Some physiological bases of agricultural and gardening practice. Carbon dioxide in vegetative communities

you are: Some physiological bases of agricultural and gardening practice

In dense crops where СО2 it is used faster, than its stock can replenish as a result of diffusion from air over crops, carbon dioxide, as well as light, can limit photosynthesis. wind accelerates air hashing in crops with free atmosphere and thus too fills up quantity СО2 in crops (fig. 14.10). Whether photosynthesis by light or СО2 is limited, depends on intensity of light, density of standing of plants and speed of a wind. In the closed systems, such as the hothouse, can be practical enrichment of air СО2 (usually reached by gas or oil burning), but is obvious that it is impossible in the field. along with increase in photosynthesis addition СО2 leads to photobreath reduction as raises relation СО2/О2.

It occurs because the same enzyme of a cycle of Calvin - Bensona can operate depending on relation СО2/О2 both as RuBp-karboksilaza, and as RuBp-oksigenaza (see gl. 4).