Investigation and quantification of the effects of environmental factors on grass growth and development
Objectives
Prediction of grass growth is a necessary component of the technology of feed budgeting on grassland farms. While programmes such as Grasscheck have provided general profiles of grass growth, the response of growth and development to variation in weather and conditions specific to site is still not fully quantified. This is particularly so in very wet years (e.g. 2002) or dry summers (e.g. 1995).
Limitations in cost and other resources do not allow trials to be carried out over a wide range of sites for a number of years with a range of sward types to quantify the effect of environmental variables on grass growth within the Province. Hence an alternative is to adopt a modelling approach. This was initiated in Project 9822 in which a theoretical model was adapted to field conditions, aided by experimental data gathered during the project.
While the model was relatively successful in predicting growth of grass in the recommended list trials at the Plant Testing Station and in the Grasscheck plots during summer and early autumn, prediction of growth in spring and late autumn was less accurate, prediction of the effect of drought was semi-quantitative, and the reason for the poor forecast for grass growth under prolonged wet conditions is not clear.
The objectives of this project are to;
- investigate the discrepencies between actual and predicted growth at times when prediction is weakest
- derive new mathematical relationships which will improve the output of the model for use in grass budgeting, based on data from experiments
- develop a reliable model to predict grass growth under conditions which the Province could experience in the next half century and so may have a role in planning at Provincial level.
Journal articles
Liu, W. J. , Zhu, Y. G. , Christie, P. , Laidlaw, A. S. (2010). Botanical composition, production and nutrient status of an originally Lolium perenne-dominant cut grass sward receiving long-term manure applications. Plant and Soil, 326(1-2):355-367
Laidlaw, A. S. (2009). The effect of soil moisture content on leaf extension rate and yield of perennial. Irish Journal of Agricultural and Food Research, 48:1-20
Hennessy, D. , O'Donovan, M. , French, P. , Laidlaw, A. S. (2008). Factors influencing tissue turnover during winter in perennial ryegrass dominated. Grass and Forage Science, 63(2):202-211
Dale, A. J. , Mayne, C. S. , Laidlaw, A. S. , Ferris, C. P. (2008). Effect of altering the grazing interval on growth and utilisation of grass and performance of dairy cows under rotational grazing. Grass and Forage Science, 63(2):257-269
Hennessy, D. , O'Donovan, M. , French, P. , Laidlaw, A. S. (2008). Manipulation of herbage production by altering the pattern of applying nitrogen fertilizer. Grass and Forage Science, 63(1):152-166
Frame, J. , Laidlaw, A. S. (2007). Temperate forage legumes for adverse conditions. CAB Reviews: Perspectives in Agriculture, Veterinary Science, Nutrition and Natural Resources, 2(1):1-11
Hennessy, D. , O'Donovan, M. , French, P. , Laidlaw, A. S. (2006). The effects of date of autumn closing and timing of winter grazing on herbage production in winter and spring. Grass and Forage Science, 61(4):363-374
Frame, J. , Pineiro, J. , Laidlaw, A. S. (2006). Extending the grazing season. Pastos, 34(1):5-30
Barrett, P. D. , Laidlaw, A. S. , Mayne, C. S. (2005). GrazeGro: a European herbage growth model to predict pasture production in perennial ryegrass swards for decision support. European Journal of Agronomy, 23:37-56
Dawson, L. E. R. , Carson, A. F. , Kilpatrick, D. J. , Laidlaw, A. S. (2005). Effect of herbage allowance and concentrate food level offered to ewes in late pregnancy on ewe and lamb performance. Animal Science Journal, 81:413-421
Laidlaw, A. S. (2005). The relationship between tiller appearance in spring and contribution to dry-matter yield in perennial ryegrass (Lolium perenne) cultivars differing in heading date. Grass and Forage Science, 60(2):200-209
Book
Frame, J. , Laidlaw, A. S. (2005). Prospects for temperate forage legumes. In: Grasslands: Developments, Opportunities, Prospects, (Eds. Reynolds, S., Frame, J.), FAO and Science Publishers, Rome, Italy pp:1-28
Development of a management information system for grass/white clover swards (CloverCheck) for use in low input grassland production
Objectives
The objective is to produce a system which will monitor growth, clover content and nutritive value of grass/white clover swards. The predictive package developed will be a combination of monitor plots to confirm immediate past growth and clover content, NIRS to provide a rapidly current estimate of nutritive value of grass-white clover swards and a mathematical model (developed under a separate growth modeling project - 0445) to predict performance of swards during the following 1-2 weeks. When developed, the system will involve production of weekly bulletins informing the industry of immediate past performance of the monitor plots, likely regional variation (using the predictive model)and forecasted performance (again from output of the model).
