ISSN:
1573-0867
Keywords:
nitrogen fertilization
;
grass varieties
;
cutting interval
;
leaf development
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Abstract Effects of five levels of applied nitrogen on field swards of each of five grasses were studied in the year of sowing, in the first full harvest year and part of the second harvest year. The plots were cut at 4-week intervals during the year of sowing; subsequently 4- and 8-week intervals between cuts were compared. The application of N increased the number of leaf primordia, the number of unemerged leaves, the rates of leaf emergence and death, total green leaf exposure time, the number of green leaves harvested per tiller, leaf blade length, width and weight, and leaf extension rate. The application of N reduced weight per unit area of leaf blade. The increases in size, weight and number of leaf blades appeared to be major reasons for the positive effect of applied N on yield, previously reported. There appeared to be scope for further positive response to applied N beyond 525 kg N ha−1 yr−1 in respect of rates of leaf emergence and extension and area per blade. The numbers of primordia and unemerged leaves and the rate of leaf emergence were greater in R v P than in Aberystwyth S.170, with the perennial ryegrasses intermediate. Doubling the interval between harvests reduced the number of leaves which emerged and increased the number which died, increased area and weight per leaf blade except in R v P, and appeared to result in some accumulation of leaf primordia and unemerged leaves. Drought (in 1976) reduced the rates of leaf emergence and extension and area per leaf blade, increased weight per unit area of leaf blade and appeared to result in some accumulation of leaf primordia and unemerged leaves. The length of shoot apex per leaf primordium was relatively constant. Leaf blade size appeared more sensitive in S.170 than in the ryegrasses to interval between harvests, moisture supply and radiation-cum-temperature (but not N supply).
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01072874
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