Fertiliser use and efficiency are discussed in the light of diminishing labour and decreasing net profits typical of modern farming. Often the use of fertilisers (and lime) is the cheapest way to increase yield and, consequently, to reduce production cost. From the mid 1950s nitrogen dressings doubled to trebled in most Western European countries, but trends for phosphorus and potassium were less spectacular. Fertiliser manufacturers are aiming at materials easy in handling, storage and distribution, and not subject to leaching losses. There is a marked tendency towards the production of high-analysis materials either used straight or as ingredients for compound fertilisers. No-pressure fertiliser solutions will become increasingly important. More efficient nitrogen fertilisers, that cover the plant’s requirements over a long period by one single dressing, will gain in interest if available at competitive prices.
Fertiliser policy in modern cropping systems is discussed.
The effects of increasing crop yields (by new varieties, disease control, irrigation), changing tillage practices, and quality aspects on fertiliser use are outlined.
Increasing grazing stock rates will promote nitrogen fertiliser use on grassland. By contrast, the use of phosphorus and potassium fertiliser is not likely to increase (much) further as the nutrients in the herbage eaten are recycled via the faeces. Purchase of (imported) concentrated feeds further precludes the use of inorganic fertiliser. Particularly the increasing numbers of housed stock create surpluses of excreta rich in these nutrients. Future trends in the overall phosphate and potash fertiliser consumption will mainly depend on the possibilities to use animal and, to a lesser extent, domestic wastes for recycling.
Dr K W Smilde, Institute for Soil Fertility, Haren, The Netherlands.
52 pages (inc. discussion), 10 figures, 28 tables, 74 references.