Weed Communities in Semiarid Rainfed Croplands of Central Argentina: Comparison between Corn (Zea mays) and Soybean (Glycine max) Crops

Weed Science ◽  
2018 ◽  
Vol 66 (3) ◽  
pp. 368-378 ◽  
Author(s):  
Ruth B. Rauber ◽  
Manuel R. Demaría ◽  
Esteban G. Jobbágy ◽  
Daniel N. Arroyo ◽  
Santiago L. Poggio
Keyword(s):  
Zea Mays ◽  
Glycine Max ◽  
Native Species ◽  
Linear Models ◽  
Floristic Composition ◽  
Central Argentina ◽  
Weed Communities ◽  
Agronomic Management ◽  
Starting Point ◽  
Original Vegetation

AbstractThe semiarid Espinal in central Argentina, being recently transformed from natural semiarid grasslands into agriculture, represents an interesting scenario to understand the early stages of weed community assembly and its relationship with crop identity and management. Our aim was to characterize the weed communities in corn (Zea maysL.) and soybean [Glycine max(L.) Merr.], the main crops of the Espinal region, under the dominant rainfed conditions. Weed surveys were carried out in 53 fields, and farmers were interviewed to collect information about crop management. Floristic composition was compared within and between crops by calculating the additive partition of the abundance-based Bray-Curtis dissimilarity. We compared the frequency and mean cover of functional groups between crops through generalized linear models. Finally, canonical correspondence analysis was carried out to analyze the associations between floristic composition and agronomic variables. Mean alpha and gamma diversity was greater in corn (10.0 and 80 species, respectively) than in soybean (7.6 and 46 species, respectively). Furthermore, species composition of weed communities was more similar among soybean fields than among either cornfields or fields of both crops. Hence, floristic differences between crops are potentially the result of different microenvironmental heterogeneity above- and belowground, with corn likely to be more permissive to weed establishment compared with soybean. The higher frequency of annual, dicotyledonous, and native species, and the high proportion of rare species, mostly native, suggest a strong legacy of the original vegetation that thrived in these recently cultivated systems. The functional composition was also affected by agronomic management, with sulfur, nitrogen, and grass herbicide application being the most important factors related to the floristic composition of weed communities. This early description can be used as a starting point for studies concerning trajectories, mechanisms, and processes of weed communities related to environment and management.

Influence of phosphate status on phosphate uptake kinetics of maize (Zea mays) and soybean (Glycine max)

1990 ◽  
Vol 124 (2) ◽  
pp. 175-182 ◽  
Author(s):  
A. Jungk ◽  
C. J. Asher ◽  
D. G. Edwards ◽  
D. Meyer
Keyword(s):  
Zea Mays ◽  
Glycine Max ◽  
Phosphate Uptake ◽  
Uptake Kinetics ◽  
Kinetics Of

scholarly journals Sistemas de cultivo e características do solo afetando a estabilidade de agregados

1998 ◽  
Vol 22 (2) ◽  
pp. 311-317 ◽  
Author(s):  
I. F. Silva ◽  
J. Mielniczuk
Keyword(s):  
Triticum Aestivum ◽  
Zea Mays ◽  
Glycine Max ◽  
Zea Mays L ◽  
Triticum Aestivum L ◽  
Digitaria Decumbens ◽  
Glycine Max L ◽  
Macroptilium Atropurpureum

Em um Latossolo Roxo de Santo Ângelo (RS), e em um Podzólico Vermelho-Escuro de Eldorado do Sul (RS), ambos com textura argilosa, submetidos o primeiro à exploração com cultivo convencional de trigo (Triticum aestivum L.) e soja (Glycine max L.) e sob setária (Setaria anceps L.), e o segundo à exploração com capim-pangola (Digitaria decumbens L.), siratro (Macroptilium atropurpureum L.), plantio direto com aveia (Avena bizantina L.)/milho (Zea mays L.) e área sem vegetação, foi realizado o presente trabalho durante a safra de verão (1990/1991), com o objetivo de avaliar a estabilidade e a agregação do solo sob diferentes sistemas de cultivo. Constatou-se, nessa avaliação, que as gramíneas perenes por meio do seu sistema radicular tiveram grande efeito na agregação e estabilidade dos agregados do solo e que os teores de carbono orgânico, de ferro e alumínio-oxalato, argila e grau de dispersão tiveram também efeitos na agregação do solo, porém insuficientes para explicar as variações entre o diâmetro médio ponderado dos agregados sob os diferentes sistemas de cultivo.

