1.2 ព័ត៌មានលម្អិតពីបុគ្គលសំខាន់ៗ និងស្ថាប័នដែលចូលរួមក្នុងការវាយតម្លៃ និងចងក្រងឯកសារនៃបច្ចេកទេស

ឈ្មោះគម្រោងដែលបានចងក្រងឯកសារ/ វាយតម្លៃលើបច្ចេកទេស (បើទាក់ទង)

Preventing and Remediating degradation of soils in Europe through Land Care (EU-RECARE )

ឈ្មោះអង្គភាពមួយ (ច្រើន) ដែលបានចងក្រងឯកសារ/ វាយតម្លៃបច្ចេកទេស (បើទាក់ទង)

Wageningen Environmental Research (Alterra) - ប្រទេសហូឡង់

ឈ្មោះអង្គភាពមួយ (ច្រើន) ដែលបានចងក្រងឯកសារ/ វាយតម្លៃបច្ចេកទេស (បើទាក់ទង)

Provincie Holland Zuid - ប្រទេសហូឡង់

ឈ្មោះអង្គភាពមួយ (ច្រើន) ដែលបានចងក្រងឯកសារ/ វាយតម្លៃបច្ចេកទេស (បើទាក់ទង)

Provincie Utrecht - ប្រទេសហូឡង់

ឈ្មោះអង្គភាពមួយ (ច្រើន) ដែលបានចងក្រងឯកសារ/ វាយតម្លៃបច្ចេកទេស (បើទាក់ទង)

LTO NOORD - ប្រទេសហូឡង់

ឈ្មោះអង្គភាពមួយ (ច្រើន) ដែលបានចងក្រងឯកសារ/ វាយតម្លៃបច្ចេកទេស (បើទាក់ទង)

Waterschap Amstel, Gooi en Vecht - ប្រទេសហូឡង់

1.3 លក្ខខណ្ឌទាក់ទងទៅនឹងការប្រើប្រាស់ទិន្នន័យដែលបានចងក្រងតាមរយៈ វ៉ូខេត

តើពេលណាដែលទិន្នន័យបានចងក្រង (នៅទីវាល)?

30/10/2015

អ្នកចងក្រង និង(បុគ្គលសំខាន់ៗ)យល់ព្រមទទួលយកនូវលក្ខខណ្ឌនានាទាក់ទងទៅនឹងការប្រើប្រាស់ទិន្នន័យដែលបានចងក្រងតាមរយៈវ៉ូខេត:

បាទ/ចា៎

2.1 ការពណ៌នាដោយសង្ខេបពីបច្ចេកទេស

និយមន័យបច្ចេកទេស:

Submerged drains are drains installed in grassland on peatsoils with the aims to decrease soil subsidence and emission of CO2 and N2O due to the oxidation of peat soil, and to maintain suitable groundwater levels in fields for grassland production and grazing.

2.2 ការពណ៌នាលម្អិតពីបច្ចេកទេស

ការពណ៌នា:

Contrary to usual drains, submerged drains are installed below ditchwater level. Submerged drains diminish the differences between ditch level and groundwater level in the fields by enabling the infiltration from ditch to field and the drainage from field to ditch.
In summer and dry periods the infiltration from ditch to field is much lower than the evapotranspiration of the grass, resulting in a lowering of the groundwater level some decimetres below ditch water level. With submerged drains the groundwater level is lowered less drastically because infiltration from ditch to field is improved. In winter and wet periods, fields are drained
more quickly compared to conventional drainage.

Purpose of the Technology: Submerged drains diminish the differences between ditch level and groundwater level in the fields by enabling the infiltration from ditch to field and the drainage from field to ditch. Under peak rainfall events groundwater levels become less high and remain at high levels for shorter times than in fields without submerged drains.
Due to the increased groundwater level in summer the decomposition of the peat soil is reduced. As a result, the rate of soil subsidence is decreased and also the emission of greenhouse gases and of N and P released to the surface water.

Establishment / maintenance activities and inputs: The installation of submerged drains is done with common drainage installation machines. Submerged drains should be installed between 15 and 25 cm below the ditch water level, and between 45 and 75 cm below the soil surface. The drain pipes should have a diameter of at least 6 cm. The distance between drains is at most 6 m. Drain length is at most 300 m. Submerged drains can be installed in the length or width direction of a field. Drains must be installed level.

