Bentonite can decrease ammonia volatilisation losses from poultry litter: laboratory studies

Abstract

Abstract. Ammonia volatilisation from manure materials within poultry sheds can adversely affect production, and also represents a loss of fertiliser value from the spent litter. This study sought to compare the ability of alum and bentonite to decrease volatilisation losses of ammonia from spent poultry litter. An in-vessel volatilisation trial with air flushing, ammonia collection, and ammonia analysis was conducted over 64 days to evaluate the mitigation potential of these two materials. Water-saturated spent litter was incubated at 25 C in untreated condition (control) or with three treatments: an industryaccepted rate of alum [4% Al 2 (SO 4 ) 3 Á18H 2 O by dry mass of litter dry mass; ALUM], air-dry bentonite (127% by dry mass; BENT), or water-saturated bentonite (once again at 127% by dry mass; SATBENT). A high proportion of the nitrogen contained in the untreated spent litter was volatilised (62%). Bentonite additions were superior to alum additions at retaining spent litter ammonia (nitrogen losses: 15%, SATBENT; 34%, BENT; 54%, ALUM). Where production considerations favour comparable high rates of bentonite addition (e.g. where the litter is to be re-formulated as a fertiliser), this clay has potential to decrease ammonia volatilisation either in-shed or in spent litter stockpiles or formulated products, without the associated detrimental effect of alum on phosphorus availability.

Manure and sorbent fertilisers increase on-going nutrient availability relative to conventional fertilisers

“…The combination of our field trial results, our pot trial leaching data, and the observations from our previous Pratt et al, 2015;Redding, 2011Redding, , 2013decreased N 2 O and NH 4 + emission, and decreased P leaching and runoff losses with ion exchanger additions) and other researchers' studies (Aghaalikhani et al, 2012;Ding et al, 2010;Gholamhoseini et al, 2013;Singh et al, 2010; establishing decreased N leaching losses with ion exchanger additions) indicate that it is possible to match the productivity of conventional N and P sources, and achieve decreased potential for nutrient losses via the use of manure materials and ion exchange sorbents.…”

“…This is probably related to the bentonite additions, which has a substantial cation exchange capacity (Table 1), which may tend to decrease water-borne transport of N and gaseous losses. Observations collected from related trials suggest that bentonite additions to SL decrease volatilisation losses during SL handling and storage (Redding, 2013). A related trial successfully used a vermiculite sorbent to decrease nitrous oxide emissions during fertiliser application of SL to the same soil .…”

Emission of Harmful Gases from Poultry Farms and Possibilities of Their Reduction

“…A similar microbial process to enteric fermentation of ruminants also leads to methane production from stored manure. Additionally, small amounts of methane are produced from manure deposited on grasing lands (Redding, 2013). However, it is not well understood whether considerable amounts of CH 4 may be emitted from litter reactions inside the building, depending on the litter management and conditions (Calvet et al, 2011).…”

“…The litter type, management, humidity and temperature affect the gas concentration and emission from broiler fattening (Redding, 2013). Also commercial egg production facilities involve variety of housing systems and manure handling practices, which can produce different magnitudes of environmental footprint.…”

Nitrous oxide, ammonia and methane from Australian meat chicken houses measured under commercial operating conditions and with mitigation strategies applied

“…Other NH 3 mitigation strategies have focussed on litter additives (i.e. Zhang et al 2011;Redding 2013) but the cost effectiveness of these strategies at the commercial scale is constrained where large volumes of litter additive are required.…”