Maintenance and capital fertiliser applications PGG Wrightson Technical Specialist - Soil Science, Dr Jay Howes, discusses the differences between maintenance and capital fertilisers. Article By: Dr. Jay Howes PGG Wrightson Technical Specialist - Soil Science Related Products Cropzeal 16N 20 kg $33.99 Including GST Nrich SOA 20 kg Price On Application SustaiN 20 kg Price On Application