96 FARMERS' INSTITUTES. 



■with liuniua that had been boiled for three hours with water contain'ng lime iu 

 the caustic state, this series l»eitig labelled " humus without ammonia." A num- 

 ber of kinds of plants were used iu these iuvestigatiims, but the discussion of 

 results is eontined to two plants — red clover representing our great tnanural 

 crop, "the nitrogen producer" of Vielle; and wheat, our great cash crop, 

 representing " the nitrogen cousumers." 



NITKIFICA.TION. 



During the season of growth a part of the inert nitrogen of humus may be 

 ■changed into active form by nitrification. This process may be modified by the 

 action of tlie growing plant, but would in other respects be the same in all of 

 the series. It could not be estimated in the soils in whicli the plants were 

 growing without changing the conditions of the experiments and deranging 

 the conditions of growth. As its benefits would be given to all the ])Iants of a 

 given ser es, no elfort at a separate estimation was attempted, the ol)ject being 

 rather to determine the dilference iu capacity of these two classes of plants to 

 Gccure nitrogen from a common source. 



PLANTING AND HARVESTING, 



The seeds for these experimental plants were planted the latter part of Feb- 

 ruary and the plants gathered the fore part of August. The time of planting 

 was selected because the chemical laboratory was iieated by steam from latter 

 part of February for balance of the college year and danger of freezing obvi- 

 ated. 



Tlie first year Clawson wheat was used as one of the experimental plants. This 

 is a winter wheat, and, l^eing grown under the conditions of spring wheat, it did 

 not head out or attempt the formation of see 1. The next year fall planting of 

 all the experimental plants was employed and the [)lants carried through the 

 winter by stove heat, and in summer the plants were carried to the greenhouses; 

 but a few days of intensely hot weather and neglect of ventilation burned up 

 the i)lants and the year's toil in experiment ended in disastrous failure, though 

 the [)lants at one time gave good promise. 



The next year a spring wheat was used which headed out and gave promise of 

 results of value, but just before the plant was harvested a mouse went through 

 ten heads. What he gathered I don't know and he never told, but the experi- 

 ment was a failure. 1 mention these things as illustrating some of the diffi- 

 culties and accidents of experimenting. 



In 1885 the Minnesota Amber was used in the experiment, and the results 

 were satisfactory both in wheat and clover. All of these crops, when their 

 scientific value had not manifestly been destroyed by accident, were gathered, 

 dried, weighed and finally their contents of nitrogen determined by analy- 

 ses, involving an amount of work not recognized by persons who have never 

 attempted similar investigations. 



RESULTS. 



To get a clear idea of the results of these experiments I present them to you 

 under two forms : I. The relative increase of the total crop as compared with 

 the seed from Avhich itgrevr. II. The relative increase of nitrogen in the crop 

 compared with that contained in the original seed. The seed is taken as the 

 unit of comparison both for the total crop and the content of nitrogen. 



