Friday, 30 September 2016

PM, CMs, Ministers sign Declaration of Commitment to make Swachh Bharat by 2019

PM, CMs, Ministers sign Declaration of Commitment to make Swachh Bharat by 2019
Swachh Bharat movement the largest ever mass mobilization in the country, says Shri Venkaiah Naidu
After a slow start, Swachh Bharat Mission picked up momentum and on course-Minister
405 cities, 20000 urban wards become Open Defecation Free
11 institutions felicitated with Best Swachh Awards

            Top leadership of the country including the Prime Ministers, Chief Ministers and Ministers from States and Union Territories today signed a Declaration of Commitment to make India Open Defecation Free and Clean by 2019.
            Prime Minister Shri Narendra Modi, Union Ministers and Chief Ministers of Andhra Pradesh, Assam, Chattisgarh, Goa, Haryana, Maharashtra and Goa besides Ministers from States and UTs signed the Declaration during the INDOSAN (India Sanitation Conference) here today. Other elected representatives from rural and urban local bodies, District Collectors, Municipal Commissioners also signed a similar Declaration.
            Addressing the inaugural session of INDOSAN, Minister of Urban Development Shri M.Venkaiah Naidu said ‘’Largest ever mass mobilization is taken place under Swachh Bharat Mission. With people leading the India Sanitation Alliance, cleanliness in rural and urban areas has been mainstreamed with political leadership at various levels for the first time. 21st century India has to get free from illiteracy and LITTERATI people who throw litter in the open”.
            Shri Naidu said “Mood Of Developing India”(MODI) over the last two years has been for a Clean India and after a  slow start, Swachh Bharat Mission has gained momentum over the last one year with good progress in implementation in both rural and urban areas.
            The Minister informed that as on date 405 cities and towns have come to be Open Defecation Free and 739 would become ODF by March next year. 24 lakh individual household toilets have so far been built in urban areas and another 19 lakhs under construction. 20,000 of the 82,000 urban wards have become ODF. 90,000 community and public toilet seats have been built and another 1.29 lakh seats under construction.
            11 institutions and organisations have been felicitated by Prime Minister for significant work to ensure cleanliness. These were: Chandigarh and Mysurr (Clean Cities in million plus population category), Gangtok (Cleanest Tourism Destination), Pune Municipal Corporation and SWaCH Cooperative Society(Best in Solid Waste Management), Rani Ki Vav, Patan, Gujarat (Cleanest Cultural Heritage Site), Surat Railway Station(Cleanest Station), Post Graduate Institute of Medical Research & Education, Chandigarh (Cleanest Hospital), Mandi district, Himachal Pradesh (ODF and Cleanest district in hilly areas), Sindhugurg district, Maharashtra (ODF and Cleanest district in plain areas) and National Cadet Corps, NCC(Exemplary nation-wide cleanliness activities).

PM delivers inaugural address at INDOSAN – India Sanitation Conference

PM delivers inaugural address at INDOSAN – India Sanitation Conference


The Prime Minister, Shri Narendra Modi, today delivered the inaugural address at INDOSAN – the India Sanitation Conference – in New Delhi today.

He said that while no one likes dirt or dirty surroundings, the habit of cleanliness takes some effort to develop.

He said children are increasingly conscious about issues regarding cleanliness. This shows that the Swachhta Abhiyan is touching people’s lives. He added that a healthy competition is now developing among cities and towns, for promoting cleanliness.

Appreciating the media for its positive role, the Prime Minister said that if there is someone who has furthered the cause of cleanliness more than me, it is the media.

The Prime Minister emphasized that cleanliness is not something to be achieved by budget allocations. It is rather, something that should become a mass movement.

Recalling Mahatma Gandhi’s Satyagraha to free us from colonial rule, the Prime Minister said that today there has to be Swachhagraha to make India free from dirt.

The Prime Minister said re-use and recycling have been our habits for a long time. He added that these need to be made more technology-driven.

The Prime Minister congratulated the award winners, and especially appreciated some of them for succeeding through Jan Bhagidaari.

Every citizen has right to clean air, clean energy: Dr Jitendra Singh

Every citizen has right to clean air, clean energy: Dr Jitendra Singh
Every citizen has a right to clean air and clean source of energy, and the day may not be far when there may be a public demand to bring in a legislation for right to clean air on the same lines as we have a law for Right to Education, Food Security, etc.
This was stated here today by Union Minister of State (Independent Charge) for Development of North Eastern Region (DoNER), MoS PMO, Personnel, Public Grievances, Pensions, Atomic Energy and Space, Dr Jitendra Singh while inaugurating the 8th Nuclear Energy Conclave organized by India Energy Forum on the theme “Meeting the non-fossil energy targets…”. Among those present on the occasion were former Chairman Atomic Energy Commission and renowned Nuclear Scientist Anil Kakodkar, President "India Energy Forum" Anil Razdan and other eminent scientists.
Dr Jitendra Singh said, as India moves up in the graph of development and growth, not only will its energy needs increase, but there would also be a pressure to opt for cost effective and cleaner source of energy. It is here that, besides solar energy and other sources of green energy, nuclear power will find an important place in our lives, he said.
Citing different instances, Dr Jitendra Singh said, he was particularly impressed by the experiment undertaken by Aligarh Muslim University under its Vice Chancellor Lt. Gen. (Retd.) Zameer Uddin Shah, where an exclusive solar plant was set up, which is catering to the entire energy requirements of the University Campus and Departments. He said, in order to promote the optimum use of alternative sources of energy, what is required is the awareness about their diverse applications and modes of utilization.
Dr Jitendra Singh said, the decision about nuclear energy has been confined mainly to its destructive power, without realizing the enormous benefit it has provided in the lives of millions of people including those, for example, seeking radiation therapies for medical management and treatment of cancer etc. Similarly, diverse positive benefits of radiation have in recent years enriched our lifestyle and made it easier, he said.
Calling for mass awareness programmes, Dr Jitendra Singh suggested that India Energy Forum should try to involve common citizens particularly adolescents and young students to spread the message for expansion of alternative sources of energy. This would also help in allaying fears among the people in different locations where public resistance is faced while setting up new nuclear plants because of certain unfounded apprehensions among the masses, he said.