Natural / human environment: Submerged drains were designed for peat soils under permanent pasture for dairy farming. More than 70 % of Dutch peat soils are under this land use. Drainage of these peat soils results in subsidence, mainly by decomposition (oxidation) of the peat (partly by shrinkage and consolidation). This is an ongoing process, because every 10 to 15 year ditchwater levels are adapted to the lowered surface in order to enable dairy farming and to prevent the conversion to wetlands. Soil subsidence causes several problems: decreased suitability for grazing and grassland farming, increased flood risk, emission of greenhouse gases, damage to infrastructure (dikes, roads, foundations, sewerage networks) and increased cost of water management.

Submerged drains were tested with a network of practitioners and 10 dairy farmers in the Dutch peat soil area between 2011 and 2013 on an area of 20 ha.

2.3 ​រូបភាពនៃបច្ចេកទេស

2.5 ប្រទេស/តំបន់/ទីតាំងកន្លែង ដែលបច្ចេកទេសត្រូវបានអនុវត្ត និងបានគ្រប់ដណ្តប់ដោយការវាយតម្លៃនេះ

2.6 កាលបរិច្ឆេទនៃការអនុវត្ត

ប្រសិនបើមិនច្បាស់ឆ្នាំ សូមបញ្ជាក់កាលបរិច្ឆេទដែលប្រហាក់ប្រហែល:

• តិចជាង 10ឆ្នាំមុន (ថ្មី)

2.7 ការណែនាំពីបច្ចេកទេស

សូមបញ្ជាក់តើបច្ចេកទេសត្រូវបានណែនាំឱ្យអនុវត្តដោយរបៀបណា:

• ពេលកំពុងពិសោធន៍
• តាមរយៈគម្រោង / អន្តរាគមន៍ពីខាងក្រៅ

• stimulated by regional authorities

មតិយោបល់ (ប្រភេទនៃគម្រោង ។ល។):

Since 2003 submerged drains have been applied on several experimental farms in The Netherlands. Implementations over larger areas (i.e. a water management unit, 'peilval' in Dutch) will be done in 2016.

2007: research on soil subsidence in the Western peat area following the large scale groundweter level lowering in the 1960s and 1970s signalled the high rate of soil subsidence (5-12 mm/y) (Van den Akker et al., 2007a)

2008: concerns about soil subsidence in the western peat area from the provincial autorities of Noord-Holland, Utrecht and Zuid-Holland in the policy document 'Voorloper Groene Hart' (2008)

2008-2012: various research projects to test the effectiveness of submerged drains to reduce soil subsidence and to improve conditions for dairy farming, and on the effects for water quality: www.waarheenmethetveen.nl, Hoving et al. (2008), Woestenburg (2009), EU project EUROPEAT, Woestenburg et al. 2009; Jansen et al., 2010; Hendriks and Van den Akker, 2012; Hoving et al. (2008, 2009, 2013)

2011-2012: research on the Peat Area Innovation Centre (VIC) to test effects of submerged drainage in combination with dynamic groundwater level management (Hoving et al., 2013)

2012- testing by research instsiutes of economic viability of submerged drains with regard to water level management and agricultural productivity, on assignment of the province Noord-Holland, waterboard Hollands Noorderkwartier.

2009-2011: various modelling studies assigned by the provinces and water boards of the western peat meadow area on the effects of submerged drains for the demand for inlet and discharge of water and effects on the decomposition of peat and the water quality.

