Kiwifruit nutrient leaching study


In a joint project with Southern Humates, Farmlands is seeking to understand opportunities for improvements in water quality and sustainability, to drive better nutrient efficiency within kiwifruit orchards.

Nitrogen leaching is fast becoming a major topic for New Zealand orchards. Currently regional councils are in the process of developing legislation and implementing policy for managing freshwater quality. Driven by the Resource Management Act and the National Policy Statement for Fresh
Water, councils will take a varied approach in setting limits across catchments and designated sensitive areas to control nitrogen losses to ground water. Overall this will impact farm, orchard and vineyard management and in some instances their economic viability.

The pilot study involving Farmlands and Southern Humates is a proof-of-concept test to validate nitrogen measurement work already underway, comparing use of humate products on Southland dairy farms.
The Southland trials are showing promise, demonstrating increased dry matter production and nitrate loss reduction. Both Farmlands and Southern Humates are enthusiastic to learn if the paradigm canshift into the horticulture industry.
The project is underway with 12 lysimeters buried in the pumice/sandy soils on 8.2ha of kiwifruit at Ross and Dell Bawden’s 37ha mixed farm property in the Bay of Plenty. The lysimeters are testing three treatments that growers
currently apply to orchards.

Two treatments will have nitrogen mitigation techniques applied. It is hypothesised that if nutrient efficiency can be obtained, then improved water quality can be achieved. Measurements will be taken after rain events and tracked over time. If the project demonstrates positive outcomes, then
further work will be undertaken to validate and model the findings.

Ross is no stranger to environmental issues within the primary sector having worked as an operations planning manager for a significant Bay of Plenty forestry business. He has witnessed
what happens when an industry runs into environmental issues and loses its social licence to operate. Ross was subsequently involved in change management processes that lead to forestry companies signing up to the Forest Stewardship Council environmental accreditation programme. This was a precursor to the
Environmental, Social and Governance standards that corporations aspire to now. Ross is quick to quip “social license is hard to get but is easy to lose.”

It is inevitable that many horticulture operations will suffer nutrient losses. However more efficient use of nutrients such as nitrogen will have strong sustainability benefits for growers, both financially and environmentally. There is a strong belief the data obtained over
time will give growers the ability to make informed decisions on how to better manage nutrients.

Watch this space.

Article supplied by Dwayne Farrington Technical
Leader – Kiwifruit & Subtropical Crops Farmlands.