Jiji Grass and Its Potential for Soil Erosion Control

Wang ku Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China

Abstract Jiji grass (Achnatherum splendens (Trin), Nerski), a perennial, belongs to the grass family. It is largely distributed in north China. Generally, its tough stem is 0.5-2.0 m high (Kuo pen-chao, 1987). Its tender leaves are good forage with high nutritional value. Jiji grass with its developed root systems has strong adaptability and resistance to drought, cold, alkali and salt. This grass is highly effective for soil and water conservation. Before afforestation and grassland establishment, it may be planted as a pioneer grass to prevent soil and water losses in erosion regions. Jiji grass is suitable to weave many articles for daily uses in rural and pastoral areas, it can also be used for paper production.

Keywords: Jiji grass erosion control

Introduction

Soil erosion is a major problem that influences the agriculture production and environment in north China. To prevent it, people have adopted many engineering methods, such as constructing terraces, dams, etc.. These methods are effective to prevent soil erosion, but have high labour and investment requirements. Biological measures have therefore potential. Generally, biological methods are less costly, and are highly efficient in controlling soil erosion, and improving and protecting the environment. Vetiver grass technology has been applied successfully in some areas of south China, its function in soil and water conservation has been endorsed by many countries of the world (Liyu Xu, 1998). But many experiments and practices revealed that vetiver is difficult to adapt to the low temperatures of north China. Experts of the World Bank and other specialists have noted that Jiji grass, a perennial grass in north China, has similar features to vetiver. Jiji grass will not only tolerate drought, salt, cold and alkali, but also adapt to low temperatures of north China. Experts found that the soil was completely conserved where the grass grew. A lot of experiments have been carried out, but more research and extension work remains to be done. The biological characteristics, applications, propagating technology of jiji grass and its various applications on the Loess Plateau are summarized in this paper.

Jiji grass loacted in Boade District of Shanxi Province. The lady is holding the stiff stems of the grass that are used for brooms. In background Jiji grass is used to stabilize the steep land above the road.

1. Ecological characteristics and distribution

Jiji grass is a halophytic and xeric-mesic grass and has a dense clump. It is distributed widely since it can grow under various ecological conditions, including flood land, dry river valley and other low land areas. In these regions, the groundwater is usually between 1- 4 m. The grass' root could develop to a deeper soil layer even to the phreatic water. Hence, this might help it to avoid the unfavorable condition of high salt in topsoil (Grasslands and Veterinary Department of Agricultural Minstry, China, 1996). There is some debate as to whether the grass could be an indicator plant for watertables. Narrow leaves and sunken stoma helps the grass to reduce transpiration rates and endure drought (Baining Lang, et. al., 1983). It will grow under hill slope conditions, and other places of low water table levels.

Jiji grass mainly grows on deep and thick salinized meadow soil or meadow salinized soil with light loam, medium loam or sandy loam textures, and some sand in the topsoil (Dong wang, 1989).

The phenological periods of Jiji grass are germination in May, flowering in July and fruiting in August (Dong wang, 1989).

Jiji grass could form a single community, when its clumps close completely and develop into a large area of “pasture”. Sometimes its community forms a strip or may be mixed in other plant communities, or forms an alternate communities with other plants. These variations are associated with soil salt, moisture and other factors (Grasslands and Veterinary Department of Agricultural Ministry, China, 1996).

Jiji grass is mainly distributed in drought and semi-drought pastoral or semi agricultural and pastoral regions of inter Mongolia, Gansu, Qinghai and Xinjiang. Besides, there are sporadic distributions in Heilongjiang, Ningxia, Jilin, Liaoning, Shanxi and Shanxi. It grows on fallow lands, sides of farmland, ridges, steep slopes and sides of highway, etc. (Pasturage and Veterinary Department of Agricultural Minstry, China, 1996, Yongguang Lu, 1999, Guichen chen, et. al., 1993).

2. Utilization

2.1 Soil and water conservation

Jiji grass has strong adaptability to diverse environment and a strong tolerance to salt, alkali, drought and cold, it has massive roots, huge bio-mass and has a character that dead stems do not easy fall off (Qingchun Hou, 1999). All of these make it an excellent plant to reduce runoff, conserve topsoil and prevent wind erosion.

Jiji grass is often found as natural tussocks at the sides of highway, slopes, hills and other places on the Loess Plateau. This grass plays an important role in stabilizing sand, blocking mud, separating flow, and preventing erosion of gully heads, protecting embankments of highway and preventing slope slippage, etc.. Some sandy dunes of 50-60 cm in height fixed by the grass clump at base can be found in the wind erosion regions. The clump of Jiji grass can also accumulate snow in winter. This is beneficial to increase soil moisture.

Clumps of Jiji grass found in a village of Boade District of Shaanxi Province, China. Note no other vegetation appears to be growing in this very dry location.

2.2 Forage

Jiji grass overwinters well and seeds germinate early in Spring. Therefore, it can provide good grazing for livestock from Spring to Autumn. Its tender leaves are palatable for animal especially for horses and camels. But when the grass is mature, only the spikes are eaten. Jiji grass has high nutritional value. According to the data of the Comprehensive Survey Team of Chinese Academy of Sciences, the nutrient content of Jiji grass in different growing periods is as follows (Comprehensive Survey Team of Inter Mongolia and Ningxia, 1985, Comprehensive Survey Team of Loess Plateau, 1991 ):

Table 1. Composition of Jiji grass (mg/kg)

2.3 Other usage

Jiji grass can be used to make high quality paper paste, artificial silk, to weave basket, cage, curtain, broom, etc. At present, it has got a patent for the technique of making paper with Jiji grass by a company of Zhengzhou. Besides, the grass stems can be used for culturing edible fungus (Tingfu Guo, 1995, Comprehensive Survey Team of Loess Plateau, 1991).

