Crop residues on short-term CO2 emissions in sugarcane 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.

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Factors affecting the operation of the weed-sensing Detectspray system

Weed Science ◽

10.1017/s0043174500090287 ◽

1998 ◽

Vol 46 (1) ◽

pp. 127-131 ◽

Cited By ~ 11

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.

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Peat decomposability in managed organic soils in relation to land use, organic matter composition and temperature

Biogeosciences ◽

10.5194/bg-15-703-2018 ◽

2018 ◽

Vol 15 (3) ◽

pp. 703-719 ◽

Cited By ~ 14

Author(s):

Cédric Bader ◽

Moritz Müller ◽

Rainer Schulin ◽

Jens Leifeld

Keyword(s):

Land Use ◽

Organic Matter ◽

Co2 Emissions ◽

Field Experiments ◽

Crop Residues ◽

Organic Soils ◽

Emission Rates ◽

Data Set ◽

Plant Materials ◽

C Cycle

Abstract. Organic soils comprise a large yet fragile carbon (C) store in the global C cycle. Drainage, necessary for agriculture and forestry, triggers rapid decomposition of soil organic matter (SOM), typically increasing in the order forest < grassland < cropland. However, there is also large variation in decomposition due to differences in hydrological conditions, climate and specific management. Here we studied the role of SOM composition on peat decomposability in a variety of differently managed drained organic soils. We collected a total of 560 samples from 21 organic cropland, grassland and forest soils in Switzerland, monitored their CO2 emission rates in lab incubation experiments over 6 months at two temperatures (10 and 20 °C) and related them to various soil characteristics, including bulk density, pH, soil organic carbon (SOC) content and elemental ratios (C / N, H / C and O / C). CO2 release ranged from 6 to 195 mg CO2-C g−1 SOC at 10 °C and from 12 to 423 mg g−1 at 20 °C. This variation occurring under controlled conditions suggests that besides soil water regime, weather and management, SOM composition may be an underestimated factor that determines CO2 fluxes measured in field experiments. However, correlations between the investigated chemical SOM characteristics and CO2 emissions were weak. The latter also did not show a dependence on land-use type, although peat under forest was decomposed the least. High CO2 emissions in some topsoils were probably related to the accrual of labile crop residues. A comparison with published CO2 rates from incubated mineral soils indicated no difference in SOM decomposability between these soil classes, suggesting that accumulation of recent, labile plant materials that presumably account for most of the evolved CO2 is not systematically different between mineral and organic soils. In our data set, temperature sensitivity of decomposition (Q10 on average 2.57 ± 0.05) was the same for all land uses but lowest below 60 cm in croplands and grasslands. This, in turn, indicates a relative accumulation of recalcitrant peat in topsoils.

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Understanding mechanisms of reduced annual weed emergence in alfalfa

Weed Science ◽

10.1614/p2002-140 ◽

2003 ◽

Vol 51 (6) ◽

pp. 876-885 ◽

Cited By ~ 23

Author(s):

H. R. Huarte ◽

R. L Benech Arnold

Keyword(s):

Field Experiments ◽

Plant Density ◽

Seedling Emergence ◽

Soil Surface ◽

Bare Soil ◽

Winter Period ◽

Soil Temperatures ◽

Bull Thistle ◽

Weed Emergence ◽

Selection Of

Field experiments were carried out at the Facultad de Agronomía, Universidad de Buenos Aires, Argentina (34°25′S, 58°25′W), to evaluate the possibility of reducing weed seedling emergence through the use of alfalfa cultivars with low levels of winter dormancy and by increasing plant density from 200 to 400 plants m−2. It was hypothesized that these treatments would alter the temperature regime and the red (R)–far-red (FR) ratio of radiation to which seeds were exposed. Responses to management treatments were recorded for bull thistle, cotton thistle, plumeless thistle, tall rocket, mustard, curly dock, and pigweed. During the alfalfa establishment year, pigweed and curly dock emergence was reduced by the nondormant cultivar established at high density. This reduction disappeared when soil beneath the canopy was fitted with heaters that mimicked bare-soil temperatures. Crop canopy presence during the establishment year was not effective in reducing mustard, cotton thistle, bull thistle, plumeless thistle, and tall rocket emergence. During the second and third years after crop establishment, the canopy of the nondormant alfalfa cultivar was effective in reducing germination of weed seeds placed on the soil surface during fall and winter. In contrast, the winter-dormant cultivar allowed the establishment of weeds during the winter period. These reductions in weed emergence were associated with a modification in the R–FR ratio perceived by the seeds located at the soil surface and could largely be removed by using FR filters to increase the R–FR ratio. These results suggest that the selection of a nondormant cultivar combined with an increase in plant density could effectively reduce weed populations in alfalfa.

