scholarly journals Characterization of Emergence Flows of Volunteer Corn as Function of the Type of Harvest Grain Loss

2018 ◽  
Vol 10 (5) ◽  
pp. 258
Author(s):  
Alexandre Silva ◽  
Fernando Adegas ◽  
Germani Concenço
Keyword(s):  
Field Experiments ◽  
Crop Residues ◽  
Soil Surface ◽  
Climatic Conditions ◽  
Surface Deposition ◽  
Soil Layers ◽  
Different Types ◽  
Volunteer Corn ◽  
Corn Plants

Volunteer corn resistant to glyphosate is constant as weed in soybeans planted in succession. This work aimed to identify the emergence flows of volunteer corn plants in the period of time from the harvest of corn planted following soybean (autumn corn) to the plenty establishment of the canopy of the following soybean crop (summer soybean), as a function of different types of propagules generated by preceding corn harvest losses. Four field experiments were carried out in 2013 and 2014, at a Cerrado location (Sinop, MT) and a subtropical location (Londrina, PR), Brazil. Treatments included the distribution of corn crop residues (factor “A”) either on soil surface or incorporated into superficial soil layers. Four types of propagules (factor “B”) were characterized as ears with whole husk; ears with half husk; broken ears, no husk; and loose grains. The density of emerged plants was recorded fortnightly between August and December. When partially incorporated into soil, propagules generate an increased density of emerged plants as compared to the surface deposition treatments. The main sources of volunteer plants, in descending order of importance, were: (1) loose grains, (2) broken ears, (3) ears with damaged husk, and (4) ears with intact husk. Ears emerged later compared to loose grains or broken ears. Climatic conditions influence the emergence pattern. For the climate of (Savannah-like) Cerrado, the beginning of the rainy season is preponderant for the start of corn emergence. Under subtropical climatic conditions, mild low temperatures, associated or not to rainfall, determine the emergence peaks.

scholarly journals Crop residues on short-term CO2 emissions in sugarcane production areas

2013 ◽  
Vol 33 (4) ◽  
pp. 699-708 ◽  
Author(s):  
Mariana M. Corradi ◽  
Alan R. Panosso ◽  
Marcílio V. Martins Filho ◽  
Newton La Scala Junior
Keyword(s):  
Co2 Emissions ◽  
Field Experiments ◽  
Crop Residues ◽  
Soil Surface ◽  
Dry Mass ◽  
Agricultural Crop ◽  
Short Term ◽  
Sugarcane Production ◽  
Soil Temperatures ◽  
Production Areas

The proper management of agricultural crop residues could produce benefits in a warmer, more drought-prone world. Field experiments were conducted in sugarcane production areas in the Southern Brazil to assess the influence of crop residues on the soil surface in short-term CO2 emissions. The study was carried out over a period of 50 days after establishing 6 plots with and without crop residues applied to the soil surface. The effects of sugarcane residues on CO2 emissions were immediate; the emissions from residue-covered plots with equivalent densities of 3 (D50) and 6 (D100) t ha-1 (dry mass) were less than those from non-covered plots (D0). Additionally, the covered fields had lower soil temperatures and higher soil moisture for most of the studied days, especially during the periods of drought. Total emissions were as high as 553.62 ± 47.20 g CO2 m-2, and as low as 384.69 ± 31.69 g CO2 m-2 in non-covered (D0) and covered plot with an equivalent density of 3 t ha-1 (D50), respectively. Our results indicate a significant reduction in CO2 emissions, indicating conservation of soil carbon over the short-term period following the application of sugarcane residues to the soil surface.

scholarly journals Economic Threshold of Volunteer Corn GR® in Soybean as a Function of Emergence Time and Origin of Corn

2018 ◽  
Vol 36 (0) ◽  
Author(s):  
C. PIASECKI ◽  
M.A. RIZZARDI
Keyword(s):  
Field Experiments ◽  
Individual Plant ◽  
Yield Losses ◽  
Emergence Time ◽  
Economic Threshold ◽  
Control Cost ◽  
Soybean Yield ◽  
Volunteer Corn ◽  
Corn Plants

