Grass Flashcards
(283 cards)
1
Q
Benefits of red clover in the diet
A
Can improve the fatty acid content of milk, but don’t feed to sheep 6-8 weeks pre/post mating
2
Q
What is the grazing residual of red clover?
A
6cm
3
Q
What is the inclusion rate of RC?
A
4kg
4
Q
Benefits of a clover sward?
A
Produces more milk with a higher quality intake
5
Q
How much N can WC fix?
A
140kg N/ha/year
6
Q
What is the life expectancy of clover?
A
5 years
7
Q
How much clover do you sow when over-sowing?
A
5kg/ha with one bag of 0:70:30 but if it is an existing clover sward then only sow 2.5kg/ha
8
Q
In what soils is there maximum clover productivity?
A
Medium to free draining loam soils
9
Q
Every 1 tonne of grass utilised increases profitability by how much on dairy farms?
A
€181/ha on dairy farms and €105/ha on dry stock farms
10
Q
What is the DM intake of a 600kg cow per day?
A
15-19kg
11
Q
How long do cows spend grazing?
A
7-9 hours per day
12
Q
What is the rotation length in a leader follower system?
A
4-5 days
13
Q
How much CP is in grazed grass?
A
180-250g/kg/DM
13
Q
Best indication of pasture quality?
A
Organic Matter Digestibility, used to calculate GE content. Higher the OMD, higher the UFL
14
Q
What is the DMD of Autumn grass?
A
80%
15
Q
What is the substitution rate for grass for every 1kg DM of grass silage fed?
A
0.9kg DM
16
Q
What is the optimum proportion of maize silage in the diet?
A
33%
17
Q
What benefits does maize silage have in the diet?
A
Good energy, increased DMI
18
Q
What are the maize nutrient requirements?
A
180kg/ha potash, 40kg/ha of phosphate and 150kg/ha of N
19
Q
Overgrazing
A
Post grazing sward height of less than 3.5cm
20
Q
3.5-4cm represents how many kg DM/ha?
A
0.50kg DM/ha
21
Q
What is the grass organic matter digestibility (OMD) used for?
A
Energy content/UFL/UFV value
22
Q
What is the water soluble carb (WSC) content of grazed grass?
A
150-200kg DM
23
Q
Length of true stem in PRG
A
3cm
24
Length of the final grazing rotation of the year?
40-45 days
25
Average farm cover in late November?
550-600kg DM/ha @ 2.5 LU/ha
26
60:40 autumn grassland plan?
60% grazed by 1st November
27
Spring turnout farm cover?
900-1000kg DM/ha
28
Complete 1st rotation by what date?
1st April to 15th April
29
3 pieces of info the spring rotation planner needs?
Date of turnout, date of finished 1st rotation, and area of ground to be grazed
30
Forward creep grazing of lambs can increase weaning weight by?
2kg
31
Target weight gain of a lamb at grass post-weaning?
150g/day
32
Issue of over-lush grass with horses
Inefficient use and risk of laminitis
33
Consequences of selective grazing?
Patchy swards, weeds, overgrazing, and nutrient depletion
34
How much of long established horse pasture is grazed?
10%
35
How to tackle patchy swards?
Mixed grazing and over-sowing
36
How much N is applied to horse pasture?
25-30kg N/acre
37
Rest period for horse grazing benefits?
Decrease worm burden
38
Target pH of horse paddocks?
6-6.5
39
Sheep more favourable in mixed grazing with horses because?
Less damage during wet weather
40
Why is harrowing carried out in the spring?
Remove dead material from the base of the sward
41
Chain harrowing in autumn purpose?
Break up dung patches and increase breakdown rate
42
What depth does shallow compaction go down to?
10cm
43
Research in Teagasc suggested what as a strategy to permit early spring grazing?
Allow cows restricted access time to grazed pasture daily
44
In early grazing, what sort livestock should be let out first?
Lighter cattle should be let out first
45
Grass DM requirement of an animal?
