ISSN:
1573-5036
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Summary An experiment was conducted under glasshouse conditions to study the effects of nitrogen rate and moisture supply on growth, nitrogen uptake and fertilizer nitrogen loss from micro-swards ofLolium perenne L. The fate of nitrogen applied as fertilizer was followed by labelling the nitrogen source with N15. Moisture treatments were designed to simulate field conditions typical of the northern tablelands of New South Wales. The growth response to fertilizer nitrogen was reduced substantially by increasing moisture stress, the proportional reduction in yields being greater at the higher rates of nitrogen. When moisture was non-limiting there was a highly significant linear relationship between nitrogen recovered in the plants and that applied; this relationship became curvilinear under conditions of moderate moisture stress. Nitrogen uptake was less affected by moisture stress than was herbage production, there being little difference in nitrogen yield between the two higher moisture treatments at the lower nitrogen rates; however, nitrogen uptake was considerably reduced under severe moisture stress. Percentage recovery of fertilizer nitrogen by the whole plant was 91.9, 46.8 and 15.6 per cent for the high, medium and low moisture treatment respectively. Soil nitrogen uptake increased with rate of fertilizer nitrogen applied in the high moisture treatment. Less soil nitrogen was recovered by plants under moisture stress, the amount declining with increasing nitrogen rate. A relationship, based on the experimental results, is proposed between plant growth, nitrogen fertilizer rate and the ratio of actual to potential evapotranspiration.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02186970
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