The soil survey programme of the canton of Basel-Landschaft also includes the survey of the development of the soil erosion risk. Every 10 years more than 70 agricultural farms are questioned about their methods of cultivation and the risk of soil erosion is evaluated. The results of the last questioning dating from 2002 show that there are regional differences in the development of soil erosion risk rates. The intensively cultivated soils of the loess area show the same average erosion risk rate as 10 years before. The documented reduction of the crop rotation factors in the Jura region, however, resulted in a decreased soil erosion risk rate. This is mainly caused by a structural change in the direction of extensive farming combined with an increasing percentage of sown meadow (artificial grassland) and fallow land instead of maize and winter corn and not by a more gentle soil cultivation. The majority of the farms have a slightly decreased erosion risk, but some of the farms being in a conversion phase show an increased one. More measures such as mulching and the concentration of root crops on plots with a lower erosion risk are taken in order to protect the soil than before. To sum up it has to be stated that soil cultivation isn’t orientated on the rate of the natural soil erosion risk and that the actual erosion risk is still too high, especially on the most fertile cultivated areas. The survey results in a number of conclusions for consulting purposes.
Symbiotic nitrogen fixation by bacteria in the soil coexisting with legumes leads to reduced fertiliser requirement. It is not easy to measure this variable on farms, however. Now researchers from Agroscope have developed a method for estimating nitrogen input via symbiotic fixation at farm level.
With increasing global and regional temperatures, even in Switzerland the growing season has lengthened considerably. Using data from the Federal Office of Meteorology and Climatology, Agroscope has traced the development of the growing season since the start of the previous century.
The phosphate mineral reserves required for fertiliser production could be exhausted on a global scale in just a few decades. This study presents a method for recycling a Swiss industrial by-product into a phosphate fertiliser.