1. Bedding additives reduce ammonia emissions during storage and after
application of cattle straw manure, and improve N utilization by grassland
G.A. Shah*, J.C.J. Groot, P.W.G. Groot Koerkamp and E.A. Lantinga
Background Results and discussion
The control of N losses during one phase of the manure management All the additives reduced NH 3 emissions by about 87% during
chain (animal housing, manure storage and manure application) could storage and on average 69% after surface application to grassland
enhance them in subsequent phases. Therefore, it is crucial to develop and (Table 1) . This could be attributed to adsorption of ammonium
evaluate effective measures that will reduce the losses throughout the (NH 4 + ) by all of the additives and possible formation of struvite salt
whole chain and enhance crop N utilization after manure field application. by the lava meal.
Objectives The herbage apparent N recovery was increased from 11%
To quantify the mitigating effects of three bedding additives, i.e. zeolite, (control) to about 26% by all of the additives (Table 2) . This could
lava meal and sandy farm topsoil (Fig. 1) , on NH 3 emissions during storage be attributed to:
and after land application of cattle straw manures. I. The reduced losses of NH 3 and other gaseous N compounds.
To determine herbage apparent N recovery (ANR) after surface spreading II. Prevention of nitrification and subsequent nitrate leaching
of the manures on grassland. through NH 4 + adsorption.
TABLE 1: Total NH 3 emission during 80 days of storage and average
NH 3 concentration during 3 days after application on grassland
Treatm ent During storage After
application
Total NH 3 -N em ission NH 3 conc entration
(g Mg-1 of fresh manure) (µg m-3)
(a) (b) Control‡‡ 25.3a† (100)‡ 117.5a (100)
(c)
Fig. 1. Bedding additives: (a) zeolite (b) lava meal and (c) sandy farm Zeolite 3.2b (13) 30.1b (26)
topsoil Farm topsoil 3.6b (14) 29.4b (25)
Lava meal 2.7b (11) 50.9b (43)
‡‡ Untreated manure.
† Means in the same column with different letters differ significantly (P < 0.05).
‡Values in parentheses in the same column represent relative losses compare to the control.
TABLE 2: Total herbage dry matter (DM) yield, N uptake and
apparent N recovery (ANR) over 3 cuts
Treatm ent Total of 3 cuts
DM yield N uptake A NR
(a) (b)
Fig. 2. Measurement of NH 3 concentrations (a) during storage and (b) (Mg ha ) -1
(kg ha ) -1
(%)
after land spreading of cattle straw manure
Zero 2.2 a† 43.1 a
Material and methods Control‡ 3.6 b 87.6 b 11 a
Bedding additives were applied inside a naturally ventilated sloping-floor barn
at rates proportionally to the daily straw dosage of 5 kg per livestock unit, i.e. Zeolite 5.1 c 148.2 c 26 b
10% of zeolite, 20% of lava meal and 33% of sandy farm topsoil.
Farm topsoil 4.9 c 141.7 c 25 b
The trampled-down straw manures by the bulls were collected twice daily from
the barn and stockpiled inside a roofed building as four separate heaps. Lava Meal 5.3 c 153.8 c 28 b
After storage, all the manures were surface-spread manually on cut
grassland at an application rate of 4 00 kg N ha -1 . ‡ Untreated manure.
† Means in the same column with different letters differ significantly (P < 0.05).
H erbage ANR was calculated with the N difference method.
Conclusion
NH 3 emissions from the surface of each manure heap were determined
by using a photoacoustic gas monitor (Fig. 2a).  U se of the bedding additives not only reduc ed NH 3
emissions impressi vely during storage and after field
NH 3 concentration in the air above each plot was measured immediately
application, but also inc reased herbage A NR from the
after manure spreading by means of diffusion samplers (Fig. 2b) for 72
hours and corrected for the background concentration.
manures more than twofold.
*Organic Farming Systems Group, Department of Plant Sciences, Wageningen University and
Research Centre, Droevendaalsesteeg 1, 6708 PB Wageningen, the Netherlands.
Phone: + 31 (0)317481192, E-mail*: ghulam .shah@wur.nl