8 Steps to Prevent Industrial Accidents

8 Steps to Prevent Industrial Accidents

Some of the steps for preventing industrial accidents are as follows : 1. Proper safety measures 2. Proper selection 3. Safety conscious 4. Enforcement of discipline 5. Incentives 6. Safety committees 7. Proper maintenance of machines, equipment and infrastructural facilities 8. Safety training.

1. Proper safety measures:

The proper safety measures should be adopted to avoid accidents Government also provides guidelines for enacting measures for checking accidents, these should be properly followed.

2. Proper selection:

Any wrong selection of workers will create problems later on. Sometime employees are accident prone, they may not be properly suitable for the particular jobs. So the selection of employees should be on the basis of properly devised tests so that their suitability for jobs is determined.

3. Safety conscious:

The employees should be made conscious of various safety measures to be followed. There should be proper working slogans and advises to the worker for making them conscious.

4. Enforcement of discipline:

Disciplinary action should be taken against those who flout safety measures. There may be negative punishments like warnings, lay off, terminations of workers.

5. Incentives:

Workers should be given various incentives for maintaining safety. There may also be safety contrasts among workers. Those who follow safety instructions properly should be given monetary and non­monetary incentives.

6. Safety committees:

Safety measures are in the interest of both employers. There should be committees consisting of representatives of workers and employees for devising and enforcing safety programmes.

7. Proper maintenance of machines, equipment and infrastructural facilities:

Accidents may occur on account of the fault in machines or equipment. There should be proper maintenance of machines. These should be regularly checked and frequently inspected by engineering

8. Safety training:

The workers should be given training regarding safety measures. They should know the hazards of the machines, the areas of accident proneness and the good working possible precautions in case of some accident.

Accident Proneness in Industries: (External and Psychological Factors)

Accident Proneness in Industries: (External and Psychological Factors)

Accident Proneness in Industries: (External and Psychological Factors)!

External Factors:

Many non-psychological factors have been noticed to influence the accident rate and, to some extent, determine an employee’s accident proneness. For example, as pointed out by Vernon, the accident rate increases during the latter part of the working day.

According to Vernon’s results, this tendency is so marked that during a twelve-hour working day women experienced two and one half times as many accidents as during a ten hour day. Although this increase has often been attributed to fatigue, the fact that the time of maximum accident rate as compared with hours worked is reversed on the night shift indicates that psychological rather than physiological factors are operating.

Although Vernon’s results attach a lot of importance to the length of the working day, it is frequently seen that as the working day is lengthened, the accident rate increases in greater proportion than the increase in number of hours worked.

Psychological Factors Related to Accident Proneness:

Basically, accidents are caused either due to the work situation or due to personal variables like accident proneness. Because of their psychological makeup, some people are more susceptible to accidents than others. Generally, the work situation determines the liability of accidents. Some work situations e.g. coal mining, quarry, marine transportation etc. are more hazardous than others.
If, there are consistent differences in accident frequency among the individuals in the same work situation and thereby same liability, then it can be assumed that there are one or more personal variables contributing to the consistent individual differences.
It is important to identify the personal variables that are associated with accident frequency on the job in question. As these vary from job to job, the variables operating in a particular situation can be identified only through systematic investigation.

What are the Causes of Industrial Accidents? – Answered!

What are the Causes of Industrial Accidents? – Answered!

Industrial accidents are the result of a combination of factors.
According to safety experts accidents normally occur due to following factors:
1. Unsafe working conditions.
2. Unsafe activities of workers
3. Other causes.

All these causes have been discussed as follows:
1. Unsafe working conditions:

These causes are associated with defective plants, equipment, tool materials etc.

(a) Defective equipment/ machines.

(b) Complicated procedure of performing a job.

(c) Inadequate safety devices.

(d) Wrong and faulty layout of the production unit.

(e) Improper or insufficient light.

(f) Improper ventilation

(g) Improperly guarded equipment.
2. Unsafe activities of workers:

These activities may be the result of inexperience, deficiency of knowledge, inadequate training etc.

These acts include:

(a) Casual behaviour of workers.

(b) Lack of interest and indifferent attitude of workers towards work.

(c) Wrong placement of workers.

(d) Failure to adopt and obey safety measures.

(e) Lack of experience for the job given.

(f) Fear of supervisory staff leading to consciousness.

(g) Using intoxicants while working

(h) Longer hours of continuous work without rest pause.
3. Other causes:

Accidents may also be caused by factors not directly related to conditions and facts.

Such factors may include the followings:

(a) There are more accidents during night shift than during day shift.

(b) Untrained or less trained workers are more prone to accident than experienced workers.

(c) Women employees have better safety records than their male counterparts.

(d) Persons working under any kind of stress (emotional, family problems, threat of losing a job) have record of more accidents than those who do not.

Industrial Accidents: Types and Causes of Accidents (explained with diagram)

Industrial Accidents: Types and Causes of Accidents (explained with diagram)

Industrial Accidents: Types and Causes of Accidents (explained with diagram)!
The ever increasing mechanisation, electrification, chemicalisation and sophistication have made industrial jobs more and more complex and intricate. This has led to increased dangers to human life in industries through accidents and injuries. In fact, the same underlines the need for and importance of industrial safety. Let us first understand what industrial accident actually means.

Industrial Accident:

An accident (industrial) is a sudden and unexpected occurrence in the industry which interrupts the orderly progress of the work. According to the Factories Act, 1948: “It is an occurrence in an industrial establishment causing bodily injury to a person who makes him unfit to resume his duties in the next 48 hours”.
In other words, accident is an unexpected event in the course of employment which is neither anticipated nor designed to occur. Thus, an accident is an unplanned and uncontrolled event in which an action or reaction of an object, a substance, a person, or a radiation results in personal injury. It is important to note that self-inflicted injuries cannot be regarded as accidents.


An industrial injury is defined as “a personal injury to an employee which has been caused by an accident or an occupational disease and which arises out of or in the course of employment and which could entitle such employee to compensation under Workers’ Compensation Act, 1923”.

Types of Accidents:

Accidents may be of different types depending upon the severity, durability and degree of the injury. An accident causing death or permanent or prolonged disability to the injured employee is called ‘major accident. A cut that does not render the employee disabled is termed as ‘minor’ acci­dent. When an employee gets injury with external signs of it, it is external injury.
Injury without showing external signs such as a fractured bone is called an internal one. When an injury renders an injured employee disabled for a short period, say, a day or a week, it is a temporary accident. On the contrary, making injured employee disabled for ever is called permanent accident. Disability caused by accident may be partial or total, fatal or non-fatal.


