REPORT OP THE DIRECTOR. 35 



SESSIONAL PAPER No. 16 



(ietrimental. Nevertheless, much useful iuformation has been acquired, some of a 

 l>usitive and some of a negative character, by this long-conducted and extensive series 

 of tests. The information now gained from year to year throws light in many ways 

 001 the action of fertilizers and is increasingly useful. 



VALUABLE INFORMATIOX GAINED. 



As results of these trials, it has been shown that barn-yard manure can be most 

 economically used in the fresh or unrotted condition; that fresh manure is equal, ton 

 for ton, in crop-producing power to rotted manure, which, other experiments have 

 shown, loses during the process of rotting about 60 per cent of its weight. In view of 

 the vast importance of making the best possible use of barn-yard manure, it is diffi- 

 -eult to estimate the value of this one item of information. 



At the time when these experiments were planned, the opinion was very generally 

 held that untreated mineral phosphate, if very finely ground, was a valuable fertilizer, 

 which gradually gave up its phosphoric acid for the promotion of plant growth. Ten 

 years' experience has shown that mineral phosphate, untreated, is of no value as a 

 fertilizer. 



The use of sulphate of iron, which at the time the?e tests were begun, was highly 

 recommended by an authority at that time emiuent, as a reliable means of producing 

 increased crops, has also been proven to be almost useless for this purpose. 



Common salt, which has long had a reputation with many farmers for its value 

 as a fertilizer for barley, while others disbelieved in its efficacy, has been shown to 

 be a most 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 proven 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 useful- 

 ness of single and combined fertilizers. 



(;nANGES 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, 7 and on No. 8, also 

 in all the different series of plots, excepting roots. In 1898 and 1899, similar weights 

 of the Thomas' phosphate was 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 

 htimus, 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 favouTable. In 1899 the experiments were modified and an effort made to restore 

 some proportion of the humu's 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 10 pounds of 

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

 oats. The clover seed germinated well, and after the grain was cut 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 

 xmder. The growing of carrots and potatoes on one-half of the cereal plots, has been 

 discontinued since 1898 and each plot of the whsat, barley and oats has occupied the 

 full tenth of an acre. 



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