1. Title of project:

Jiji Grass for Erosion Control and Economic Tree Protection on Loess Plateau -- China

2. Short summary of the project

Soil erosion became more critical with increasing population. The erosion raised the level of river beds, threatened people's life, aggravated poverty, and led to disastrous consequence. As one of the most eroded area in the world with total area of 626 800 km2 on the Loess Plateau, there is 530 000 km2 of erosion area, producing 1,600 million ton sediments into the Yellow River each year.

In recent years, farmers in developing countries have increasing interests in clearing forests for economic tree (commercial trees) production. Because lack of protection measures, it usually led to more soil erosion, resulting in the decline of soil fertility. Consequently, the economic trees can not grow well. More often, soil was usually eroded off before economic trees and new vegetation grew up.

Vetiver grass (Vetiveria zizanioides) has been proved to be very efficient for soil conservation in tropical China, but it can not stand cold climate in north China as Loess Plateau. The proposed program is to study effects and consequence of jiji grass (Achnatherum splendens) hedgerows on erosion control and economic tree production.

The proposed project is to study the possibility of using Jiji grass to protect soil from erosion, promote the growth of economic trees, and provide farmers with higher and long term profit and multiple products. The results will be also valuable for embankment stabilization for engineering purpose, such as new roads, mine tailings.

Field investigation will be undertaken to study growth behavior of Jiji grass and its effect on soil.

3. Key words (broad and specific)

vetiver, Jiji-grass, soil conservation, hedgerow, sustainable land use

4. Starting date and duration

March 2001-- March 2003, two years

5. Implementing Institution

China Vetiver Network/ Institute of Soil Science,

No.71, East Beijing Road

P.O.Box 821

Nanjing 210008,

China, P.R.

Fax 86-25-3353590

Phone 86-25-3367364

Email: [email protected]

6. Detailed description of joint project

The proposed program is to study the effects and consequence of Jiji grass on erosion control, slope stabilization and economic tree protection by field investigation and plot experiment.

Field investigation will include: 1) growth behavior and factors influencing its growth (micro-landform, sunshine, moisture, etc.); 2) its effects on soil cohesiveness, penetrability, erodibility; 3) its effect on soil physical properties (moisture content, bulk density, porosity, water-stable aggregates; its effect on soil nutrient properties; 4) its effect on gully control; 5) rooting properties and its effect on soil stability.

Plot experiment will study Jiji grass hedges on soil and water erosion. Randomized complete block design with six treatments and three replications will be implemented on the slope land with 20 degree (36.4%) in Shanxi of Loess Plateau area of China. The area of each plot will be 20 x 5 m. The economic trees to be protected will be highly profitable with local priority spiecies Prunus armeniaca in China.

The six treatments will be:

1) single grass hedgerow 4 m apart;
2) double grass hedgerows 4 m apart;
3) single grass hedgerow 4 m apart plus economic tree in between hedgerows;
4) double grass hedgerows 4 m apart plus economic tree in between hedgerows;
5) economic trees without grass hedgerows;
6) control (with neither grass hedgerow nor economic tree).

All of the grass hedgerows will be planted along contour and with a same density. The hedges will be pruned once just before the dry season. Fertilizer will be used for each plot and managed similarly. The fresh grass prunings will be weighed and sampled to determine dry weight and the contents of N,P,K, and fiber and protein. The prunings will be used as mulch between economic trees.

To determine the effect of grass hedges on soil erosion control, the runoff and sediments will be measured for each treatment with rainfall simulator, and sampled to determine the contents of N, P, K, etc.

To determine decomposition rates of mulching prunings by means of nylon bag method, samples will be weighed and set up on the ground surface in the middle between grass hedgerows with three replications per plot and will be weighed every 2 months. Local crop stem will be used as control.

To evaluate the competition for water, neutron access tubes will be installed to the depth of 1.5 m every 40 cm apart from the hedgerow. The soil moisture content above and under the depth of 30 cm will be measured by means of oven-dried method and neutron moisture gauge. To monitor the dynamics of water potential, tensionmeters will be installed at the depth of 10 cm, 20 cm, 40 cm, 100 cm, 150 cm, and every 40 cm apart from hedgerows. The two items will be recorded every 5 days.

Soil samples of the depth of 0-5 cm, 5-10 cm, and 10-20 cm will be collected at the end of growing season to determine organic matter content, pH, CEC, total N, P, K, and available N, P, K, and soil bulk density. All of these items will be also sampled and determined at the beginning of the experiments.

At the same time, time series model will be made and applied to diagnosis the effects of different treatments on soil water especially in dry season.

The growth behavior of the economic trees will be monitored and recorded such as the length and diameter of annual stems to determine the effect of grass hedgerows on the economic trees.

