
9 4 Soil-forming processes in humid landscapes 268
9 4
1
Vegetation as indicator of swamp tvpes 273
9 4 2 Classification of peats 275
94 3 Macroscopic definition of peat decomposition degree 276
9 4 4 Diagnostics of sapropels and their properties 280
9 5 Drainage of waterlogged and boggv soils 281
9 5 1 Principles for choosing a drainage object 281
95 2 Objectives of drainage Concepts of drainage method and technique 283
9 6 Drainage systems 284
9 6 1 Construction of drainage systems 284
9 6 2 Kinds of drainage svstems 288
9 6 3 Drainage kinds 293
9 6 3 1 Open drainage 293
9 6 3 2 Closed drainage 293
9 6 3 2
1
Materiale drainage 293
9 6 3 3 Subsurface drainage 302
9 6 3 3
1
Mole drainage 302
9 6 3 3 2 Fissure drainage 304
9 7 Drainage time, rate and depth, drain spacing 306
9 7 1 Drainage time 306
9 7 2 Drainage rate 307
9 7 3 Drainage depth and drain spacing 309
97 4 Subsidence of boggy soils during their drainage 310
9 7 5 Calculation of drain spacing 311
9 7 5 1 Conditions for water flow to drains 312
9 7 5 2 Determination of drain spacing by hydromchamcal calculation
9 7 5 3 Calculation of drain spacing by physical-mechanical soil properties 313
9 7 5 3
1
Calculation of drain spacing by soil texture 318
9 7 6 Evaluating the stability of mole drains in soils 319
9 7 7 Drains filling by iron hydroxide and preventive control measures 323
9 7 7
1
General notion 326
9 7 7 2 Conditions for iron hydroxide accumulation m drain tubes and
diagnostics of this phenomenon 326
9 7 7 3 Washing out of silt-and iron hydroxide-filled drains 327
97 8 Drainage of waterlogged soils with low permeability 334
9 7 8
1
Soil suitability for agricultural traffic 336
9 7 8 2 Hydrotechmcal measures for accelerating the surface and drainage
runoff 338
9 7 8 3 Agromehorativc measures for accelerating the surface runoff 338
9 7 8 4 Agromehorativc measures for accelerating the subsurface runoff
(mole plowing, deep meliorative loosening, chieseling) 340
9 7 8 4
1
Alternative measures for increasing the subsurface runoff by
agrophytoamelioration 348
9 7 8 5 Vertic soils and their amelioration 349
9 7 8 5
1
Peculiar genesis and properties of vertic soils 350
9 7 8 5 2 Amelioration of vertic soils 351
9 7 9 Drainage, cultivation and conservation of peat soils 352
9 7 9 1 General notion 352
9 7 9 2 Use of peat soils in different farming systems 356
9 7 9 3 Pyrogenic degradation of drained peat soils 362
9 7 9 3
1
Concept of pyrogenic degradation 362
9 7 9 3 2 Pyrogenic formations and pyrogemcally-transformed soils 366
9 7 9 3 3 Preventive control measures to protect the peat soils against
pyrogenic and hydrotlicrmal degradation 369
9 7 9 4 Rehabilitation of degraded peat soils 375
9 8 lhe two sided control over moisture regime in drained soils Kinds
of lockage 379
446