scholarly journals Consórcio soja-milho: V. efeito de sistemas de consórcio e de semeadura do milho

1998 ◽  
Vol 28 (2) ◽  
pp. 199-204
Author(s):  
Deny Alves Alvarenga ◽  
Pedro Milanez de Rezende ◽  
Messias José Bastos de Andrade ◽  
Luiz Antônio de Bastos Andrade
Keyword(s):  
Zea Mays ◽  
Glycine Max ◽  
Zea Mays L ◽  
Glycine Max L

O presente trabalho foi realizado com o objetivo de avaliar o comportamento da soja [ Glycine max (L.) Merrill ] cultivar Doko e do milho (Zea mays L.) cultivar BR 201 quando consorciados em diferentes sistemas de semeadura. O experimento foi conduzido no ano agrícola 1992/1993. em área experimental da Universidade Federal de Lavras, em Latossolo roxo distrófico, textura argilosa. O delineamento experimental utilizado foi blocos casualizados, com três repetições em esquema fatorial (3x3+4) constituído por três sistemas de consórcio (soja na linha do milho; soja na entrelinha do milho e soja em ambas linha e entrelinha) e três formas de semeadura do milho uma planta a cada 25cm, duas plantas e cada 50cm e quatro plantas a cada 100cm e mais 4 tratamentos adicionais representados pelos monocultivos das três formas de semeadura do milho e a da soja. A cultura do milho não foi influenciada pelos sistemas de semeadura empregados e nem pela presença da cultura da soja em consórcio. A soja consorciada em relação ao monocultivo apresentou maior acamamento e menor rendimento de grãos. Entre os sistemas de consórcio, a semeadura simultânea de soja nas linhas e entrelinhas do milho foi o que proporcionou o maior rendimento de grãos. A eficiência dos sistemas consorciadas sobre o monocultivo foi evidenciado com valor médio da razão de área equivalente (RAE) de 1,40.

scholarly journals Efeitos do plantio direto e da consorciação soja-milho sobre inimigos naturais e pragas

2001 ◽  
Vol 36 (2) ◽  
pp. 235-241 ◽  
Author(s):  
Francisco Jorge Cividanes ◽  
José Carlos Barbosa
Keyword(s):  
Zea Mays ◽  
Glycine Max ◽  
Zea Mays L ◽  
Anticarsia Gemmatalis ◽  
Glycine Max L

Procurou-se avaliar os efeitos do plantio direto e da consorciação soja (Glycine max (L.) Merrill) e milho (Zea mays L.) sobre pragas e inimigos naturais. Os tratamentos constituíram um fatorial 3 x 2 (monocultura de soja, monocultura de milho, consorciação soja-milho x plantio direto, plantio convencional), em blocos casualizados. Os insetos foram amostrados pelo método do pano, rede entomológica, procura visual e armadilha de sucção. Entre os insetos-pragas do milho, Maecolaspis assimilis ocorreu em maior número no sistema de plantio convencional; o mesmo ocorreu com os predadores Cycloneda sanguinea e Doru sp. Por outro lado, M. assimilis e o predador Toxomerus sp. foram mais numerosos na monocultura de milho em relação à cultura do milho consorciado com soja. Dos insetos-pragas da soja, destacaram-se pelo maior número Anticarsia gemmatalis e Diabrotica gracilenta, no sistema de plantio convencional, e o mesmo aconteceu com a espécie da família Trichogrammatidae, enquanto as espécies da família Eulophidae foram mais numerosas na soja sob sistema de plantio direto. Na soja consorciada com milho foi maior o número de insetos-pragas Megalotomus sp. e Maecolaspis sp. e dos inimigos naturais Geocoris sp., Lebia concina, Orius sp., Braconidae e Scelionidae.

