Prospects of improving efficiency of fertiliser nitrogen in Australian agriculture: a review of enhanced efficiency fertilisers

Abstract

Fertiliser nitrogen use in Australia has increased from 35 Gg N in 1961 to 972 Gg N in 2002, and most of the nitrogen is used for growing cereals. However, the nitrogen is not used efficiently, and wheat plants, for example, assimilated only 41% of the nitrogen applied. This review confirms that the efficiency of fertiliser nitrogen can be improved through management practices which increase the crop’s ability to compete with loss processes. However, the results of the review suggest that management practices alone will not prevent all losses (e.g. by denitrification), and it may be necessary to use enhanced efficiency fertilisers, such as controlled release products, and urease and nitrification inhibitors, to obtain a marked improvement in efficiency. Some of these products (e.g. nitrification inhibitors) when used in Australian agriculture have increased yield or reduced nitrogen loss in irrigated wheat, maize and cotton, and flooded rice, but most of the information concerning the use of enhanced efficiency fertilisers to reduce nitrogen loss to the environment has come from other countries. The potential role of enhanced efficiency fertilisers to increase yield in the various agricultural industries and prevent contamination of the environment in Australia is discussed.

Effects of 3,4-dimethylpyrazole phosphate (DMPP) on nitrification and the abundance and community composition of soil ammonia oxidizers in three land uses

“…According to the prediction of the International Fertilizer Industry Association (IFA), the global demand for N fertilizers will continuously increase and reach approximately 161 million metric tonnes in 2018 (IFA 2014). However, a major concern associated with the use of synthetic N fertilizers is the substantial N losses into the environment and the low nitrogen use efficiency (NUE) (Chen et al 2008). Furthermore, the rising costs of synthetic N fertilizers have strengthened farmers' commercial incentive to reduce N fertilization and as a consequence N losses (Ernfors et al 2014).…”

“…Of the available NIs, 3,4-dimethylpyrazole phosphate (DMPP) has been widely used together with synthetic N fertilizers (Weiske et al 2001;Di and Cameron 2011;Liu et al 2015) and animal manure (Hatch et al 2005;Fangueiro et al 2009;Maienza et al 2014). To achieve comparable effects, DMPP requires much lower application rates than other NIs such as dicyandiamide (DCD) (Chaves et al 2005;Chen et al 2008). More importantly, no negative effect of DMPP on non-target microorganisms in soils has been reported (Tindaon et al 2012;Kong et al 2016).…”

The Use of Urease Inhibitor Fertilizers (Agrotain) and Their Effect on Cereal Crops and Cotton Yield

“…Agrotain refers to a liquid product containing 25% NBPT as the active ingredient. Granular urea applications with NBPT have been reported by a number of researchers to be effective in delaying urea hydrolysis as well as increasing productivity under a range of cropping and pasture systems (Chen et al, 2008;Martin et al, 2008). Urease inhibitor (NBPT) is commercially available under the trade name of Agrotain.…”

Influence of enhanced efficiency fertilisation techniques on nitrous oxide emissions and productivity response from urea in a temperate Australian ryegrass pasture

“…Various EEFs have been developed to target particular N loss pathways (Chen et al 2008). Urease inhibitors, such as N-(nbutyl) thiophosphoric triamide (NBTPT), slow urea hydrolysis and are designed to decrease ammonia (NH 3 ) volatilisation from surface-applied granular urea.…”

“…In Australia, agriculture represents 76% of the national total N 2 O emissions, with around 50% of this from mineral fertiliser application (DCCEE 2011). Enhanced efficiency fertilisers (EEFs), including urease inhibitors, nitrification inhibitors, fine particle sprays, and controlled-release fertilisers, have the potential to decrease N losses from agriculture by either altering the rate of N transformations or slowing the release of N from fertiliser granules (Chen et al 2008). …”