Abstract
Abstract Perennial ryegrass (Lolium prenne L.) has been introduced to Japan as a cool season turfgrass. In spite of relatively mild winter in most parts of the country, it still goes to winter dormancy. A well‐balanced fertility ratio and rate may prevent such dormancy without causing winter injury. Therefore, this experiment was designed to find a balanced rate and ratio among nitrogen (N), potassium (K), and phosphorus (P) fertilizers in order to prevent winter dormancy and promote growth during the winter in Japan. Yorktown 2 perennial ryegrass was used in this experiment. Nitrogen and K application rates were 50, 150, 250, 350, 450, 550, and 650 kg K/ha; whereas P rates were 50, 150, and 250 kg P/ha. These rates were applied in 30 different ratios. Growth, color, and density of the turf were estimated and used as the parameters for finding a suitable rate and ratio for these three major nutrients. Color, density, and growth were increased as the rate of N fertilizer increased, but there was no visual response to P or K rates. It is suggested that increases in color, density, and growth were function of N rates, whereas K and P rates maintained the cold hardiness of the turf when high N rates were applied under the conditions of this experiment. Fertility ratio and the rates of 450 kg N/ha, 250 kg K/ha, and 50 kg P/ha were sufficient to prevent dormancy, promote growth, and produce good quality turf throughout the winter. Thus, it is concluded that fertility ratios and rates are the main factors limiting growth and quality of perennial ryegrass in transitional zones similar to Japan.
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Claims 5
Claim · model-written summary
Increasing nitrogen fertilizer rate increased turf color, density, and growth.
- Taxon
- perennial ryegrass
Lolium perennet0 - Treatment
- rate of N fertilizere0
- Outcome
- Color, density, and growthe0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Color, density, and growth were increased as the rate of N fertilizer increased”
t0“perennial ryegrass”
Claim · model-written summary
Turf had no visual response to phosphorus rates.
- Taxon
- perennial ryegrassLolium perennet0
- Treatment
- Pe0
- Outcome
- visual responsee0
- Direction
- no visual responsee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“there was no visual response to P or K rates”
t0“perennial ryegrass”
Claim · model-written summary
Turf had no visual response to potassium rates.
- Taxon
- perennial ryegrassLolium perennet0
- Treatment
- Ke0
- Outcome
- visual responsee0
- Direction
- no visual responsee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“there was no visual response to P or K rates”
t0“perennial ryegrass”
Claim · model-written summary
Potassium and phosphorus rates were suggested to maintain cold hardiness under high nitrogen rates.
- Taxon
- perennial ryegrassLolium perennet0
- Treatment
- K and P ratese0
- Outcome
- cold hardinesse0
- Qualifier
- when high N rates were appliede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“K and P rates maintained the cold hardiness of the turf when high N rates were applied”
t0“perennial ryegrass”
Claim · model-written summary
The 450 kg N/ha, 250 kg K/ha, and 50 kg P/ha regime prevented winter dormancy and promoted growth and turf quality.
- Taxon
- perennial ryegrassLolium perennet0
- Treatment
- 450 kg N/ha, 250 kg K/ha, and 50 kg P/hae0
- Outcome
- prevent dormancy, promote growth, and produce good quality turfe0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Fertility ratio and the rates of 450 kg N/ha, 250 kg K/ha, and 50 kg P/ha were sufficient to prevent dormancy, promote growth, and produce good quality turf throughout the winter.”
t0“perennial ryegrass”
The same questions in other papers
nitrogen · quality: general · Lolium perenne (perennial ryegrass)Positive and negative results
3 in the opposite direction · 1 reporting no difference from an alternative
- negative
- no effect
- no effect
1 paper more in this group
See all 5 papers →fertilization · quality: postharvest · Lolium perenne (perennial ryegrass)Results agree
2 papers in the same direction as this paper
- positive
- positive
Claims are grouped by organism, treatment and what was measured or targeted. A paper counts as positive when any of its claims in the group is positive.