2) provide acceptable weed suppression at lower cover crop biomass levels compared with cereal rye alone. This experiment was also designed to assess high-residue cultivation as a supplemental weed management tool. Barley and cereal rye were seeded in a replacement series, and a split-block design with four replications was used with management treatments as main plots and cover crop seeding ratio treatments (barley:cereal rye, 0:100, 50:50, and 100:0) as subplots. Management treatments included high-residue cultivation and standard no-till management without high-residue cultivation. Despite wider leaves in barley, mixing the species did not increase shading, and cereal rye dominated cover crop biomass in the 50:50 mixtures in 2013 and 2014, representing 82 and 93% of the biomass, respectively. Across all treatments, average weed biomass (primarily common ragweed, giant foxtail, and yellow foxtail) in late summer ranged from 0.5 to 1.1 Mg ha−1in 2013 and 0.6 to 1.3 Mg ha−1in 2014, and weed biomass tended to decrease as the proportion of cereal rye, and thus total cover crop biomass, increased. However, soybean population also decreased by 29,100 plants ha−1for every 1 Mg ha−1increase in cover crop biomass in 2013 (P=0.05). There was no relationship between cover crop biomass and soybean population in 2014 (P=0.35). Soybean yield under no-till management averaged 2.9 Mg ha−1in 2013 and 2.6 Mg ha−1in 2014 and was not affected by cover crop ratio or management treatment. Partial correlation analyses demonstrated that shading from cover crops prior to termination explained more variation in weed biomass than cover crop biomass. Our results indicate that cover crop management practices that enhance shading at slightly lower cover crop biomass levels might reduce the challenges associated with excessive biomass production without sacrificing weed suppression in organic no-till planted soybean.


Author(s):  
Rugare Joyful Tatenda ◽  
Pieterse Petrus Jacobus ◽  
Mabasa Stanford

The effects of one- and two-year maize-cover crop rotations on weed seed bank density and species composition were evaluated in fields at the University of Zimbabwe (UZ) and the International Maize and Wheat Improvement Center (CIMMYT, Harare) between 2014 and 2017. Nine cover crops were rotated, and maize and weed seed bank analyses were done using the seedling emergence method. Maize was used as the control. The results indicated that weed seed density was not significantly (p > 0.05) affected by cover crop mulch type across the seasons. There was a significant (p < 0.05) decline in weed density in the second maize phase of the rotation in UZ Field A. Bidens pilosa, Galinsoga parviflora, Amaranthus hybridus and Eleusine indica were the dominant weeds. B. pilosa density significantly decreased in the second season in UZ Field A but did not vary significantly among cover crops. Significant changes in weed species richness, evenness, and diversity were observed only in the second phase of the rotation in UZ Field A. The results suggest that maize-cover crop rotations could be effective in reducing seed bank size in the short term but have no short-term effect on weed species community composition.


2018 ◽  
Vol 53 (4) ◽  
pp. 435-442 ◽  
Author(s):  
Cesar Tiago Forte ◽  
Leandro Galon ◽  
Amauri Nelson Beutler ◽  
Felipe José Menin Basso ◽  
Felipe Nonemacher ◽  
...  

Abstract: The objective of this work was to evaluate the density and composition of the soil weed seed bank when bean, corn, and soybean are cultivated in the no-tillage system (NTS) in rotation with winter cover crop species and in the conventional tillage system (CTS). The experiment was installed in a complete randomized block design with three replicates. The evaluation of the seed bank was performed on soil samples (0-10 and 10-20 cm) in four points of each experimental unit, at 15, 30, 60, and 90 days of cultivation. Bean, corn, and soybean crops were sown in the NTS with different soil cover crops in rotation, as well as in the CTS. The NTS provided a more dense and abundant soil seed bank of the species Gnaphalium spicatum and Oxalis corniculata when corn, soybean, and bean were cultivated. The species Lolium multiflorum showed lower density and less seeds in the soil seed bank when the NTS was adopted. The use of the winter cover crops black oat and cow vetch, cultivated individually or in consortium, resulted in a lower density of weed species, especially of L. multiflorum. The NTS provides a lower density of weed species in the soil seed bank than the CTS.


2021 ◽  
Vol 9 (3) ◽  
pp. 111
Author(s):  
Marcos Cesar Mottin ◽  
Edleusa Pereira Seidel ◽  
Emerson Fey ◽  
Jaqueline Vanelli ◽  
André Luiz Alves ◽  
...  

