FOURTEENTH ANNUAL YEAR BOOK— PART X. 



719 



Given herewith is an outline of one of the simplest and most practical 

 series of plot experiments, and it is recommended for all normal types of 

 Iowa soils on which common farm crops are grown. 



The series of soil treatments listed below really includes two distinct 

 systems of farming. For instance, the treatments recommended for 

 plots one to four inclusive, represent a live stock system of soil man- 

 agement, while plots five to eight inclusive represent a grain farming 

 system. It is suggested that any farmer who does not wish to use as 

 many as ten plots may confine his experiments to either the live stock 

 or the grain system. If this is done, in some cases it may be advisable 

 to include the treatment suggested for plot nine, and thus make the 

 test include potassium. 



PL-AN FOR PLOT EXPERIMENTS. 



a— Pertilitj' t€st. b— Live stock system, e— Grain farming system. 



Plot Ko. Soil Treatment 



f 



1 None. 



a^ 



b^ 



2 Manure. 



3 Manure and limestone. 



4 Manure, limestone and phos- 

 phorus. 



5 None. 



6 Crop residues. 



7 Crop residues and limestone. 



S Ctop residues, limestone and 



phosphorus 



a Crop residues, Jimestone, phos- 

 phorus and potassium. 



10 _■ None. 



DETAILS OF EXPERI:MEXT PLAN. 



The following explanations regarding the details of this plan for plots 

 experiments in the field should be carefully noted: 



1. Manure of good quality, but fairly representative of that commonly 

 produced on the farm, should be applied at the rate of eight or ten tons 

 per acre, once in a four year rotation and in proportionate amounts for 

 rotations which cover a shorter or longer period of time. When it is 

 possible to do so, the manure should be put on the clover field and plowed 

 under for corn the following year. 



2. Ground limestone or limestone screenings should be applied to the 

 land after it has been plowed, at the rate of two or three tons per acre, 

 once in a four year rotation. The application of lime may be made at 

 any convenient time of the year. 



3. Phosphorus may be applied in finely ground rock phosphate, 

 steamed bone meal or acid phosphate. The rock should be used at the rate 

 of 2,000 pounds per acre, the steamed bone meal at the rate of 800 pound? 



