Plants and the person. ' Green revolution '

you are: Plants and the person

In the sixties our century some prophets inclined to imaginations drew pictures of completely mechanised agriculture of 80th years with sharply increased crops of all basic cultures. It was told about crops of corn which will reach 500 bushelej on an acre, i.e. Will increase six times. The fast development of technics which are urged on by aspiration to development of a space, has formed a basis for the first prediction, and the improbable increase of the crops which have followed application of results of scientific selection of plants in a combination to a heavy use of fertilizers and pesticides, has generated confidence that similar improvement can proceed eternally. Believed that ' green revolution ', based on use of the high-yielding grades created by selectors at corresponding quantity of fertilizers, water and pesticides, will serve as the base to construction of a certain agricultural Utopia. However up to now in extensive territories people continue to starve, and the considerable part of huge former stocks of grain thaws. ' Green revolution ' in that kind in what it has been conceived, has failed. What was to that the reason?

First of all, and this most important thing, in the sixties the world did not expect possibility of an energy crisis which became now a reality. At that time oil was cheap, and its stocks seemed unlimited, but now owing to too prodigal consumption and some political, events the price for oil has increased several times. now we understand that oil world's reserves will be exhausted the next hundred years, and can be, even earlier and that before it will occur, the price for it will steadily grow. Meanwhile both creation, and use of agricultural cars, fertilizers, pesticides and irrigating constructions entirely depends on fossil fuel. The huge majority of farmers of globe now not in a condition to grow up the whimsical grades created during an epoch ' of green revolution ', and come back to old grades which though are less productive, but provide stabler crops, without demanding or nearly so without demanding some fertilizer and a soil irrigation; besides they possess known stability to wreckers and activators of illnesses, i.e. Allow to do without some pesticides.

During the period ' green revolution ' not only the grades prospering in the conditions of intensive agriculture were created., consuming it is a lot of energy, but also borders of areas of cultivation of the earth were moved apart, and the agriculture began to get into areas where cultivation of vegetative cultures was economically unprofitable before or even it is impossible. Damp rainforests as, for example, woods of Amazon with their magnificent vegetation, seemed highly productive and approaching for cultivation. But, after them raskorchevali with application of the technics which has absorbed considerable quantities of energy, it has appeared that it is possible to benefit by them only during short time. Lateritnye soils of these areas actually are astable and poor nutritious elements; the most part of nutrients contains in vegetation of this damp wood through which they constantly pass, making the circulation. Wood prevents erosion and promotes preservation of structure of soil partially thanks to allocation and adjournment of organic substance which the microorganisms participating in maintenance of stability of soil eat. When trees cut down, nutrients are washed away, the surface lateritnyh soils often is exposed to erosion, and its other part can turn to firm weight on which nothing will grow. Precious stabilising influence of the balanced community of a damp rainforest if it once to break, is difficult or even it is impossible to restore. It is necessary to hope that we will learn from this a lesson before all damp rainforests will be destroyed. It is necessary to keep the most part of these woods already at least because they have stabilising influence on exchange СО2-О2 on the scale of all globe.

Other disappointment was brought by attempt to cultivate some droughty or semidroughty earths. Some cultures, having got accustomed in semidroughty areas, can perfectly grow, if their roots get into soil to level of underground waters which the local vegetation with more superficial root system cannot use. However such underground waters, probably, collected for many years, and their stocks at an exhaustion cannot replenish so quickly as it is necessary for continuous cultivation of culture. Besides, at destruction of local vegetation the wind often blows off a fertile top layer from the bared dry soil, leaving only rather infertile podpochvu and causing dusty storms. At a corresponding irrigation position changes also desert blossoms, but is besides frequent only for a while. The water used for an artificial irrigation, almost always contains significant amounts of the dissolved salt which remains in soil after water transpiriruetsja or evaporates. Such accumulation of salt can be prevented only its strengthened washing away, but only in rare instances there is a possibility to spend water enough to remove from soil the salt which has collected in it. Thus, fertile soils gradually become more and more salted and eventually appear unsuitable for agriculture. The quantity of the earths on globe, suitable for cultivation, actually is limited, and almost all of them are already used now.

Even crops of agricultural crops increase in the countries most developed technically now not with such speed, as throughout last fifty years. All ' easy ' ways of increase of crops - introduction of hybrid grades and the strengthened application of fertilizers, an artificial irrigation and pesticides - are already used. To achieve the further increase of productivity now it is more difficult. So, productivity of corn, apparently, has reached a maximum level - hardly above 100 bushelej on an acre - and was stabilised at this level. The further increase in manufacture of grain, possibly, it will be possible to reach, changing plants so that to raise quality of an end-product as, for example, in case of corn with the high maintenance lizina, and to eliminate taking place losses, and also as a result of more reasonable use of areas with adverse conditions of environment. Sociologists, criticising ' green revolution ', specified also that introduction of the grades demanding application of the newest agricultural machinery, gave priority to large-scale enterprises (' to agrobusiness ') over small, family farms that often resulted in undesirable from the social point of view.