2%
46
Target number of days: April-June, July-August, September-closing
April-June = 12-14 days, July-August = 16-18 days, September-closing = 25 days
47
3 elements in KT grassland management programme?
Soil fertility, reseeding policy, and grass utilisation
48
% of mid-season lambs to be drafted by end of September?
70-85%
49
How long should it take to graze out a paddock during the main grazing season?
5 days
50
Rest period length for paddocks over the winter months?
120 days
51
Grass DM that a lactating ewe will eat daily?
3.2kg DM/day
52
Characteristics of RC?
Short life span, erect growth habit, good winter hardiness
53
What is the function of PPO (Polyphenol Oxidase)?
Inhibition of post-harvest proteolysis by inhibiting activity of the plant proteases in the silo
54
How many tillers present in high sward density?
30,000
55
Clover in horse pasture?
0%
56
Laminitis definition?
Inflammation and weakening of the laminae that bonds the hoof wall to the pedal bone in the hoof – Spring and Autumn high risk periods
57
What is in ragwort to make it poisonous?
Pyrrolizidine alkaloids – causes inhibitions of normal repair in the liver and inhibits its regeneration
58
What is the % of silage in the feed budget in beef and dairy farms?
Beef = 24-38%, Dairy = 19-25%
59
Buffering capacity definition?
The equivalents of acid per unit DM required to lower crop pH from 6 to 4
60
Typical buffering capacity in grass?
250-350 mEq/kg
61
What is the DM content of crimped grain?
60-70%
62
What is the DM content of urea-treated grain?
65-72%
63
Why is 85% of maize grown under film?
Increases temperature & DM yield
64
When should silage be tested?
At least 6 weeks after ensiling
65
What is the annual average of clover that should be in the sward?
20-25%
66
Why is RC more drought resistant than WC?
RC has tap roots
67
How much N can RC fix?
200kg of N/ha/year
68
How much N can WC fix annually?
100-150kg of N/ha/year
69
A PRG/RC sward can yield how many tonnes of DM per year?
11-13t DM/year
70
What is the cost of producing 1t of usable silage DM at a yield of 5t?
€125 for 1st cut and €140 for 2nd
71
What is forage preservation based on?
Lactic acid fermentation under anaerobic conditions
72
What is the purpose of epiphytic lactic acid bacteria?
Fermentation of water soluble carbohydrates in the crop to lactic acid and acetic acid
73
As pH is decreased…
Spoilage organisms are inhibited
74
What are the 4 phases of the ensiling process?
Aerobic phase, fermentation phase, stable phase, and feed-out phase
75
How long does the anaerobic stage of the ensiling process last?
Few hours
76
What will develop if fermentation is successful?
Lactic acid bacteria
77
What is the pH range of silage?
3.8-5.0
78
What are the 2 phases of feed out?
Degradation of preserving OA’s and rise in pH/activity of spoilage organisms
79
What can DM increase be achieved by?
Delaying harvest and wilting
80
What helps to accelerate loss of water from a plant?
Disruption of the cuticle
81
What are the primary fermentable substrates in temperate grasses?
Glucose, fructose, sucrose, and fructans
82
Disadvantages of RC?
Unsuitable to intensive grazing, yield declines over time, can lead to bloat in ruminants
83
When sowing a RC/PRG mix what should the ratio in the seed mix be?
3:1
84
Why is it important to encourage stolon growth throughout the year?
To ensure high survival rates over the winter
85
How much WC should be included per ha?
4.63kg/ha
86
How much grass is sown per ha?
14kg/ha for diploid and 16kg/ha for tetraploid
87
If a plant has a caespitose growth habit, what does it mean?
Grows in tufts
88
What type of growth habit does WC have?
Stoloniferous
89
What is the usual inclusion rate of WC in a seed mixture?
1kg/ha
90
How much clover would you usually find in a permanent pasture in Ireland?
Rarely more than 5%
91
For high clover establishment, how much will need to be incorporated in a seed mix?
3-4kg/ha
92
In relation to WC, what are the characteristics of varieties with medium sized leaves?