The various types of accidents are now shown in Figure 20.1.
Types of Accidents
No accident occurs automatically. Instead, certain factors cause accidents. It has been noticed that an accident does not have a single cause but a multiplicity of causes, which are often closely related. The same is discussed subsequently.

Causes of Accidents:

The industrial safety experts have classified the various causes of accidents into three broad categories:
1. Unsafe Conditions

2. Unsafe Acts
3. Other Causes?
These are discussed, in brief.

1. Unsafe Conditions (work-related):

Unsafe working conditions are the biggest cause of acci­dents. These are associated with detective plants, tools, equipment’s, machines, and materials. Such causes are known as ‘technical causes’. They arise when there are improper guarded equipment’s, defective equipment’s, faulty layout and location of plant, inadequate lighting arrangements and ventilation, unsafe storage, inadequate safety devices, etc.
ADVERTISEMENTS:
Besides, the psychological reasons such as working over time, monotony, fatigue, tiredness, frustration and anxiety are also some other causes that cause accidents. Safety experts identify that there are some high danger zones in an industry. These are, for example, hand lift trucks, wheel-barrows, gears and pulleys, saws and hand rails, chisels and screw drivers, electric drop lights, etc., where about one-third of industrial accidents occur.

2. Unsafe Acts:

Industrial accidents occur due to certain acts on the part of workers. These acts may be the result of lack of knowledge or skill on the part of the worker, certain bodily defects and wrong attitude.
Examples of these acts are:
(a) Operating without authority.
(b) Failure to use safe attire or personal protective equipment’s,
(c) Careless throwing of material at the work place.
(d) Working at unsafe speed, i.e., too fast or too low.
(e) Using unsafe equipment, or using equipment’s unsafely.
(f) Removing safety devices.
(g) Taking unsafe position under suspended loads.
(h) Distracting, teasing, abusing, quarrelling, day-dreaming, horseplay
(i) One’s own accident prone personality and behaviour.

3. Other Causes:

These causes arise out of unsafe situational and climatic conditions and variations. These may include excessive noise, very high temperature, humid conditions, bad working conditions, unhealthy environment, slippery floors, excessive glare, dust and fume, arrogant behaviour of domineering supervisors, etc.
Of late, industrial accidents have become common happening in our country. A brief catalogue of major accidents in the recent past in India is produced here:
Exhibit 20.1 Major Accidents in the Last Decade:
Bhopal, December 1984: In world’s worst chemical disaster, a methylisocyanate gas leak from the Union Carbide plant in the city killed over 4000 people. Thousands suffered irreversible health damage.
Delhi, December 1985: An oleum gas leak from the Sriram Foods and Fertilisers Plant in Delhi severely affected workers and those living in the neighbourhood.
Rourkela, December 1985: Blast furnace accident in Rourkela Steel Plant. 18 workers affected.
Durgapur, June 1987: Chlorine leak at Durgapur Chemical Factory created panic all around. Long distance trains were halted. Over 100 were affected.
Bombay, November 1988: Fire at the Bharat Petroleum Refinery at Mahul, north-east Bombay, killed 32.
Ramagunaam, September 1989: Major gas leak at Fertilisers Corporation of India unit at Ramagundam, killed 7.
Nagothane, November 1990: Explosion at the Indian Petrochemicals, Nagothane com­plex, 35 persons killed, over 50 suffered 70 per cent bums.
Bombay, July 1991: Accident in a Hindustan Organic Chemicals unit near Bombay kills 7 workers.
Gwalior, December 1991: Blast at the dyeing department of GRASIM unit at Gwalior. 14 Killed and 22 severely injured.
Panipat, August 1992: Ammonia leak at the National Fertilisers Plant, Panipat killed 11, many injured.
Kahalgaon, October 1992: Boiler explosion in the National Thermal Power Corporation (NTPC), 11 killed and several injured.
It is reported that in every twenty seconds of every working minute of every hour throughout the world, someone dies as a result of an industrial accident. Industrial accidents cause losses to the employees and organisations as well. Table 20.1 gives an idea about the enormous losses that acci­dents have caused to the industrial establishments in our country.
Table 20.1: Accidents—Estimated Loss:
  Accidents—Estimated Loss
Accidents causing losses to the industrial establishments need to be avoided. Adequate safety measures can avoid accidents. The subsequent discussion focuses on certain questions: What? Why?, and How safety?

Safety:

In simple words, safety means freedom from the occurrence or risk of injury or loss. As regards, industrial safety, it means the protection of employees/workers from the danger or risk of industrial accidents. In other words, industrial safety refers to protection against accidents occurring in the industrial establishments.

Thursday, 29 September 2016

Water Quality Standard_IS 10500,1991_2011


























Base Flow vs. Storm Flow

Data is reported as being in a storm flow condition when a judgment is made by the data gatherer that the volume of water in the stream has significantly increased beyond a base flow condition, usually because of recent precipitation.

Temperature

Water temperature is affected by air temperature, stormwater runoff, groundwater inflows, turbidity, and exposure to sunlight. In considering the health of organisms, it is necessary to consider their maximum temperature and optimum temperature. The maximum temperature is the highest water temperature at which the organism will live for a few hours. The optimum temperature is the temperature at which it will thrive.
Fish Short-term maximum Optimum for Spawning
  Celsius Fahrenheit Celsius Fahrenheit
Bluegill 35 95 25 77
Brook trout 24 75 9 48

pH

pH is a measure of a solution's acidity. In water, small numbers of water molecules (H2O) will break apart or disassociate into hydrogen ions (H+) and hydroxide ions (OH-). Other compounds entering the water may react with these, leaving an imbalance in the numbers of hydrogen and hydroxide ions. When more hydrogen ions react, more hydroxide ions are left in solution and the water is basic; when more hydroxide ions react, more hydrogen ions are left and the water is acidic. pH is a measure of the number of hydrogen ions and thus a measure of acidity. pH is measured on a logarithmic scale between 1 and 14 with 1 being extremely acid, 7 neutral, and 14 extremely basic. Because it is a logarithmic scale there is a ten fold increase in acidity for a change of one unit of pH, e.g. 5 is 100 times more acid than 7 on the pH scale. The largest variety of freshwater aquatic organisms prefer a pH range between 6.5 to 8.0.

