Effects of nitrogen fertilization on potato yields and soil nitrate leaching

Zisheng Xing1,2, Bernie. J. Zebarth1, Sheng Li1,2*, Fanrui Meng2, Herb. W. Rees1, Noura Ziadi3, and Lien Chow1

1 Fredericton Research and Development Centre, Agriculture and Agri-Food Canada, PO Box 20280, 850 Lincoln Road, Fredericton, New Brunswick, Canada E3B 4Z7,*Corresponding Author: [email protected]

2 Faculty of Forestry & Environmental Management, University of New Brunswick, Fredericton, New Brunswick, Canada E3B

3 Quebec Research and Development Centre, Agriculture and Agri-Food Canada,  2560 Blvd. Hochelaga, Québec QC G1V 2J3, Canada, presenter: [email protected] / Tel: 418-210-5052 / TTY:  613-773-2600

Abstract

A 2-year field trial with a randomized complete block design with four replications was conducted in New Brunswick, Canada to evaluate N fertilization effects on potato (Solanum tuberosum L.) tuber yields and quality as well as soil nitrate leaching. Eight N fertilizer treatments were examined, including three N sources (i.e. conventional, controlled-release and organic fertilizers) at two application rates (100 and 200 kg N ha-1),  a split application of conventional fertilizer at the high rate and a zero N fertilizer input as control. Application of N-fertilizer significantly increased tuber yield (by 76% maximum) and quality over the unfertilized treatments whereas differences between the two N fertilizer application rates were non-significant. Fertilizer use efficiency varied from 16% to 56% over treatments and years. Low application rates resulted in lower seasonal soil and soil solution NO3- concentrations than high application rates. The controlled-release and organic form of fertilizer both reduced seasonal mean soil and soil solution N concentrations than conventional fertilizer, with low leaching potential.