2011: model research on effects of submerged drains on the water demand of the western peat area until 2050 under climate change (Van den Akker et al., 2011)

2010-2013 experimental research in 3 pilots initiated by the province of Utrecht and Zuid-Holland, four water boards and the farmers' organisation LTO Noord. Aim: to test if the application of submerged drains results in larger amounts of water to supply and to discharge from the peat meadow area, and to test if the submerged drains result in a larger load of nutrients to ditches,

3.2 ប្រភេទដីប្រើប្រាស់មួយប្រភេទ (ច្រើនប្រភេទ) ដែលបានអនុវត្តបច្ចេកទេស

មតិយោបល់:

Major land use problems (compiler’s opinion): The major land use problems in the Western Dutch peat soil area is soil subsidence due to the lowering of the groundwater level in the 1960s and 1970s. The soil subsidence amounts to 0-2.5 cm per year. It is mainly caused by the oxidation of peat soil, which releases nutrients to soil and surface water, and CO2 and N2O to the atmosphere. The soil subsidence causes several problems:
- damage to buildings and infrastructure
- increasing costs of water management: high groundwater levels require pumping of water to enable agricultural use, and storage of rainfall excess water during peak rainfall events
- drainage of nature reserves to lowered agricultural land
- water pollution: the lowering of the groundwater level causes upward seepage of nutrient-rich water to polders
- greenhouse gas emissions (2-3% of total CO2 emissions in The Netherlands)
- loss of peat soils (2% per year in the NL)
- increased flood risk (due to combination with sealevel rise)

Major land use problems (land users’ perception): Grassland and arable farming are hampered by high groundwater levels due to a lowered bearing capacity and too wet conditions for crops. Maintaining the groundwater level at a level high enough to prevent the decomposition of peat soil would imply a conversion to wetlands and forest swamps. This is not acceptable to various kinds of land users (nature managers, farmers, users of built-up area). This would also mean the loss of the cultural historic open landscape and habitat for meadow birds, strongly reduced economic possibilities and an increased demand of water from the rivers (view of water managers and governments).

Future (final) land use (after implementation of SLM Technology): Grazing land: Gi: Intensive grazing/ fodder production

ប្រសិនបើដីមានការប្រែប្រួលបន្ទាប់ពីការអនុវត្តបច្ចេកទេស សូមបញ្ជាក់ពីការប្រើប្រាស់ដីមុនពេលអនុវត្តន៍បច្ចេកទេស:

Grazing land: Gi: Intensive grazing/ fodder production

3.3 ព័ត៌មានបន្ថែមអំពីអ្នកប្រើប្រាស់ដី

ការផ្គត់ផ្គង់ទឹកនៅកន្លែងអនុវត្តបច្ចេកទេស:

• ទឹកភ្លៀង

សូមបញ្ជាក់:

Longest growing period in days: 270Longest growing period from month to month: April-October

ដង់ស៊ីតេនៃសត្វចិញ្ចឹម (បើពាក់ព័ន្ធ):

> 100 LU /km2

3.4 ក្រុម SLM ដែលបច្ចេកទេសស្ថិតនៅក្នុង

• ការបែងចែកទឹក និងប្រព័ន្ធបង្ហូរ
• ការគ្រប់គ្រងទឹកក្រោមដី

3.5 ការសាយភាយនៃបច្ចេកទេស

មតិយោបល់:

Total area covered by the SLM Technology is 0.054 m2.

The measure was tested in three pilots in the areas Krimpenerwaard, Keulevaart and Demmerkiksekade. Each pilot covered two fields: one with submerged drains and one without. The area given refers to the pilot in the Krimpenerwaard.

3.6 វិធានការ SLM ដែលបញ្ចូលនូវបច្ចេកទេស

មតិយោបល់:

Main measures: management measures

Specification of other management measures: maintaining high groundwater level

3.7 កំណត់ប្រភេទនៃការធ្លាក់ចុះគុណភាពដីសំខាន់ៗដែលបច្ចេកទេសនេះបានដោះស្រាយ

មតិយោបល់:

Main type of degradation addressed: Cn: fertility decline and reduced organic matter content, Ps: subsidence of organic soils, settling of soil

Secondary types of degradation addressed: Pw: waterlogging, Hg: change in groundwater / aquifer level, Hp: decline of surface water quality

Main causes of degradation: other human induced causes (specify) (lowering of the groundwater level to enable agricultural use of the peat soils results in soil subsidence and detioration of ground- and surface water quality due to capillary rise)

Secondary causes of degradation: change in temperature (higher temperatures under climate change increase the decomposition rate of peat soil; subsidence and CO2 emissions will increase by 75%), change of seasonal rainfall (decrease in summer rainfall (23% in warm and dry CC scenario for NL)), inputs and infrastructure: (roads, markets, distribution of water points, other, …) (maintenance of high water levels in built-up and natural areas increases the difference in groundwater level with agricultural land onb peat soils)