Turbidity

Turbidity is a measure of how particles suspended in water affect water clarity. It is an important indicator of suspended sediment and erosion levels. Typically it will increase sharply during and after a rainfall, which causes sediment to be carried into the creek. Elevated turbidity will also raise water temperature, lower dissolved oxygen, prevent light from reaching aquatic plants which reduces their ability to photosynthesize, and harm fish gills and eggs.

Conductivity

This is a measure of the capability of a solution such as water in a stream to pass an electric current. This is an indicator of the concentration of dissolved electrolyte ions in the water. It doesn't identify the specific ions in the water. However, significant increases in conductivity may be an indicator that polluting discharges have entered the water. Every creek will have a baseline conductivity depending on the local geology and soils. Higher conductivity will result from the presence of various ions including nitrate, phosphate, and sodium.
The basic unit of measurement for conductivity is micromhos per centimeter (µmhos/cm) or microsiemens per centimeter (µS/cm). Either can be used, they are the same. It is a measure of the inverse of the amount of resistance an electric charge meets in traveling through the water. Distilled water has a conductivity ranging from 0.5 to 3 µS/cm, while most streams range between 50 to 1500 µS/cm. Freshwater streams ideally should have a conductivity between 150 to 500 µS/cm to support diverse aquatic life.

Dissolved Oxygen

Dissolved oxygen is oxygen gas molecules (O2) present in the water. Plants and animals cannot directly use the oxygen that is part of the water molecule (H2O), instead depending on dissolved oxygen for respiration. Oxygen enters streams from the surrounding air and as a product of photosynthesis from aquatic plants. Consistently high levels of dissolved oxygen are best for a healthy ecosystem. Levels of dissolved oxygen vary depending on factors including water temperature, time of day, season, depth, altitude, and rate of flow. Water at higher temperatures and altitudes will have less dissolved oxygen. Dissolved oxygen reaches its peak during the day. At night, it decreases as photosynthesis has stopped while oxygen consuming processes such as respiration, oxidation, and respiration continue, until shortly before dawn.
Human factors that affect dissolved oxygen in streams include addition of oxygen consuming organic wastes such as sewage, addition of nutrients, changing the flow of water, raising the water temperature, and the addition of chemicals.
Dissolved oxygen is measured in mg/L.
0-2 mg/L: not enough oxygen to support life.
2-4 mg/L: only a few fish and aquatic insects can survive.
4-7 mg/L: good for many aquatic animals, low for cold water fish
7-11 mg/L: very good for most stream fish

Nitrate

Nitrogen is abundant on earth, making up about 80% of our air as N2 gas. Most plants cannot use it in this form. However, blue-green algae and legumes have the ability to convert N2 gas into nitrate (NO3-), which can be used by plants. Plants use nitrate to build protein, and animals that eat plants also use organic nitrogen to build protein. When plants and animals die or excrete waste, this nitrogen is released into the environment as NH4+ (ammonium). This ammonium is eventually oxidized by bacteria into nitrite (NO2-) and then into nitrate. In this form it is relatively common in freshwater aquatic ecosystems. Nitrate thus enters streams from natural sources like decomposing plants and animal waste as well as human sources like sewage or fertilizer. Nitrate is measured in mg/L. Natural levels of nitrate are usually less than 1 mg/L. Concentrations over 10 mg/L will have an effect on the freshwater aquatic environment. 10 mg/L is also the maximum concentration allowed in human drinking water by the U.S. Public Health Service. For a sensitive fish such as salmon the recommended concentration is 0.06 mg/L.
Water with low dissolved oxygen may slow the rate at which ammonium is converted to nitrite (NO2-) and finally nitrate (NO3-). Nitrite and ammonium are far more toxic than nitrate to aquatic life.

Phosphate

Phosphorus in small quantities is essential for plant growth and metabolic reactions in animals and plants. It is the nutrient in shortest supply in most fresh waters, with even small amounts causing significant plant growth and having a large effect on the aquatic ecosystem. Phosphate-induced algal blooms may initially increase dissolved oxygen via photosynthesis, but after these blooms die more oxygen is consumed by bacteria aiding their decomposition. This may cause a change in the types of plants which live in an ecosystem. Sources of phosphate include animal wastes, sewage, detergent, fertilizer, disturbed land, and road salts used in the winter.
Phosphates do not pose a human or health risk except in very high concentrations. It is measured in mg/L. Larger streams may react to phosphate only at levels approaching 0.1 mg/L, while small streams may react to levels of PO4-3 at levels of 0.01 mg/L or less. In general, concentrations over 0.05 will likely have an impact while concentrations greater than 0.1 mg/L will certainly have impact on a river.





















Soil Nitrogen Supply

Soil Nitrogen Supply

Key points

  • The release of mineral nitrogen from decomposition of organic matter is a significant source of nitrogen for grain crops in Australia.
  • Soil nitrogen supply is a laboratory test that reflects the release of mineral nitrogen from organic matter.
  • Soil nitrogen supply reflects how much mineral nitrogen may be released from organic matter but not when the nitrogen will be released.

Plant uptake of soil nitrogen

Plants require more nitrogen (N) than any other nutrient but only a small portion of the nitrogen in soil is available to plants; 98 % of the nitrogen in soil is in organic forms. Most forms of organic nitrogen cannot be taken up by plants, with the exception of some small organic molecules.
In contrast, plants can readily take up mineral forms of nitrogen, including nitrate and ammonia. However, mineral nitrogen in soil accounts for only 2 % of the nitrogen in soil. Soil microorganisms convert organic forms of nitrogen to mineral forms when they decompose organic matter and fresh plant residues. This process is called mineralisation.

