Introduction to Sericea Lespedeza
Sericea lespedeza offers numerous advantages as a forage crop. It is a drought-tolerant, non-bloating perennial legume; it is resistant to diseases and is rarely attacked by insects; and mature plants are quite competitive with grasses. It is much more tolerant of soil acidity than most other legumes and is alsovery tolerant of low fertility.
Forage yields of sericea are good, and forage quality is better than most warm season perennial grasses. It is a surprisingly economical forage crop to grow due to the fact that it does not require any nitrogen fertilizer, It has also been well documented that sericea is an excellent soil builder.
Lespedeza will grow on almost any soil. It does well on sandy and loam-type soils. Sericea is a deep-rooted perennial that also does well on shallow soils with drainage restrictions. Lespedeza will tolerate lower pH (more acid) soils than clover.
Tannin is the compound that confers the nonbloating characteristic to lespedeza, but it also decreases palatability and digestibility. Low tannin varieties are now available. These have greatly improved forage quality, finer stems and contain enough tannin to prevent bloat. Sericea lespedeza is deep-rooted. It is the highest-yielding and most drought-tolerant of the two lespedeza cultivars, and it tolerates the lowest pH and poorest soil. It grows from middle September on the highveld and is killed back to the crown by hard frosts.
Research has proved that due to the tannin in Sericea Lespedeza there is a marked decline in the fecal egg count of gastrointestinal parasites of ruminants while they are fed Lespedeza, Feeding sericea lespedeza therefore has potential to reduce effects of parasitic nematodes on animal health and to lower pasture contamination.
Livestock often show preference for grasses when first exposed to sericea, but will eat it readily after a day or two. Intake may eventually decline if animals only have access to sericea for extremely long periods of time, but this is rare.
Preservation of sericea lespedeza forage as hay has a major effect with regard to reducing tannin content. Because sericea hay has lower tannin content than fresh forage, ruminant intake and digestibility are increased.
Sericea lespedeza is normally planted at the rate of 20Kg/Ha in mid-spring. This plant has poor seedling vigor and thus is normally planted in pure stands. However, where adapted, a cool season perennial grass such as tall fescue can be drilled into established sericea with high probability of obtaining a mixed sericea/grass stand.
It is imperative to inoculate seed, since this bacterial culture enables the lespedeza plant to make its own nitrogen. Use a strain of inoculum recommended for lespedeza. Properly inoculated lespedeza will need no nitrogen application.
Plant in late spring with 20Kg/Ha and no later than February on the highveld... The earlier the planting date the better.
Harvesting sericea lespedeza for hay at the right stage is important for quality. The best stage of growth to harvest to assure good yields and maintain quality is at a height of 350mm to 400mm. A common test to tell when sericea is too mature is the "stem test." If the stem breaks when bent, it is too mature. The top should bend all the way to the ground without breaking the stem for best quality. If it breaks when bent, it has already lost some quality.
Sericea also dries quickly following harvest. In hot weather, wilting for only a few hours is sufficient. Sericea can be cut in the morning and baled that afternoon. Remember -- the leaves shatter if left too long between cutting and baling.
Lespedeza can be mowed, windrowed and conditioned in the same operation to minimize leaf loss, and use of tedders and rakes on nearly-dry lespedeza should be avoided. Baling will also cause excessive leaf loss if the lespedeza is too dry — baling when dew is present may minimize this problem. Properly baled lespedeza hay should contain more than 55% leaf.
Since sericea is a perennial, seed production is not necessary to maintain a stand. However, a stand will last longer if you have two harvests of hay and allow the regrowth following the second cut to stand until after frost. This not only allows some seed production, but it also allows the root system to store more carbohydrates for food reserves. This helps it come out vigorously in the spring for early grazing.
Once it gains a foothold, it can crowd out native plants and develop an extensive seed bank in the soil, ensuring its long residence at that site.
Scarification is necessary for the germination of lespedeza seeds. Experience here in South Africa has shown that dehulling results in a better germination and seedling viability.
Sericia is slow to establish in the planted season it seems to give priority to root development. It is said that Sericia sleeps the first year creeps the second and leaps the third season . Be patient with it, many hectares have been destroyed that if were given a little chance would have been very productive pastures, as once established it gets better and better every year.
Manage sericia to keep the plants vigorously growing. Rotationally graze when plants are 150mm to 200mm tall. Harvest for hay when plants reach a height of 350mm as it starts becoming unpalatable due to a tannin buildup but the cutting and curing process in haymaking reduces the tannin, and tall hay is acceptable to animals. Sericia provides good quality forage in summer when dry weather has reduced the growth of other forage crops.
Note that buds at the crown near the soil surface give rise to new stems in the spring, after cutting or grazing new growth also comes from the remnant stems. It is therefore VERY important not to cut or graze it down below 120mm for optimum regrowth and subsequent yield.
Frost kills all above ground growth and consequently it is of very little use as a winter foggage. Naturally the hay gathered in summer is an excellent and cheap winter feed.
Mr. John Fair who introduced sericea lespedeza to me and persevered with me through the first years of establishing my 100 Ha.
The information herein is my experience with lespedeza and gleanings from the internet.