About 1% of New Zealand farmland is managed organically. Nitrogen is the nutrient most likely to limit organic crop production. A potential solution is incorporation of compost to supply N. About 726,000 t of municipal garden and kitchen wastes are sent to landfills annually. Composting offers a means of reducing the impact of landfill wastes on the wider environment. Organically certified compost (N content typically 2% to 2.5%) is available from some municipal composting plants. To be effectively used on organic farms, the rate of N release (mineralization) must be known. Laboratory incubations were conducted to quantify mineralization of compost N under controlled (temperature and moisture) conditions. Nitrogen availability and crop yields from a one-off application of compost (25-100 t¨ha´1) were also assessed in two field trials (using cereal and forage crops). The results suggested that a relatively small part (13%-23%) of compost N was used by the crops in 3-4 years. Much of this was mineral N present at the time of application. Mineralization rates in the laboratory and field studies were much lower than expected from published work or compost C:N ratio (considered an important indicator of N mineralization potential of composts).

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An integrated pest management (IPM) strategy was compared with farmers' conventional pest management practices on twelve spring-and autumn-sown seed and forage brassica crops. Demonstration trials were conducted in Canterbury from spring 2015 to autumn 2017 by splitting farmers' paddocks in half and applying the two management approaches side by side. A farmer participatory approach was used, with management decisions based on monitoring pests and biological-control agents. Farmer and adviser training with a focus on monitoring and identification was carried out. Biological-control agents capable of contributing to pest control were identified in all brassica crops. There was a 35% reduction in the number of insecticides applied under IPM compared with conventional management, negligible crop yield differences, and the type of insecticides applied was different. IPM adoption at these farms was high by the end of the 3-year project with 11 of the 12 farmers implementing IPM across 90-100% of their brassica crops. This project was a starting point for an industry-wide change of practice to IPM, which has become more widespread since its completion.

Six crops of autumnsown wheat managed under integrated pest management (IPM) were compared to six adjacent crops grown under the participating farmers current pest management practices in demonstration trials in Canterbury during the 200809 and 200910 seasons Farmer training with a focus on monitoring and beneficial predator identification was carried out The presence and abundance of key pests and diseases (slugs aphids yellow dwarf virus (YDV)) and beneficial predators was determined Carabid beetles and other beneficial insects capable of contributing to pest control were present in the arable cropping systems There was an increasing trend in the number of beneficial organisms a reduction in pests and a 50 reduction in the number of insecticides applied in the IPM managed crops There were negligible YDV and crop yield differences between the two approaches IPM adoption at these farms was very high after these participatory trials