Improving nitrogen use efficiency, sustainability and fruit quality in high-density apple orchards


TF 214 - Improving nitrogen use efficiency, sustainability and fruit quality in high-density apple orchards

Start Date: 
Completion Date: 
Project Leader: 
Dr Eleftheria Stavridou
TF 214

Industry representative: Nigel Kitney

HDC project cost: £94,599


Project summary:


Traditional apple orchards are being replaced by high-density irrigated systems in which fertigation is used to apply nitrogen (N) and other nutrients. Nitrogen is applied in greater amounts than any other plant nutrient but fruit trees acquire only about 20% of applied N. Among the factors that affect N use efficiency are the fertigation rate, frequency of application and the irrigation regime. Excess irrigation water can leach N below the root zone and reduces N use efficiency. Excessive N nutrition may also increase vegetative growth and reduce fruit quality and storage potential. New guidelines are needed to improve the efficiency of N fertiliser use in intensive apple production. The proposed project aims to optimise N management in irrigated high-density apple orchards by maximising the efficiency of N fertigation regimes and minimising nitrate leaching in the deep soil layers. Moreover, the effects of different fertigation treatments on the quality and the storage potential of fruits will be evaluated.


Aims and objectives:


Project aim(s):

1. To optimise nitrogen fertiliser use efficiency in high-density apple orchards at East Malling Research (EMR)
2. To improve profitability and sustainability of fertigated high-density UK apple production
Project objective(s):
1. To quantify nitrate leaching in high-density ‘Gala’/M.9 and ‘Braeburn’/M.9 orchards under a commercial fertigation/irrigation scheduling regime
2. To investigate the effects of fertigation on soil acidification
3. To schedule fertigation to match demand with supply and minimise nitrogen leaching in high-density apple orchards
4. To determine the effects of the fertiliser regimes on components of apple quality and storage potential
5. To disseminate the results to the industry
Benefits to industry:
a) Reduced N input (reduced vegetative growth, improved fruit colour development, and storage quality)
b) Improved firmness, shelf-life and storage potential (less susceptibility to internal breakdown, bitter pit and cork spot)
c) Improved sustainability and reduced environmental impact (more efficient use of nutrients, lower nitrogen leaching in the ground water, lower production costs, compliance with legislation (The Nitrate Directive)
d) Lower production costs (reduced spend on fertilisers and foliar nitrogen applications, lower pruning costs)