18 .Apr.2018

Focus on white clover

Graham Tweddle relies on white and red clover for grazing and silage

White clover is the most flexible perennial forage legume, providing reliable companionship to grasses in both grazing and silage leys. Its creeping growth habit gives it the ability to self-repair, infill and spread throughout the sward.

As a feed, white clover is a good source of protein and minerals and retains high digestibility throughout the growing season, as there is continual renewal of leaves and little stem development. It will increase the crude protein content of first cut silage by 1% for every 10% increase in the amount of clover in the sward.

The other important feature of white clover is the ability to convert atmospheric nitrogen into nitrates in the soil which feeds the companion grasses – up to as much as 150kg N/ha (61kg N/acre).

Size of leaf
There are three main groups of clover, categorised by leaf size. The most popular groups for dairy farms are medium and large-sized leaf varieties such as Buddy, Iona and Violin.

Clover likes soil pH to be around 6 to 6.5 and phosphate and potash indices above 2. It should be sown into warm soil from April to August.

“Clover seed is very small and prefers to be surface sown onto a firm seedbed,” says Rod Bonshor, general manager for Oliver Seeds. “When it is in a grass seed mixture aim to sow within the top centimetre of soil and pass over with a Cambridge roll to finish.”

After sowing, protection against slug attack is essential, especially in the first three months. 

“In the past three years, there has been an increase in Sitona weevil attacks with small semi-circular ‘bite marks’ seen,” adds Mr. Bonshor. “The larvae also attack the roots and the clover will not perform as it should. Poor field drainage and compaction can also inhibit clover growth.”

Levels of N fertiliser
The optimum amount of clover is a field is 30% of the dry matter (DM) of the total sward. To reach 30% clover, the swards needs to look more like there is 50 to 60% clover at its peak growth in August.

“One of the biggest factors affecting the level of clover in a grass sward is in the amount of fertiliser nitrogen (N) applied,” says Mr. Bonshor. “High rates over 100kg N/ha applied in one go will speed the grass plants forward and suppress clover growth. Little and often fertiliser applications work best.”

Organic clover
White clover drives the family business of Graham Tweddle which produces, processes and retails organic milk.

Based on the edge of the A1 at Darlington, he runs 300 cows on 122ha (330 acres), owned by the Church Commissioners for England. An additional 163has (400 acres) of neighbouring arable acres came along as a Farm Business Tenancy two years ago. This will allow herd expansion up to 500 cows. 

The farm entered organic conversion in 1998 and stopped growing maize to establish clover-based leys under peas. This was successful but resulted in heavily rutted fields. Different mixes of grass and clover were trialled, but over the past 18 years the farm has seen the benefit of specialising in late perennial ryegrasses and white clover swards. 

The silage fields are given dressings of composted manure or slurry ideally in early March. Compost is applied at 20t/ha (8.2t/acre) and slurry at 42cu/ha (17cu/acre). In recent years the farm has also used polysulphate organic fertilizer on silage ground. The grazing fields are given nothing apart from what the animals return and what is fixed by the leguminous clover – potentially worth up to 150kg N/ha (61kg N/acre).

The cows are now a three way cross of Dairy Shorthorn, Swedish/Norwegian red and Meuse-Rhine-Issel (MRI), producing what Mr. Tweddle calls a ‘Ford Mondeo’ of a cow. Strong, fertile, good feet, easy calving and averaging 7,000 litres of milk a year predominantly from forage. 

Graham Tweddle’s milking cows tucking into their TMR

“The cows are not fed in the parlour, just a TMR in their sheds, consisting of grass silage, ground maize flour, an 18% crude protein pellet and wholecrop for fibre. This year we are also going to make some hay to provide more fibre,” says Mr. Tweddle. “We produce consistent high protein silage across three cuts, but with the high proportion of clover in the silage, we need additional fibre to slow down digestion in the cows.” 

The cows are normally turned out in March and housed in the third week of October. A level milk supply into their Acorn Dairy is vital, and the cows calve all year round.

Regular reseeding
Each year approximately 30ha (73 acres) is reseeded after wholecrop barley and peas. The peas provide nitrogen for the barley and leave some for the following grass crop. At the same time the peas help provide a smothering effect to prevent weeds establishing in the open soil. 

After the barley/peas are harvested in July a stubble cultivator is used on a weekly basis to catch germinating weeds and create a sterile seedbed. Even after this, if conditions require it may still be ploughed.  After rolling, the seeds mixture is broadcast with an air seeder on a grass harrow and the field rolled again. Sheep graze for five weeks over winter to encourage tillering and help with weed control. 

On the newly rented land Oliver Seeds Organic Century has been sown, which is built on five late perennial ryegrasses including Pastour, Romark and Maurice, with 11% Timothy and 10.5% white clover blend of different sized leaf varieties, including Buddy, Violin and Iona. Mr. Tweddle also has Tonic plantain and Choice chicory added to the mix.

This produces excellent D values and palatability for optimum intake and performance throughout the season. Surplus growth makes excellent silage, with Mr. Tweddle’s first cut from last year producing 14t/ha of 74 D Value, 11.8 MJ ME at 17.5% protein and a pH of 4.2. 

“A lot of people think about red clover for use in silage crops – but we have proven that white clover is just as good, and can produce phenomenal silage,” adds Mr. Tweddle. 

Delegates on the British Grassland Society Summer Meeting to County Durham this July will be able to visit the Tweddle’s farm and dairy. See www.britishgrassland.com for more details.

This article first appeared in the March 2018 issue of Cow Management magazine.