ABSTRACT: Volunteer corn is extremely competitive with soybean and the degree of interference varies with the corn density, time of emergence and origin. The objectives of this work were to determine the economic threshold (ET) of volunteer corn GR® F2 in soybean as a function of the time of emergence (same day and nine days after soybean) and origin (individual plants or clumps). Each clump was manually adjusted to have seven corn plants. Four field experiments were conducted in randomized blocks design with four replicates in Passo Fundo, RS, Brazil. The soybean yield losses (%) were calculated and adjusted to the model of the rectangular hyperbola and generated the parameters for the determination of the ET, that was calculated based on the volunteer corn control costs (US$ ha-1), efficiency of control (%), price paid for soybean (US$ kg-1) and soybean yield (kg ha-1). The ET mean was 0.3 and 0.48 for individual corn plants m-2 emerged together and nine days after soybean, and 0.08 and 0.03 m-2 for individual plants and clumps, respectively. Increases in grain yield and price paid for soybean, greater control efficiency of corn and lower control cost promote reduction in the ET of volunteer corn in soybean. The control of volunteer corn is justified in a density less than 0.5 individual plant m-2 and is close to zero when corn originates from clumps. Volunteer corn is one of the most competitive weed in soybean crops.

Factors affecting the operation of the weed-sensing Detectspray system

Weed Science ◽  
1998 ◽  
Vol 46 (1) ◽  
pp. 127-131 ◽  
Author(s):  
Robert E. Blackshaw ◽  
Louis J. Molnar ◽  
Duane F. Chevalier ◽  
C. Wayne Lindwall
Keyword(s):  
Near Infrared ◽  
Field Experiments ◽  
Crop Residues ◽  
Soil Surface ◽  
Physical Factors ◽  
Weed Detection ◽  
Factors Affecting ◽  
Green Foxtail ◽  
Infrared Wavelengths ◽  
Herbicide Use

Field experiments were conducted for 3 yr to determine the effect of various biological and physical factors on the operation of the weed-sensing Detectspray system. Plant detection is achieved by sensors measuring differential reflectance of red and near-infrared wavelengths of light from green plants, crop residues, and soil. Weed detection was greatly reduced 70 to 80 min after sunrise and before sunset when operated at lat 50°N because of reduced solar irradiance. Tall, dense-standing crop stubble limited detection of small weeds at the soil surface. Weed detection varied with plant species. Canola with three to four leaves consistently was detected, but wheat or green foxtail usually required five to six leaves to be detected. Small weeds were detected if present at densities greater than 70 plants m−2. Growers and commercial applicators need to be aware of the limitations of the Detectspray system to use it effectively to control weeds with concurrent reductions in herbicide use.

SEASONAL VARIATION IN THE COMPOSITION OF THE BACTERIAL SOIL FLORA IN RELATION TO PLANT DEVELOPMENT

1957 ◽  
Vol 3 (2) ◽  
pp. 131-134 ◽  
Author(s):  
H. G. Gyllenberg
Keyword(s):  
Seasonal Variation ◽  
Plant Development ◽  
Bacterial Population ◽  
Field Experiments ◽  
Soil Surface ◽  
Growth Season ◽  
Soil Layers ◽  
Rhizosphere Population ◽  
In The Beginning

In field experiments with oats the composition of the bacterial population in the rhizosphere was found to be almost stable during the whole period of plant development from young seedlings to maturity. In the beginning of the growth season the soil flora was quite different from that of the rhizosphere. It was, however, successively changed, and became, toward the end of the season, similar in composition to the rhizosphere population. This change proceeded from the soil surface into deeper soil layers, and it can be concluded that it was due to the development of roots, and to a migration of bacteria from the rhizosphere into the soil.

Decomposition of sugarcane harvest residue in different climatic zones

Soil Research ◽  
2007 ◽  
Vol 45 (1) ◽  
pp. 1 ◽  
Author(s):  
Fiona A. Robertson ◽  
Peter J. Thorburn
Keyword(s):  
Field Experiments ◽  
Late Phase ◽  
Soil Surface ◽  
Climatic Conditions ◽  
Cane Yield ◽  
N Loss ◽  
Soil C ◽  
South Wales ◽  
C Decomposition ◽  
C And N

Sugarcane in Australia is increasingly grown under the green cane trash blanket system where harvest residues (trash) are retained on the soil surface instead of being burnt. This is considered a more sustainable system, but relatively little is known about its effects on soil carbon (C) and nitrogen (N). As part of a study to understand the effects of trash retention on soil C and N dynamics, we measured the composition and decomposition of sugarcane trash in terms of dry matter (DM), C, and N in 5 field experiments in contrasting climatic conditions in Queensland and New South Wales. The trash from newly harvested sugarcane contained large quantities of DM (7–12 t/ha) and C (3–5 t/ha), which could be estimated from cane yield, and significant quantities of N (28–54 kg/ha), which could not be predicted from cane yield. Trash quality was low (C : N  ratio >70) and it took a year for most of the trash to decompose. Cumulative thermal time was the variable most closely associated with cumulative DM and C decomposition. Variation in the rate of trash DM and C decomposition between sampling dates was partially related to temperature and rainfall at 2 of the 3 sites, but was considered to be influenced by other factors (such as soil, trash, and management) as much as by climate. There were 2 phases of decomposition: an early phase when C : N ratios were high and variable and net N loss or gain was not related to C loss; and a late phase when C : N ratios were much lower and similar across experiments and net N loss was related to C loss. The rate of N loss from trash during the first 12 months was slow (1–5 kg/month), which would have been of little immediate significance for plant growth. The potential value of trash for soil N supply lies in cumulative effects over the medium–long term.