3.8 ការពារ កាត់បន្ថយ ឬស្តារឡើងវិញនៃការធ្លាក់ចុះគុណភាពដី

បញ្ជាក់ពីគោលដៅរបស់បច្ចេកទេស ដែលផ្តោតទៅការធ្លាក់ចុះគុណភាពដី:

• ការកាត់បន្ថយការធ្លាក់ចុះគុណភាពដី

4.1 គំនូសបច្ចេកទេសនៃបច្ចេកទេសនេះ

4.2 លក្ខណៈពិសេសនៃបច្ចេកទេស/ ពណ៌នាពីគំនូរបច្ចេកទេស

The picture shows a cross section through an agricultural field, bounded by two ditches. A submerged drain (yellow bar in the picture) is installed at 80 cm below the soil surface. It ends in the ditch on the left side at 20 cm below the water level in the ditch. The dotted line indicates the position of the groundwater table in the situation without the submerged drain; the continuous blue line indicates the position in the situation where the submerged drain is installed. The lines show that in summer the groundwater level is raised to nearly the level of the ditch water by the submerged drain, whereas the level would be approximately 30 cm lower without the drain.
In winter, in the situation with the submerged drain, the groundwater level is around 40 cm below the soil surface. This enables the farmer to use the field for grazing or to traffic the field. However, in the situation without the drain, the groundwater level nearly reaches the soil surface in the centre of the field, impeding traffic or grazing on the field.

Technical knowledge required for field staff / advisors: moderate (Estimates of economic benefits due to increased grass production and grazing periods vary between years with meteorological conditions.)

Technical knowledge required for land users: moderate (Specific conditions apply to the dimensions and positioning of submerged drains in the fields. Level position and lebgth are critical.)

Technical knowledge required for companies installing the drains: moderate (Specific conditions apply to the dimensions and positioning of submerged drains in the fields. Level position and lebgth are critical. Soil must have sufficient bearing capacity during installation.)

Technical knowledge required for water board: moderate (submerged drains increase the water supply and discharge from groundwater level management units. Additional pumping effort can be prevented by informed water level management.)

Technical knowledge required for researchers: (the implications of submerged drains on the water management in an entire management unit should be explored using coupled hydraulic and rainfall-runoff models.)

Main technical functions: improvement of topsoil structure (compaction), maintaining soil organic matter

Secondary technical functions: increase of infiltration, increase / maintain water stored in soil, drainage of excess rainfall

Other type of management: Maintaining high groundwater levels.

4.3 ព័ត៌មានទូទៅដែលពាក់ព័ន្ធនឹងការគណនាធាតុចូល និងថ្លៃដើម

ផ្សេងៗ/ រូបិយប័ណ្ណជាតិ (បញ្ជាក់):

euro

កំណត់អត្រាប្តូរប្រាក់ពីដុល្លាទៅរូបិយប័ណ្ណតំបន់ (បើទាក់ទង)៖ 1 ដុល្លារ =:

1,09

4.4 សកម្មភាពបង្កើត

	សកម្មភាព	ប្រភេទវិធានការ	ពេលវេលា
1.	maintenance of drains and outlet in ditch	រចនាសម្ព័ន្ធ
2.	installation of submerged drains	ការគ្រប់គ្រង	in dry periods

4.5 ថ្លៃដើម និងធាតុចូលដែលត្រូវការសម្រាប់ការបង្កើតបច្ចេកទេស

	បញ្ជាក់ពីធាតុចូល	ឯកតា	បរិមាណ	ថ្លៃដើមក្នុងមួយឯកតា	ថ្លៃធាតុចូលសរុប	% នៃថ្លៃដើមដែលចំណាយដោយអ្នកប្រើប្រាស់ដី
កម្លាំងពលកម្ម	maintenance of drains and outlet in ditch	ha	1,0	30,14	30,14	100,0
កម្លាំងពលកម្ម	installation of submerged drains	ha	1,0	1980,0	1980,0	100,0
ថ្លៃដើមសរុបក្នុងការបង្កើតបច្ចេកទេស					2010,14

