Desirable physical condition of the soil 220
The breaking-plow 221
Types of plows 221
Subsoiling 223
Time of plowing 223
Method of plowing 224
The disk harrow 225
Cultivation of plants 227
Controlling root-growth 227
Elimination of competition 228
Length of cultivation 229

CHAPTER XXII

CONTROL OF SOIL MOISTURE 230-236
Value of water in the soil 230
The soil a reservoir 231
The land-roller 232
The plank-drag 233
The mulch 233
Mulches of foreign material 234
Plowing straw down 235
The summer-fallow 235
The modern fallow 236

CHAPTER XXIII

DRAINAGE 237-246
Underdrainage 237
Counting the cost 238
Where returns are largest 239
Material for the drains 239
The outlet 240
Locating main and branches 240
The laterals 241
Size of tile 241
Kind of tile 242
The grade 243
Establishing a grade 243
Cutting the trenches 244
Depth of trenches 245
Connections 245
Permanency desired 246

ILLUSTRATIONS

Alfalfa and Corn in Indiana _Frontispiece_

Facing Page

A Good Crop for a Poor Soil 4

Red Clover on Limed and Unlimed Land 20

Turning down Organic Matter with a Gang Plow 36

Red Clover on the Farm of P.