Journal articles
Black, A. D. , Laidlaw, A. S. , Moot, D. J. , O'Kiely, P. (2009). Comparative growth and management of white and red clovers. Irish Journal of Agricultural and Food Research, 48:149-166
Humphreys, J. , Casey, E. , Laidlaw, A. S. (2009). Comparison of milk production from clover-based and fertiliser N-based grassland on a clay-loam soil under moist temperate climatic conditions. Irish Journal of Agricultural and Food Research, 48:189-207
Book
Frame, J. , Laidlaw, A. S. (Editors) (2011). Improved Grassland Management, The Crowood Press, Marlborough, 352 pp.
Knowledge transfer
Laidlaw, A. S. , McHenry, M. (2010). CloverCheck 2010 - Monitoring white clover performance. Final article in series
Laidlaw, A. S. , McHenry, M. (2010). CloverCheck 2010 Bulletin 14. Fortnightly bulletin in series
Laidlaw, A. S. , McHenry, M. (2010). CloverCheck 2010 Bulletin 12. Fortnightly bulletin in series
Laidlaw, A. S. , McHenry, M. (2010). CloverCheck 2010 Bulletin 13. Fortnightly bulletin in series
Laidlaw, A. S. , McHenry, M. (2010). CloverCheck 2010 Bulletin 9. Fortnightly bulletin in series
Laidlaw, A. S. , McHenry, M. (2010). CloverCheck 2010 Bulletin 10. Fortnightly bulletin in series
Laidlaw, A. S. , McHendry, M. (2010). CloverCheck 2010 Bulletin 1l. Fortnightly bulletin in series
Laidlaw, A. S. , McHenry, M. (2010). CloverCheck Bulletin 7. Fortnightly bulletin in series
Laidlaw, A. S. , McHenry, M. (2010). Clovercheck 2010 Bulletin 8. Fortnightly bulletin in series
Laidlaw, A. S. , McHenry, M. (2010). CLoverCheck 2010 Bulletin 5. Fortnightly bulletin in series
Laidlaw, A. S. , McHenry, M. (2010). CloverCheck 2010 Bulletin 6. Fortnightly bulletin in series
Laidlaw, A. S. , McHenry, M. (2010). CloverCheck 2010 Bulletin 3. Fortnightly bulletin in series
Laidlaw, A. S. , McHenry, M. (2010). CloverCheck 2010 Bulletin 4. Fortnightly bulletin in series
Laidlaw, A. S. , Lowe, D. E. , McHenry, M. (2010). CloverCheck 2010 Launch. Fortnightly bulletin in series
Laidlaw, A. S. , McHenry, M. (2010). CloverCheck 2010 Bulletin 2. Fortnightly bulletin in series
Laidlaw, A. S. , McHenry, M. (2009). CloverCheck Bulletins from April 2009. 15 fortnightly CLoverCheck bulletins for press and 2 websites
Laidlaw, A. S. (2009). CloverCheck-Making the most of free fixed nitrogen fertiliser. AFBI publicity pre-RUAS Show
Laidlaw, A. S. , McHenry, M. (2008). CloverCheck - An aid for the management of grass/white clover swards. Circulated to farming press
Adaptation of a herbage growth model to predict herbage growth and legume content in swards containing grass and white or red clover
Objectives
The aim of the project is to adapt an existing grass growth model for use in predicting growth and crude protein content of grass-white clover and grass/red clover swards subject to the range in management and environmental conditions likely to be encountered in Northern Ireland. The existing PTS Grass Growth model has been validated successfuly against data from plot experiments receiving a range of levels of nitrogenous fertilizer. The aim is to introduce clover into the model in association with grass, taking account of the interaction between the two. The model will be validated against data from field trials carried out in previous projects in APSD on red and white clover under a range of fertiliser, management and environmental conditions.
By deriving mathematical equations to explain the main sources of variation in legume content in mixed swards, it will be possible to adapt other grass growth models for use in mixed swards e.g. the grass model used by DAERA/ARINI to forecast growth under high fertiliser levels in the monitoring and forecasting system, GrassCheck.
Journal Article
Laidlaw, A. S. (2010). Herbage growth models as an aid for managing intensively grazed grassland in western Europe. Field and Vegetable Crops Research, Not Specified: (In-Press)