scholarly journals Analysis of Induction and Establishment of Dwarf Bunt of Wheat Under Marginal Climatic Conditions

Plant Disease ◽  
2011 ◽  
Vol 95 (4) ◽  
pp. 478-484
Author(s):  
Blair J. Goates ◽  
Gary L. Peterson ◽  
Robert L. Bowden ◽  
Larry D. Maddux
Keyword(s):  
United States ◽  
Winter Wheat ◽  
Field Experiments ◽  
Soil Surface ◽  
The United States ◽  
Climatic Conditions ◽  
Assessment Model ◽  
Susceptible Cultivar ◽  
Winter Climate ◽  
Dwarf Bunt

Dwarf bunt caused by Tilletia contraversa is a disease of winter wheat that has a limited geographic distribution due to specific winter climate requirements. The pathogen is listed as a quarantine organism by several countries that may have wheat production areas with inadequate or marginal climate for the disease—in particular the People's Republic of China. Field experiments were conducted in the United States in an area of Kansas that is a climatic analog to the northern winter wheat areas of China to evaluate the risk of disease introduction into such areas. The soil surface of four replicate 2.8 × 9.75 m plots, planted with a highly susceptible cultivar, was inoculated with six teliospore concentrations ranging from 0.88 to 88,400 teliospores/cm2. A single initial inoculation was done in each of three nurseries planted during separate seasons followed by examination for disease for 4 to 6 years afterward. Any diseased spikes produced were crushed and returned to the plots where they were produced. One nursery had no disease during all six seasons. In two nurseries, the disease was induced at trace levels at the three highest inoculation rates. Disease carryover to the second year occurred during one year in one nursery in plots at the highest inoculation rate, but no disease occurred the following three seasons. A duplicate nursery planted in a disease conducive area in Utah demonstrated that the highest rate of inoculum used in the experiments was sufficient to cause almost 100% infection. This study demonstrated that in an area with marginal climatic conditions it was possible to induce transient trace levels of dwarf bunt, but the disease was not established even with a highly susceptible cultivar and high levels of inoculum. Our results support the conclusions of the 1999 Agreement on U.S.-China Agricultural Cooperation which set a tolerance for teliospores in grain, and supports the Risk Assessment Model for Importation of United States Milling Wheat Containing T. contraversa.

Studies of the preceding crop effect of ley in ecological agriculture

2000 ◽  
Vol 15 (2) ◽  
pp. 68-78 ◽  
Author(s):  
Artur Granstedt ◽  
Gärd L-Baeckström
Keyword(s):  
Organic Matter ◽  
Soil Fertility ◽  
Field Experiments ◽  
Crop Residues ◽  
Climatic Conditions ◽  
Clay Soils ◽  
N Leaching ◽  
Botanical Composition ◽  
Preceding Crop ◽  
Potentially Mineralizable N

AbstractTwo field experiments were conducted from 1991 to 1996 on clay soils in central Sweden to provide information for improving soil fertility, minimizing N leaching, and increasing the benefits of ley to subsequent crops in organic farming. The results show that it is possible to calculate the amount of N mineralized during the 2-year period following incorporation of ley-crop residues, based on the proportion of incorporated organic matter stabilized in the more resistant humus fractions (i.e., the humification coefficient, calculated to be 35–40%), C:N ratios of the ley biomass, and ley age (humification appears to be higher in older crop residues). The fractions of potentially mineralizable N that are actually mineralized in the first and second years after ley incorporation vary depending on ley age and botanical composition and climatic conditions.

