852 Summary of Agricultural Experiments, [jan., 



outside under the ordinary conditions of the district, the same food 

 being given to both lots. At the start both lots weighed 1,782 lb.; at 

 the end of two months — a period regarded as quite long enough for 

 shed feeding — the outside-fed lot had gained 186 lb., while the shed-fed 

 lot had gained 284 lb., or 98 lb. more. It is stated that the weather 

 was exceptionally stormy during the feeding, but that this only empha- 

 sizes the advantage of having the means of carrying on sheep-feeding 

 under equable conditions at all seasons. 



Manuring for Milk (Midland Agric. and Dairy Coll., Repts. on 

 Expts. with Crops and Stock, 1909-10). — Mr. Blackshaw points out ir* 

 this report that in the Midlands and other dairying districts there are- 

 many pastures that are not yielding to their full capacity. Milk is sold 

 continuously, and the farmyard manure returned to the land, even 

 when increased in value by purchased feeding stuffs, is not sufficient 

 to keep up fertility. The only special manures used to any extent are 

 basic slag and bone manures, and this experiment was designed to see 

 whether superphosphate and sulphate of potash would give profitable 

 returns. 



A field in poor condition adjoining the college farm was taken, and 

 two plots of four acres each fenced in. The soil was of a strong, clayey 

 nature, typical of most soils on the Keuper Marl formation. On account 

 of indications of lack of lime, 10 cwt. of ground lime per acre were 

 applied over both plots. On one plot 4 cwt. of superphosphate and 

 i\ cwt. of sulphate of potash per acre were broadcasted on April 12th,. 

 while to the other plot no manure other than the lime was given. The 

 effect of the manures was tested by the milk yield of cows. Two cows 

 were grazed on each plot for a fortnight ; they were then changed over, 

 the two that had been on the no-manure plot going to the manured 

 plot, and vice versa. This continued for five months, so that each lot 

 of cows visited each plot five times. In order to allow the cows 

 time to get accustomed to the different pasture, the milk of the second 

 week of each fortnight only was taken into account, and the amount 

 doubled to represent the fortnight's milk. By thus changing the cows 

 from one plot to the other the effect of differences between the cows 

 was minimised, and the only factor that would influence the result 

 would be the manures applied. By the middle of July the condition of 

 the manured plot was so much better than that of the other and so- 

 much ahead of the cows, that a third cow was put on it and kept 

 there till the end of the experiment. During the five months the 

 yield of the two cows while on the unmanured plot was 5,531 lb., and 

 while on the manured plot 6,753 lb. The yield of the third cow on the 

 latter plot was 2,267 lb., so that the total excess on the manured plot 

 was 3,489 lb., or 84 gallons per acre. At 6d. per gallon this would 

 be worth £2 2s., and deducting the cost of the manures, £1 gs., the 

 gain due to their use would be 135. per acre. Mr. Blackshaw considers 

 that the results would be even more in favour of the manuring but 

 for the well-known fact that a cow may be made to lose in yield much 

 more readily than she can be made to recover. Thus the big drop 

 that always took place when the cows were moved to the poorer plot 

 was never completely made up afterwards on the richer pasture, even 

 when the natural drop due to advance in the period of lactation is 

 allowed for. The advantage from keeping cows always on manured 



