REPORT OF THE DIRECTOR 19 



SESSIONAL PAPER No. 16 



Common salt, wlTich has long had a reputation for its value as a fertilizer for 

 barley, with many farmers, while others disbelieved in its efficacy, has been shown to be a 

 valuable agent for producing an increased crop of that grain, while it is of much 

 less use when applied to crops of spring wheat or oats. Land plaster or gypsum has 

 also proved to be of some value as a fertilizer for barley, while of very little service 

 for wheat or oats. Some light has also been thrown on the relative usefulness of single 

 and combined fertilizers. 



CHANGES MADE IN THE EXPERIMENTS. 



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, Y 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. 



Aft-er constant cropping for ten or eleven years, it was found that the soil on these 

 plots to which no barnyard manure had been applied, was much depleted of humus, 

 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 

 favourable. In 1899, the experiments were modified and an effort made to restore some 

 proportion 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. No barnyard manure was applied on plots 1 and 2 in each series 

 from 1898 to 1905. 



In 1900 all the fertilizers on all the plots were discontinued, and from then to 1905 

 the same crops were grown on all these plots from year to year without fertilizers, 

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

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

 unexhausted values of the different fertilizers which had been used on these plots 

 since the experiments were begun. In 1905-6-7-8 all the fertilizers were again used as 

 in 1898. 



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 places, in the 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 ground in each case to decay and add to the fertility of the 

 soil. The clover was left over for further growth in the sprmg 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 also crops of Indian corn and roots 

 v.-ere grown on these plots. In 1903 the land was again devoted to clover and was in 

 Indian corn and roots again in 1904 and each year since. 



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