Nutrient Status and Fruiting Response of Young Chinese Chestnut Trees Following Application of Nitrogen

Abstract

Development of nitrogen (N) fertilization guidelines for Chinese chestnut trees in North America has been hampered by the paucity of research-based information. Thus, a study was conducted to determine the effect of selected annual N application rates (56, 84, 112, 140, or 168 kg·ha ^-1) on vegetative growth and fruiting of young ‘Peach’ Chinese chestnut ( Castanea mollissimaBl.) trees applied in four sequential years. Foliar N and other macro-and micro-nutrient levels were also determined to establish survey ranges for North American-grown Chinese chestnut. Cumulative nut yield, nut number, and trunk circumference increased linearly as the rate of N increased. Estimated net profitability during three years of nut production increased by 43% when annual N applications were increased from 56 to 168 kg·ha ^-1. Foliar N of chestnut trees producing the greatest cumulative nut yields during the early years of cropping ranged from 2.23 to 2.51%. The survey range was 0.09 to 0.16% for phosphorous (P) and 0.36 to 0.63% for potassium (K). Macro- and micronutrient survey ranges reported herein from leaves of ‘Peach’ Chinese chestnut trees provide baseline data for assessing their nutritional status.