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ORCHARD NUTRITION 



Warren C. Stiles 

 Department of Pomology 

 Cornell University, Ithaca, NY 



Orchard nutrition is often a major factor influencing orchard 

 productivity and fruit quality. More intensive planting systems, 

 higher yields, and changes in production management systems require 

 re- evaluation of orchard nutrition needs. 



Orchard nutrition management starts with an evaluation of 

 conditions that exist in the soil and in the trees. Limited soil 

 depth and imperfect internal drainage limit root development and 

 the volume of soil from which the tree can obtain nutrients and 

 water. Likewise, coarse- textured soils may have limited exchange 

 capacity as well as limited water holding capacity. Any factor 

 that limits root development or water supply will influence tree 

 nutrition. Soil pH , cation exchange capacity, inherent nutrient 

 supplying power as determined by parent materials and organic 

 matter content must also be considered in developing fertilizer 

 programs . 



Soil Testing 



Soil testing is one means of m.easuring chemical soil factors. 

 Soil testing to determine pH , lime requirement, calcium (Ca) , 

 potassium (K) , magnesium C^g) a^id phosphorus (P) levels gives 

 some information on nutrient status and possible causes of pro- 

 blems. Samples of both topsoil (o to 8") and subsoil (12 to 24") 

 should be examined. When preparing a new site or in renovating 

 an old orchard site, soil tests are the only feasible means of 

 determining the amounts of lime, type of lime, and amounts of 

 other nutrients that must be added before the trees are planted. 

 After trees have been established, soil testing is useful in moni- 

 toring soil pH and may help to explain abnormalities detected in 

 leaf sample analyses. 



Soil pH and Lime Requirements 



Adjustment of soil pH and incorporation of lime is easier and 

 more effective during site preparation than after trees have been 

 planted, particularly if large corrections are required. The 

 amount of lime required to raise the plow depth to a pH of 6.2 to 

 6.5 varies with soil texture and initial pH approximately as 

 follows : 



1 

 Associate Professor of Pomology 



