Fertilizer applications

Although only relatively small amounts of fertilizer nutrients are required in the very early stages of plant growth, high concentrations of nutrients in the root zone at that time are beneficial in promoting early plant growth. This is the period when all the different plant parts are being initiated and begin to grow. Even though the amount of nutrients taken up is relatively small, final size of the leaves, ear and other plant parts depends to a large degree upon having an adequate supply of nutrients available to the plant during this early part of the growing season.

During early growth, the root system is limited and the soil is often cold. The seminal (seed) root system which is elongating when the plant emerges from the soil serves as the main root system during the first weeks after plant emergence. Fertilizer placement in a band about 5.1 cm (2 inches) to the side and slightly below the seed is important so the seminal roots may intercept the band of fertilizer. Roots will branch and proliferate in and near the band of fertilizer after they contact it; but they are not attracted toward the fertilizer band, so fertilizer must be placed where the roots are going to be. Placing the fertilizer too near the seed can result in salt injury to the young plant.

At later stages of growth, the plants require much larger amounts of nutrients. These nutrients must be in moist soil for effective root uptake. For all tillage systems, a soil testing high in P and K should provide adequate nutrients and placement is not a major concern. For conservation tillage systems on soils low in P and K, a starter band or injection 6 to 8 inches deep may be advantageous over broadcast applications. Time and placement of nitrogen fertilizers should be based on greatest efficiency, minimizing potential loss, and fitting into the production system.

The nodal roots begin to develop above the coleoptiles node at about VE. Within 2 or 3 weeks, after plant emergence the nodal roots become the main root system of the plant. This nodal root system becomes well distributed in the soil, so precise fertilizer placement is less critical after these roots have developed.

Care should be taken that roots are not destroyed by cultivation or by side dressing of fertilizer after the root systems of the plants become established.

The amount of grain produced by the corn factory will depend upon the rate and length of time of dry matter accumulation. Take advantage of these implications by using these pointers to produce high yields: Fertilize according to soil tests for the production level you want.

Select the hybrid best suited to your farm operation.

Plant early at the correct population and spacing (density).

Eliminate competition from weeds, diseases and insects.

Carry out all other cultural practices to maximize the rate and length of time of dry matter accumulation in the grain.

Text №4 Nature protection

The range of environmental problems is wide. But the matters of people's great concern nowadays are atmosphere and climate changes, depletion of the ozone layer, freshwater resources, oceans and coastal areas, deforestation and desertification, biological diversity, biotechnology, health and chemical safety. United Nations Environment Program (UNEP) concentrates its activities on these issues. Acid Rains One of the most alarming forms of air pollution is acid rain. It results from the release into the atmosphere of nitrogen oxides that react with water droplets and return to earth in the form of acid rain, mist or snow. Acid rain is killing forests (Nearly every species of tree is affected) It has acidified lakes and streams and they can't support fish, wildlife, plants or insects. Depletion of the Ozone Layer The protective layer of the Earth, the ozone layer, which protects the Earth from the sun's destructive UV (ultraviolet) rays, is being damaged by CFCs (chlorofluorocarbons). They are released by the daily use of industrial and household products: refrigerators, air conditioners, foam insulation, cleaning chemicals, food packaging. In the ozone layer they attack the ozone molecules making a «hole». This «hole» allows more UV rays to penetrate to the Earth. It increases the risk of skin cancer, weakens the immune system of people. Besides, UV rays influence the oceans, the growth of plankton, an essential part of the marine-life food chain in the negative way; reduce economically important-crops (rice, cotton, soy beans). The life cycle is going to be undermined by the ozone. Destruction of the Tropical Forest It’s generally agreed that the destruction of the tropical forest has a major impact on the world climate. The tropical rain forest is a natural recycler, provider and protector for our planet. It recycles carbon, nitrogen and oxygen, helps determine temperature, rainfall and other climatic conditions and supports the most diverse ecosystem in the world. Deforestation could cause one fourth of all species on earth to vanish in the next 25 years. These forests in Amazonians, South-East Asia and West and Central Africa are being destroyed at an alarming rate of 42 million acres per year. Measures to Be Taken We have only a few years to attempt to turn things around. We must review our wasteful, careless ways, we must consume less, recycle more, conserve wildlife and nature, act according to the dictum «think locally, think globally, act locally». To my mind, we are obliged to remove factories and plants from cities, use modern technologies, redesign and modify purifying systems for cleaning and trapping harmful substances, protect and increase the greenery and broaden ecological education. These are the main practical measures, which must be taken in order to improve the ecological situation. Some progress has been already made in this direction. 159 countries-members of the UNO have set up environmental protection agencies. They hold conferences discussing ecological problems, set up environmental research centers and take practical urgent measures to avoid ecological catastrophe.

TEXT №5