122 STATE BOARD OF AGRICULTUEE. 



the effect of the manure this year. On digging down below the manure, which 

 had kept the grass down, the soil was full of ucav roots of the tree. Some roots 

 of trees are running here and there all over the soil. If they meet with plenty 

 of food, they enlarge and send out more branches. In this case, it ha-i taken a 

 little time for the tree to increase the number of roots to take in the good food 

 near the trunk. Other trees with manure spread all over the grass have shown 

 some benefit sooner than the one last mentioned. 



We have had two severe winters since beginning the experiments, in which 

 the thermometer sank to '62° in 1873, and 33° in 1875. The trees well culti- 

 vated stood the winters better than those left in grass. 



Perhaps I should repeat here Avhat was stated in a previous rejwrt, that the 

 trees now in grass were cultivated till they had been set about fourteen years. 



OTHEE EXPERIMENTS 



have been going on for two years, as treating certain rows of trees to a bushel 

 or more of unleached ashes to each tree spread evenly over the ground. 



In autumn of 1875 a thorough mulch of old clover hay was put evenly under 

 eleven trees, extending as far as the lines between this row and the rows on 

 each side of it. These trees are on the east end of the sixth row from the 

 south side, running east and west. This spring (187G) another heavy mulch of 

 straw was added all over the same ground, so scarcely any thing could grow in 

 the line of weeds and grass. 



Seven trees, at the east end of the eighth row from the south, were this 

 spring treated to a large load each of coarse manure, evenly spread, a rod from 

 the tree each way. These mulched and manured trees had been cultivated for 

 two years before. The maiiure on these trees showed itself in the greener color 

 of the leaves this summer and autumn. 



J. J. Thomas, the well known pomologist and so long one of the able editors 

 of the Country Gentleman, visited the College apple orchard in the summer of 

 1873. He expressed great interest in these experiments, and has since made 

 frequent quotations of our reports in the Country Gentleman, and last year (1875) 

 made the following mention of them in his essay on ^'Culture of Orchards,'^ 

 read at the meeting of the American Pomological Society, held in Chicago. 



"Prof. Bcal, of the Michigan Agricultural College, showed me last year an 

 orchard on the College grounds, which had been fourteen years planted, the 

 trees being about twelve or fourteen feet high. The roots were found on exam- 

 ination to be thickly matted beneath the whole surface, or had extended so as 

 to meet and cross each other, and were traced within six feet of the next rows, 

 which were thirty-three feet apart. In other words, these trees, not over fourteen 

 feet high, had thrown out roots to a distance of twenty-seven feet. The soil 

 was a medium loam, and there is no reason to believe that this extent of roots 

 was an exceptional case. There is no question that the roots of apple trees gen- 

 erally extend to a distance greater than the height. A part of the orchard just 

 referred to had been plowed over the whole surface, after it had remained many 

 years in grass. The result Avas a great increase in tlie vigor of the trees. An- 

 other portion was plowed, with the exception of grass circles ten feet in diameter, 

 left at the base of the trunks. There was no apparent difference in the vigor 

 of the trees where the whole surface was plowed, and Avhere the ten feet circles 

 were left in grass. This result is ea-ily explained. The roots extending twenty- 

 seven feet on each side formed a circle of fibres for each tree fifty-four feet in 

 diameter, and tbis circle had an area more tlian twenty-four times as great as 



