REPORT OF STATE BOARD OF HORTICULTURE. 125 



extent lost, provided tlie soils thus formed are subjected to 

 heavy leaching, which will be the case throughout the region 

 in question. The character of the parent rock of these soils 

 is mainly basalt, resulting from the great laA'"a overflow, and 

 the lesser subsequent ones which covered the whole of North- 

 ern California, and a great part of Oregon, Washington, and 

 Idaho. It is true that basalt is a complex rock, and carries 

 the fertilizing elements of a variety of rock, but it is still 

 further true that the composition of the constituent minerals 

 in the basalt influences the chemical characteristics of the 

 soil. 



"The idea that clay soils are rich in potash sprang from the 

 wide predominance of such soils resulting from the orthoclase 

 feldspars of the«east. It is a great mistake to make this con- 

 clusion a general one, for the plagioclastic division of feld- 

 spars, including, as it does, oliogoclase labradorite, anorthite 

 or andesite, are all non-potash bearing, but it is one or more of 

 the plagioclastic feldspars — soda lime compounds — which ex- 

 ists in the basalts of this region. From a prior reason of soil 

 origin we would expect to find the soil to be quite limited in 

 potash contents. This condition is still more to be expected 

 from the tendency of the potash ingredients toward loss in the 

 progress of soil decomposition. This is illustrated by a rock 

 of this character carrying eighty-one per cent, of potash, after 

 decomposition by weathering showed but twenty per cent., a 

 loss of seventy-one per cent, of the total. Still further, there 

 might be added the annual loss of available potash compounds 

 through the medium of very heavy rains common to this sec- 

 tion during the winter months." 



SPRAYING. 



This is an old yet ever new subject, and it seems surprising 

 that after so much has been said and written about it that there 

 should still be unbelievers in the beneficial results obtained 

 from spraying, or others meeting with poor results. For this 

 latter there are many reasons, but absolutely none for the 

 former. 



In different parts of this report I cite numerous instances of 

 the beneficial results obtained by systematic spraying with the 

 properly prepared compounds, and I do not desire to refer to 

 it again here. 



