Pelletized organo-mineral fertilizer product as a nitrogen source for potato production

Abstract

Replacement of mineral fertilizer with organo-mineral fertilizer products made with animal manures is one strategy for reducing the environmental impact of agricultural production. This study evaluated a pelletized organo-mineral fertilizer product with a nutrient analysis of approximately 7-4-4 produced from composted solid poultry, solid dairy and liquid hog manure as a N source for processing potato (Solanum tuberosum L.) production in Atlantic Canada. The availability of N in the organo-mineral fertilizer product was estimated, and tuber yield, size distribution and quality parameters and soil NO3-N content at harvest were compared at similar application rates of N as mineral or organo-mineral fertilizer. Field trials were conducted in 2000 to 2002 to compare different rates of mineral (0–200 kg N ha-1 as NH4NO3) or organo-mineral (0–3 t product ha-1) fertilizer band-applied at planting, followed by split applications of variable rates of mineral fertilizer. Apparent recovery of N from the mineral fertilizer, estimated as the slope of the regression of plant N accumulation against the rate of N applied and expressed as a percentage, was 65, 33 and 78% in 2000, 2001 and 2002, respectively. Apparent recovery of total N in the organo-mineral fertilizer was 6 0 , 26 and 57% in 2000, 2001 and 2002, respectively. Fertilizer N equivalency of the total N in the organo-mineral fertilizer, estimated as the apparent recovery of organo-mineral fertilizer N divided by apparent recovery of mineral fertilizer N and expressed as a percentage, was 92, 79 and 73% in 2000, 2001 and 2002, respectively. Application of equivalent rates of N as mineral or organo-mineral fertilizer at planting generally resulted in comparable values of tuber yield, size distribution and quality parameters and soil NO3-N content at tuber harvest. We recommend application of 1.5 t ha-1 of organo-mineral fertilizer at planting, with additional mineral fertilizer applied as a split application if warranted, as a suitable N source for processing potato production. Key words: Solanum tuberosum, yield, tuber size, tuber nitrate, tuber specific gravity, soil nitrate