| 摘要 |
1. A controlled release particulate fertiliser comprising the reaction product of urea and formaldehyde containing, as part of its total nitrogen, polymeric nitrogen in the form of methylene urea polymers of varying chain length, characterised in that at least 60% by weight of the polymeric nitrogen is in the form of cold water soluble nitrogen polymers such as methylene diurea, dimethylene triurea or mixtures thereof, wherein the average degree of polymerisation is greater than 1.5.
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