scholarly journals Melliferous flora and pollen characterization of honey samples of Apis mellifera L., 1758 in apiaries in the counties of Ubiratã and Nova Aurora, PR

2013 ◽  
Vol 85 (1) ◽  
pp. 307-326 ◽  
Author(s):  
ELIZABETE S. SEKINE ◽  
VAGNER A.A. TOLEDO ◽  
MARCELO G. CAXAMBU ◽  
SUZANE CHMURA ◽  
ELIZA H. TAKASHIBA ◽  
...  
Keyword(s):  
Glycine Max ◽  
Apis Mellifera ◽  
Native Species ◽  
Ricinus Communis ◽  
Cultivated Plants ◽  
Melia Azedarach ◽  
Native Vegetation ◽  
Pollen Types ◽  
Pollen Analyses

The aim of this study was to carry out a survey of the flora with potential for beekeeping in the counties of Ubiratã and Nova Aurora-PR through the collection of plants and pollen analyses in honey samples collected monthly. 208 species of plants were recorded, distributed in 66 families. The families that showed the major richness of pollen types were: Asteraceae, Myrtaceae and Solanaceae. Approximately 80 pollen types were found in honey samples, most of them were characterized as heterofloral. Cultivated plants, such as Glycine max (soybean) and Eucalyptus spp., were representative in some months of the year. Exotic species, such as Ricinus communis and Melia azedarach, were also frequent. However, over than 50% of the pollen types belong to native species of the region, such as Schinus terebinthifolius, Baccharis spp. Alchornea triplinervia, Parapiptadenia rigida, Hexaclamys edulis, Zanthoxylum sp. and Serjania spp., indicating the importance of the native vegetation for the survival of the colonies.

scholarly journals Cultivation of Rice (Oryza sativa), Corn (Zea mays) and Soybean (Glycine max) Based on Land Suitability

2020 ◽  
Vol 11 (1) ◽  
pp. 9-16
Author(s):  
Suntoro SUNTORO ◽  
◽  
Mujiyo MUJIYO ◽  
Hery WIDIJANTO ◽  
Ganjar HERDIANSYAH ◽  
...  
Keyword(s):  
Zea Mays ◽  
Oryza Sativa ◽  
Glycine Max ◽  
Land Suitability

Superphosphate and stocking rate effects on a native pasture oversown with Stylosanthes humilis in central coastal Queensland. 3. The balance of native species in the pasture

1978 ◽  
Vol 18 (95) ◽  
pp. 808 ◽  
Author(s):  
NH Shaw ◽  
MB Dale
Keyword(s):  
Native Species ◽  
Floristic Composition ◽  
Exchange Capacity ◽  
Response To Treatment ◽  
Data Sets ◽  
Heteropogon Contortus ◽  
Native Pasture ◽  
Total Exchange Capacity ◽  
Highly Correlated ◽  
Stocking Rates

The percentage frequency of all herbaceous species in a native pasture oversown with S. humilis (T.S.) was measured at the beginning and end of an eight-year grazing experiment. Treatments imposed were three levels of molybdenized superphosphate (nil; 125 kg ha-1 annually; 250 kg ha-1 annually plus an extra 250 kg ha-1 initially) in factorial combination with four stocking rates and two sowing methods for T.S. (ground sowing into spaced cultivated strips or aerial sowing). Stocking rates were gradually increased during the experiment and for the last three years overlapping ranges were used for the three fertilizer levels; the overall range was then from 0.55 to 1.65 beast ha-1. Treatments did not induce any major changes in the proportions of native species in the pasture. Heteropogon contortus remained dominant and its frequency increased in all treatments. Of the total of 113 species recorded, only 18 reached 10 per cent frequency in at least one paddock on one occasion. Several of these showed statistically significant changes in response to treatment, but their relative importance was not greatly changed. Examination of the results by principal co-ordinate and canonical analysis, showed that the first vectors of the two data sets were highly correlated, indicating that the major control on floristic composition was not changed by oversowing with T.S. or by the treatments imposed. Treatment effects dominated in the second and third vectors in the final year. The controlling vector was found to be highly correlated with soil calcium, potassium, total exchange capacity and organic carbon, but the basis for the correlations remains undetermined.

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