The use of soil cover plants has varied effects on crops grown in succession, depending on the cover plant used. The objective of this study was to evaluate the effect of soil cover plants from the Poaceae and Fabaceae families grown in the autumn and winter on yields of corn and soybean grown in succession. The experiment was carried out for two years and the experimental design used was randomized block design, with six replications. Both in the first year and the second, the plots consisted of the cultivation of corn or soybeans on the different biomasses of four cover crops cultivated in autumn and winter intercropped with corn. The cover crops were two Poaceae plants (black oats and brachiaria) and two Fabaceae plants (forage pea and white lupine). The production and productivity parameters of summer corn and soybean commercial crops were evaluated Cover plants of the Poaceae (black oat and brachiaria) and Fabacea (pea and white lupine) families intercropped with corn grown in autumn-winter did not affect their yield components and yield; as well as the productivity of soybeans in succession. According to the results of this work, the cultivation of black oat, brachiaria, forage pea and lupine increases the number of species that the farmer can cultivate intercropped with corn, favoring the crop rotation system in no-till.


Weed Science ◽  
2018 ◽  
Vol 66 (3) ◽  
pp. 379-385 ◽  
Author(s):  
Charles L. Mohler ◽  
Alan G. Taylor ◽  
Antonio DiTommaso ◽  
Russell R. Hahn ◽  
Robin R. Bellinder

AbstractIncorporation of cover crop residue into the soil has been suggested as a means for reducing weed seedbanks. To explore this hypothesis, we buried mesh bags of seeds mixed with sand at 15-cm depth in late fall in plots that had been planted with rye (Secale cerealeL.) or hairy vetch (Vicia villosaRoth.) or left unplanted. Separate bags contained either velvetleaf (Abutilon theophrastiMedik.), giant foxtail (Setaria faberiHerrm.), Powell amaranth (Amaranthus powelliiS. Watson), or common lambsquarters (Chenopodium albumL.). The experiment used a randomized complete block design with five replications, and enough bags were buried to allow a final recovery in each of the following three springs. Each spring, bags were exhumed, and seeds were either counted and tested for viability or mixed with chopped cover crop material or simply stirred for control bags, and the material was reburied. The experiment was completed twice with initial burials in fall of 2011 and 2013. Rye had no consistent effect on persistence of seeds of any of the species. For two observation intervals, rye increased persistence of a species; for another two intervals, it decreased persistence relative to the control; but mostly rye did not affect persistence. Hairy vetch decreased persistence ofC. albumandA. powelliiin both runs of the experiment but had no effect on persistence ofA. theophrastiandS. faberi. Germination of the first two species is promoted by nitrate, whereasA. theophrastigermination is not sensitive to nitrate, andS. faberiis only rarely nitrate sensitive. We suggest that nitrate released during decomposition of hairy vetch may have promoted fatal germination ofC. albumandA. powellii. Incorporation of legume cover crops like hairy vetch may provide a means for decreasing the seedbanks of the many weed species whose germination is promoted by nitrate. The lack of any reduction ofA. theophrastiandS. faberiseed persistence in response to hairy vetch and the inconsistent and mostly negligible effect of rye indicate that a general increase in readily decomposable organic matter through incorporation of cover crops may be ineffective at reducing weed seedbanks.


2012 ◽  
Vol 30 (1) ◽  
pp. 1-8 ◽  
Author(s):  
L.A.O. Penha ◽  
C.A. Khatounian ◽  
I.C.B Fonseca

Weed control has always been an important issue in agriculture. With the advent of no-till systems, soil erosion was reduced but herbicide use was increased. Organic no-till systems try to adjust reduced erosion to the no use of herbicides. Nevertheless, this adjustment is limited by the cost of mechanical weed control. This cost may be reduced by improved cultural weed control with cover crops mulches. In this paper we report a study on the application of compost manure on an oats winter cover crop, preceding soybean, instead of on the soybean summer crop. Treatments comprised a control without compost manure, and compost manure doses of 4 and 8 Mg ha-1 applied either on oats in winter or soybean in summer, organized in a randomized block design, with five replications. In summer, plots were split into weed-controlled or not controlled subplots. The timing of application and the manure doses did not affect the oats biomass or the soybean performance. However, in summer, without water stress, the application of manure at 8 Mg ha-1 directly on soybean has reduced weed biomass in this crop.


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