170 MASSACHUSETTS HORTICULTURAL SOCIETY. 



ognized b}' Professor Atwater in an admirable lecture given here 

 a few weeks ago, when in recapitulating the principles of plant 

 nutrition he said that " Soils fail to furnish food for crops, not so 

 much because the3' have not abundant stores, as because the mate- 

 rials are not in available forms." " The infertility of many soils," 

 he adds, " is due more to their mechanical condition than to lack 

 of plant food. Such soils want amendment first and manures 

 afterwards." And he further adds, " The indirect action of fertil- 

 izers in improving the mechanical condition of the soil is often 

 very important." Now, while barnyard manure and these com- 

 mercial fertilizers do, by chemical action and combination, incideu- 

 tallj- thus act upon this raw material, tlie great agents for enlisting 

 the latter in the service of plant growth are air and water. These 

 are what disintegrate the mass, separate the useful from the 

 useless part, arouse them from their inactivity, and summon them 

 to do something towards covering the fields with green. 



And this is to be accomplished chiefl}' by frequent ploughing, 

 keeping the earth light, and in gardens by a constant use of the 

 hoe and spade or the broad-tined fork, so that the water as it 

 falls in rain may freely penetrate the soil and perform its wonder- 

 ful mission. This is really- a process of irrigation akin to that 

 which in Colorado, by the use of water alone, converts arid wastes 

 into fertile fields. The idea that the plough is a tool to be used 

 only about twice in the year, — once in the spring and then in the 

 fall, — and that the hoe is chiefly intended for keeping the garden 

 free from weeds, is entirely false. Tile draining aids in the 

 same work, inviting the water to find its way into and then down 

 through the soil. 



We are to bear in mind that it is not the value of water as mere 

 moisture that we are now considering, or as a medium by which 

 available nutrition is carried up as liquid into the growing plant, 

 but it is with special reference to water as an agent for converting 

 raw material into available food. Many a farmer or horticulturist 

 neglects thus to regard the agency of water and so to supply it, 

 leaving thereby unused in the soil what is waiting his call, while 

 he applies with liberal hand other forms of food to his garden. 

 Now, so to do would seem as unwise as for a man with oxen idle 

 in his barn to hire, year after year, his neighbor's to plough and 

 harrow his fields. 



But after all which the free admission of air and water into the 