Moderate stolon density and suitable for frequent close grazing
93
Characteristics of large leaves?
Longer petioles and fewer stolons, suitable for lax rotational grazing
94
When does WC have a lower leaf photosynthesis than grasses?
Spring
95
When does WC have a higher leaf photosynthesis than grasses?
Summer
96
Over the summer period, which animals should be grazed on WC ground?
Priority stock
97
When does WC rebuild its stolon/leaf reserves?
Autumn
98
What is the recovery period over the winter for WC swards?
100-150days
99
What would the CP content of a WC/PRG sward be?
21%
100
Advantages of WC?
Increased intakes and mineral content
101
Disadvantages of WC?
Persistence issues, bloat, difficult to control docks
102
On a heavy farm what should the grazing targets be?
Turnout late Feb/early March, 30% grazed by March 10th. 60% grazed by March 27th and 100% grazed by mid-April
103
Target average farm cover during main grazing season?
450-600kg DM/ha
104
Stocking rate for adequate feeding of cows at pasture?
4.5 cows/ha
105
What % of leaf should you maintain in the sward ahead of the cows?
65%
106
Stocking rate of 2.5 cows/ha how much ground can be taken off for silage?
45-50%
107
Priority when supplementing grass?
Maximise production
108
Advantages of mixed grazing?
Increases pasture utilisation and reduces pasture burden
109
What is the maximum ratio of field sides in grazing systems?
4:1
110
% N in atmosphere?
78%
111
Type of plant that has the ability to fix atmospheric N?
Legumes
112
What type of bacteria form a symbiotic relationship with legumes?
Rhizobium
113
What is N gas converted to in the root nodules of the plant?
Ammonia (NH3)
114
What form of N do bacteria provide for the legume plant?
Ammonium
115
Benefit of symbiotic relationship for bacteria?
Legume provides them with CHO for energy
116
What is growth in legumes directly related to?
Rate of N fixation
117
118. What height should grass be cut to when measuring using a quadrat and shears?
a. 4cm
118
During periods of continuous rain what should you estimate grass DM to be?
12-15%
119
DM in 1st rotation in spring?
18-19%
120
DM during drought?
22-23%
121
For high clover establishment, how much will need to be incorporated in the seed mix?
3-4kg/ha
122
What grazing technique should be employed on WC ground in spring to ensure grazing quality for later in the season?
Frequent rotational or continuous grazing
123
Why is it important to maintain a well-cushioned turf?
For horses to exercise, particularly young stock
124
What happens to overgrazed areas?
They become depleted of nutrients
125
After rejuventation, how much of a horse pasture will be grazed?
20-30%
126
With horses, when should grazing occur?
Just before the rate of grass leaf growth declines
127
What is the carrying rate of high quality grassland?
3-4 light horses (400kg)/ha, 4-6 smaller ponies/ha
128
How much do heavy breeding mares (700-800kg BW) require on good temperate summer grassland?
0.7-10ha/mare and foal
129
When following cattle, how much should be allocated to a mare and foal?
1.5-2.0ha
130
Rotational grazing, cutting excess herbage and N input of 80-150kg N/ha can support how many horses?
2-2.5 growing horses/ha
131
Why should hay be made from paddocks that have been previously grazed by horses?
Parasite control
132
Compare tetraploid to diploid varieties of PRG
Tetraploid have larger tillers, lower tiller densities, lower DM content, higher WSC, are susceptible to poaching
133
What is the average farm size in Ireland?
32ha
134
Grassland accounts for what % of total land use in Ireland?