3. Propagation and cultivation techniques

3.1 Asexual reproduction

Jiji grass has strong tillering ability. Transplantation of the plant should be carried out in Spring or Autumn. In Spring, the best time for it is about the last ten-day of March and the first ten-day of April. During this time the plants do not sprout and the soil is just thawing. In Autumn, it should be planted before the soil freezes. In order to improve plant seedling growth, survival rate, and to decrease evaporation and nutrients consumption, the soil should be compacted and irrigated after it transplanted (Jimin cheng, 1998, Yongguang lu, 1998).

3.2 Sexual reproduction

Seeds of Jiji grass should be harvested from August to September. It can be sowed while harvesting or sowed in the following Spring. Suitable sowing depth is about one finger (1 cm). The best time for sowing is before or after rain, and finished by the first ten-day of July (Jimin cheng, 1998).

4. Current status of research and application

Due to unique characteristics such as its tall and tough leaves and stems, massive root system and tolerance to salt, alkali, drought, cold, grazing and trampling, Jiji grass has been potential for conserving soil and water. A Jiji grass hedgerow experiment relating to sowing and planting in erosion areas, financed by the World Bank, was conducted in Daqi of Inner Mongolia in 1992. Jiji grass was planted on the edges of terrace at Changtan town of Zhunqi in 1995 (Yongguang lu, 1998). Because of drought and lacking planting materials, these experiments did not reach its anticipated results. Currently, research data relating to Jiji grass is scarce, but many experiments are now being carried out. Research about Jiji grass hedgerow for soil and water conservation and agroforesry application is being conducted on the Loess Plateau by Nanjing Institute of Soil Science, Chinese Academy of Sciences. In addition, experiments about the biological characteristic of Jiji grass will be carried for, amongst others, salt-resistance, drought-endurance, acid-resistance, etc.. A late study showed that the tolerance of Jiji grass ranges from pH4.0 to pH 9.0. It germinates well in the soil of Shanxi Province, germinates badly in red soil. Therefore a conclusion might be drawn that germination of Jiji grass is associated with many soil factors.

With regard to introducing Jiji grass to south China, a great deal of work has been done. Experiments on sowing and planting Jiji grass have been carried out by Nanjing Institute of Botanical Science, Nanjing Institute of Soil Science and some units in Guangzhou. Because of the lack of knowledge about the transplanting and management technologies of Jiji grass, none of these experiments were successful. But it is worth noticing that one of the tillers planted by Nanjing Institute of Soil Sciences survived, and grew well. This demonstrates that Jiji grass can grow in south China.

Currently, there are many examples about applications of Jiji grass in north China. In wind erosion region of inter Mongolia, people purposefully planted Jiji grass along contour to stabilize dune and reduce the damage brought out by wind erosion. At the sides of mountainous highway, Jiji grass is planted to protect the embankment of road.In some poor mountainous areas of Shanxi, farmers planted Jiji grass around their cave dwellings to protect their houses. Besides, Jiji grass is also used to protect terrace edges.

Jiji Grass used to stabilize a highway embankment in Shanxi Province

5. Perspective of research and application

The resources of Jiji grass are plentiful in China with an estimated total area of 220,000 ha. The area in Inner Mongolia is the largest, estimated at about 180,000 ha, accounting for 73 percent of the total (Yongguang lu, 1998, Water Conservation Bureau of Shanxi, 1978). Jiji grass in north China equates with vetiver grass' ability to control erosion in south China. Thus it is important to research, use and protect the grass resource.

5.1 Improve and bring its function of soil and water conservation into full play

Forestry and grassland development within an agroforestry system is important for sustainable agricultural development (Zhaopu liu, 1996). Jiji grass hedgerow if planted on slopes along the contour could slow down or intercept runoff and increase soil moisture and protect fields from damage. Furthermore, the hedgerows are less costly and are easily established. Thus, economic trees could be planted among the contour hedgerows. This agroforestry system could conserve soil, improve environment and increase agricultural incomes. Therefore, the agroforestry model including Jiji grass should be an important research component. Also investigating the role of Jiji grass for the protection of engineering facilities (such as edges of terrace, embankment of highway, etc.), controlling the extension of erosion gully, preventing the movement of sand dunes, should also be undertaken.

5.2 Strengthen the research of its biological habits and characteristics

Although the function of soil and water conservation of Jiji grass is widely accepted, little is known about the grass, especially in its reproduction. The knowledge especial the quantitative index about its tolerance to alkali, salt, drought and cold etc. is limited or lacking. These fields need to strengthened and further researched. In addition, ways and means to process and use Jiji grass as materials for various products are worth studying.

5.3 Protecting the resources of wild Jiji grass

Jiji grass is a good herbage for large animals in spring and winter in north China. At present, most of grassland is seriously degenerating, because of overgrazing, some grasslands are close to extinction. Therefore, it is a critical task to protect and use the grass resource properly.

Reference

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