Production improvement technology of sandy and alkaline degraded grassland
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1. Introduction
This technology is mainly applied to improve soil deterioration and low productivity of sandy and alkaline grassland in semi-arid sandy area. The method integrates a variety of application technologies such as soil improvement, introduction of superior species and fertilization, and forms a comprehensive supporting technology, which can greatly improve grassland productivity, physical and chemical properties of soil and biological activities. The technology points include: ① enclosure; ② 20 cm tillage and fine rotary tillage; ③ Supplementary sowing of perennial leguminous forages; ④ Increase the use of soil conditioner biochar or CaSO4; ⑤ Apply acid N fertilizer or biological carbon based compound fertilizer. In practice, these can be combined used to specific conditions. This technology is suitable for areas with flat terrain, continuous sandy grassland and alkaline grassland, where mechanized operation works well. It would be better if cooperated with shelter forest belt around. The regions should be enclosed after improvement, and furthermore, could be suitable for pasture. The scope of application: sandy grassland, sandy farmland of returning farmland to grassland, alkaline grassland, nebkhas with sparse herbaceous vegetation, and dune slacks with an area > 50 mu.
2. Applicable conditions
2.1 The main use(s) of the technology
√ increase production(crop, fodder, wood/ fibre, water, energy)
√ reduce, prevent, restore land degradation (soil, water, vegetation)
√ conserve ecosystem
□ preserve / improve biodiversity
□ reduce risk of disasters (e.g. droughts, floods, landslides)
□ adapt to climate change / extremes and its impacts (e.g. resilience to droughts, storms)
□ mitigate climate change and its impacts (e.g. through carbon sequestration)
√ create economic benefits (e.g. increase income / employment opportunities)
□ create social benefits (e.g. reduce conflicts on natural resources, support marginalized groups)
□ other purposes (specify): ……………………………………………………………………………………………
2.2 Types of degraded land to which the technology is applicable
□ Semi-fixed sandy land
□ Shifting sandy land
√ Desertified grassland
√ Saline-alkali grassland
□ Active wind-erosion pit
□ Degraded forestland
√ Desertified cultivated land
□ Other types
2.3 The climatic conditions to which the technology is applicable
Climate zone: temperate semi-arid zone
Annual precipitation: 300-400 mm.
Annual evaporation: 2200-2500 mm.
Annual average temperature: about 6.0 ℃.
Maximum temperature: 37 ℃.
Minimum temperature: - 28 ℃.
Annual average wind speed: < 4.5 m / s
2.4 The origin of the technology
Ashhan Sumu Ulan Aodu area, Ongniud Banner, Inner Mongolia Autonomous Region (43 ° 20 ˊN, 119°39 ˊE)
3. Site conditions suitable for the technology
1 Topographical conditionsElevation 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 2 Soil conditionSoil 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%) 3 Vegetation statusVegetation types Community coverage Vegetation degradation status □ Planted forest: (what kind of community) □ < 5% □ Light ■ Sandy vegetation: (Annual Chenopodiaceae, Gramineae and Artemisia are the main plants) □ 5-15% ■ Moderate ■ Bush: (Caragana microphylla, Artemisia chabaga, Polygonum cuspidatum and other sparse shrubs) □ 15-25% ■ Severe □ Grassland: (what kind of community) □ 25-40% □ Artificial forest with dead treetops ■ Meadow: (Leymus chinensis - miscellaneous grass community, reed community, Stellera chamaejasme community, tiger tail grass community, etc) ■ > 40% □ Artificial forest with dead trees □ Others: 4 Groundwater statusAverage buried depth □ < 1 m ■ 1-3 m ■ 3-5 m □ 5-10 m □ > 10 m 4. Technical contents
5 For specific technologies, please fill in the relevant technical information by selecting the technology category below.Technological flow The main points of the technology Time (season or month) 1. Raking and replanting of leguminous forages Sandy and alkaline grasslands are mechanically harrowed more than 20 cm (rubber wheel tractor with five ploughs), rototilled and then sown with leguminous forages. Sandy grassland can be sown with Astragalus adsurgens Pall.; alkaline grassland can be sown with Astragalus adsurgens Pall., Medicago sativa L., Melilotus officinalis (L.) Pall., or a mixture of Astragalus adsurgens Pall. and Medicago sativa L. The sowing rate is 1.0-1.5 kg per mu, with space between rows 40 cm and thickness of casing soil of less than 2 cm. Project is carried out after the local windy period, usually from late May to early June. Late construction affects the yield of the year. 2. additional application of soil conditioners The soil structure can be greatly improved by combining the application of biochar (1 t/mu or more) on the basis of harrowing and rototilling for 20 cm before sowing with leguminous forage. Good results were achieved in both sandy and alkaline grasslands; in severely alkaline areas, additional biochar or CaSO4 can be applied as an amendment to reduce the unit weight and pH and improve the soil structure. Ibid 3. Base fertilizer and topdressing in rainy season Add biochar-based fertilizer as a base fertilizer after tilling and rototilling, and not more than 100 kg per mu for alkaline grassland and more than 100 kg per mu for sandy grassland, can increase grass production by 1-2 times. Before the rainy season (before mid-July), topdress with nitrogen fertilizer or compound fertilizer, and biochar-based compound fertilizer or (NH4)2SO4 at 15-25 kg per mu. For sandy grassland is 25 kg or more. It is better to fertilize before the rainy season each year. Application of carbon-based fertilizer substrate in company with rototilling; topdressing before the rainy season (before mid-July) 4. Field management Alkaline grasslands do not need to be irrigated; sandy grasslands should be properly watered 2-3 times during the seedling period, especially when there is a long period of drought and little rain. June-July 5. Technological costs
