Stem-growth response of Pinus sylvestris and Picea abies to nitrogen fertilization as related to needle nitrogen concentration

Trees ◽  
1998 ◽  
Vol 12 (4) ◽  
pp. 208-214 ◽  
Author(s):  
U. Sikström ◽  
Hans-Örjan Nohrstedt ◽  
Folke Pettersson ◽  
Staffan Jacobson
Keyword(s):  
Picea Abies ◽  
Pinus Sylvestris ◽  
Nitrogen Fertilization ◽  
Growth Response ◽  
Nitrogen Concentration ◽  
Stem Growth

Initial rates and limit values for decomposition of Scots pine and Norway spruce needle litter: a synthesis for N-fertilized forest stands

2000 ◽  
Vol 30 (1) ◽  
pp. 122-135 ◽  
Author(s):  
Björn Berg
Keyword(s):  
Picea Abies ◽  
Pinus Sylvestris ◽  
Norway Spruce ◽  
Scots Pine ◽  
Nitrogen Fertilization ◽  
N Fertilization ◽  
Simple Equation ◽  
Forest Stands ◽  
Limit Values ◽  
Needle Litter

Nitrogen fertilization increased concentrations of N, P, S, and K in Scots pine (Pinus sylvestris L.) needle litter, and in those of N, S, and Ca in Norway spruce (Picea abies (L.) Karst.). Lignin concentrations increased for both species. Initial rates and limit values for decomposition were estimated using a simple equation. For Scots pine litter, initial rates ranged between 0.0618 and 0.2986%/day with P, K, N, and Mg being positively related, but lignin and Ca negatively related. For Norway spruce, initial rates were low (0.0455-0.1007%/day) and positively related with initial concentrations of water solubles, K, and P but negatively with N, Ca, and lignin. Limit values for Scots pine litter ranged from 53.1 to 94.3% decomposition in fertilized plots and from 71.5 to 93.2% in controls. They were negatively related to N concentrations and positively to Mn and Ca. Limit values for Norway spruce litter ranged from 53.8 to 74.3% in controls and from 48 to 71.3% in fertilized plots and were positively correlated to Mn and Ca but not to N. The paper concludes that N fertilization will increase the fraction of Scots pine litter that accumulates as humus but not for Norway spruce.

EFFECT OF CULTIVATION AND NITROGEN ON FRUIT QUALITY, YIELD AND COLOR OF McINTOSH APPLES GROWN IN IRRIGATED GRASS SOD COVER CROP

1969 ◽  
Vol 49 (2) ◽  
pp. 149-154 ◽  
Author(s):  
J. L. Mason
Keyword(s):  
Nitrogen Fertilization ◽  
Cover Crop ◽  
Nitrogen Concentration ◽  
Titratable Acidity ◽  
Fruit Color ◽  
Soluble Solids ◽  
Apple Trees ◽  
Pressure Test ◽  
Nitrogen Treatments ◽  
Plot Design

Nitrogen treatments from 0.15 to 0.90 kg of nitrogen and cultivation treatments from zero to three shallow rotovations were applied in a split-plot design to 30-year-old McIntosh apple trees growing in irrigated grass sod.Fruit quality was very largely unaffected by the treatments. Pressure test after harvest was reduced from 6.61 to 6.44 kg (P = 0.10) as nitrogen increased. Number of rots increased from 2.7 to 3.9 per 60-fruit sample with increasing nitrogen. Titratable acidity and soluble solids after harvest and pressure test, titratable acidity, soluble solids, stem-cavity browning and core flush in tests after storage were all unchanged. In addition, none of these tests were affected by cultivation except pressure test, which decreased with more cultivation (P = 0.10).Yield was not changed by either the nitrogen or the cultivation treatments, and terminal length increased only slightly with more cultivation. However, nitrogen concentration in the leaf was increased from 1.90 to 1.98% by the nitrogen treatments and from 1.83 to 1.98% by increasing cultivation. Extra Fancy grade was reduced and C grade increased by increasing nitrogen (P = 0.10), but cultivation had no effect.The conclusion is drawn that grass sod can very largely eliminate the effect of widely different nitrogen fertilization levels on McIntosh apple, and that moderate cultivation changes this effect only slightly. In many mature orchards of high initial fertility, nitrogen fertilizer may be required in only small amounts or even not at all for optimum fruit color.

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