61 research outputs found
Intra-Row Weed Control by use of Band Steaming
Soil disinfection by steam is a well-known technique used within horticulture and market gardening. The most common steam application technique is sheet steaming, where the soil is covered with a thermo resistant sheet, which is sealed at the edges and then blowing steam under the sheet so that the steam penetrates through the soil. The method is effective for control of weed, plant pathogens and nematodes. However, high fuel consumption and low capacity are serious disadvantages. Moreover all living organisms, harmful and useful, in the treated soil are killed, and therefore the method is not in line with the basis ideas of organic farming. A new concept and technique for performing band heating has been developed. By heating only a narrow band of 6–8 cm around the rows to a depth of 5 cm, energy savings of more than 90% can be obtained. In practice, the system may be combined with a computer-controlled sowing machine for the subsequent sowing of plants in the centre of the treated bands. The system will result in the crop growing in rows free of plant competition. It was seen that soil temperatures of 80-90°C, were needed to achieve god effect in the field
Thermal Band Heating for Intra-Row Weed Control
Surface steaming of soil is a very energy-intensive process, and consequently, efforts have been made to develop a machine for narrow-band steaming of the soil under and around rows of cultivated plants prior to seeding. The use of this machine may achieve up to 90% energy savings, and will also reduce the amount of damage to the flora and fauna. A special test rig has been developed with the objective of obtaining new information about narrow-band soil steaming. For a detailed analysis of the temperature profile in a cross-section of the processed band, an apparatus has been developed especially to record the temperatures obtained at 63 locations and at seven levels across the ditch. On the basis of the results from the test rig, a prototype band-steamer for field use has been developed. Tests have shown that soil temperatures exceeding 70C will be needed to protect against germination of weed seeds. For band heating such a treatment in 50 cm rows requires about 5.8 GJ/ha
FeederAnt - An autonomous mobile unit feeding outdoor pigs
Small robots and the concept of decentralized animal husbandry make it possible to renew the principles of organic agriculture. The farm animals will be able to use the same type of housing and are placed integrated with the fields. This is expected to achieve a better utilization of nutrients and a better survival rate for useful insects and micro organisms. The small fields are flexible and could fit to the variation in soil structure topography. This type of precision agriculture has the possibility of increasing biodiversity.
The paper presents the concept of an autonomic feeding system for outdoor piglets. Initial results are presented using a remote controlled feeding unit (a prototype of the FeederAnt) to feed several pens with piglets. The FeederAnt drives into the grass paddocks twice a day and position itself in a new location for each feeding. This will help to distribute the manure from the animals evenly over the grass paddock to prevent point leaching of nutrients. The FeederAnt replaces many stationary feeding tables and reduce the amount of daily manual feeding routines. Further, it is expected that the problem with vermins will be solved since no feed residues will be left within the pens.
Udsædsbårne sygdomme i økologisk såsæd - betydning og skadetærskler
Det økologiske projekt ORGSEED har givet ny viden om skadetærsklerne for de vigtigste udsædsbårne sygdomme i korn og ærter. I projektets sidste del vil disse tærskelværdier blive vurderet med henblik på justering. Sammenholdt med nye metoder til bestemmelse af den faktiske forekomst af udsædsbårne sygdomme, vil det give en mere sikker karakterisering af den økologiske såsæd og hermed mindre unødig kassation
Embedded Protostars in the Dust, Ice, and Gas In Time (DIGIT) Key Program: Continuum SEDs, and an Inventory of Characteristic Far-Infrared Lines from PACS Spectroscopy
We present 50-210 um spectral scans of 30 Class 0/I protostellar sources,
obtained with Herschel-PACS, and 0.5-1000 um SEDs, as part of the Dust, Ice,
and Gas in Time (DIGIT) Key Program. Some sources exhibit up to 75 H2O lines
ranging in excitation energy from 100-2000 K, 12 transitions of OH, and CO
rotational lines ranging from J=14-13 up to J=40-39. [O I] is detected in all
but one source in the entire sample; among the sources with detectable [O I]
are two Very Low Luminosity Objects (VeLLOs). The mean 63/145 um [O I] flux
ratio is 17.2 +/- 9.2. The [O I] 63 um line correlates with Lbol, but not with
the time-averaged outflow rate derived from low-J CO maps. [C II] emission is
in general not local to the source. The sample Lbol increased by 1.25 (1.06)
and Tbol decreased to 0.96 (0.96) of mean (median) values with the inclusion of
the Herschel data. Most CO rotational diagrams are characterized by two
optically thin components ( = (0.70 +/- 1.12) x 10^49 total particles). N_CO
correlates strongly with Lbol, but neither Trot nor N_CO(warm)/N_CO(hot)
correlates with Lbol, suggesting that the total excited gas is related to the
current source luminosity, but that the excitation is primarily determined by
the physics of the interaction (e.g., UV- heating/shocks). Rotational
temperatures for H2O ( = 194 +/- 85 K) and OH ( = 183 +/- 117 K)
are generally lower than for CO, and much of the scatter in the observations
about the best fit is attributed to differences in excitation conditions and
optical depths amongst the detected lines.Comment: 58 pages, 37 figures; accepted to Ap
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