6 BULLETIN 499, U. S. DEPARTMENT OF AGRICULTURE. 



.•ill over the ground. The soil in (his orchard was uniform, and the trees were 

 all of the same age — seven years. Part of the rows had been heavily mulched 

 all over the ground with vegetable matter, grass, and weeds for throe years, 

 part of it for two years, part for li years, and another part for nine months 

 only. A few rows in the middle of the orchard had not heen mulched at all, 

 but had heen plowed and cultivated to conserve moisture during the dry 

 season, during the whole period of seven years. The difference between the 

 mulched and unmulched trees was very marked and almost beyond belief. 

 The trees mulched for three years past without cultivation had foliage of 

 good color, were vigorous, comparatively free from scale insects, bearing a 

 large amount of smooth-skinned, bright fruit, and the trees were two to four 

 times as large in diameter of trunk and two to four times as large in spread 

 of branches. The trees were also free from chlorosis. On the unmulched tract 

 the trees were small, stunted, with small yellow, starved-looking leaves, with 

 limbs dying back, and with only a very few fruits, these being russeted and in- 

 ferior in quality. There was at least four to six times as much fruit on the 

 mulched as on the unmulched trees. The trees mulched for two years instead 

 of three also showed a proportional improvement. Even the trees mulched for 

 only nine months showed marked improvement in color and the amount of the 

 last new growth. The improvement in this orchard was in definite proportion to 

 the length of time the soil had been covered with vegetable mulch. 



At Santiago de las Vegas on heavy, red, sticky soil, Mr. H. A. Van Herman 

 had been mulching heavily all over the soil for the last five years and had 

 stopped cultivating entirely during that time. Previous to that he had prac- 

 ticed deep and frequent cultivation, and the trees were said to have gone back 

 rather than forward. Since beginning this heavy mulching, the trees have 

 grown rapidly, are healthy and green in appearance, and have on them a 

 large crop of fruit. Mr. Van Herman was one of the first to advocate heavy 

 mulching all over the ground as a general practice in Cuba. He is con- 

 vinced that it is the proper practice for most soils in a climatic condition like 

 that of Cuba. 



Some excellent groves were seen, however, on red clay soils, and also on deep 

 clay-loam soils where a system of nearly clean cultivation was used, plowing 

 in large amounts of organic matter and fertilizing liberally with commercial 

 fertilizer. Many growers were placing a vegetable mulch directly under the 

 trees, but cultivating and raising summer cover crops between the rows. 



Dr. Felix Lohnis, of the Bureau of Plant Industry, informs the 

 writers that a permanent organic mulch is often employed in the 

 culture of fruit trees in Germany, especially along the roadsides. 

 Leaves, straw, manure, and other organic material are used for this 

 purpose. Coarse peat is also extensively used as a mulching ma- 

 terial in districts where it is available. 



THE MULCHED BASIN. 



In 1913 an opportunity was presented to lay out an experimental 

 tract in a commercial orange grove at Sunny Mountain, near River- 

 side, Cal., to test further the effect of mulching without cultivation. 

 At this time it was decided to combine mulching with a basin method 

 of irrigation, and accordingly each tree in the section of the grove 

 selected was basined by throwing up dikes 6 to 8 inches high midway 

 between the tree rows in both directions, so that each dike formed a 



