A broiler chicken produces an average 115g excrements a day; this amounts to 2 million tons a year in Germany alone. In terms of plant nutrients this is equivalent to 33 million kg nitrogen (N) and 7 million kg phosphorus (P). The environmetal effects of these nutrients and their interaction with different production systems has been investigated by scientists of the Institute of Plant Nutrition and Soil Science of the Federal Agricultural Research Centre (FAL) in Braunschweig, Germany.
Intensive indoor broiler production
Photograph: Martina Wolf-Reuter
Organic free range broiler production wth mobile housing
Photograph: Martina Wolf-Reuter
A nationwide study compared intensive indoor, free range and organic broiler production systems. In the intensive indoor system with 22-24 animals per square metre, i.e. altogether 20,000-40,000 animals in one building (picture 1), the birds achieve their final weight of 1.8 kg after roughly 6 weeks and during that time they have produced "only" about 5 kg excrements per broiler. However these accumulated high amounts of excrements cannot be disposed of easily and only by following the approved codes of "good agrcultural practice", which states the amount per acre according to be applied according to the approved N and P needs of plants.
The free range chicken, shares a square meter with 13 others, in flocks of about 6,000-15,000 birds and an average stocking rate of about 1 m2 per bird in the free range. This makes their life not only more varied but also a bit longer. In spite of the same final fattening weight of 1.8 kg, their life is extended by two weeks, which therefore leaves more droppings. An additional problem: During the study the birds mostly stayed near their building, so hardly more than 30 % of the actual exercise area was used with the consequence, that it received a far higher enrichment with N and P, to the extent that it was a potential pollution risk to the ground- and surface waters.
New 3-D model predicts best planting practices for farmers
26.06.2017 | Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign
Fighting a destructive crop disease with mathematics
21.06.2017 | University of Cambridge
Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.
For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...
What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.
To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...
The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....
A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...
Physics supports biology: Researchers from PTB have developed a model system to investigate friction phenomena with atomic precision
Friction: what you want from car brakes, otherwise rather a nuisance. In any case, it is useful to know as precisely as possible how friction phenomena arise –...
21.07.2017 | Event News
19.07.2017 | Event News
12.07.2017 | Event News
21.07.2017 | Earth Sciences
21.07.2017 | Power and Electrical Engineering
21.07.2017 | Physics and Astronomy