An evaluation of recent advances in the use of anhydrous and aqueous ammonia overseas and their application in New Zealand horticulture: A thesis submitted in partial fulfilment of the National Diploma in Horticulture of the Royal New Zealand Institute of Horticulture

The object of this study is to evaluate recent advances in the use of anhydrous and aqua ammonia as nitrogenous fertilisers, with emphasis on the prospects and needs there are for their usage in New Zealand. There is at present a large dependence on New Zealand made organic and imported artificial fertilisers which are mostly low analysis materials. These nitrogenous fertilisers, with their low nitrogen content, have a high cost per pound of nitrogen. Anhydrous and aqua ammonia are high analysis materials whose use could prove worthwhile in this country on the grounds of economy and practicability. An appraisal of these prospects would appear to offer advantages in the development of horticulture (and agriculture) in New Zealand. Part I deals with the aspects of nitrogen in the soil and in plants. This introduces the trends in nitrogenous fertilisers and usage of the various forms, particularly anhydrous and aqua ammonia. Also dealt with is the history of nitrogenous fertilisers. Part II illustrates the usage of ammonia as a fertiliser. The manufacture, use for crops, equipment and basic economics are discussed, with a view to demonstrating that anhydrous and aqua ammonia fertilisers have been shown to be both efficient and very economical fertilisers overseas. Part III deals with the position in New Zealand. The types of nitrogen fertilisers used and the economic aspects of their usage. Prospects for anhydrous and aqua ammonia in New Zealand are looked at. In conclusion the general findings are summarised and recommendations are made with a view to future needs in New Zealand for anhydrous and aqua ammonia. This thesis attempts to tentatively answer the question, "Is there a place for anhydrous and aqua ammonia fertiliser in New Zealand, and what action should be taken to examine this subject more closely".