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

Journal of Agricultural Science ◽

10.5539/jas.v10n5p258 ◽

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.

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Rusle parameters for modeling the loss of a soil subjected to pig slurry application

Pesquisa Agropecuária Brasileira ◽

10.1590/s0100-204x2018001000010 ◽

2018 ◽

Vol 53 (10) ◽

pp. 1167-1176

Author(s):

Maria Aparecida do Nascimento dos Santos ◽

Ildegardis Bertol ◽

Danieli Schneiders Kaufmann ◽

José Mecabô Júnior ◽

Bárbara Bagio

Keyword(s):

Crop Residues ◽

Soil Surface ◽

Dry Mass ◽

Water Erosion ◽

Control Treatment ◽

Pig Slurry ◽

Soil Consolidation ◽

Erosion Modeling ◽

Avena Strigosa ◽

Simulated Rain

Abstract: The objective of this work was to determine adjustment parameters for the revised universal soil loss equation (Rusle) of a soil subjected to pig slurry application. Treatments consisted of 0, 50, 100, and 200 m3 ha-1 pig slurry (PS), after the cultivation of black oat (Avena strigosa), besides the application of 50 m3 ha-1 PS for six times onto the soil surface in a temporal sequence, and a control treatment of soil without cultivation and without pig slurry application. The evaluations were performed for black oat shoot dry mass, root mass and crop residues semi-incorporated into the soil (RMR), soil losses by means of simulated rain, and the parameters for water erosion modeling. The pig slurry application onto soil surface caused a reduction in the values of the soil consolidation parameter (Cf), an increase in the mass of living and dead roots and cultural residues incorporated in the upper layer (0.0-0.1 m) of the soil (Bu), and a reduction in the subfactor prior land use (PLU) of the Rusle.

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In-row Preplant Manure Composting Reduces Weed Populations

HortScience ◽

10.21273/hortsci.39.6.1456 ◽

2004 ◽

Vol 39 (6) ◽

pp. 1456-1460 ◽

Cited By ~ 1

Author(s):

Barakat Abu-Irmaileh ◽

Azmi Abu-Rayyan

Keyword(s):

Field Experiments ◽

Organic Materials ◽

Poultry Manure ◽

Soil Surface ◽

Environmental Pollutant ◽

Olive Pomace ◽

Sheep Manure ◽

Health Related ◽

Soil Temperatures ◽

Manure Amendments

Fresh manure is normally broadcasted on the soil surface in vegetable growing areas of Jordan as a source of nutrients and organic matter. However, it can be an environmental pollutant and may lead to the outbreak of many health-related pests, especially houseflies. Field experiments were conducted in two locations to study the effect of in-row composting of four different fresh manures and olive pomace on preplant weed control in vegetables. In the first experiment, main treatments were as follows. 1) Organic materials were applied preplant and then the soil was covered with black polyethylene (BPE) sheets for 6 weeks (M). 2) Treatments were the same as in (M) but the soil surface was covered by BPE mulch for the whole growing season (MP). 3) There was soil incorporation of organic materials preplant, but the soil surface was unmulched during the 6-week period and weeds were controlled chemically later in the season (MC). 4) For the control (C), fresh organic materials were soil incorporated manually at time of planting. Each main treatment included four subtreatments. Each subtreatment received a different source of organic material: cow, poultry, or sheep manure or olive pomace. In the second experiment, the rates of poultry manure (0, 5, and 10 kg·m-2) comprised the main treatments. Each treatment included four subtreatments in which the manure was soil-incorporated then subplots were covered by BPE sheets for either 0, 2, 4, or 6 weeks. The composting process in the main treatments M and MP raised soil temperatures significantly at a 15-cm depth above soils without manure amendments. Soil temperatures were higher, especially with poultry manure, athough not significantly different in all cases. Composting poultry manure was more effective in reducing weed dry weights compared with other organic materials.