59%
135
Leys advantages
soil fertility, weed, pest and disease control
136
Common sown grasses
PRG, IRG, Cocksfoot, Timothy, Meadow Fescue
137
PRG Characteristics
Rapid establishment, good tillering, dense sward, high DM yields and good digestibility, excellent production response to fertile conditions and fertiliser N
138
Heading Date
Approximate date around which 50% of reproductive tillers will produce seed heads
139
What 3 species account for nearly all of the agricultural grass/clover seed sold in Ireland
PRG, IRG, WC
140
3 seed categories based on heading dates
early, intermediate, late
141
Early seed
heads in first half of May, use of this declined due to stemmy regrowth in summer
142
Intermediate seed
head in second half of May, produce high quality silage cuts, good sward density
143
Late seed
head in first half of June, high tiller density, well suited to long term grazing pastures, good quality silage cuts in early June
144
Diploid
high tiller density, higher DM%, slightly lower DMD, lower yielding
145
Tetraploid
low tiller density, lower DM%, high DMD, higher yielding
146
Vigorous swards
a sward that can grow out of season, have a high tiller density and provide adequate grass production when required
147
Reseeding advantages
increase the productivity, higher level of regrowth, respond better to applied N, improve grass quality, reduce silage requirements
148
Temperature requirements for autumn reseeding
6oC for grass seedlings/ 8oC for clover seedlings
149
What month is the most suitable for Autumn reseeding
August
150
Soil fertility
the quality of a soil that enables it to provide nutrients in adequate amounts and in proper balance for the growth of specific plants or crops
151
Phosphorus (P) function
Essential for root development and sward establishment
152
Potassium (K) function
Controls the loss of water by transpiration through the leaf pores, sugar formation and root development, and transport of metabolites and nutrients within the plant
153
Optimum pH for grassland
pH 6.3
154
Conventional reseeding method
spray off old sward, shallow ploughing (<15cm), lime, land level, fertiliser, sow the seed, roll
155
Alternative reseeding methods to conventional
discing, one pass, direct drilling (stitching in, undersowing, oversowing)
156
Tillering
development of a plant that is similar to the parent plant from a bud that is formed as each new leaf appears in the leaf axial
157
A tiller normally develops in the axial of the first leaf at what leaf stage?
3-4 leaf stage
158
Cost of reseeding 2023
€540/ac
159
3 main elements that need to be returned to the soil following grazing/harvesting
N, P, K
160
Nitrate poisoning
caused by high nitrate levels during a flush of growth after a dry period, particularly in late autumn or winter. Build up in herbage when nitrate is taken up by plant faster than it can be converted into protein
161
Livestock manure loading shall not exceed how many kg organic N/ha/year
170kg organic N/ha/year
162
How much fertiliser N is taken up by grass
70-80%
163
Sources of N
Atmospheric deposition (12 kg/ha/year), Background release (soil organic N), Clover (100-150 kg/ha/year), Animal excreta, FYM/slurry, Fertiliser
164
Average DM% cattle slurry on Irish farms is...
6.3% (0.4-11.9%)
165
EU Nitrates Directive - National Action Programme (NAP) regulations, statutory instrument (SI) 31 of 2014 Aim to?
prevent pollution of surface waters and groundwater from agricultural sources and to protect and improve water quality
166
LESS
Low Emission Slurry Spreading
167
Concentration of Ca in grass
4-12 g Ca/kg DM
168
Soil acidity
Reduces earthworm and microbial activity, build up of dead material, tiller production is reduced, nutrients are locked up
169
Intensive and semi-intensive grasslands represent what % of total land use
2%
170
Grassland accounts for what % of Irish agricultural land area
92%
171
Why is knowing soil temp important?
To know when the plant is growing so that N fertilisers can be applied to promote growth at the opportune time
172
Hybrid Ryegrass
IRG x PRG, appearance reflect one parental type, out of season growth IRG, sward density PRG, more persistent than IRG
173
Reasons to reseed for grazing
10-20% more productive tillers, longer growing season, rapid regrowth, higher palatability/digestibility
174
Reasons to reseed for silage
higher grass quality, easier to preserve (higher sugar content), faster recovery, consistently higher yields
175
Tiller deaths greatest when?
May/June
176
Tiller numbers greatest when?
March-May and July-August
177
Average leaf longevity for PRG is...
