156 FOOD FOR PLANTS 



of nitrogenous fertilizers, fertilized trees in 1920 pro- 

 ducing about three times as much as the check trees. 

 Trees in sod in 1919 showed a greater response to 

 Nitrate of Soda than those under clean cultivation. 



Some Results Obtained from Orchards Where 

 Nitrate of Soda Has Been Used. 



At the Experiment Farm Orchard in Clermont 

 County, Ohio, where experiments are being con- 

 ducted under tillage, cover-crop culture and grass- 

 mulch culture, five pounds of Nitrate of Soda per 

 tree for four years under grass-mulch culture yielded 

 683 per cent more than the trees in the check plot. 



Year 5 lbs. Nitrate Nothing 



Average 1922 206.0 lbs.* 41.2 lbs.* 



yield 1923 176.6 " 37.2 " 



per tree 1924 328.8 " 12.2 " 



From a plot which is under tillage and a soy-bean 

 cover-crop culture, the yield was, from all varieties: 



Year 5 lbs. Nitrate Nothing 



Average 1922 128.5 lbs.* 82.9 lbs.* 



yield 1923 134.5 " 70.0 " 



per tree 1924 395.2 " 89.5 " 



At the Massachusetts Agricultural College at 

 Amherst an experiment is being conducted on 12- 

 year-old Mclntoshes under sod-culture as against 

 clean cultivation, which has run for four years. 



* The average weight of a bushel of apples is 48 lbs. 



