Saline-alkali grassland management and vegetation restoration technology
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表 1
Climate zones Temperate semi-arid zone, temperate sub-humid zone Average annual precipitation/mm 320mm Average annual evaporation/mm 1543mm Average annual temperature/℃ 0℃ Maximum temperature/℃ 19.9℃ Minimum temperature/℃ -22.3℃ Average annual wind speed/m/s 2.9m/s Note: Precipitation, evaporation, air temperature and wind speed in the table are average values over the 1980-2010 period. The climatic data were obtained from local national weather stations. 表 2
Province County Township Climate zones Longitude Latitude Elevation/m Inner Mongolia Autonomous
RegionUlagai management area Haragatu Ranch Middle temperate sub arid climate region 118°44′~119°50′ 45°29′~46°38′ 855~1335 表 3 Topographical conditions
Elevation Topography Slope gradient Slope direction Slope position □ < 100 m ■ Flat lands ■ Flat (0-5%) ■ Sunny ■ Up □ 101-500 m ■ Hillside ■ Gentle (6-15%) ■ Shady ■ Middle □ 501-1, 000 m ■ Hilly slopes ■ Slope (16-25%) ■ Half-sunny ■ Down ■ 1, 001-1, 500 m ■ Slopes ■ Steep (26-35%) ■ Half-shady □ 1, 501-2, 000 m □ Valley floor □ 2, 001-2, 500 m ■ Sand dunes □ 2501-3, 000 m ■ Flat sandy land □ Cultivated land that slopes gently 表 4 Soil condition
Soil types Soil texture Effective soil layer thickness Organic matter content of surface soils Soil hardness Soil gravel content ■ Aeolian sandy soil ■ Sandy soil ■ 0-20 cm □ High (> 3%) □ High ■ Light gravelly soil (1-5%) ■ Calcium chestnut soil ■ Sandy loamy soil □ 20-50 cm ■ Medium (1-3%) ■ Medium □ Medium gravelly soil (5-10%) □ Brown calcium soil □ Loamy soil □ 50-100 cm □ Low (< 1%) □ Low □ Gravelly soil (10-30%) □ Cinnamon soil □ Clay □ 100-200 cm □ Light gravel (30-50%) □ Saline-alkali soil □ > 200 cm □ Medium gravel (50-70%) □ Others: □ Heavy gravel soil (> 70%) 表 5 Vegetation status
Vegetation types Community coverage Vegetation degradation status □ Planted forest: (what kind of community) ■ < 5% ■ Light □ Sandy vegetation: (what kind of community) □ 5-15% ■ Moderate □ Bush: (what kind of community) □ 15-25% ■ Severe ■ Grassland: (Temperate meadow grassland) □ 25-40% □ Artificial forest with dead treetops □Meadow: (what kind of community) □ > 40% □ Artificial forest with dead trees □Others: 表 6 Groundwater status
Average buried depth □ < 1 m ■ 1-3 m □ 3-5 m □ 5-10 m □ > 10 m 表 7 For specific technologies, please fill in the relevant information by selecting the technology category below.
Technological flow The main points of the technology Season/month of implementation 1. Land preparation Soil preparation: The soil is tilled and loosened by a small hand-held rototiller on saline-alkaline patches.
Tilling depth: It is impossible for seeds to bed in the surface of the hard soil layer, roughly 10-15 cm thick, exposed out after the saline-alkaline patch drying out. So, a hand-held rotary cultivator was used to break the clods concentrated at a depth of 6-8 cm. The soil was turned over to a depth of 20 cm.
Other requirements: This step should be completed in May before the growing season and avoid the rainy season.Spring, May, before the growing season and rainy season. 2. Soil amelioration Amelioration method: Humic acid fertilizer was applied to the top soil before turnover. They enter the soil to neutralize the excess saline-alkalinity of the soil with the turnover process, improving the soil quality. Cover the surface with a grass curtain after turning over treatment to reduce the evaporation, inhibit the rise of salt from deep soil, and reduce the surface temperature and promotes the germination of young seedlings.
Types of conditioners: humic acid fertilizer; maize straw, withered grass, reed-straw curtains, etc.
Amount of soil conditioners applied: 50-100kg of humic acid fertilizer can be applied per Mu.
Other requirements: NoneSpring, May, before the growing season and rainy season. 3. Application of base fertilizer Fertilizer type: None
Amount to be applied: none
Other requirements: none4 Sowing seeds Plant species: Native or bred species adapting to the local climate and soil conditions could be selected. Seeds from annuals and perennials go together for mixed sowing to simulate the natural vegetation composition. Moderately saline grasslands, mixed sow annual grasses and perennial legumes; heavily saline grasslands, mixed sow annuals, perennial grasses and legumes.
Commonly used annuals include ryegrass, oats, and Suaeda glauca, while perennials include Puccinellia distans, Elymus dahuricus, Lymus chinensis, and sweet clover.
Seed requirements: It is advisable to select seeds of high quality, judging from the clarity, germination rate, price of seeds used, number of seeds of other plants and moisture, which should comply with GB 6141 and GB 6142.
Sowing method: Manual sowing.
Sowing quantity: 4 kg of mixed seed per Mu, determined reasonably according to the degree of degradation of the restored sample site and the suitability of the grass species.
Sowing depth: Seeds of uniformly size and small differences should be mixed and sown together to a depth of 1~2 cm, then manually sown to the surface of the treatment area and covered with a hook and rake.
Fertilizer requirements: Humic acid fertiliser is applied before the topsoil was turned over.
Watering: none
Other requirements: noneSpring, May, before the growing season and rainy season. 5 Field management Enclosure: Grazing forbidden for the first 3 to 5 years after restoration.
Fertilizer status: none
Irrigation: none
Other requirements: noneYear-round 6 Others 表 8
Labor cost: 4, 500 RMB / ha Machinery cost: 1, 500 RMB / ha Material cost: 14, 700 RMB / ha Water cost (if irrigation was required): 0 Total cost: 20, 700 RMB / ha