មតិយោបល់:

Lifespan of the drains: 30 years

4.6 សកម្មភាពថែទាំ

	សកម្មភាព	ប្រភេទវិធានការ	ពេលវេលា/ ភាពញឹកញាប់
1.	maintenance of submerged drains	ការគ្រប់គ្រង	several times in lifetime of drains (30 y)

4.7 កំណត់ថ្លៃដើមសម្រាប់ការថែទាំ/ សកម្មភាពរបស់បច្ចេកទេស (ក្នុងរយៈពេលមួយឆ្នាំ)

	បញ្ជាក់ពីធាតុចូល	ឯកតា	បរិមាណ	ថ្លៃដើមក្នុងមួយឯកតា	ថ្លៃធាតុចូលសរុប	% នៃថ្លៃដើមដែលចំណាយដោយអ្នកប្រើប្រាស់ដី
ផ្សេងៗ	Annual cost incl maintenance	ha	1,0	127,0	127,0	100,0
ថ្លៃដើមសរុបសម្រាប់ការថែទាំដំណាំតាមបច្ចេកទេស					127,0

មតិយោបល់:

Machinery/ tools: establishment and installation require specific skills and machinery; hired, not done by the farmer himself

Investment costs of 1500-1800 €/ha are based on submerged drains at 6 m distance. Costs per m of drain establishment based on drains of 6 cm diameter. Costs based on practical experience from farmers. Drains may have a lifetime of 30 years and require little maintenance.

Specific skills and machinery are required for installation and maintenance, hired from a drainage company. The farmer must only ensure that the outlets of the drains in the ditches remain open and undamaged.

4.8 កត្តាសំខាន់បំផុតដែលមានឥទ្ធិពលដល់ការចំណាយ

ពណ៌នាពីកត្តាប៉ះពាល់ចម្បងៗទៅលើថ្លៃដើម:

We do not have information on specific cost items, only on establishment costs ad between 1500 and 1800 euro/ha, and annual cost of 117 €/ha incl maintenance, assuming a 20-year life time. Establishment costs can also be expressed per m of drain, i.e. 1.10 EURO per m including materials (drain of 6 cm diameter).

Determinate factors include size and geometry of fields; installation in the length direction is cheaper, and results in fewer outlets in the receiving ditch.

5.1 អាកាសធាតុ

5.2 សណ្ឋានដី

មតិយោបល់ និងបញ្ចាក់បន្ថែមអំពីសណ្ឋានដី :

Altitudinal zone: 0-100 m a.s.l. (Submerged drains are designed for polders in lowland areas on peat soils)
Landforms: Plateau/plains (submerged drains are designed to drain level fields)
Slopes on average: Flat (submerged drains are designed to drain flat terrain, based on hydraulic prressure head differences between field and ditch)

5.3 ដី

បើអាចសូមភ្ជាប់ការពណ៌នាពីដីឱ្យបានច្បាស់ ឬព័ត៌មានដែលអាចទទួលបាន ឧ. ប្រភេទដី, pH ដី/ ជាតិអាស៊ីត, សមត្ថភាពផ្លាស់ប្តូរកាចុង, វត្តមាននីត្រូសែន, ភាពប្រៃ ។ល។:

Soil depth on average: Very deep (if the peat substrate is considered as part of the soil profile, soils are deeper than 120 cm, with peat packages up to 13 m in some parts of the western Dutch peatland area) and shallow (If the top of the C-horizon is considered as the bottom of the soil profile. C-horizons typically start at 15-30 cm below the soil surface)
Soil texture is fine/heavy (for peat soils with a clayey top layer. In peat soils without such a top layer, a soil texture indication is not applicable. Peat soils are defined as having at least 40 cm of peat in the top 80 cm)
Soil fertility is very high (peat soils are able to supply ample nutrients to plants provided that they are well drained)
Topsoil organic matter is high (Organic matter contents in the topsoil are above 20%. Peat soils are defined as having at least 40 cm of peat in the top 80 cm according to the Dutch soil classification system)
Soil drainage/infiltration is poor/none (peat soils inherently have poor drainage due to their low position with reference to the groundwater level in the regional water system. Values of Ksat reported 2.9-5.0 cm/d)
Soil water storage capacity is very high (the soil water storage capacity is very high due to the large pore space (0.70-0.90 m3/m3))

