EXPERIMENTAL STATIONS — KEPOltT FOR 1881. 



321 



and plot 17 which received no nitrogen are the lowest. Plot 

 22, which received potash salts alone, is very little better and 

 plot 12, which received undissolved phosphate alone in the form 

 of bone-ash, has produced a very poor crop. In plot 18, the 

 immediate effect of a nitrogenous manure in increasing the 

 produce of grain, and especially the produce of straw, is again 

 noticed; and plots 21 and 11 bear corresponding testimony to 

 the advantage obtained by adding phosphates and potash re- 

 spectively to the nitrogenous manure, while the largest crops 

 on the station are borne by plots all of which received an equal 

 application of nitrogen, phosphoric acid, and potash, as described 

 on the scheme already referred to. 



Plots 1 and 3 have this year borne smaller crops than others 

 of the same class at both stations, but especially at Harelaw 

 where they have been less productive than some of the plots 

 wduch received incomplete manures. Thus far we see that a 

 very similar story is told by corresponding plots on these two 

 very different stations, the one with a one-year old, and the 

 other with a four-year old experiment. 



The results obtained upon the first ten plots, which are 

 designed to test the relative value of soluble and insoluble 

 phosphates, show very markedly the great inferiority of the 

 latter form of phosphate on these soils. A considerable number 

 of experiments have been carried out during the last few 

 years to determine whether soluble or insoluble phosphates 

 are the more economical form of manure, and the results 

 obtained have been various. In Aberdeenshire and also in 

 other parts of the country it has been found that finely ground 

 insoluble phosphates may be employed with advantage, while 

 in others they have been found to be comparatively useless. 

 The results hitherto obtained at the Society's stations lie some- 

 where between these extremes. The following are the results ob- 

 tained at both stations with the oat crop this year : — 



X 