Soil nitrogen supply

Soil nitrogen supply is a laboratory test that reflects the release of mineral nitrogen from organic matter by soil microorganisms. It is measured in milligrams of nitrogen per kilogram of soil (mg/kg) and is also known as potentially mineralisable nitrogen. The laboratory test is simple but time-consuming.
Values of soil nitrogen supply can be classed into one of five descriptive categories from “Very Low” to “Very High”. The higher the value for soil nitrogen supply the more likely it is that the microorganisms in a soil will convert more organic nitrogen into mineral nitrogen for plant uptake.
However, in coarse textured soils with higher values of soil nitrogen supply, it is also more likely that nitrate will be leached down the soil profile out of reach of plant roots and possibly into waterways. Intermediate levels of soil nitrogen supply provide a balance between maximising nitrogen availability for plant uptake and minimising the risk of nitrate leaching.
The level of soil nitrogen supply that best balances the benefits and risks varies depending on the clay content of soil. In sand soils, the best balance is achieved by a “Moderate” soil nitrogen supply (25 – 50 mg-N/kg soil). In contrast, in loam and clay soils “High” soil nitrogen supply is most suitable (50 – 75 and 75 – 125 mg-N/kg soil respectively).


Figure 1: The soil nitrogen cycle showing the role of mineralisation in making organic nitrogen in soil available for plants to take up.

Soil nitrogen supply and crop growth

Conversion of organic nitrogen in soil into mineral nitrogen is a significant source of the nitrogen required by crops in Australian agriculture. For example, a wheat crop must take up approximately 50 kg-N/ha to achieve the average Australian yield of 1.9 t/ha. It has been estimated that every year 2 % of the organic nitrogen in soil is converted to mineral forms, releasing 70 kg mineral nitrogen per hectare – more than the total requirement of the wheat crop (Angus 2001).
Soil nitrogen supply is particularly important in rotations that include legumes crops and pastures. Nitrogen in the residues of legume crops and pastures is decomposed by microorganisms and can become available to subsequent crops. For example, 20 – 25 % of the nitrogen fixed by a medic pasture was converted to mineral forms of nitrogen and taken up by the following crop (Angus and Peoples 2012).
In Western Australian grain growing regions, soil nitrogen supply has a strong effect on crop growth and grain yield. A study near Corrigin, Western Australia found it was possible to predict 21% of the final grain yield using the soil nitrogen supply six weeks after seeding. In contrast, using the amount of nitrogen fertiliser applied it was only possible to predict 10 % of the grain yield. Also the amount of mineral nitrogen in soil six weeks after sowing had no effect on grain yield (Murphy et al. 2009).

Timing of nitrogen release from organic matter

Although soil nitrogen supply is useful to estimate how much nitrogen from organic matter will become available to a crop, there is a significant difficulty with this measurement. Soil nitrogen supply estimates the quantity of nitrogen released from organic matter without giving any information about when it will be released. Most nitrogen release from organic matter occurs during the growing season, providing a steady, continuous supply of nitrogen to the crop. This is because the microorganisms responsible for releasing nitrogen from organic matter require some soil moisture.
However, it is likely that some of the soil nitrogen supply will occur when plants don’t require nitrogen. When summer rainfall occurs it can lead to significant amounts of organic nitrogen being turned into mineral nitrogen.
Nitrogen released from organic matter during summer can be viewed as a pre-emergent application and in some years can be a significant source of nitrogen. However, it is also prone to leaching if heavy rainfall occurs before crop establishment. Soil testing helps to determine the value of this nitrogen.

Soil nitrogen supply and microorganisms

Research in Victorian grain growing regions shows that a greater abundance of soil microorganisms capable of decomposing organic matter is associated with high soil nitrogen supply. These microorganisms include those able to convert organic nitrogen to plant-available mineral nitrogen and thus contribute to the soil nitrogen supply.
Knowing that specific microorganisms directly influence soil nitrogen supply (and vice versa) allows us to understand how management practices affect soil nitrogen supply.
For example, when residues were incorporated into soil using a disc plough instead of being mulched the abundance of microorganisms able to convert organic nitrogen to mineral nitrogen more than doubled. As a result, disced soils contained double the amount of nitrate-N at sowing than soils where legumes residues were mulched. The mulched soils however, released nitrate-N more gradually over the next growing season than disced soils.

Further reading and references

Angus JF (2001) Nitrogen supply and demand in Australian agriculture. Australian Journal of Experimental Agriculture 41: 277–288.
Angus JF and Peoples MB (2012) Nitrogen from Australian dryland pastures. Crop and Pasture Science 63: 746–758.
Murphy DV, Osman M, Russell CA, Darmawanto S and Hoyle FC (2009) Potentially mineralisable nitrogen: relationship to crop production and spatial mapping using infrared reflectance spectroscopy. Australian Journal of Soil Research 47: 737–741.

Author: Jennifer Carson (The University of Western Australia) and Lori Phillips (The Department of Environment and Primary Industries – Victoria)

Making Sense of Biological Indicators

Making Sense of Biological Indicators

Biological indicators give information on living organisms in soil. Biological indicators of soil quality therefore measure dynamic soil properties, i.e. properties that change over time and/or with management. It is important to monitor biological indicators as they respond more quickly to changes in management or environment than physical and chemical indicators.
For most biological indicators, there is little evidence currently available which directly links the value of the indicators to productivity or, in some cases, the risk of adverse environmental impact. However, there is good evidence from field trials carried out on a range of soils in Australia of links between biological indicators and soil processes. These have been used to create guideline ranges for the biological indicators, similar to those used for the dynamic physical and chemical indicators.
  • Indicators falling in the RED zone are high risk and need to be investigated urgently.
  • Indicators falling in the AMBER zone are moderate risk and should be investigated further.
  • Indicators falling in the GREEN zone are low risk, regular monitoring should be continued.

Diseases and Nematodes

Indicators of soil inoculum status for soil borne disease and/or nematode abundance are used to guide practical paddock by paddock decisions about using control measures. The pathogen–host cycles are complex and affected by a range of environmental, crop and management factors . Because the pathogens are highly variable across a paddock, it is very important to use an appropriate sampling strategy
to gain results that are representative of the paddock (figures 1 & 2). A medium or high value obtained as part of routine soil monitoring may not lead to a high risk of the disease or significant yield loss. Approaches to managing pathogens need to be specific to each paddock and farmers should seek the advice of an appropriately qualified agronomist.




Figure 1: Cereal cyst nematode will cause distinct patches of yellowed and stunted plants. Note the likeness of symptoms to poor nutrition or water stress. (Photo by Vivien Vanstone, DAFWA, Nematology.)