5.4 ទឹកដែលអាចទាញមកប្រើប្រាស់បាន និងគុណភាពទឹក

មតិយោបល់ និងលក្ខណៈពិសេសផ្សេងៗទៀតលើគុណភាព និងបរិមាណទឹក​ :

Ground water table: <5m (Average lowest grondwater level in the pilot region is 5-10 cm below the soil surface; average highest level 55-65 cm)
Availability of surface water is good (surface water is amply available due to the low position of the peat soil area compared to the mean sea level, and due to the dense network of ditches and other surface water conveyors and bodies) and excess (surface water levels are under continuous control by the water boards. Therefore flood situations do not occur, but under high-intensity rainfall events fields may submerge)
Water quality (untreated) is for agriculutral use only (Irrigation, surface and groundwater can be used for agriculture without treatment. Nutrient rich water emerging by capillary rise in polders may not be suitable for nature.)
Biodiversity is medium (the grasslands in the western peatsoil area are suitable habtitats for meadow birds)

5.5 ជីវៈចម្រុះ

5.6 លក្ខណៈនៃអ្នកប្រើប្រាស់ដីដែលអនុវត្តបច្ចេកទេស

សូមបញ្ជាក់ពីលក្ខណៈពាក់ព័ន្ធផ្សេងទៀតអំពីអ្នកប្រើប្រាស់ដី:

Difference in the involvement of women and men: Executives of agricultural enterprises in The Netherlands are usually men.
Population density: 200-500 persons/km2
Annual population growth: 1% - 2%
100% of the land users are average wealthy and own 100% of the land.
Off-farm income specification: Dairy farmers in this part of The Netherlands spend 100% of their time on the farm. Sometimes their wives have jobs earning off-farm income.
Market orientation is commercial/market (intensive dairy farming in the NL produces for the market)

5.7 ទំហំផ្ទៃដីជាមធ្យមនៃដីផ្ទាល់ខ្លួន ឬជួលគេដែលបានអនុវត្ត​បច្ចេកទេស

5.8 ភាពជាម្ចាស់ដី កម្មសិទ្ធប្រើប្រាស់ដី និងកម្មសិទ្ធប្រើប្រាស់ទឹក

ភាពជាម្ចាស់ដី:

• ឯកជន មានកម្មសិទ្ធ

កម្មសិទ្ធិប្រើប្រាស់ដី:

• ឯកជន

កម្មសិទ្ធប្រើប្រាស់ទឹក:

• កិច្ចសន្យាជួល

5.9 ការប្រើប្រាស់សេវាកម្ម និងហេដ្ឋារចនាសម្ព័ន្ធ

6.1 ផលប៉ះពាល់ក្នុងបរិវេណអនុវត្តបច្ចេកទេសដែលកើតមាន

ផលប៉ះពាល់លើសេដ្ឋកិច្ចសង្គម

ផលិតផល

ចំណូល និងថ្លៃដើម

ផលប៉ះពាល់ទៅលើសេដ្ឋកិច្ចសង្គមផ្សេងៗ

ផលប៉ះពាល់ទៅលើវប្បធម៌សង្គម

ផលប៉ះពាល់ទៅលើអេកូឡូស៊ី

វដ្តទឹក/លំហូរ

ដី

ជីវចម្រុះ៖ ដំណាំ, សត្វ

ការកាត់បន្ថយហានិភ័យនៃគ្រោះមហន្តរាយ និងគ្រោះអាកាសធាតុ

ផលប៉ះពាល់ទៅលើអេកូឡូស៊ីផ្សេងៗ

6.2 ផលប៉ះពាល់ក្រៅបរិវេណអនុវត្តបច្ចេកទេសដែលកើតមាន

6.3 ភាពប្រឈម និងភាពរួសនៃបច្ចេកទេសទៅនឹងការប្រែប្រួលអាកាសធាតុ និងគ្រោះអាកាសធាតុ/ គ្រោះមហន្តរាយ (ដែលដឹងដោយអ្នកប្រើប្រាស់ដី)