The factors (such as pH, moisture, shading) on the growth of vetiver and Jiji grass will be studied in both green houses and field.

An investigation to the village and farmers' households around the experiment site will be undertaken to understand the basic social and economic conditions, the demands and sources of fodder and fuel, and the practice meeting the demands which could result in the decline of soil fertility and soil erosion. The market analysis will be included to understand and demand of economic tree products. Master farmers will be invited to participate in these activities.

7. Scientific information about the project

Current state of knowledge in the field

Vetiver grass (Vetiveria zizanioides) was used as hedgerows for farm land and embankment protection (highway embankment in particular) in tropical and subtropical China since 1988. Much experience on vetiver was obtained and extended in under the coordination of China Vetiver Network (CVN) in recent years. However, vetiver is not suitable for cold northern part of the country. In May 1998, a group of experts from the World Bank investigated the 4 Provinces on Loess Plateau and found that Jiji grass has similar characteristics as vetiver for soil conservation, slope stabilization, and gully control, except that it can stand cold and dry climate.

Like vetiver, the Jiji grass belongs to Gramineae and can be easily established and can grow on a very wide range of soils and needs very little management. It has strong long profuse roots that stabilize deep soils; It is usually propagated vegetatively, and is not invasive. It can be used for feeding animals with young leaves, for making basket, broom, mattress, rope, curtain, shed roof cover, medicine, pulp and mushroom cultivation.

Benefits of the project to industrial and socio-economic development in the countries concerned

Soil erosion has become a critical problem in developing countries leading to frequent flooding and other natural disasters. For example in 1998, the heavy flooding caused 4,150 death and direct economic lose of about US$31, 108 million in China. Farming and new development practices in particular aggravated soil erosion. The proposed project is to provide people under cold climate with new technology for soil erosion control, soil fertility maintenance, economic tree production, rehabilitation of wasteland. Under the protection of the grass hedgerows, economic trees can grow well and produce more profit for farmers, while pruning of the grasses can provide farmers with fodder and promote animal production, or can be used for making small items for sale. In addition the proposed project needs more labor and therefore can absorb local farmers to generate profit in situ, which is good for social stability. The proposed new system can reduce sediments down into rivers and therefore relief flooding threaten. The results will be valuable to all people who live in clod area in the world.

Objectives of the proposed project

Farmers have had increasing interests in clearing vegetation on much steeper slopes for economic tree production that can generate greater profit than annual food crops. But the economic trees can hardly grow well, and more often serious soil erosion happened before new vegetation grow up because of the lack of protection measures. The proposed project is to study the possibility of using Jiji grass to protect soil from erosion, promote the growth of economic trees, and provide farmers with higher and long term profit and multiple products. The results will be also valuable for embankment stabilization for engineering purpose, such as new roads, mine tailings.

8. Previous and present support given to institution for the proposed or related project

The Vetiver Network (TVN), USA US$ 50 000 (1997-)

International Center for Research in Agroforestry (ICRAF) Nairobi US$ 27 000 (1993-95)

Winrock International US$ 4000 (1994-96)

World Bank (Small Grant) US$15000 (1997)

9. Facilities available at each institution for the project

Equipment plant, soil and water analysis equipment, computer

Expendable supplies documentation and communications

(fax, xerox, etc)

Field work Experimental field, board and lodging

facilities in institute and stations

Training Seminar room and all related equipment

Other green house for pot cultivation study

10. Names and addresses of internationally renowned scientists for the evaluation of the project

Dr Paul Truong, Natural Sciences Precinct, Dept. Natural Resources, 80 Melers Road, Indooroopilly Qld 4068, Brisbane Australia, Fax 07-38969591, Email: Paul Truong <[email protected]>

Mr Dick Grimshaw, The Vetiver Network, 709 Briar Rd, Bellingham, WA 98225, USA,

Email: [email protected], Homepage: www.vetiver.org, Phone: 360 671 5985

Dr Mark H. Powell, WINROCK INTERNATIONAL, 38 WINROCK DRIVE, MORRILTON

ARKANSAS 72110-9370, USA, Tel. (505)727 5435 ext.242, Fax (505)727 5417, Email: [email protected]

11. Breakdown of costs requested

Equipment

240 tensionmeters and accessories US$ 1600

neutron moisture gauge (LNW-50) and neutron access tubes US$ 2600

calorimeter US$ 750

Consumable laboratory supplies

Cement and other construction materials US$ 1200

for plots establishment

Planting materials and their transportation US$ 550

Chemicals for plants, soil, and water analysis US$ 1300

Rainfall simulator (rent fee) US$ 3300

Labor for field work US$ 1200

Literature and documentation US$ 500

Travel US$ 1 000

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Total US$ 14 000

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