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

Canadian Journal of Soil Science ◽

10.4141/cjss95-079 ◽

1995 ◽

Vol 75 (4) ◽

pp. 559-565 ◽

Cited By ~ 3

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

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

Phytopathology ◽

10.1094/phyto-97-8-0971 ◽

2007 ◽

Vol 97 (8) ◽

pp. 971-978 ◽

Cited By ~ 33

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.

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Autumn, Winter and Spring Soil Temperatures in Okstindan, Norway

Journal of Glaciology ◽

10.3189/s002214300002325x ◽

1974 ◽

Vol 13 (69) ◽

pp. 521-533

Author(s):

Charles Harris

Keyword(s):

Snow Cover ◽

Snow Depth ◽

Soil Surface ◽

Soil Freezing ◽

Dominant Factor ◽

Freezing And Thawing ◽

Short Term ◽

Air Temperatures ◽

Soil Temperatures ◽

Freezing And Thawing Cycles

Soil temperatures were recorded over periods of several weeks in the years 1909 and 1970 in two sites to a depth of 100 cm. It was found that snow depth was of major importance in the rate of freezing of the soil in winter; where snow cover was less than 5 cm in depth freezing rates were almost double those where snow depth was over 1 m. Snow cover also insulated the soil surface from above-zero air temperatures during spring, and soil thawing commenced from the surface only following the clearance of snow. Similarly, insulation of the soil surface by snow prevented short-term freezing and thawing cycles penetrating the soil, although even where snow cover was absent such short-term cycles were not observed to penetrate the soil to depths in excess of 5 cm. This surficial freezing and thawing of the soil took place more readily in spring than in the autumn. It was concluded that the annual cycle of soil freezing and thawing was the dominant factor in the thermal regime of these soils, short-term freezing cycles affecting only the immediate surface soil layers.

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The effect of conventional cultivation, direct drilling and crop residues on soil temperatures during the early growth of wheat at Murrumbateman, New South Wales

Soil Research ◽

10.1071/sr9860049 ◽

1986 ◽

Vol 24 (1) ◽

pp. 49 ◽

Cited By ~ 8

Author(s):

AR Aston ◽

RA Fischer

Keyword(s):

Crop Residues ◽

Soil Surface ◽

Dry Weight ◽

Adjacent Area ◽

Wet Season ◽

Growing Seasons ◽

Shoot Dry Weight ◽

Stage Of Development ◽

South Wales ◽

Soil Temperatures

Soil temperatures were measured at different depths under wheat crops sown by three different methods in a dry (1982) and a wet season (1983). A conventionally cultivated treatment, which comprised a short cultivated fallow, was compared with one which was directly drilled with full disturbance of the soil surface after previous crop residues had been burned, and with another treatment which was directly drilled with minimum disturbance into soil carrying 2-4 t ha-' stubble. Generally the soil temperatures at any particular depth of the conventionally cultivated treatment were warmer during the day and cooler during the night than the soil temperatures at the same depth in the direct drilled treatments. These patterns persisted throughout both the growing seasons, but in the wet year (1983) there was little difference between temperatures under conventional cultivation and direct drill with stubble burning and full disturbance. Similar temperature patterns were measured when the same treatments were imposed on an adjacent area which had previously been growing fertilized ryegrass/clover pasture. It was found that wheat sown by conventional means had a larger shoot dry weight per plant at the 4 1/2 leaf stage of development than direct drilled wheat. The improved early vigour of wheat sown by conventional cultivation practices could at least partially have been due to the patterns in soil temperature.

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