ការប្រែប្រួលអាកាសធាតុ

ការប្រែប្រួលអាកាសធាតុ

	រដូវកាល	ប្រភេទនៃការប្រែប្រួលអាកាសធាតុ/ព្រឹត្តិការណ៍	លក្ខណៈឆ្លើយតបនៃបច្ចេកទេសទៅនឹងការប្រែប្រួលអាកាសធាតុ
សីតុណ្ហភាពប្រចាំឆ្នាំ		កើនឡើង	ល្អ

គ្រោះអាកាសធាតុ (មហន្តរាយ) ​

គ្រោះមហន្តរាយធម្មជាតិ

	លក្ខណៈឆ្លើយតបនៃបច្ចេកទេសទៅនឹងការប្រែប្រួលអាកាសធាតុ
ព្យុះភ្លៀងតាមតំបន់	ល្អ
ព្យុះកំបុតត្បូងតាមតំបន់	ល្អ

គ្រោះមហន្តរាយអាកាសធាតុ

	លក្ខណៈឆ្លើយតបនៃបច្ចេកទេសទៅនឹងការប្រែប្រួលអាកាសធាតុ
រាំងស្ងួត	មិនស្គាល់

គ្រោះមហន្តរាយទឹក

	លក្ខណៈឆ្លើយតបនៃបច្ចេកទេសទៅនឹងការប្រែប្រួលអាកាសធាតុ
ទឹកជំនន់ទូទៅ (ទន្លេ)	ល្អ

ផលវិបាកដែលទាក់ទងនឹងបរិយាកាសផ្សេងៗទៀត

ផលវិបាកដែលទាក់ទងនឹងបរិយាកាសផ្សេងៗទៀត

	លក្ខណៈឆ្លើយតបនៃបច្ចេកទេសទៅនឹងការប្រែប្រួលអាកាសធាតុ
កាត់បន្ថយពេលដាំដុះ	ល្អ

មតិយោបល់:

Under extreme rainfall events, submerged drains cannot prevent that the groundwater level rises to above the soil surface. However, the groundwater level will fall more quickly with submerged drainas than without, on average to 10 cm lower levels.

Effects of dry summers have not yet been measured in experiments.

6.4 ការវិភាគថ្លៃដើម និងអត្ថប្រយោជន៍

តើផលចំណេញ និងថ្លៃដើមត្រូវបានប្រៀបធៀបគ្នាយ៉ាងដូចម្តេច (ទស្សនៈរបស់អ្នកប្រើប្រាស់ដី)?

តើផលចំណេញ និងការថែទាំ/ ជួសជុលត្រូវបានប្រៀបធៀបគ្នាយ៉ាងដូចម្តេច (ទស្សនៈរបស់អ្នកប្រើប្រាស់ដី)?

មតិយោបល់:

A longer grazing season and the extra yield of fodder are the basis for a viable implementation of submerged drainage for land users. The CBA considers establishment and maintenance costs together: establishment costs of € 1800,-/ha, discounted over 20 years, including maintenance, result in annual cost of € 117,-/ha (6.5% of the investment). Benefits include 500 kg DM/ha extra grass use and 30 extra grazing days. This would yield € 171/ha, resulting in a net saldo of € 54,-. In addition SMD are an investment in sustainable soil management, resulting in an increased economic value of the land in the long term.

6.5 ការទទួលយកបច្ចេកទេស

បើអាច សូមបញ្ជាក់ពីបរិមាណ (ចំនួនគ្រួសារ និង/ ឬតំបន់គ្របដណ្តប់):

13

ក្នុងចំណោមគ្រួសារទាំងអស់ដែលអនុវត្តបច្ចេកទេស តើមានប៉ុន្មាន​គ្រួសារ​ដែល​ចង់​ធ្វើ​ដោយ​ខ្លួន​ឯង ដោយមិន​ទទួល​បាន​សម្ភារៈ​លើក​​ទឹកចិត្ត/​ប្រាក់ឧបត្ថម្ភ?​:

• 90-100%

មតិយោបល់:

13 land user families have adopted the Technology without any external material support

Comments on spontaneous adoption: The area under submerged drainage implemented by the 10 dairy farmers from the Community of Practice is 20 ha. The area under SMD in the three pilots described in this questionnaire is roughly an additional 0.05 km2 per farm.

