The 19th summer trawl survey of hoki, hake, ling, and associated species in the Sub-Antarctic was carried out from 24 November to 23 December 2020. Seventy-three of 83 planned phase one stations were completed. All strata were surveyed. There was insufficient time to carry out phase two. When compared with the previous survey in 2018, core biomass estimates were up 22% for hoki (37 851 t, CV 12.3%), up by 5% for ling (22 343 t, CV 12.4%), and down by 3% for hake (1310 t, CV 23.2%).

Researchers took data from a long-term experiment on elevated atmospheric carbon dioxide (CO2) impacts on grassland and applied them to a real farm. They used an ecosystem model and a farm system optimisation model to compare the current farm with the farm in the future under elevated CO2. The future farm made more profit but required more P fertiliser, greater management input and had higher farm total greenhouse gas emissions. The next stage should be to run the farm with climate as well as CO2 changes.

Keywords: FACE, climate change, impacts, elevated carbon dioxide, APSIM, AgInform

This report addresses using scenarios to identify climate risks for the primary sector, different modelling methods to quantitatively estimate risk impacts and the costs/benefits of adaptation options,.and reviews indicator frameworks used by the US, UK and EU. The report recommends that risk assessment should include a range of risk drivers, including physical and socio-economic and that an indicator programme is needed.

Keywords: Climate change, adaptation, risk assessment, risk identification, scenarios, primary sector, indicators

This report addresses climate-change impacts on kiwifruit and apple, avocado, blueberry, cherry and wine grape. In the future obtaining adequate winter chill will become more challenging in many areas where these crops are currently grown, and this will be critical if the future climates resemble those of RCP 8.5 than RCP 2.6. At the same time, climate change could improve the suitability many locations for other growing criteria.

This report reviews the suitability of the FracLEACH parameter used to estimate the proportion of nitrogen (N) applied to agricultural land that is lost via leaching and runoff of N. The current inventory methodology employs a uniform FracLEACH of 0.07 of key N inputs, which is used for estimating a proportion of the indirect nitrous oxide emissions from agriculture.

The NZ Greenhouse Gas Inventory assumes that limestone products have 100% purity, however the purity varies depending on which sedimentary period the limestone was deposited in. This report analyses a range of historic literature, data and new samples to provide an estimate of the actual purity of limestone and dolomite applied to agricultural soils.