452 REPORT OF THE HorTICULTURAL DEPARTMENT 
of improving it is by plowing under cover crops. Cover crops, 
if legumes, also add nitrogen, and all add humus to the soil; rotate 
legumes, grains and cruciferous plants in accordance with the needs 
of the land and of the fruit. Sow cover crops when the trees have 
made the proper season’s growth and plow under the following 
Spring. 
Study the trees, the soil, and the particular conditions of each 
orchard.— No two worn-out orchards have reached the condition 
through the same causes; hence, no two require the same treat- 
ment in renovating. A special study must be made of each par- 
ticular case to determine the treatment needed. 