6Labour costs: Labor cost: 1, 500 RMB / ha Material cost: No soil conditioner added: 2, 475 RMB / ha (225 RMB / ha for seed and 2, 250 RMB / ha for fertilizer) Add soil conditioner: 4, 725 RMB / ha (seed: 300 RMB/ ha, fertilizer: 2, 250 RMB / ha, modifier: 22, 500 RMB / ha) Water cost (if irrigation was required) Sandy grassland: 750 RMB / ha (2-3 times of irrigation in the first year) Saline-alkali grassland: no irrigation required Total cost: 4, 725 RMB / ha; If soil conditioner is added, it will cost 27, 225 RMB / ha 6. Demonstrations
Stand landscapes comparison before and after technology implementation
1 Improvement effect of saline alkali grassland (the left one is of the first year and the right one is of the second year; the height of the grass group is 1.6 m, raking + supplementary planting of Astragalus adsurgens + biochar + base fertilizer)(shot on August 13, 2017 and August 26, 2018, Wulanaodu area, Wengniute Banner, Inner Mongolia) -
图 1 Improvement effect of saline alkali grassland (the left one is of the first year and the right one is of the second year; the height of the grass group is 1.6 m, raking + supplementary planting of Astragalus adsurgens + biochar + base fertilizer)
(shot on August 13, 2017 and August 26, 2018, Wulanaodu area, Wengniute Banner, Inner Mongolia)
表 1 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 2 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 3 Vegetation status
Vegetation types Community coverage Vegetation degradation status □ Planted forest: (what kind of community) □ < 5% □ Light ■ Sandy vegetation: (Annual Chenopodiaceae, Gramineae and Artemisia are the main plants) □ 5-15% ■ Moderate ■ Bush: (Caragana microphylla, Artemisia chabaga, Polygonum cuspidatum and other sparse shrubs) □ 15-25% ■ Severe □ Grassland: (what kind of community) □ 25-40% □ Artificial forest with dead treetops ■ Meadow: (Leymus chinensis - miscellaneous grass community, reed community, Stellera chamaejasme community, tiger tail grass community, etc) ■ > 40% □ Artificial forest with dead trees □ Others: 表 4 Groundwater status
Average buried depth □ < 1 m ■ 1-3 m ■ 3-5 m □ 5-10 m □ > 10 m 表 5 For specific technologies, please fill in the relevant technical information by selecting the technology category below.
Technological flow The main points of the technology Time (season or month) 1. Raking and replanting of leguminous forages Sandy and alkaline grasslands are mechanically harrowed more than 20 cm (rubber wheel tractor with five ploughs), rototilled and then sown with leguminous forages. Sandy grassland can be sown with Astragalus adsurgens Pall.; alkaline grassland can be sown with Astragalus adsurgens Pall., Medicago sativa L., Melilotus officinalis (L.) Pall., or a mixture of Astragalus adsurgens Pall. and Medicago sativa L. The sowing rate is 1.0-1.5 kg per mu, with space between rows 40 cm and thickness of casing soil of less than 2 cm. Project is carried out after the local windy period, usually from late May to early June. Late construction affects the yield of the year. 2. additional application of soil conditioners The soil structure can be greatly improved by combining the application of biochar (1 t/mu or more) on the basis of harrowing and rototilling for 20 cm before sowing with leguminous forage. Good results were achieved in both sandy and alkaline grasslands; in severely alkaline areas, additional biochar or CaSO4 can be applied as an amendment to reduce the unit weight and pH and improve the soil structure. Ibid 3. Base fertilizer and topdressing in rainy season Add biochar-based fertilizer as a base fertilizer after tilling and rototilling, and not more than 100 kg per mu for alkaline grassland and more than 100 kg per mu for sandy grassland, can increase grass production by 1-2 times. Before the rainy season (before mid-July), topdress with nitrogen fertilizer or compound fertilizer, and biochar-based compound fertilizer or (NH4)2SO4 at 15-25 kg per mu. For sandy grassland is 25 kg or more. It is better to fertilize before the rainy season each year. Application of carbon-based fertilizer substrate in company with rototilling; topdressing before the rainy season (before mid-July) 4. Field management Alkaline grasslands do not need to be irrigated; sandy grasslands should be properly watered 2-3 times during the seedling period, especially when there is a long period of drought and little rain. June-July 表 6
Labour costs: Labor cost: 1, 500 RMB / ha Material cost: No soil conditioner added: 2, 475 RMB / ha (225 RMB / ha for seed and 2, 250 RMB / ha for fertilizer) Add soil conditioner: 4, 725 RMB / ha (seed: 300 RMB/ ha, fertilizer: 2, 250 RMB / ha, modifier: 22, 500 RMB / ha) Water cost (if irrigation was required) Sandy grassland: 750 RMB / ha (2-3 times of irrigation in the first year) Saline-alkali grassland: no irrigation required Total cost: 4, 725 RMB / ha; If soil conditioner is added, it will cost 27, 225 RMB / ha -