ISSN:
1573-5036
Keywords:
asparagus
;
Asparagus officinalis
;
nitrogen fertilizer
;
15N
;
plant uptake
;
soil nitrogen fractions
;
time of application
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Abstract The effect of nitrogen (N) fertilizer on the production of a 6-year-old asparagus (Asparagus officinalis L.) crop was examined over 2 years by the application of 0, 50 or 100 kg N ha−1 as ammonium sulphate at three times; 1) prior to fern growth (9 months before harvest), 2) prior to harvest, or 3) early-harvest prior to the main period of spear production. The utilization of N fertilizer was examined by applying 15N-enriched ammonium sulphate to 2 m×2.5 m microplost within the 50 kg N ha−1 treatments. There was a 12% response in spear production to added N in the first harvest year only and there was no significant effect of rate or time of N application. Plant uptake of added 15N by the end of the first harvest period was 25, 11 and 4% of the total applied for the pre-fern, pre-harvest and early-harvest treatments respectively. About 60% of the 15N applied pre- or early-harvest remained in the soil at the end of the first harvest period. Most of the 15N in soil in the pre-harvest treatment occurred as inorganic N and had been leached into the 150–600 mm soil depth. In contrast, most of the 15N that remained in soil from the early-harvest application was in the 0–75 mm depth and 40% of this had been immobilized into organic N. In the short-term (less than one year), utilisation of 15N-labelled N fertilizer by asparagus was greatest when applied prior to fern growth. However, after 2 years there was no difference between treatments in 15N recovery in plant or soil. Thus, time of application of N fertilizer had no long-term effect on production or utilization of N fertilizer by asparagus.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00009369
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