ISSN:
1573-5036
Keywords:
grass
;
leaching
;
legume
;
mineralisation
;
N fixation
;
nitrate
;
urine
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Abstract The paper presents integrated measurements of N fixation, net mineralisation, pasture yield and change in soil mineral N over a 12 month period for dairy pastures on a sandy loam soil in the South East of South Australia. The two adjacent pastures studied were an irrigated perennial white clover-ryegrass and an annual non-irrigated subterranean clover with mixed annual grasses. This produced the most comprehensive mineral N balance reported for grazed pastures, to the authors' knowledge, allowing calculation of gaseous and leaching losses of N (210 kg ha−1 in the irrigated and paddock and 81 kg ha−1 in the non irrigated paddock) primarily from urine patches. In both paddocks these losses were about three times the N yield in milk (61 and 28 kg N ha−1 respectively) and were replenished by biological N fixation (294 and 100 kg N ha−1). However, mineralisation of soil organic N, excretal N and pasture residues (687 and 438 kg N ha−1) was the major source of mineral N for cycling and losses. The results demonstrate the enormous impact of pasture management on N fluxes and reinforce the importance of livestock urine on the magnitude of N fluxes including gaseous and leaching losses.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1004838323594
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