Subject: POSTER: Sweet Sorghum-A fine forage crop for the Beijing region, China
Li Dajue and Song Guangwei
Beijing Botanical Garden, Institute of Botany,
Chinese Academy of Sciences, Beijing 100093, China
E-mail: lidj@ibcas.ac.cn
Sweet sorghum (Sorghum bicolor (L.) Moench) is a C4 plant, ranging
in height between 3-5 m. It is not only known as a "high energy crop"
for having a high photosynthetic rate, but it is also called "the camel
among crops" with its characteristics such as drought resistance,
tolerance to water logging and saline-alkali resistance as well as its
wide adaptability. Sweet sorghum is a versatile crop that can be used
for silage making, alcohol production and as a grain crop.
Since 1974, a large number of quality varieties of sweet sorghum has
been introduced by the Beijing Botanical Garden. Comparative
experimentation has shown that the yield of green forage of the
varieties 'M-81E' and 'Theis' reached 128 and 125 t/ha, respectively
(Table 1). Sweet sorghum is an excellent crop for silage making.
The sown area of sweet sorghum cv 'Rio' in the Nanjiao Livestock
Farm of Beijing was increased from 10 ha in 1979 to 400 ha in 1982. The
average yield of green forage of sweet sorghum per unit area was 76.8%
more than that of maize in 1980 and 1981. According to the statistics
of the Beijing Administrative Bureau of Farming, since 1989 the sown
area of 'M-81E' reached over 1333 ha in the outskirts of Beijing every
year. Since 1991, the sown area of 'M-81E' has occupied 84% of the
total harvested area in summer in the Beijing region. Because of the
high yield of 'M-81E', an area of about 1300 ha could be used for
sowing winter wheat and other grain crops. Most sweet sorghum is used
for silage making.
There are similar situations in many other provinces and cities. In
the Tianjin Municipality Worker-Peasant Alliance Agriculture-Livestock
Farm, for example, the yield of green forage of sweet sorghum was 149%
compared with maize and 191% compared with barley. The Institute of
Agricultural Science of Changde District, Hunan Province showed that
the biomass yield of 'M-81E' reached 125 t/ha, which is 181 % of that
of maize.
Sweet sorghum can be grown not only in North China but also in South
China. The total accumulative harvested area in recent years has been
about 1000 ha in Bright Farm, Shenzhen City.
Table 1 shows the yields of different fractions of the crop of a
number of cultivars tested in China.
It will be of great significance through popularisation of sweet
sorghum as a silage crop to change the livestock farming structure by
devoting greater effort to the development of grazing-livestock farming
(cattle, sheep, rabbits, geese, etc.), in order to increase the total
output of meat and reduce the pressure on grain used for poultry.
[Photo available in PDF and HTM versions]
Harvesting sweet sorghum for silage making
Table 1. Mean yield of stalk, fermentable sugar, alcohol, fresh
biomass and seed of sweet sorghum in experiments at the Beijing
Botanical Garden
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CULTIVAR
Theis M-81E Wray Keller Brandes Rio
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Stalk (kg/ha) 95 89 76 76 62 52
Fermentable sugar (t/ha) 10.6 9.6 10.3 10.5 6.4 6.2
Alcohol (l/ha) 6159 5607 5981 6131 3696 3617
Fresh material (t/ha) 125 128 106 107 89 82
Seed (kg/ha) 6674 6213 1426 1960 3500 2866
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