Methods of measuring carbon storage in kiwifruit orchards
The project has four parts:
A) Identify a robust methodology for measuring carbon storage in kiwifruit orchards
We will design and test a scientifically rigorous, practically feasible and cost effective framework to measure carbon storage. In selected orchards we will quantify the carbon storage of a) the above-ground vine-row, grass-alley, and shelter-belt system and b) the respective soil system including plant roots.
With regards to soil testing we will consider to what depth the soil needs to be sampled; what the appropriate volume of soil is needed and how many sample sites are needed to characterize the properties soil carbon content.
B) Quantify carbon storage in kiwifruit orchard systems with different carbon management
We will survey the carbon storage in different kiwifruit orchards mainly in the Bay of Plenty but also in other kiwifruit-growing regions according to our methodology and combine the survey with existing data from ARGOS and GroPlus. We will identify if the amount of carbon storage is determined by carbon management, the kiwifruit variety, the soil texture, the regional climate or by a combination of these factors.
C) Quantify the carbon footprint, production cost and profit per tray of kiwifruit in the orchards in the carbon storage survey
We will estimate the carbon footprint of the orchard production of a tray of kiwifruit, using the methodology of the recent MAF funded project ‘Carbon footprinting of the kiwifruit supply chain’. We will also quantify the production cost and profit per tray of kiwifruit. The necessary data will be extracted from existing data sets and will be complemented with questionnaires sent to the respective growers that will be followed up by personal interviews. We will identify if carbon management, the kiwifruit variety, the soil texture, the regional climate or a combination of them determines the carbon footprint, production cost and profit.
D) Quantify the drainage and nitrogen losses from the main root zone in the rows of a few kiwifruit orchards of the carbon storage survey that represent a wide range of different carbon storage
We will install drainage fluxmeters under the main root zone in the vine row of six kiwifruit orchards and measure drainage liquid and nitrogen loss over one year. We will identify if carbon storage of a particular soil is a significant factor for its water use efficiency and nitrate losses. This work will be based on methodology developed in earlier SFF funded projects on water use efficiency and nutrient management.
E) Develop grower guidelines for carbon storage in kiwifruit orchards. Identify carbon storage management that is economically and environmentally sustainable.
We will estimate the economic benefit of carbon storage by comparing the profit/production cost of a tray of kiwifruit to the soil carbon and total carbon storage. Based on these results we will develop guidelines for growers and the industry.