Project Nitrogen – Measure It and Manage It

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                                 Milestone: Completed

Lead Organisation FAR Project Leader Diana Mathers

Project completed  – Final report produced     Read here 17957-~1      Over the past 3 years, the approach has been tested and refined across 18 trial sites located on commercial cropping enterprises around New Zealand. Crops have included maize (five sites), potatoes (six sites), broccoli (two sites), cabbage (one site), lettuce (two sites) and spinach (two sites). At each site two N management approaches were compared (each replicated five times) and these include

 A standard grower area where side-dressing N was applied at rates equivalent to the cooperating grower’s application regime in the rest of the field

 A QTMB area where pre-planting and side-dressing N applications were based on outputs from the N mass balance.

Objectives – This project will deliver a practical, reliable and cost-effective in-field approach to nitrogen management for farmers and consultants. The project deliverables will be disseminated through a range of field demonstrations, industry events and popular press articles. At the completion of this project farmers will have a cheap, (each quick test strip costs < $1), and quick, (results are immediately available), and validated alternative to the standard Mineral N test and a QTMB field guide to assist with the development of crop mass balance budgets for fertiliser decisions.

20-04-2018 Update

One approach to help guide nitrogen (N) management decisions is the use of a nitrogen mass balance to determine fertiliser N requirements as a function of crop N demand and soil N supply However, measuring soil N is costly and time consuming, so alternative methods are required. The nitrate quick test has been used successfully both overseas and in New Zealand as a cost effective and sufficiently reliable proxy for soil mineral N supply. This SFF project is in its second year of three and looks at the usefulness of the Quick N test in potatoes and other vegetable crops.