20 EXPEBIMENTAL FARMS 



4-5 EDWARD Vli., A. 1905 

 CHANGES MADE IN THE EXPERniENTS. 



After ten years' experience had demonstrated that finely-ground, untreated mineral 

 phosphate was of no value as a fertilizer, its use was discontinued in 1898. Prior to this 

 it had been used in each set of plots in Nos. 4, 5, 6, 7 and 8, in all the different series 

 of plots, excepting roots. In 1898 and 1899, similar weights of the Thomas' phosphate 

 were used in place of the mineral phosphate, excepting in plot 6 in each series. In 

 this plot the Thomas' phosphate was used in 1898 only. 



After constant cropping for ten or eleven years, it was found that the soil on those 

 plots to which no barn-yard manure had been applied was much depleted of humus, 

 and hence its power of holding moisture had been lessened ,and the conditions for plant, 

 growth, apart from the question of plant food, had on this account become less favour- 

 able. In 1899 tlie experiments were modified and an effort made to restore some pro- 

 portion of the humus and at the same time gain further information as to the value 

 of clover as a collector of plant food. In the spring of that year ten pounds of red 

 clover seed per acre was sown with the grain on all the plots of wheat, barley and oats. 

 The young clover plants made rapid growth, and by the middle of October there was 

 a thick mat of foliage varying in height and density on the different plots, which was 

 ploughed under. 



In 1900, 1901, 1902, 1903 and 1904, clover was again sown on all the grain plots, 

 and was ploughed under in October. In 1900 and 1901 a good growth of clover was 

 obtained, but in 1902 a severe frost in the spring destroyed a large proportion of the 

 young plants, so that the crop available for ploughing under in the autumn was very 

 light. In 1903 and 1904 the crop of clover ploughed under in the autumn was fairly 

 good. 



APPLICATION OF FERTILIZERS DISCONTIKUEn. 



Another direction in which information was sought was in reference to the length 

 of time which a liberal application of barn-yard manure would continue to affect subse- 

 quent crops, and in 1899 on plots 1, 2 and 6 the barn-yard manure, which had been 

 used for ten or eleven years in succession, was discontinued. The phosphate fertilizer 

 was also omitted on plot 6 in each series. 



In 1900 all tlie fertilizers on all the plots were discontinued, and since then the 

 same crops have been grown on all these plots from year to year without fertilizers, 

 sowing clover with the grain each season. In this way some information has been 

 gained as to the value of clover as a collector of plant food, and also as to the unex- 

 hausted values of the different fertilizers which have been used on these plots since 

 the experiments were begun. 



SPECIAL TREATMENT OF PLOTS OF INDIAN CORN AND ROOTS. 



As it was not practicable to sow clover with the Indian corn and root crops, the 

 sowing of these latter crops was discontinued in the spring of 1900 and clover sown 

 in their place in tlie proportion of 12 pounds per acre. The clover on these plots made 

 strong growth, so strong as to necessitate twice cutting during the season, the cut clover 

 being left on the groiond in each case to decay and add to the fertility of the soil. 

 The clover was left over for further growth in the spring of 1901, and ploughed under 

 for the roots about May 10, and for corn about the middle of that month. Then roots 

 and Indian corn were again sown. In 1902 crops of Indian corn and roots were grown 

 on these plots, but in 1903 the land was again devoted to clover. 



WHEAT PLOTS. 



The seed sown on each of these plots from the beginning has been in the propor- 

 tion of li bushels per acre, excepting in 1894 ; and the varieties used were as follows :— 