33 days
178
What is the most abundant element in the atmosphere
Gaseous N (78%)
179
Minimum g N/kg DM required for optimum photosynthesis
30 g N/kg DM
180
15t DM/ha/year requires the uptake of how many kg N/ha
15,000 kg DM @ avg. 18.75% CP (18.75 x 16% protein = 3% N) = 450 kg N/ha
181
Nitrogen banding: kg N/year for band 1, 2, and 3 based on milk yield p.a.
Band 1 - 80kg N/year for <4,500kg milk yield p.a.
Band 2 - 92kg N/year for 4,501-6,500kg milk yield p.a.
Band 3 - 106kg N/year for >6,500kg milk yield p.a.
182
CAN has what % N?
27% N
183
Urea has what % N?
46% N
184
Grazing height for cattle
5-8cm
185
Grazing height for sheep
3-6cm
186
What % of ammonia emissions come from agriculture?
99%
187
K content of grass in g/kg DM
25-40g/kg DM
188
Crude protein content of grass
~18.75%
189
What is the Irish land area in hectares?
6.9 million
190
AAU stands for what?
Agricultural Area Utilised
191
Grassland accounts for what percent of the world’s surface?
40%
192
Land use change is...
Very slow
193
What is the temperature range in Ireland?
9oC to 10.5oC
194
What is the variation of the length of rainfall in Ireland?
200-270 days
195
In relation to Food Wise 2025, what target are dairy farmers looking to meet?
Increasing grass utilisation to 10t/ha
196
What is the variation of annual rainfall in Ireland?
750-1450mm
197
In what month does grass growth almost cease?
November
198
What is the annual DM yield in Ireland?
11-15t/ha
199
What percent of global land use does total grassland make up?
25%
200
What percentage of global grassland is located in Europe?
13%
201
Intensive and semi-intensive grasslands represent what percentage of total land use?
2%
202
Species-rich grassland began forming approximately how many years ago?
15-13,000 years ago
203
Grassland accounts for what percentage of land use in Ireland?
59%
204
On average, how many hours of sunshine does Ireland receive each year?
1400-1700
205
In Ireland’s coastal areas, how many days of frost occur on average?
<25
206
Topography governs what aspect of soil?
Position on the landscape
207
Permeability refers to soil's ability to:
Allow water to pass through
208
What is the annual profitability variance between well-drained and poorly drained soils in Ireland?
28k
209
What percentage of national greenhouse gases did Irish agriculture contribute in 2021?
37.5%
210
Ireland aims to reduce greenhouse gas emissions by what percentage by 2030?
25%
211
Grassland comprises what percentage of agricultural land in Ireland?
90-92%
212
How much were Irish dairy exports worth in 2021?
5 billion
213
The dairy sector accounts for what percentage of agriculture-related emissions in Ireland?
40%
214
The dairy sector uses approximately what percentage of all chemical nitrogen?
50%
215
Approximately how many days is Ireland’s grazing season?
200-300+
216
Annual dry matter yield for grassland in Ireland ranges between
11-15t/ha
217
Biomass is defined as:
Weight of living organisms at a specific time
218
How long does a short-term ley last?
1-2 years
219
How many years is a medium-term ley?
3 years+
220
Permanent pasture is defined as land that has been under grass for at least how many years without other crops?
5 years
221
A ley is made up of grass and what other plant?
Legumes
222
Leys gained popularity around which historical period?
World War II
223
Ireland is required to maintain what minimum percentage of permanent grassland?
>5%
224
How many species of volunteer grasses are found in Ireland?
100
225
Westerwolds and Multiflorum are species of which type of grass?
IRG
226
Perennial Ryegrass (PRG) makes up what percentage of grass seed sales in Ireland?
95%
227
The heading date is defined as the date when what percentage of reproductive tillers produce seed heads?
50%
228
Which category of heading date is the most popular?
Late (84%)
229
Grass ploidy refers to the number of what in the cell nucleus?
Chromosomes
230
PRG have flattened spikelets containing how many florets?
8-12
231
Italian ryegrass only lasts approximately how many years?
3
232
What weight in kg of PRG seeds were imported?
