EXPERIMENT STATION REPORTS. 221 



The Michigan Potato Producers Association cooperating with the Exten- 

 sion Speciahsts vnW inspect this year approximately 1,100 acres of potatoes 

 for certification. 



SOILS. 



The Extension schools which occupy the winter season, are usually held in 

 cooperation with the county agent. The problems in which the farmer is 

 most interested are discussed as fully as time will warrant. At a number 

 of meetings samples of soils and marls are brought in by farmers and simple 

 tests for acidity or lime contents are conducted, explaining where equipment 

 for such work can be obtained, the reactions of tests and how such tests can 

 be carried on by the farmer under field conditions. 



The summer field work is divided into two divisions, namely the carrjdng 

 on of accurately controlled demonstration plots and the field meetings held 

 on such demonstration fields. The demonstration plots consist of work along 

 the following lines: the use of commercial fertilizers of different kinds and 

 amounts on various soil types; rate of application of manure and effect of 

 reinforcing of manures with phosphate ; different kinds and applications of 

 limes and marls ; the effect of fineness of division of ground limestone as cov- 

 ering a rotation; the use of various crops as green manure crops and their 

 period of duration in the soil, and the effect of tillage operations on control of 

 moisture and crop growiih. Accurate records are kept of these projects not 

 only for one year but for a number of years. Field records are also kept, the 

 yields being taken by the field man rather than by the farmer or the person 

 with whom we are cooperating. Field meetings are usually held on the 

 demonstration plots during the growing season. 



New work on different soil types and lime and fertilizer treatment on the 

 catch and growth of alfalfa and clovers, as well as fertilizer demonstrations 

 on corn, have been the principal lines of new work undertaken in the last year. 



MUCK CROPS. 



The service offered to owners of muck soils is based upon the fact that muck 

 and peat soils have basic, physical and chemical factors not present in upland 

 soils and consequently present different problems. The phases of work em- 

 phasized have been the determination of the agricultural adaptabilities of 

 muck areas, fertilizer requirements of certain crops on certain types of muck, 

 systems of farm management for muck lands, and problems of clearing, 

 breaking, tilling and draining muck lands. 



It has been the purpose to assemble all knowledge and experience relating 

 to muck problems and make it available to owners of muck soils. In this 

 effort the two phases of muck cropping have been kept in mind and that which 

 applies to intensive culture of vegetable crops has not been confused with the 

 extensive culture of general farm crops. In the absence of experimental 

 data the most successful experiences of the best farmers have been depended 

 upon, and supplemented with results from demonstration tests conducted 

 cooperatively with them. 



In general phosphorus and potash have been found to be the essential 

 elements necessary for high limed mucks; while lime, nitrogen, phosphorus 

 and potash are all necessary on the low limed mucks. 



Because of its magnitude and need for help, special effort has been given to 

 the celery industry. Assistance was given the growers in the choice of com- 

 mercial fertihzers in regions previously depending upon Chicago manure 