Figure 2: Patchiness in crop caused by Root lesion nematode. (Photo by Vivien Vanstone, DAFWA, Nematology.)

Total organic carbon

Organic matter in soil refers to all the materials that are or were associated with living organisms. It is difficult to measure directly and total organic carbon (usually expressed as % C—the percentage of carbon in the soil), is measured instead. The value for total organic carbon can be converted to give tonnes of carbon per hectare using information about bulk density and gravel content . Low levels of total organic carbon can indicate that there might be problems with unstable soil structure, low cation exchange capacity and nutrient turnover. Where total organic carbon in a paddock is lower than the soil’s capacity to store organic matter it may be increased by increasing ground cover, reducing fallow, retaining stubble, increasing the proportion of pasture in the rotation or other management strategies that increase inputs of organic materials into the soil.



Total organic carbon can be separated into its components (termed fractions or pools) which differ in their chemical structure. The labile pool which turns over relatively rapidly (<5 years), results from the addition of fresh residues such as plant roots and living organisms. In contrast, resistant residues are slower to turn over (20 – 40 years) because they are physically or chemically protected. Soils in Australia also contain charcoal as a result of burning which is almost totally recalcitrant. The proportion of total organic carbon in the labile fraction can be used to identify soils with low amounts of regular residue input. In sand soils, 10 % of the total organic carbon should ideally be in the labile fraction; in loam soils 15 % and in clay soils 20 %.

Microbial biomass




The size of the soil microbial biomass (measured as mg C per kg) is affected by climate and many soil properties (see Microbial Biomass fact sheet). Microbial biomass is the powerhouse of almost all biological processes in soil (figure 3). Generally up to 5 % of the total organic carbon can be found in the living tissues of the microbial biomass.


Figure 3: The main soil properties affecting the microbial biomass and factors influenced by it.

Author: Elizabeth Stockdale (Newcastle University, UK)

Soil Biological Fertility

Soil Biological Fertility

Key points

  • Soil fertility depends on three major interacting components: biological, chemical and physical fertility.
  • Soil organisms improve soil fertility by performing a number of functions that are beneficial for plants. This article examines six of these functions.
  • Some management practices may help improve and maintain the biological fertility of soil.

Releasing nutrients from organic matter

Soil microorganisms (figure 1) are responsible for most of the nutrient release from organic matter. When microorganisms decompose organic matter, they use the carbon and nutrients in the organic matter for their own growth. They release excess nutrients into the soil where they can be taken up by plants. If the organic matter has a low nutrient content, micro-organisms will take nutrients from the soil to meet their requirements.
For example, applying organic matter with carbon to nitrogen ratios lower than 22:1 to soil generally increases mineral nitrogen in soil. In contrast, applying organic matter with carbon to nitrogen ratios higher than 22:1, generally results in microorganisms taking up mineral nitrogen from soil (Hoyle et al. 2011).


Figure 1: Colonies of bacteria shown in light blue in soil, each bacterium approximately 1 micron in size. (image: Karl Ritz)

Fixing atmospheric nitrogen

Symbiotic nitrogen fixation is a significant source of nitrogen for Australian agriculture and may account for up to 80% of total nitrogen inputs (Unkovich 2003). In the symbiosis, rhizobia or bradyrhizobia fix nitrogen gas from the atmosphere and make it available to the legume. In exchange, they receive carbon from the legume. The symbiosis is highly specific and particular species of rhizobia and bradyrhizobia are required for each legume. For more information see fact sheet “Legumes and Nitrogen Fixation”.

Increasing phosphorus availability

Most agricultural plants (except lupins and canola) form a symbiosis with arbuscular mycorrhizal (AM) fungi (figure 2) that can increase phosphorus uptake by the plant. The hyphal strands of AM fungi extend from plant roots into soil and have access to phosphorus that plant roots cannot reach. The AM fungi can provide phosphorus to plants and in return they receive the carbon they need to grow.
Importantly, this symbiosis is only beneficial for plants when available phosphorus in soil is insufficient for the plant’s requirements. Increasing phosphorus availability may be especially beneficial on phosphorus fixing soils in Australia, which are widespread and can store 100 kilograms of phosphorus per hectare (Cornish 2009).


Figure 2: A mycorrhizal fungi growing into plant cells where it has formed tree-like structures (arbuscules) that allow phosphorus to be transferred from the fungi to the plant. (image: Lynette Abbott).

Degrading pesticides

The degradation of agricultural pesticides in soil is primarily performed by microorganisms. Some microorganisms in soil produce enzymes that can break down agricultural pesticides or other toxic substances added to soil. The length of time these substances remain in soil is related to how easily they are degraded by microbial enzymes.

Controlling pathogens

Some microorganisms and soil animals infect plants and decrease plant yield. However many organisms in the soil control the spread of pathogens. For example, the occurrence of some pathogenic fungi in soil is decreased by certain protozoa that consume the pathogenic fungi. The soil food web contains many relationships like this that decrease the abundance of plant pathogens.

Improving soil structure

Biological processes in soil can improve soil structure. Some bacteria and fungi produce substances during organic matter decomposition that chemically and physically bind soil particles into micro-aggregates. The hyphal strands of fungi can cross-link soil particles helping to form and maintain aggregates (figure 3). A single gram of soil can contain several kilometres of fungal hyphae (Young and Crawford 2007). In addition, soil animals increase pores by tunnelling through soil and increase aggregation by ingesting soil.


Figure 3: Fungal hyphae (shown in blue) extending through soil (image Karl Ritz).

Managing soil biological fertility

We currently understand less about how management practices affect soil biological fertility than how they affect soil chemical and physical fertility. However, the management practices described below may help improve and maintain the biological fertility of soil.
  1. Minimise erosion as soil organisms are predominantly located in the surface layers, which are most easily eroded.
  2. Maintain or increase the organic matter content of soil as organic matter is an important source of carbon, energy and nutrients for soil organisms.
  3. Use diverse rotations as they result in diverse inputs of organic matter and a diverse population of soil organisms.
  4. Select nitrogen fixing bacteria that match the host plant and can tolerate your soil characteristics (e.g. pH) as nitrogen fixing bacteria form specific associations with legumes.
  5. Consider the release of nutrients from organic matter when determining fertiliser applications.
  6. Use fertiliser inputs that complement the activities of arbuscular mycorrhizal fungi as they only increase plant uptake of phosphorus in phosphorus-deficient soils.
  7. Choose crop rotations and management practices that decrease the suitability of soil for plant pathogens.
  8. Be patient as soil biological processes take time to develop.

