Morozov A.N.

Lecture 2. Water contained in plants.

Water is presented in plants and as well as in their seeds as constituent. Alive plant contains water up to 95% of its own weight. But that is quite small amount relatively to water which volume the plant consume until it grows and gives yield.
Requirement in water for various plants only for evaporation (transpiration) by the plants themselves and evaporation from soil surface comparatively to the weight of the plants in conditions of Uzbekistan is hundreds times more than weight of water contained in the adult plant and in its fruitery

And what for do plants need in the water?
Which function does it perform?
What for so much water do need plants?

Let us start from the point that plants do not "want" to eat or drink neither. So, nutrients should be delivered to leaves along trunks and branches. The nutrients swallowed up together with soil moisture by roots prebuilt as semi-finished product are delivered by vessels to leaves - which are manufacturers of organic substances.

Plants is cooled by evaporating water via its leaves therefore not giving a way to its overheating, and at the same time getting carbon dioxide from air (in exchange for evaporated water) which serves as a material for creation of all the organic substances for the plants growing.

Picture 2.1. Diagram of plant "functioning".
(Borrowed from "Green plant life" book. A.Galstone, P.Davis, R.Setter).

The scientists that thoroughly investigated plants water requirements were significantly discouraged by variability of so called transpiration ratios which were showing relationship between water requirements for production of unit of weight of dry plant weight even for the same plants, (saying nothing about their differences for hygrophilous and drought-resistant plants.
Water requirements for yield unit are varied very much depending on growing conditions. It was noticed, that when soils are poor with nutrients then the plant transpires more water than at soils that are rich with nutrients.

Plants, having much good quality water accessible for them spend it "with pleasure", and that gross their vegetative weight, but they are not in a hurry to bear fruit. In such cases they say that the plants "grow fastidious".

"Behavior" of plants in conditions of limited deposit of moisture is quieter. They consume less of water, moderately develop their vegetative weight and quicker come into blooming and seed formation period.

But plants, supplied with too small amount of water not only have poor development of their vegetative weight and stop to yield fruits but they can simply dry.

Plants usually cultivated at our fields with using actual tillage systems can not obtain water from deep levels like wildings (and even like cultivated plants) at virgin desert soils.

It is necessary for us to get sustainable yields not only in years with fair precipitation but also in dry years. That is why; farmer actions to pile and keep moisture in root zone of plants heavy yield is rewarded by crops.

Flowering time and fruit blossom period almost for all plants is critical growth phase (when drought prove most deleterious effect upon them). As for permanent grasses that are used in fresh form of it or in form of hay for forage to animals, then, most vulnerable in respect of moisture for them are periods after cutting for hay.

It is preferable to keep moisture at root zone not lower than the defined limits in the critical growth phases, and it is not easy to define that even with using scientific concepts, but anyway, we shall try.

Although that the ways of supplying of plants with water are very similar at different climatic zones, nevertheless there are quite differences in methods of soil water conservation and in techniques of its replenishment depending on soil characteristics, soil-forming materials, soil moistening with ground waters, degree of its salinization and surface slopes.

Contacts with us

Back to home page.