Varying the ratio of 15N-labelled ammonium and nitrate-N supplied to perennial ryegrass: effects on nitrogen absorption and assimilation, and plant growth

1998 ◽  
Vol 140 (3) ◽  
pp. 505-518 ◽  
Author(s):  
J. S. BAILEY
Keyword(s):  
Plant Growth ◽  
Perennial Ryegrass ◽  
Nitrogen Absorption ◽  
Nitrate N

The response of perennial ryegrass to nitrogen in various periods of the growing season

1970 ◽  
Vol 75 (3) ◽  
pp. 539-546 ◽  
Author(s):  
D. W. Cowling ◽  
D. R. Lockyer
Keyword(s):  
Perennial Ryegrass ◽  
Dry Matter ◽  
Radiant Energy ◽  
Animal Husbandry ◽  
Growing Season ◽  
Experimental Results ◽  
Response Curves ◽  
Fertilizer Nitrogen ◽  
Nitrate N ◽  
Yield Responses

SUMMARYThe response of irrigated, perennial ryegrass to fertilizer nitrogen was studied in four consecutive periods of the growing season by applying 0–350 kg N/ha to a fresh sward at the start of each period, and measuring both herbage dry matter and its content of nitrogen.Responses in yield were highest in the first period, which ended at inflorescence emergence; in this period, both the percentage recovery of nitrogen and the extent of its utilization in producing dry matter were greater than in the later periods. Some damage to the sward was seen following the harvest of grass grown with the high levels of nitrogen in the first period. When the yields were 90% of the predicted maximum the nitrate-N content of the herbage ranged from 1000 to 2000 ppm, except in the first period when it was 200 ppm.The response curves were used to calculate the nitrogen requirements of the grass which would maintain given incremental yield responses. To produce near-maximum yields, irrigated grass swards may require fertilizer nitrogen equivalent to 2 kg N/ha/day prior to inflorescence emergence, and up to 5 kg N/ha/day for the remainder of the growing season.The apparent efficiency of conversion of the radiant energy, usable for photosynthesis, into plant energy averaged 3·2%; it did not vary greatly among the four periods.The experimental results indicate the seasonal requirements of grass for fertilizer nitrogen and some of the implications for animal husbandry are discussed.

scholarly journals Effects of the Fungal Endophyte Epichloë festucae var. lolii on Growth and Physiological Responses of Perennial Ryegrass cv. Fairway to Combined Drought and Pathogen Stresses

2020 ◽  
Vol 8 (12) ◽  
pp. 1917
Author(s):  
Fang Li ◽  
Tingyu Duan ◽  
Yanzhong Li
Keyword(s):  
Plant Growth ◽  
Soil Water ◽  
Perennial Ryegrass ◽  
Disease Incidence ◽  
Bipolaris Sorokiniana ◽  
P Uptake ◽  
Fungal Endophyte ◽  
Photosynthetic Parameters ◽  
Epichloë Festucae ◽  
Combined Stresses

Perennial ryegrass (Lolium perenne) is widely cultivated around the world for turf and forage. However, the plant is highly susceptible to disease and is sensitive to drought. The present study aims to determine the effect of the fungal endophyte Epichloë festucae var. lolii of perennial ryegrass on the combined stresses of drought and disease caused by Bipolaris sorokiniana in the greenhouse. In the experiment, plants infected (E+) or not infected (E−) with the fungal endophyte were inoculated with Bipolaris sorokiniana and put under different soil water regimes (30%, 50%, and 70%). The control treatment consisted of E+ and E− plants not inoculated with B. sorokiniana. Plant growth, phosphorus (P) uptake, photosynthetic parameters, and other physiological indices were evaluated two weeks after pathogen infection. The fungal endophyte in E+ plants increased P uptake, plant growth, and photosynthetic parameters but decreased the malondialdehyde concentration, proline content, and disease incidence of perennial ryegrass (p < 0.05). E+ plants had the lowest disease incidence at 70% soil water (p < 0.05). The study demonstrates that the fungal endophyte E. festucae var. lolii is beneficial for plant growth and stress tolerance in perennial ryegrass exposed to the combined stresses of drought and B. sorokiniana.

The effect of interval between harvests and nitrogen application on the concentration of nitrate-nitrogen in the total herbage, green leaf and ‘stem’ of grasses

1986 ◽  
Vol 106 (3) ◽  
pp. 467-475 ◽  
Author(s):  
D. Wilman ◽  
P. T. Wright
Keyword(s):  
Field Experiment ◽  
Perennial Ryegrass ◽  
Nitrate Nitrogen ◽  
Italian Ryegrass ◽  
Green Leaf ◽  
N Application ◽  
Total N ◽  
Nitrate N ◽  
N Concentration ◽  
Time Of Year

SummaryThe effect of six intervals between harvests and three levels of N application on the concentration of nitrate-N and total N in total herbage, green leaf and ‘stem’ was studied in two varieties of perennial ryegrass during 30-week periods in each of the first two harvest years of a field experiment. The effect of two intervals between harvests on the concentration of nitrate-N in Italian ryegrass total herbage was studied in the same experiment. The effect of two intervals between harvests and three levels of N application on the concentrations of nitrate-N and total N in total herbage was studied in five grasses during a 32-week period in a second field experiment.Increasing the interval between harvests tended to increase the concentration of nitrate-N in herbage; however, this seemed due mainly to the average date of harvest being later in the year with the longer intervals. The concentration of nitrate-N in herbage increased from June to September. Italian and hybrid ryegrass and tall fescue were much higher than perennial ryegrass in nitrate-N concentration at the highest level of applied N (525 kgN/ha per year). Apart from the species and time of year effects, the nitrate-N concentration seemed to be determined mainly by the amount of N applied divided by the number of days between the date of application and the date of sampling. The ‘stem’ of perennial ryegrasa tended to be slightly higher in nitrate-N concentration than green leaf. The proportion of nitrate-N in total N was increased by increasing the interval between harvests and by applying N and was nearly twice as high in ‘stem’ as in green leaf. Both the nitrate-N and the total N concentration of herbage, particularly the latter, seemed to be inversely related to solar radiation receipt.

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