3,000,000kg
233
In regards to tetraploid vs diploid, which of the following has a higher DM?
Diploid
234
What does DUS stand for?
Distinct, Uniform, and Stable
235
What does VCU stand for?
Value for Cultivation and Use
236
Diploids have how many chromosomes, and Tetraploids have how many?
2=Diploid
4=Tetraploid
237
For a grass variety to make the national list, it must be how much better than the existing variety?
50%
238
What percentage of land is reseeded annually?
2-3%
239
What is the target turnaround time for reseeding?
60 days (8-9 weeks)
240
How many months does it take for a sward to fully establish?
11 months
241
What percentage of PRG should you aim for in a sward?
60%
242
Creeping bentgrass has only what percent production potential of PRG?
75%
243
By what percent does milk output increase per hectare after reseeding compared to permanent pasture?
8%
244
Autumn reseeding takes longer for grass to establish; how long does it take?
8-10 weeks compared to 4-6
245
What does an embryo contain?
Tissues that develop into the new seedling plant
246
What is the Coleorhiza?
A protective covering for the primary root
247
How deep should you plough when reseeding?
15cm
248
When direct drilling, what space should you leave between each grass slot?
2-5 inches
249
Which reseeding method does not require spraying off with glyphosate before reseeding?
Chemical application of diquat to suppress existing sward (diq)
250
In kg, how much seed is recommended to sow per hectare?
35kg/ha
251
What is the maximum amount of tetraploids you should use with your silage mixture?
40%
252
What is the maximum amount of tetraploids you should use with your wetland mixture?
15-20%
253
What is the maximum amount of tetraploids you should use with your dryland mixture?
35-50%
254
PRG seeds germinate within how many days if conditions are correct?
5-10 days
255
Passive uptake of water takes place within how many hours?
12-24 hours
256
How many days after planting does tall fescue begin to show?
0-6 days
257
At what depth should a seed be buried to emerge successfully?
1-2cm
258
Tillering is the development of a new plant from a bud formed where?
Leaf axial
259
Which of the following is a factor affecting tiller production?
Defoliation
260
How many leaves should perennial ryegrass (PRG) have at the time of grazing?
3 leaves
261
What type of root system does perennial ryegrass (PRG) have?
Fibrous root system
262
Which of the following is a pest commonly found in reseeding?
Leatherjackets
263
Which element is removed in the highest amounts from grass?
Potassium (K), second only to Nitrogen (N)
264
Where is potassium primarily concentrated within the grass plant?
Cell sap
265
What is the maintenance requirement of phosphorus (P) for first-cut silage and hay in soils with index levels 1-3?
20kg/ha
266
What is the maintenance phosphorus (P) requirement for second-cut hay and silage?
10kg/ha
267
What is the ideal grassland stocking rate?
170kg/ha
268
Good fertile soils should have a pH of approximately?
6.2
269
What is the optimum pH target for grassland, according to Teagasc?
Above 6.3, with a target of 6.5
270
When does surface acidity in grassland typically occur?
High rainfall and heavy use of nitrogen (above 55mm)
271
What is the concentration range of calcium (Ca) in grass?
4-12 g/kg DM
272
The optimum pH for cereal crops is?
6.5
273
The optimum pH for white clover is?
7.0
274
What type of bacteria do legume plants provide for energy?
Carbohydrate (CHO) bacteria
275
What is the typical concentration of phosphorus (P) in herbage?
2-4 g/kg DM
276
What is fixation?
Conversion of dinitrogen gas to chemically reactive forms
277
What percentage of fertiliser nitrogen (N) is typically taken up by grass?
70-80%
278
What percentage of nitrogen consumed in herbage is excreted?
75-90%
279
When should you apply urea?
When the temperature is above 5°C and increasing
280
What is leaching?
The process by which nitrate is leached easily when excess water percolates through the soil
281
What is the function of potassium (K) in plants?
Regulates cell water content
282
What is the optimum soil pH level for grassland?
At or above 6.3