Did you know?

  • There are more organisms in a handful of soil than there are people on Earth, but most of them can only be seen under a microscope.
  • The weight of organisms in the surface 10 cm of a cropping soil in southern Australia can be as much as 2 t/ha.
  • About a quarter of all the organisms in an agricultural soil are located in the surface 2 cm of soil.
  • At any one time, most soil organisms (>70 %) are inactive as soil conditions are not usually optimal.
  • Although there are a few pest nematodes species, there are over 95 non-pest species (figure 4).


Figure 4: A non-pest soil nematode (image Karl Ritz).

Further reading and references

Cornish PS (2009) Phosphorus management on extensive organic and low-input farms. Crop & Pasture Science 60: 105 – 115.
Young IM and Crawford JW (2004) Interactions and self-organisation in the soil-microbe complex. Science 304: 1634 – 1637.
Hoyle FC, Baldock JA and Murphy DV (2011) ‘Soil organic carbon – Role in rainfed farming systems: with particular reference to Australian conditions’, in Rainfed farming systems, Springer Science-Business Media BV, Netherlands.
Unkovich (2003) ‘David and Goliath: Symbiotic nitrogen fixation and fertilisers in Australian agriculture’, Proceedings of the 12th Australian nitrogen fixation conference. Glenelg, SA Sep 2003.

Total Organic Carbon

Total Organic Carbon

Key points

  • Total organic carbon is a measure of the carbon contained within soil organic matter.
  • Continuous pasture builds organic carbon quicker than other rotations.
  • Plant residue removal and constraints to crop growth reduce organic inputs.
  • Erosion events remove topsoil which contains the bulk of a soil’s organic matter. This can take years of good management to replace.
  • Micro-organisms breakdown soil organic carbon as an energy source – this occurs faster when the soil is moist and warm.
  • Cultivation can also enhance breakdown as soil aggregates are disrupted; making protected organic matter available to micro-organisms to decompose and because better soil aeration increases microbial activity.
  • Gravel in soils will ‘dilute’ the total carbon in your paddock when total organic carbon is calculated on a per hectare basis.

The role of organic carbon

Total organic carbon influences many soil characteristics including colour, nutrient holding capacity (cation and anion exchange capacity), nutrient turnover and stability, which in turn influence water relations, aeration and workability.
In soils with high clay content the contribution to cation exchange from the organic fraction is generally small compared to that from clay. In sandier soils the relative contribution of the organic fraction is higher because there is less clay, even though the amount of total organic carbon present may be similar or less to that in clays.
By providing a food source for micro-organisms, organic carbon can help improve soil stability by micro-organisms binding soil particles together into aggregates or ‘peds’. Bacteria excretions, root exudates, fungal hyphae and plant roots can all contribute to better soil structure.
Moist, hot and well-aerated conditions favour rapid decay of organic additions. If the rate of organic matter addition is greater than the rate of decomposition, the organic fraction in a soil will increase (figure 1). Conversely, if the rate at which organic matter is added to soil is lower than the decomposition rate, the organic fraction will decline.
At a steady state level, the rate of addition is equal to the rate of decomposition. Large organic additions can temporarily increase the organic fraction in a soil, but unless additions are maintained, the soil will revert to its steady state equilibrium, which is usually low.


Figure 1: An example of organic carbon levels over time under different management systems.

Definitions

A fundamental understanding of the different components of soil organic matter is required to best use it to improve farming systems. Total organic carbon forms are derived from the decomposition of plants and animals. They are capable of decay or are the product of decay. They contain organic compounds whose molecules contain carbon, oxygen, nitrogen and hydrogen; therefore carbonates, bicarbonates and elementary carbon like graphite are not organic carbon.
Total carbon is the sum of three carbon forms; organic (described above), elemental (which is insignificant in most soils) and inorganic (usually carbonates and bicarbonates). The term total carbon is different to total organic carbon, which refers specifically to the organic carbon fraction.
The terms total organic carbon, soil organic carbon and organic carbon are the same.
Organic matter is commonly and incorrectly used to describe the same soil fraction as total organic carbon. Organic matter is different to total organic carbon in that it includes all the elements (hydrogen, oxygen, nitrogen, etc) that are components of organic compounds, not just carbon.
Organic matter is difficult for laboratories to measure directly, so they usually measure total organic carbon. This is probably why organic matter and organic carbon are often confused and used interchangeably. A conversion factor of 1.72 is commonly used to convert organic carbon to organic matter:

Organic matter (%) = Total organic carbon (%) x 1.72

This conversion factor assumes organic matter contains 58 % organic carbon. However this can vary with the type of organic matter, soil type and soil depth. Conversion factors can be as high as 2.50, especially for subsoils.
Total organic carbon can be further defined as fractions that vary in size and decomposability. The passive fraction is chemically stable and can take more than 2500 years to turnover. Consequently, it is the largest pool and the least likely to be influenced by changes in management practice.
The slow fraction, with a turnover rate of 20-40 years, consists primarily of organic compounds that are either resistant to decomposition or physically protected. Soil manipulations that disrupt soil aggregates (e.g. tillage) can influence the turnover of this pool, by exposing previously protected organic material to microbial decomposition.
The active or labile fraction consists of smaller pools that can be readily utilised by micro-organisms. This fraction originates from new residues and living organisms (including micro-organisms) and turnover generally occurs within 2 – 3 years. The microbial component of this fraction represents only 1 – 5 % of total soil organic matter. However, since this soil fraction is more sensitive to changes in management practices, significant differences can generally be measured earlier than in the larger, more stable pools. The capacity of a soil to supply nutrients is often defined by the proportion of total soil organic carbon that is labile.

Gravel in soil

In addition to converting total organic carbon (%) to a tonne per hectare basis, it is important to account for gravel content in the soil. As with most soil measurements, total organic carbon is measured only on those soil particles that are less than 2 mm (‘fine earth’), everything larger is classed as the ‘coarse fraction’ of gravel. If there is a significant gravel fraction in your soil, this means the organic carbon is concentrated into only the less than 2 mm component of the soil. So for any given organic carbon (%) when gravel is taken into account on a hectare basis the more gravel the lower the tonnes of organic carbon per hectare.

