the greater tree height and bloom were evident in the 

 third season indicating that the cumulative effect of 

 compost on tree size was not short-lived. 



Soil fertility was enhanced by the addition of 

 compost, but little influenced by the addition of MAP, 

 as shown for the year of planting in Table 1. The 

 addition of compost resulted in higher soil pH and 

 cation exchange capacity in each of the three seasons 

 after planting, compared to the plots without compost 

 (data not shown). Compost increased both soil organic 

 matter and P, while MAP and urea had no effect. 

 Compost also increased soil Mg, Ca, and K. 



Compost increased tree growth and flowering by 

 improving soil fertility and tree nutrient status, and 

 most likely, by increasing soil water holding capacity 

 and soil aeration. An increase in the water holding 

 capacity of the soil would have been advantageous in 



1998, when the newly planted trees were generating 

 new roots to replace those lost in transplanting, and in 



1999, a season in which little precipitation occurred 

 before September. Foliar nutrient status was favorably 

 affected by compost (Figure 2). Compost increased 

 leaf N and K compared to trees in plots without 

 compost in all three seasons after planting. Leaf P and 

 Ca were not affected by compost. There was no 

 difference between urea and MAP in their effect on 

 leaf N or K, or leaf P, Ca, or Mg. Compost decreased 

 leaf Mg in the first season after planting, but had no 

 effect in the second or third season. The large increase 

 in soil K following compost incorporation may have 

 interfered with Ca and Mg uptake, so that even though 

 soil Ca and Mg were greater, foliar levels were not. 

 Leaf micronutrients were not affected by any of the 

 pre-plant treatments. 



Pre-plant incorporation of P fertilizer had no effect 

 on tree growth or flowering in this study. In British 

 Columbia, P fertilization previously has been shown to 



increase flowering when it results in greater leaf P. In 

 our study the soil level of P was within the optimum 

 range before treatment, and was increased to above 

 optimum by compost. Although the level of P in the 

 soil was increased with compost, there was no increase 

 in foliar P. These results are consistent with most 

 previous studies in showing no benefit from P 

 fertilization for apple. 



Conclusions 



Pre-plant compost incorporation was more 

 effective than P fertilization for increasing tree growth 

 during the establishment years. The practice of adding 

 P to the planting hole may not be appropriate for 

 Northeastern sites, particularly those where the soil 

 test indicates that P is adequate before planting. Soil 

 incorporation of compost increased tree growth and 

 flowering into the third year after planting. This was 

 most likely due to improved N and K status of the trees, 

 and through improved soil aeration and water-holding 

 capacity. Our results suggest that trees planted in soil 

 amended with apple-pomace compost would poten- 

 tially fill their space more quickly and be able to 

 support more fruit growth in the first years of cropping. 



Ackno H'ledgem en ts 



This project was supported in part by a grant from 

 the New England Tree Fruit Growers Research 

 Committee. The authors wish to thank Chick Orchards 

 for supplying the compost, and the technical staff at 

 Highmoor Farm for their assistance with this research. 

 Special thanks go to John McCue, Sheri Koller, and 

 Michelle Handley for maintaining this project during 

 the transition between project leaders. 



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Fruit Notes, Volume 67, Winter, 2002 



