The effect of interval between harvests and nitrogen application on the digestibility and digestible yield and nitrogen content and yield of four ryegrass varieties in the first harvest year

Wilman, D.; Droushiotis, D. N.; Koocheki, A.; Lwoga, A. B.; Shim, J. S.

doi:10.1017/s0021859600054861

Cited by 20 publications

(23 citation statements)

References 8 publications

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“…There were several occasions on which perennial ryegrass herbage was low enough in nitrate-N to be perfectly safe for feeding, whereas the equivalent herbage of other species was more than twice as high in nitrate-N and a cause for concern if fed as a major part of the diet. The higher concentration of nitrate-N in Italian than in perennial ryegrass is in accord with the results of Behaeghe & Carlier (1974), Wilman et al (19766), Wilman & Wright (1978) and Sekimura et al (1979).…”

Section: Discussionsupporting

confidence: 91%

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

Wilman

Wright

1986

J. Agric. Sci.

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The 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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Section: Discussionsupporting

confidence: 91%

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

Wilman

Wright

1986

J. Agric. Sci.

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“…Rate of application of N fertilizer had a large effect on both WSC and N concentrations of ingested herbage during early and mid‐season, with WSC concentration in the ingested herbage decreasing and N concentration increasing with higher rates of application of N fertilizer. This is in agreement with other studies (Wilman et al. , 1976; Peyraud and Astigarraga, 1998).…”

Section: Model Application: the Efficacy Of Grassland Management Toolsupporting

confidence: 94%

“…Rotation length was shown to be an important tool for increasing the quality of herbage (Figure 6). The N concentration of ingested herbage was decreased and the WSC concentration was increased with increasing rotation length, which is in line with other studies (Davies, 1965; Wilman et al. , 1976; Fulkerson and Donaghy, 2001).…”

Section: Model Application: the Efficacy Of Grassland Management Toolsupporting

confidence: 92%

Modelling the concentrations of nitrogen and water‐soluble carbohydrates in grass herbage ingested by cattle under strip‐grazing management

Hoekstra

Schulte

2008

Grass and Forage Science

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There is scope of increasing the nitrogen (N) efficiency of grazing cattle through manipulation of the energy and N concentrations in the herbage ingested. Because of asymmetric grazing by cattle between individual plant parts, it has not yet been established how this translates into the concentrations of N and watersoluble carbohydrates (WSC) in the herbage ingested. A model is described with the objective of assessing the efficacy of individual tools in grassland management in manipulating the WSC and N concentrations of the herbage ingested by cattle under strip-grazing management throughout the growing season. The model was calibrated and independently evaluated for early (April), mid-(June, regrowth phase) and late (September) parts of the growing season. There was a high correlation between predicted and observed WSC concentrations in the ingested herbage (R 2 = 0AE78, P < 0AE001). The correlation between predicted and observed neutral-detergent fibre (NDF) concentrations in the ingested herbage was lower (R 2 = 0AE49, P < 0AE05) with a small absolute bias. Differences in the N concentration between laminae and sheaths, and between clean patches and fouled patches, were adequately simulated and it was concluded that the model could be used to assess the efficacy of grassland management tools for manipulating the WSC and N concentrations in the ingested herbage. Model application showed that reduced rates of application of N fertilizer and longer rotation lengths were effective tools for manipulating herbage quality in early and midseason. During the later part of the growing season, the large proportion of area affected by dung and urine reduced the effect of application rate of N fertilizer on herbage quality. In contrast, relative differences between high-sugar and low-sugar cultivars of perennial ryegrass were largest during this period. This suggests that high-sugar cultivars may be an important tool in increasing N efficiency by cattle when risks of N losses to water bodies are largest. The model output showed that defoliation height affects the chemical composition of the ingested herbage of both the current and the subsequent grazing period.

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“…The drying and milling of herbage and the determination of digestibility (by the method of Tilley & Terry, 1963) and of N content (Faithfull, 1971) were as for the 1973 samples (Wilman et al 19766).…”

Section: Methodsmentioning

confidence: 99%

The effect of interval between harvests and nitrogen application on the proportion and yield of crop fractions and on the digestibility and digestible yield and nitrogen content and yield of two perennial ryegrass varieties in the second harvest year

1976

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SummaryThe effect of six intervals between harvests and three levels of N application on the dry-matter yield of total herbage, the proportion and yield of green leaf, dead leaf, ‘stem’ and inflorescence of the sown species, the proportion and yield of unsown species, the digestibility and digestible yield and N content and yield was studied in S. 23 and S. 321 perennial ryegrass during a 30-week period in the second harvest year in a field experiment. In S. 23 the ‘stem’ was divided into true stem, leaf sheath, unemerged leaf and unemerged inflorescence.The results supported the main findings from the first harvest year (Wilman et al. 1976a, b).There was marked ingress of unsown species in the second harvest year with 3-, 4- and 5-week intervals in S. 321. The combination of 262–5 or 525 kg N/ha/year and 8- and particularly 10-week intervals over 2 years was too severe a treatment for the satisfactory survival of S. 23. With 525 kg N and 10-week intervals, S. 321 was equally badly affeoted.The application of 525 kg N/ha/year compared with nil reduced the proportion of green leaf in total herbage of the sown species by 11 percentage units, on average, and increased the proportion of ‘stem’ by 12 percentage units, in the second harvest year. The effect of N application on the proportion of crop fractions was found in both varieties and in all months of harvest. The effect was much greater than in the first harvest year. In S. 23 the application of 525 kg N compared with nil in the second harvest year increased the proportions of both true stem and leaf sheath (in total herbage of the sown species), true stem being the more important of the two, in this context, with the longer intervals and leaf sheath being the more important with the short intervals.Digestibility was not in general affected by N application despite the higher proportion of stem and leaf sheath and the lower proportion of green leaf blade resulting from N application. N did, however, tend to reduce digestibility at the harvests at which the proportion of stem was highest.Digestibility varied from one time of the year to another with a constant interval between harvests, but not as much as in the previous year. Lower digestibility of leafy crops in summer and autumn than in April and early May in both years may have been partly due to a higher proportion of dead material.Three periods were distinguished approximately in both years: May-June, July-August, and September-October. Only in the first of these periods was there a substantial increase in yield of digestible organic matter as a result of doubling the interval between harvests. Doubling the interval reduced digestibility in all three periods, but especially at harvests within the second period. Yield response to N was large in the first period, intermediate in the second, and low in the third. Apparent recovery of N was low and N content of herbage unduly high in the third period. N content of herbage was low with the long intervals between harvests at harvests in the first two periods. Applied N increased N content at these harvests and at all other times.

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The effect of interval between harvests and nitrogen application on the digestibility and digestible yield and nitrogen content and yield of four ryegrass varieties in the first harvest year

Cited by 20 publications

References 8 publications

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

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

Modelling the concentrations of nitrogen and water‐soluble carbohydrates in grass herbage ingested by cattle under strip‐grazing management

The effect of interval between harvests and nitrogen application on the proportion and yield of crop fractions and on the digestibility and digestible yield and nitrogen content and yield of two perennial ryegrass varieties in the second harvest year

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