Hieracium, or hawkweed species, serious weeds in South Island high country, may be controlled by appropriate pastoral management. Experimental trials at Lake Tekapo, related to S and P fertiliser rates of 0-100 kg ha-l yr-l, 27 different combinations of over-drilled and resident species and different seasons or intensities of grazing treatments on Hieracium dominated fescue tussock were conduct...

Yield mapping of crops obtained by harvest with a combine equipped with yield metering device and GPS positioning system, has in recent years, become an important tool in crop management. With respect to nitrogen fertilisation, it is now technically possible to change practices from uniform application to differentiated, site-specific application. The presentation introduces and discusses a met...

Agricultural perturbations to the global nitrogen cycle, directly and indirectly, lead to enhanced biogenic production of nitrous oxide (N2O). Direct pathways include microbial nitrification and denitrification of fertiliser and manure nitrogen that remains in agricultural soils or animal waste management systems. Indirect pathways involve nitrogen that is removed from agricultural soils and an...

A 58-yearold burning and trashing trial receiving fertiliser and no fertiliser was used to quantify treatment effects on soil penetrometer resistance. The results showedthat penetrometer resistance was significantly lowerin thosetreatments whereno fertiliser wasapplied. Increased soilwatercontentin treatments witha trashcoverdid notreducepenetrometer resistance values in the soil wherefertilise...

A new version of the Integrated Nitrogen in Catchments model (INCA) was developed and tested using flow and streamwater nitrate concentration data collected from the River Kennet during 1998. INCA is a process-based model of the nitrogen cycle in the plant/soil and instream systems. The model simulates the nitrogen export from different land-use types within a river system, and the in-stream ni...

Input costs for sugarcane production have escalated sharply over the past five years, especially fertiliser costs. It has become imperative for growers to manage fertiliser input costs by ensuring that they have an accurate nutrition management programme in place. The South African Sugar Association Experiment Station has, over many years, contributed hugely through their research and extension...