“In a field trial it was investigated whether soil can be tilled more considerate with onland ploughing (all four wheels of the tractor run on the untilled soil surface) than with conventional ploughing (two wheels of the tractor run in the furrow). As expected conventional ploughing caused the highest soil stress at 35 cm depth, the peak stress values coming from the rear wheel of the tractor. Surprisingly the soil structure at 35 cm, partly even at 55 cm depth responded to these stresses in both ploughing treatments by an increase of total and macropore volume as well as by a decrease of bulk density. Saturated hydraulic conductivity and flow paths of stained water showed that the conventional ploughing treat-ment caused strong changes of soil structure below the wheel tracks at 25 cm depth. This kneading action lead to a considerable deterio-ration of pore continuity (ï¿½plough pan-formation””). The dynamic character of soil stresses during ploughing could also be identified by measurements of soil displacement. The results of this comparison of two ploughing treatments show that with onland ploughing plough pan-formation and subsoil stresses can be reduced. Therefore onland ploughing can contribute to sustainable soil tillage and to physical soil protection. Possible reasons of the unexpected changes of soil structure at 35 and 55 cm soil depth are discussed.”
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.