Plant and Soil

, Volume 154, Issue 1, pp 81–88

Effects of fertilization levels in two farming systems on senescence and nutrient contents in potato leaves

  • A. Berchtold
  • J.-M. Besson
  • U. Feller
Article

DOI: 10.1007/BF00011075

Cite this article as:
Berchtold, A., Besson, JM. & Feller, U. Plant Soil (1993) 154: 81. doi:10.1007/BF00011075

Abstract

The influence of fertilization on senescence and nutrient remobilization in potato leaves was investigated in two farming systems on a soil with a poor potassium availability. The ‘Conventional’ farming system followed good local practices including industrial products, while in the ‘Bio-Dynamic’ farming system industrial fertilizers and synthetic pesticides were avoided. Potassium concentrations in the dry matter of mature leaves varied over a wide range. Nitrogen compounds (protein, chlorophyll) were less affected, and phosphorus concentrations in the dry matter were similar. Magnesium and potassium concentrations in the leaves were negatively correlated. In both farming systems senescence was advanced in plants with a low nutrient supply. Alkaline pyrophosphatase and aminopeptidase activities (in general highest in expanding and mature leaves) were lower and endopeptidase activities peaked earlier on plots with low fertilizer levels. A high percentage of potassium was remobilized from senescing leaves on unfertilized plots, but the phosphorus concentration remained high at the end of the season. The results suggest that the differential net remobilization of nitrogen, phosphorus and potassium depended on actual source/sink relations in the plants.

Key words

farming system fertilization magnesium nitrogen potassium potato proteolytic enzymes senescence Solanum tuberosum L. 

Copyright information

© Kluwer Academic Publishers 1993

Authors and Affiliations

  • A. Berchtold
    • 1
  • J.-M. Besson
    • 2
  • U. Feller
    • 1
  1. 1.Institute of Plant PhysiologyUniversity of BernBernSwitzerland
  2. 2.Swiss Federal Research Institute for Agricultural Chemistry and Environmental HygieneLiebefeldSwitzerland