Zero Tillage for Mitigating Global Warming Consequences and Improving Livelihoods in South Asia

2017 ◽  
pp. 126-161 ◽  
Author(s):  
Rajan Bhatt
Keyword(s):  
Global Warming ◽  
South Asia ◽  
Crop Residues ◽  
Water Productivity ◽  
Soil Surface ◽  
Biological Properties ◽  
Climatic Conditions ◽  
Zero Tillage ◽  
Climatic Regions ◽  
Smart Agriculture

Declining land and water productivity, rising global temperature, underground water availability, energy, labour availability, increasing cost of production, burning of crop residues and changing climatic conditions are major challenges faced by both scientists and farmers in South Asia. To address these challenges, different resource conservation technologies were promoted in the South Asia. Zero tillage was generally practiced in the region, which retains the previous crop residues on the soil surface while establishing main crop viz. wheat seeds directly drilled in standing anchored rice straw. Further such tillage systems required no pre-sowing irrigation which further improves the irrigation water productivity. The current chapter reviews the consequences of zero tillage on soil physical, chemical and biological properties, land and water productivity and in mitigating global warming potential in texturally divergent soils under different agro-climatic regions. Our review revealed that positive effects of zero tillage are visible only after 4-5 years up to which farmer might have to sacrifice some yields. Thus, there is need to recommend an integrated climate smart agriculture package/approach, which effectively solves weed pressure problems, helps in improving land and water productivity, mitigates global warming consequences and uplifts livelihoods in South Asia.

Species, herbicide and tillage effects on surface crop residue cover during fallow

1995 ◽  
Vol 75 (4) ◽  
pp. 559-565 ◽  
Author(s):  
R. E. Blackshaw ◽  
C. W. Lindwall
Keyword(s):  
Soil Erosion ◽  
Crop Residue ◽  
Field Experiments ◽  
Crop Residues ◽  
Lignin Content ◽  
Soil Surface ◽  
Plant Residues ◽  
Canadian Prairies ◽  
Erosion Risk ◽  
Stubble Retention

Fallow continues to be a common agronomic practice on the Canadian prairies but it has been associated with increased soil erosion. Risk of fallow erosion can be reduced by maintaining adequate levels of crop residue on the soil surface. Field experiments were conducted at Lethbridge, Alberta from 1991 to 1993 to determine if commonly grown prairie crops differ in their rates of crop residue degradation during fallow and to assess the effect of herbicides and wide-blade tillage on loss of crop residues. The ranking of crop residue losses during fallow was lentil > canola > rye > barley > wheat > flax. High N content in residues usually increased the rate of biomass loss. Flax straw, perhaps because of its high lignin content, did not follow this pattern and was the most persistent of all crop residues. Up to three applications of the herbicides, glyphosate, paraquat, and 2,4-D, at recommended rates did not alter field degradation of any of these crops. These herbicides maintained greater amounts of anchored and total surface crop residues than wide-blade tillage during both fallow seasons. Results are discussed in terms of crops grown before fallow, weed control during fallow, and maintenance of sufficient surface plant residues to reduce the risk of soil erosion. Key words: Glyphosate, paraquat, 2,4-D, reduced tillage, soil erosion, stubble retention

scholarly journals Population Dynamics of Fusarium spp. and Microdochium nivale in Crops and Crop Residues of Winter Wheat

2007 ◽  
Vol 97 (8) ◽  
pp. 971-978 ◽  
Author(s):  
J. Köhl ◽  
B. H. de Haas ◽  
P. Kastelein ◽  
S. L. G. E. Burgers ◽  
C. Waalwijk
Keyword(s):  
Population Dynamics ◽  
Winter Wheat ◽  
Field Experiments ◽  
Crop Residues ◽  
Soil Surface ◽  
Microdochium Nivale ◽  
Head Blight ◽  
Fusarium Spp ◽  
Inoculum Sources ◽  
Wheat Tissues

Naturally occurring populations of Fusarium avenaceum, F. culmorum, F. graminearum, F. poae, and Microdochium nivale were studied in two field experiments from anthesis in June 2003 until harvest in crops of winter wheat, and subsequently during 10 months after harvest until June 2004 on their residues exposed on the soil surface under field conditions. The dynamics of the different pathogens were estimated by quantifying the amount of DNA present in wheat tissues using TaqMan-polymerase chain reaction. While colonization of grain by Fusarium spp. and M. nivale was low, high amounts of DNA of F. avenaceum, F. graminearum, and F. culmorum were found in ear residues, internodes, and nodes of the mature crop. Amounts of DNA of pathogens decreased significantly during the following 10 months in residues of internodes and nodes, but not in residues of stem bases. Knowledge on population dynamics of pathogens will help to develop preventive measures aimed at reduction of inoculum sources of head blight pathogens.

Sign in / Sign up

Export Citation Format

Share Document