Most manure is spread on meadowland

Agriculture currently accounts for around 95 per cent of the emissions of ammonia to air in Norway. The sources of ammonia emissions in agriculture are livestock, commercial fertilizer and ammonia treatment of straw, with livestock accounting for the main source. Emissions from livestock are highly correlated to the number of animals and occur from livestock rooms, manure storage facilities and fields where manure is spread. Emissions also take place when animals are in pastures.

Under the Gothenburg Protocol, emissions of ammonia in Norway in 2010 should not exceed the level in 1990. To achieve a better data basis on the storage and spreading of manure, Statistics Norway conducted, at the request of the Ministry of Agriculture, a sample survey in 2000.

The survey in 2000 covered holdings with a livestock production corresponding to at least 1.0 calculated animal manure unit. (Calculated animal manure unit is a unit for livestock defined according to the amount of nutrients secreted as dung and urine. One calculated animal manure unit is equal to 1 dairy cow, 3 breeding pigs, 7 winter-fed sheep/goats, 80 hens etc.) The survey was furthermore limited to holdings that applied for agricultural production subsidies as of 31 July 2000. Livestock production on holdings that did not apply for subsidies is insignificant.

Slurry dominant method of storage

In 2000, 46 200 holdings were engaged in livestock production corresponding to at least 1.0 calculated animal manure unit. The manure produced on these holdings was equal to 867 500 calculated animal manure units. The bulk of the manure was stored as slurry. 67 per cent of the manure was stored as slurry in manure cellars and 9 per cent in manure pits. Stores of solid dung and urine accounted for 19 per cent, while indoor built up or deep litter accounted for 4.5 per cent.

64.5 per cent of manure came from holdings with cattle as the main livestock, while 14.5 per cent came from holdings with sheep or goats. Pork production accounted for 12 per cent, poultry 8 per cent and horses, fur animals and rabbits for 1 per cent of the quantity of manure produced.

Manure spread on 3.62 million decares of agricultural area

Spreading of manure is primarily associated with holdings with livestock, but not all farmers spread manure every year. Of a total of 46 200 holdings, 42 300 spread manure on their own land in 2000. 39 200 holdings spread manure from only their own animals, while 3 100 received manure from others. 5 200 holdings sold or delivered manure to others. The difference between deliveries and recipients consists mostly of deliveries to holdings without livestock.

A total of 3.62 million decares of agricultural land was fertilized, accounting for 47 per cent of the agricultural area in use on holdings with livestock. Holdings with cattle as the main livestock accounted for 78 per cent of the agricultural area on which manure was spread.

Meadows for mowing and pastures made up 70 per cent of the spreading area

Spreading of manure is mainly associated with meadowlands. Almost 30 000 holdings spread manure on 2.53 million decares of meadowland at least once in 2000. Spreading of manure is most significant in the spring and summer, and then before and after mowing or pasturing. In 2000, 2.20 million decares of meadows were fertilized in the spring and 1.63 million decares fertilized in the summer.

Loss of ammonia takes place mainly during the application of the manure and before the manure penetrates into the soil. The loss percentage increases with declining precipitation and increasing temperature.

To simplify the spreading of manure, water is often mixed with the manure. New research has also shown mixing water into manure reduces the loss of ammonia. In 2000, 19 500 holdings added water to manure prior to application. The meadowland affected totalled 1.89 million decares.

New equipment such as direct injection equipment and band (?) spreaders greatly reduce ammonia loss. This equipment is currently not in extensive use in Norway. Results show that barely 1 800 holdings used direct injection or band spreaders on 7.4 per cent of the meadowland on which manure was spread.

Three-fourths of manure spread on open fields was worked into the soil within 12 hours

In 2000, 31 600 holdings spread manure on open fields. Manure was spread on a total of 1.18 million decares of open fields at least once in the course of the year. Open fields in this connection also include meadows that were ploughed and resown.

The time from the spreading of the manure to when it is worked into the soil is an important factor. Ammonia losses are smallest when little time elapses from spreading to working it into the soil. The results from the survey show that manure was worked into the soil from 4 to 12 hours after spreading on 59 per cent of the area, while on 24 per cent of the area more than 12 hours elapsed. 16 per cent of the area was worked into the soil within 4 hours.

 

Tables

• Table 1 Holdings with various kind of storage for livestock manure. 2000*
• Table 2 Number of calulated animal manure units by kind of storage for livestock manure. 2000*
• Table 3 Holdings with spreading/whitout spreading of livestock manure and holdings with sale/delivery to others. 2000*
• Table 4 Holdings with livestock manure spreading and area fertilized at least once. 2000*
• Table 5 Holdings with livestock manure spreading on crop land and area of crop land that were fertilized, by time of spreading. 2000*
• Table 6 Spreading of livestock manure on crop land, by time of spreading and m³ manure per decares. 2000*. Decares
• Table 7 Holdings with spreading of livestock manure on madows for mowing and pastures and area of madows that were fertilized, by time of spreading. 2000*
• Table 8 Spreading of livestock manure on madows for mowing and pastures, by time of spreading and m³ manure per decares. 2000*. Decares