Sericea lespedeza: A 30 year learning curve

Lessons learnt from cultivating Sericea lespedeza.

Sericea lespedeza has converted very poor soil into humus-rich soil.
Photo: John Fair

The first commercial planting of Sericea lespedeza in South Africa took place in 1984. Recently, I had the pleasure of visiting the site. What a thrilling experience: the stand of this amazing legume has never looked better in 30 years! What makes this all the more remarkable is that the lespedeza was planted on badly eroded land with virtually no top soil and has never seen a gram of fertiliser since planting.

When Willie Nel, who farms in the Free State’s Ficksburg district, bought the small adjoining farm Hertzog to add to his existing Moolmanshoek property, he knew that most of its steeply sloping lands were unsuitable for cash cropping. He therefore earmarked them for permanent pasture. At the time, Willie and I were wrestling with the problem of finding suitable legumes to grow on Moolmanshoek.

Willie wanted to develop productive pastures that would not require nitrogen every year. We visited the USA in 1982 in the hope of finding suitable legumes. In Georgia, we called in at the Pennington Seed Company and met Bruce Pennington. After we had described to him the relatively low and unpredictable rainfall pattern of the eastern Free State and the poor soils involved, he said: “There’s only one legume you can take back and that’s poor man’s lucerne.”

Bruce went on to explain that this name for lespedeza had been derived from the fact that this legume had originally been used mostly by farmers who could not afford the lime and phosphorous required for planting lucerne (Medicago sativa). Willie’s autumn planting in 1984, however, was a disaster. Germination was poor and the seedling growth was dismally slow. To make matters worse, the land was soon overrun with weeds. I wanted Willie to plough out and start again.

He went back to the notes we’d made on our tour and found that Bruce had said: “After planting, lock the gate and don’t come back for a year.” It was three years, however, before Willie really began to benefit from his pasture – but then he made up for lost time. He grazed the stand with his Dohne Merino stud ewes, which had twins at foot. When the pasture threatened to get too tall, he brought in cattle to graze it. He also made good hay from it.

Under Willie’s management, the pastures improved year after year. He eventutally sold Hertzog, but retained the right to make hay from the lespedeza land.

Crucial lessons
So, what are the most important lessons I’ve learnt with Sericea lespedeza over the past 30 years?

  • Drop the name ‘poor man’s lucerne’ – ‘poor-soil lucerne’ would be more suitable. Small-stock state vet Dr Gareth Bath likes to call it ‘smart man’s lucerne’. (His research has revealed that this legume has compounds that suppress internal parasites in sheep.)
  • Don’t use seed older than two years. Lespedeza seedling viability weakens with age. 
  • Don’t be too hasty to plough out a planting that at first seems to be a failure. Lespedeza seed appears to have a small percentage of hard seeds that germinate the following year. Moreover, it seeds itself readily; poor stands invariably thicken up in time. 
  • Plant it in early summer in summer rainfall areas, provided weeds are effectively controlled with herbicides (consult your local supplier). Don’t plant after the first spring rains, as these are often followed by several dry weeks. Wait for follow-up rain. 
  • It is a mistake to think that Lespedeza does not need to be fertilised. Yes, it does not need nitrogen, but if soils are low in essential minerals such as calcium, phosphorous, potash and sulphur they should be applied, as they will increase the dry matter yield and animal performance. 

Based on research by Prof William Albrecht in the 1940s, I have calculated that adding lime and phosphorous could result in an additional gross income of R4 000/ ha to R5 000/ ha when the hay is fed to weaned lambs. Remember that hay removes nutrients from the land.

  • Buy seed from a reliable source with a proven germination percentage and free of weeds. Dodder is becoming a problem weed; a small percentage of dodder seed can result in a significant reduction in the productivity of Lespedeza.
  • A good way to utilise Lespedeza is to graze it in early spring, allow it to grow out for a hay cutting in late summer and graze it again in autumn until the first frost defoliates it. 

John Fair heads up Fair’s Biofarm Assist, and can be contacted on 058 622 3585 or [email protected].