תפריט נגישות
ניגודיות עדינהניגודיות גבוהה
מונוכרום
הדגשת קישורים
חסימת אנימציה
פונט קריא
סגור
איפוס הגדרות נגישות
להורדת מודול נגישות חינם תפריט נגישותניגודיות עדינהניגודיות גבוההמונוכרוםהדגשת קישוריםחסימת אנימציהפונט קריאסגוראיפוס הגדרות נגישותלהורדת מודול נגישות חינםTypical soilless media are commonly defined by root constraint and limited volume of substrate and accordingly, low buffer capacity for solution composition and limited supply of nutrients. Therefore optimal plant production necessitates specific and different attention to the chemical characteristics of the substrates. The surface charge properties and the dissolution characteristics of the substrate solids are important since they affect the ionic composition of nutrient solutions. Throughout the growth period organic compounds excreted from the plant roots or resulting from decomposition processes accumulate in the substrate. Consequently the surfaces of the newly formed solids become heterogeneous and the chemical properties of the mixture may be significantly different from those of the single, well-defined component that was characterized before use. The general objective of this chapter is to define the chemical characteristics of soilless media. The specific objectives are: (1) to describe the charge characteristics of typical substrate used in the horticultural industry and to assess the interactions between pH, solution concentration of cations\anions, and substrate solids, especially adsorption and precipitation reactions. Special attention was dedicated to describe the solubility and possible interactions of nutritional elements with the substrate and to discuss the expected horticultural implications and (2) to illustrate the effects of plant-induced changes in the rhizosphere and to evaluate its effects on plant nutrition.
Typical soilless media are commonly defined by root constraint and limited volume of substrate and accordingly, low buffer capacity for solution composition and limited supply of nutrients. Therefore optimal plant production necessitates specific and different attention to the chemical characteristics of the substrates. The surface charge properties and the dissolution characteristics of the substrate solids are important since they affect the ionic composition of nutrient solutions. Throughout the growth period organic compounds excreted from the plant roots or resulting from decomposition processes accumulate in the substrate. Consequently the surfaces of the newly formed solids become heterogeneous and the chemical properties of the mixture may be significantly different from those of the single, well-defined component that was characterized before use. The general objective of this chapter is to define the chemical characteristics of soilless media. The specific objectives are: (1) to describe the charge characteristics of typical substrate used in the horticultural industry and to assess the interactions between pH, solution concentration of cations\anions, and substrate solids, especially adsorption and precipitation reactions. Special attention was dedicated to describe the solubility and possible interactions of nutritional elements with the substrate and to discuss the expected horticultural implications and (2) to illustrate the effects of plant-induced changes in the rhizosphere and to evaluate its effects on plant nutrition.
