xii LIST OF TABLES 



TABLE PAGE 



30. Plant Food recovered from Food Consumed (Illinois) . . .201 



31. Plant Food recovered from Food Consumed (Pennsylvania) . . 202 



32. Plant Food recovered from Six Months' Feeding (Ohio) . . 204 



33. Fixation of Nitrogen by Alfalfa 214 



34. Nitrogen in Sweet Clover 220 



35. Composition of Crimson Clover 221 



36. Composition of Legumes and Other Plants . . . . 222 



37. 38, 39, and 39^. Comparison of Raw Phosphate and Acid Phosphate 



247-253 



40. Ohio Experiments with Manure, Phosphate, Kainit, Gypsum, and 



Complete Fertilizers . . 256 



41. Balance Sheet for Nitrogen and Phosphorus in Manure-phosphate 



Experiments . . 257 



42. Maryland Experiments with Different Phosphates ... . . 262 



43. Pennsylvania Experiments with Different Phosphates . '. . 264 



44. 45, 44C, and 45^. Rhode Island Experiments with Nine Phosphates 



268-274 



46 and 47. Maine Experiments with Different Phosphates . . 276, 277 

 48 and 49. Massachusetts Experiments with Different Phosphates 279, 282 



50. Illinois Experiments with Raw Rock Phosphate . . . 285 



51. Steamed Bone Meal and Raw Rock Phosphate .... 287 



52-58. Rotation Crops on Agdell Field 346-352 



59. Summary of Crop Yields and Values, Agdell Field . . . . 360 

 6oand6i. Wheat Yields, Broadbalk Field, Averages . . . 364,365 



62. Wheat Yields at Rothamsted, Comparisons .... 372, 373 



63. Wheat Yields, Broadbalk Field, Nitrogen Increments . . . 374' 



64. Wheat Yields at Rothamsted, Summaries 375 



65. Rothamsted Records, Rainfall and Drainage ..... 377 

 66 and 67. Barley Yields on Hoos Field 380, 381 



68. Potato Yields on Hoos Field 386, 387 



69. Residual Effect of Fertilizers on Hoos Field . . . . . 390 



70. Hay Yields on The Park at Rothamsted 393 



71. Root Crops on Barn Field 399,400 



72. Rothamsted Fields abandoned to Nature 404 



73. Plant Food in Soil of Broadbalk Plots .411 



74. Composition of Drainage Waters from Broadbalk Field . . . 413 



75. Nitrogen in Soil of Agdell Plots . . . . . . . 416 



76. Composition of Crops grown on Agdell Field 417 



77. Composition of Hay from The Park, Rothamsted . . . .418 



78. Pennsylvania Crop Yields in Field Experiments . . '. . 423 

 79 and 80. Pennsylvania Experiments by Twelve-year Periods . 428, 429 

 81. Pennsylvania Experiments : Financial Summary .... 431 

 8iP. Pennsylvania Experiments : Twenty-five-year Average . . . 434 



