Pollution | Environmental problems | Photosynthesis

 ANALYSIS OF PLANTING MATERIALS

Introduction:

Plants play an important role in the environment and in society and serve as a source of food for animals and humans.

Plants play an important role between the atmosphere and the earth's environment with positive and potentially harmful effects.

Plants convert carbon dioxide from the atmosphere through photosynthesis and turn it into a living thing that can be used as a source of energy by plants, animals, and humans,↠ at the same time filling the air with the most important source of oxygen.

6CO₂ + 6H₂O + hv    ↠    C₆H₁₂O₆ + 6O₂

This primary product is a source of food on which all animals, including humans, depend. Organisms can be used to produce the energy needed for various vital functions (reproduction, growth, etc.) by living organisms by respiration:

C₆H₁₂O₆ + 6O₂    ↠     6CO₂ + 6H₂O + Energy

Breathing releases carbon dioxide and water back into the atmosphere, thus balancing the chemical activity of photosynthesis. These equations form the basis of the major chemical cycle in the biosphere, the carbon cycle. Earth's vegetation, along with its aquatic counterparts, the phytoplankton, plays a vital role in keeping the earth's environment fit for life. Phytoplankton supplies about 75% of the oxygen in the biosphere, while earth-based plants provide the rest.

Civilization, as we know it, arose when people began to learn to use plant growth for their own needs by growing crops, and to this day agriculture remains the most important (essential) of all activities, to ensure the continuity of our competition. In addition, we have plants for which we should be grateful not only for meeting our natural energy needs, but also for our modern society. The tremendous amount of energy that is consumed each day worldwide is almost exclusively provided by what once was a living plant. Mineral oils, derived from extinct plants and other organisms, provide about 90% of the world's energy.

Environmental Problems

Many of today's environmental problems are closely linked to plants. The very same fire, 150 years ago, released into the atmosphere a large amount of carbon dioxide that took the environment millions of years to convert, through photosynthetic action of plants and other chemical processes, from atmospheric CO₂ to coal, oil and gas.

 By simply comparing the timescales of anthropogenic and environmental processes, one cannot escape the conclusion that it is too late before the fragile balance of nature is broken. Agricultural practices themselves face many environmental problems:

·        Emission of greenhouse gas methane (CH₄) emissions from rice fields and cattle farming.

·        Deforestation, either by fire, or otherwise, contributes to an increase in the atmospheric content of CO₂ and other greenhouse gases.

·        Organic matter caused by N and P fertilizers.

·        Acidification by N fertilizer and S0₂ and NO in biomass combustion.

·        The desolation of bad farming practices.

·        Collection of toxic substances.

Plants and Pollution

Pollution can affect plants in the atmosphere, such as in the case of SO2 damage to the leaves, or in the roots of plants, such as in the case of Al.

Plant pollution worries for two reasons:

1. Pollutants can have direct or indirect phytotoxic effects on the plants themselves, which has led to a decline in crop yields and a threat to our food. For example, SO₂ contamination can cause permanent and severe damage to plants, alone, or from synergism with N0₂ or ozone, while soil acidification by rain from the same SO, can incorporate toxic Al into the soil and cause damage to plants.

2. Plants can act as a vehicle for transmitting contaminants into the food chain. For example, Cd is easily collected by plants, and levels that may not be harmful to plants themselves can be very dangerous to animals and plant-eating people.

·        This is a major concern for public health officials because contaminants that enter the food chain can eventually affect people's health.

·        Heavy metals and pesticides are the main pollutants in this regard. There have been major concerns about various pesticides (insecticides, herbicides, fungicides, rodenticides)  although high levels of chlorine-containing hydrocarbons (e.g. DDI, aldrin, chlordane, dicldrin), are resistant to chemical degradation, banned in many developed countries, many developing countries continue to use them.

·        Pesticides, such as organophosphates and carbonates have been developed, but these are often toxic to invertebrates. Pesticides residues in plants can be transported by food chains or washed away from the soil and contaminate surface water and groundwater.

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·        Met Heavy metals can end up in the soil from a variety of sources, which is a major concern for the incorporation of sewage into agricultural soils. Under ideal conditions this can damage plant roots, cause serious damage to plants or accumulate and spread to food chains. Both combinations of organochlorine and toxic metals can be accumulated as they pass through the food chain.

The direct effects of air pollution on plants can vary from subtle to negative depending on:

§  Type of dirt

          pollution congestion

          plant species

   Time for exposure

There are also variations in sensitivity within plant species, depending on environmental conditions (temperature, nutrient availability, soil moisture, etc.). Phytotoxic pollutants include SO₂, NO₃, O₃ peroxyacetyl nitrate (PAN) and formaldehyde. Both adverse and long-term effects have been observed. In addition, two or more impurities can work together to produce a greater effect than the sum of the individual effects on what is known as synergism.

Plant Analysis

Plant analysis is the determination of chemical substances in a specific plant part. Substances determined in plant analysis include:

·        Macronutrients (e.g. N, P, K)

·        Micronutrients (e.g. Zn, Mo)

·        Biologically important organic compounds (e8. amino acids, hormones) Pesticides (eg. Dieldrin, Aldrin, Malathion)

·       Heavy metal pollutants (e.g. Pb, Cd)

SAMPLING AND SAMPLE PREPARATION

Obtaining a plant tissue sample which is representative of the general population is both important and difficult. General Field variation of biological materials greatly exceeds any introduced during analysis in the laboratory. Therefore, it is essential to evaluate the field variation if the results are to be meaningful and serve the objectives of the analysis.

 The elemental content of a plant may vary in different parts of a plant, it may vary from plant to plant (even in plants belonging to the same species).it may vary with the season, and even with the time of day. Major considerations when planning a sampling strategy are:

1.       Which plant part to sample?

2.       When to sample?

3.       Which chemical substance to determine?