Organic carbon in your paddock

Soil organic carbon is usually reported as a percentage of your topsoil (0 – 10) cm. This value can be converted to a meaningful volume for a paddock. For example:


i.e. 10,000 m2 in one hectare x 0.1 m soil depth x 1.4 g/cm3 bulk density x 1.2 % = 16.8 t/ha.

Authors: Wayne Pluske (Nutrient Management Systems), Daniel Murphy (The University of Western Australia) and Jessica
Sheppard
(Avon Catchment Council).

How Much Carbon Can Soil Store

How Much Carbon Can Soil Store

Key points

  • Increasing the total organic carbon in soil may decrease atmospheric carbon dioxide and increases soil quality.
  • The amount of organic carbon stored in soil is the sum of inputs to soil (plant and animal residues) and losses from soil (decomposition, erosion and offtake in plant and animal production).
  • The maximum capacity of soil to store organic carbon is determined by soil type (% clay).
  • Management practices that maximise plant growth and minimise losses of organic carbon from soil will result in greatest organic carbon storage in soil.

Background

Recent interest in carbon sequestration has raised questions about how much organic carbon (OC) can be stored in soil. Total OC is the amount of carbon in the materials related to living organisms or derived from them. In Australian soils, total OC is usually less than 8 % of total soil weight (Spain et al., 1983) and under rainfed farming it is typically 0.7 – 4 %. Increasing the amount of OC stored in soil may be one option for decreasing the atmospheric concentration of carbon dioxide, a greenhouse gas.
Increasing the amount of OC stored in soil may also improve soil quality as OC contributes to many beneficial physical, chemical and biological processes in the soil ecosystem (figure 1) (see Total Organic Carbon fact sheet). When OC in soil is below 1 %, soil health may be constrained and yield potential (based on rainfall) may not be achieved (Kay and Angers, 1999).


Figure 1: Some of the beneficial physical, chemical and biological processes in soil that total OC contributes to.

Carbon budgets in soil – Inputs and losses of organic carbon

The amount of OC stored in soil is the difference between all OC inputs and losses from a soil. The main inputs of OC to soil in rainfed farming systems are from plant material, such as crop residues, plant roots, root exudates and animal manure. Inputs of plant material are generally higher when plant growth is greater.
Losses of OC from soil are from decomposition by microorganisms, erosion of surface soil and offtake in plant and animal production. Decomposition occurs when microorganisms use OC in soil to obtain the carbon, nutrients and energy they need to live. During decomposition, OC is lost from soil because microorganisms convert about half of the OC to carbon dioxide gas (CO2). Without continual inputs of OC, the amount stored in soil will decrease over time because OC is always being decomposed by microorganisms.
Losses of OC from erosion of surface soil can have a large impact on the amount of OC stored in soil. This is because OC is concentrated in the surface soil layer as small particles that are easily eroded. In Australian agriculture, erosion can cause the annual loss of 0.2 t/ha of soil from a pasture, 8 t/ha from a crop and up to 80 t/ha from bare fallow.
Offtake of OC in plant and animal production is also an important loss of OC from soil. Harvested materials such as grain, hay, feed and animal grazing all represent loss of OC (and nutrients) from soil.


Figure 2: The influence of soil type, climate and management factors on the storage of organic carbon (OC) that can be achieved in a given soil. Based on Ingram and Fernandes (2001).

Soil type determines the potential storage of organic carbon

The potential storage of OC in soil depends on the soil type (figure 2). Clay particles and aggregates can reduce losses of OC by physically protecting organic matter from decomposition. Particles of organic matter can become adsorbed to clay surfaces, coated with clay particles or buried inside small pores or aggregates. All of these processes make it difficult for microorganisms to come in contact with organic matter. Therefore, the amount of OC stored in soil tends to increase with increasing clay content (figure 3). In contrast, in sand soil microorganisms are able to more easily access OC. This causes greater loss of OC by decomposition.
The potential storage of OC in soil is rarely achieved because climate reduces inputs of OC to soil.


Figure 3: The relationship between clay content and the organic carbon content of 220 soils in a 10 hectare area of a paddock under cereal-legume rotation in the central agricultural region of Western Australia.

Climate determines the attainable storage of organic carbon

Climate determines the attainable storage of OC in soil by regulating plant production (figure 2). Under dryland agriculture, rainfall is the climate factor that has most influence on plant productivity and therefore inputs of OC to soil. In regions with high rainfall, soils tend to have greater attainable storage of OC than the same soil type in a lower rainfall region.
Although it is not possible to increase the attainable storage of OC in soil, management practices determine whether or not the attainable storage of OC in soil is achieved.

Management determines the actual storage of organic carbon in soil

Management practices determine the actual storage of OC in soil by increasing inputs and decreasing losses (figure 2). Practices that can increase the amount of total OC stored in soil include:
  • Increased plant growth generally increases inputs of OC to soil in shoot material, roots and root exudates, e.g. optimal nutrition, increasing water use efficiency, decreasing disease.
  • Growing plants for longer periods each year generally increases inputs of OC to soil, e.g. shorter fallow, conversion from cropping to pasture, conversion from annual to perennial pasture.
  • Improving soil structure can increase the amount of OC stored in soil by reducing losses of OC from soil by decomposition and erosion, e.g. retaining stubble, maintaining ground cover and reducing compaction by vehicles and stock.

Further reading and references

Hoyle F, Murphy D and Baldock G (2009) Soil organic carbon: Role in Australian farming systems. In: Rainfed Farming Systems. Springer, Chapter 14.
Ingram JSI and Fernandes ECM (2001) Managing carbon sequestration in soils: Concepts and terminology. Agriculture, Ecosystems & Environment. 87: 111-117.
Kay BD and Angers DA (1999) Soil structure. In: Handbook of Soil Science. (Ed ME Sumner), pp A-229-276. CRC Press, Boca
Raton USA.
Spain AV, Isbell RF and Probert ME (1983) Soil organic matter. In: Soils – An Australian viewpoint, pp 551-563. CSIRO,
Melbourne Australia. Academic Press, London UK.