Grassland
Balanced fertilisation for the best fodder
Sodium for high fodder productivity and fertility
High protein contents are only possible with sulphur
Supplementing liquid manure with mineral fertilisation
Video on nutrient supply to grassland
Balanced fertilisation for the best fodder
Frequently, little attention is given to the nutrient requirement of fodder crops including grass. However due to the bulky nature of fodder crops, they have a high nutrient demand if large quantities are to be produced. Additionally, many nutrients applied to forage crops are then made available for animals eating the herbage. In this way, both the quantity, quality and nutriational value of feed can be greatly enhanced through careful nutrient planning.
High yield and top-quality of fodder can only be achieved with an optimum fertilisation. Fertilisation affects:
- yield
- the extent of its utilisation
- the mineral content
- the botanical composition
- the energy value and protein content
… and hence the productivity and fertility of the livestock.
The nutrient demand (kg ha-1) is great and must be met by provision of sufficient fertiser
| Grassland |
Yield t ha-1 DM
|
N
|
P2O5
|
K2O
|
MgO
|
S
|
|---|---|---|---|---|---|---|
| 3 cuts |
7.5
|
165
|
70
|
220
|
35
|
20
|
| 4 cuts |
9.0
|
245
|
90
|
270
|
45
|
25
|
| 5 cuts |
11.0
|
305
|
110
|
330
|
55
|
30
|
| Clover grass |
15.0
|
380
|
130
|
630
|
60
|
35
|
Sodium for high fodder productivity and fertility
- Fodder must be sufficiently supplied with sodium.
- The animals’ potential to take up sodium chloride from additional feed using animal salts, salt lick blocks and mineral feed is limited physiologically due to risk of diarrhoea.
- The K:Na ratio of max. 20:1, required by animals is rarely achieved through sodium free fertilisation.
- A wider ratio of K:Na ratio in the feed results in fertility problems.
- Magnesia-Kainit increases the sodium content of feed and improves therefore the K:Na ratio below 20:1.
- Sodium and chloride improve the palatability of the feed and therefore can result in higher productivity of meat or milk due to increased DM intake
Improvement of the dietary cation-anion difference (DCAD) of fodder using Magnesia-Kainit
- The calculation of the dietary cationanion difference (DCAD) is intended to estimate the risk of milk fever and hypocalcaemia of dairy cattle after calving. The DCAD value should be very low during the dry period.
- The DCAD value is calculated by deduction of sulphur and chloride content from the potassium and sodium content of the fodder.
- A program using Magnesia-Kainit increases the sulphur and chloride content of the fodder which decreases the DCAD value substantially.
Magnesium
- The fodder must provide an adequate amount of magnesium.
- Magnesium deficiency of fodder decreases the magnesium content of the blood of the animals.
- This presents a particular danger in spring when the fodder is young, has little fibre and is rich in protein.
- Hypomagnesaemia, commonly known as grass tetany or ‘staggers’ in ruminants is the consequence
- Magnesium content of slurry is poor and inadequate for the fodder, particualry at early growth stages.
High protein contents are only possible with sulphur
The quality of fodder is influenced by the protein content and the fibre content (digestibility). The time of harvest is mainly determined by this parameter but also by its end use (grazing, silage or hay).
- The protein content of fodder is mainly influenced through its supply with sulphur.
- Sufficient supply of plant available sulphur is essential.
- The use of organic fertilisers is depending on the proportion of clover type plants and the use of the growth.
- Only around 5-10% of the very low sulphur content of slurry is available to the plant.
- Sulphur content of slurry is poor and inadequate for the fodder, particualry at early growth stages.
- Numerous feeding trials conducted by the LUFA (German agricultural research and analysis Institute) have demonstrated an inadequate sulphur supply in approximately 75% of silage samples analysed.
- A N:S-ratio of less than 12:1 is optimal.
A one-off application of Magnesia-Kainit, Korn-Kali or ESTA Kieserite gran covers the require-ments for sulphur and magnesium for the entire growing season.
Supplementing liquid manure with mineral fertilisation
- The nutrient content of cattle manure varies largely and the analysis of individual samples of slurry and FYM is advisable.
- The balance of potassium on forage land is usually negative because the reintroduction of nutrients via liquid manure is mostly over-estimated. Even very intensive cattle units with an RGV (large cattle unit) of 2.5 per ha risks the danger that the potassium deficit cannot be met using liquid manure only.
- Similar deficits as evident with potassium are also apparent with the nutrients magnesium, sulphur and sodium. The concentration of these nutrients are proportionally low in liquid manure.
Assessment of potassium requirement in intensive forage in kg ha-1
Basis of data: DVO (withdrawal), LWG Aulendorf (Liquid manure content)
| Cattle 7,5% TS m3 year-1 |
K2O from manure
|
Withdrawal of 10t TM K2O
|
Fertiliser require-ment at "C" K2O
|
Supplement with
|
|---|---|---|---|---|
| 22 (1 RGV) |
106
|
300
|
194
|
500 kg ha-1 Korn-Kali
|
| 33 (1,5 RGV) |
158
|
300
|
142
|
350 kg ha-1 Korn-Kali
|
| 44 (2 RGV) |
211
|
300
|
89
|
800 kg ha-1 Magnesia-Kainit
|
| 55 (2,5 RGV) |
264
|
300
|
36
|
350 kg ha-1 Mag-nesia-Kainit
|
Fertiliser recommendations
Recommendations for soil applications
-
350-800 kg ha-1 Magnesia-Kainit for pasture and grassland supplementary to liquid ma-nure. Application at the beginning of the growing season, preferably in early spring – even on frozen but impact resistant soil land
-
350-500 kg ha-1 Korn-Kali for areas without liquid manure application or low K contents in the soil.
-
200-400 kg ha-1 ESTA Kieserite gran. for fulfilling magnesium and sulphur requirements during a high potassium supply
Video on nutrient supply to grassland
Nutrient supply for grassland – powerful grassland crops – high milk yield and healthy livestock
The key to the success of dairy farming is in high fodder performance. Farms with high milk production have long term only in combination with high fodder performance a healthy herd with long service life. However, high yields and top quality of fodder crops including grass only can be achieved through optimal grassland management and fertilisation. The nutrients potassium and sodium play an important role – but also magnesium and sulphur are essential for high protein content in fodder.
Listen to and watch what our consultant has to say on the production of top-grade grassland crops and yields.