There is a moderate trend towards spontaneous adoption of the Technology

Comments on adoption trend: Due to the growing interest in the peat soil area because of the relevance for climate mitigation and the economic risks of soil subsidence there is growing interest in SMD in combination iwth dynamic groundwater level management to reduce the rate of soil subsidence. Subsidy arrangements are in preparation, which will stimulate adoption of the technology by more dairy farmers.

6.7 ភាពខ្លាំង/ គុណសម្បត្តិ/ ឱកាសនៃបច្ចេកទេស

ភាពខ្លាំង/ គុណសម្បត្តិ/ ឱកាសនៅកន្លែងរបស់អ្នកប្រើប្រាស់ដី
Submerged drains increase the number of days with a good bearing capacity of grassland, and therefore enable a longer grazing season and less trampling of grass.
Higher effective yield in total.
Short term: slightly cost effective. Long term: good cost effective.

ភាពខ្លាំង/ គុណសម្បត្តិ/ ឱកាស​ ទស្សនៈរបស់បុគ្គលសំខាន់ៗ
Submerged drains allow a strong reduction of soil subsidence and GHG emissions (at least 50%, even >50% if combined with higher ditch water levels). How can they be sustained / enhanced? Further implementation by dairy farmers in the peat-meadow area. For this purpose the Community of Practice is recommended, as well as the arrangement of subsidies and the active involvement of regional government and water board. This applies to all mentioned advantages.
The quality of surface water in ditches will slightly improve.
Less problems with difference between subsiding soil surfaces and constant water levels in lakes and high water ditches (along houses).
Less sub-polders with a certain fixed ditch water level, and possibility to create areas with a high surface level (with submerged drains) and a low surface level (without SD).

6.8 ភាពខ្សោយ/ គុណវិបត្តិ/ ហានិភ័យនៃបច្ចេកទេស និងវិធីសាស្ត្រដោះស្រាយ

ភាពខ្សោយ/ គុណវិបត្តិ/ ហានិភ័យ ទស្សនៈរបស់អ្នកប្រើប្រាស់ដី	តើបច្ចេកទេសទាំងនោះបានដោះស្រាយបញ្ហាដូចម្តេច?
Grass yield is lower due to reduced mineralization of nitrogen.	Yield could be increased due to better usage of manure (better NUE). On the other hand yield is increased due to increased number of days with a good bearing capacity of grassland, and a longer grazing season and less trampling of grass.

ភាពខ្សោយ/ គុណវិបត្តិ/ ហានិភ័យ ទស្សនៈរបស់អ្នកចងក្រងឬបុគ្គលសំខាន់ៗ	តើបច្ចេកទេសទាំងនោះបានដោះស្រាយបញ្ហាដូចម្តេច?
Submerged drains require more inlet water to polders.	Reduction of inlet requirement is possible by smart water management. This implies water level margins of +/- 10 cm and the use of weather forecasting.
Submerged drains require a bit more pumping to drain water under extreme rain events.

7.2 ឯកសារយោងដែលបានចេញផ្សាយ

ចំណងជើង អ្នកនិពន្ធ ឆ្នាំ ISBN:

Several reports on submerged drainage are available from Alterra, Wageningen UR (in Dutch). The report used for this WOCAT QT is:Effecten van onderwaterdrains in peilvak 9 van polder Groot-Wilnis Vinkeveen : modelstudie naar de effecten van onderwaterdrains op maaivelddaling, waterbeheer, wateroverlast en waterkwaliteit in peilvak 9 Author(s)Hendriks, R.F.A.; Akker, J.J.H. van den; Jansen, P.C.; Massop, H.Th.L. SourceWageningen : Alterra Wageningen UR, 2014 (Alterra-rapport 2480) - p. 124Other literature (in Dutch): Waarheen met het veen. Woestenberg, M. 2009. Uitegeverij Landwerk and Alterra, Wageningen URhttp://www.levenmetwater.nl/static/media/files/Boek_wmhv_def.pdf

មានប្រភពមកពីណា? ថ្លៃដើមប៉ុន្មាន?

Alterra Reports are available atlibrary.wur.nl