An Introduction Towards One Of An Introduction Towards One Of

The Massive Soil Issues…The Massive Soil Issues…

BROUGHT TO YOU BY…BROUGHT TO YOU BY…{HS 1- ST. AGNES 08-09}{HS 1- ST. AGNES 08-09}

•John Allan Yayen --- research

•Reynold Christian Zuniga

--- evaluation

•Maria Angelika Villegas --- output

•Karen See --- PowerPoint & images

““We know more about We know more about the the movement of the movement of the celestial bodies than celestial bodies than about the soil about the soil underfoot.”underfoot.” ---Leonardo Da ---Leonardo Da VinciVinci

TABLE OF TABLE OF CONTENTSCONTENTS

• The Soil ItselfThe Soil Itself

--- 6 - 9--- 6 - 9• Land DegradationLand Degradation

--- 10 - 28--- 10 - 28• Trends Of Land Trends Of Land DegradationDegradation

--- 29 - 35--- 29 - 35• Vital StatisticsVital Statistics

--- 36 - 49--- 36 - 49• Opinions On The MatterOpinions On The Matter

--- 50 - 52--- 50 - 52• The SummaryThe Summary

--- 53 - 55--- 53 - 55

THE SOIL THE SOIL ITSELFITSELF

Things You Are Just Ought To Things You Are Just Ought To Know…Know…

^_^^_^

And before we proceed to the topic itself, let’s first go over some guidelines on soil…

If there is anything on Earth that seems simple and ordinary, it is the soil beneath our feet. Other than farmers, people hardly think of it except when tending to their lawns, and even when we do turn our attention to the soil, we tend to view it as little more than a place where grass grows and earthworms crawl.

Yet the soil is a complex mixture of minerals and organic material, built up over billions of years, and without it, life on this planet would be impossible.

And there in the picture can you see the different soil regions spread across the world.

• And not only that, soil is home to a vast array of species that continually process it, enriching it as they do.

• Nor are all soils the same; in fact, there are a great variety of soil environments and a great deal of difference between the soil at the surface and that which lies further down, closer to the bedrock.

Well, now that you had an idea on Well, now that you had an idea on what soil is, it is now time we what soil is, it is now time we

move on with…move on with…

LAND DEGRADATION

And like any other, there are what we call “soil issues”. And it just so happens that “land degradation” is sadly one of them.

Land degradation ---means reduction, or loss of the biological

or economic productivity and complexity of rainfed cropland, irrigated cropland, or. range, pasture, forest and woodlands

And it is resulting from land uses, or from a process or combination of processes, including processes arising from human activities and habitation patterns, such as…

Soil erosion

Deterioration of the properties

of soil

Long-term loss of natural vegetation.

How does the soil get affected by this?

Based from the graph, it shows that certain processes happen especially when land degradation takes place. And these processes are…

Process # 1 –-- “Erosion”

Erosion is the term given to soil loss due to the mobilization of topsoil by the forces of water and wind. Wind and water move the eroded particles to some other location, where it is deposited as sediment. In other words, soil erosion is a natural process that removes soil from the land.

Could either be caused by one of the following: {Farming} {Building} {Logging} {Overgrazing} {Off-road Vehicles} {Fire}

Process # 2 –-- “Desertification”

Desertification occurs whenever a non-desert area starts to exhibit the characteristics of a true desert.

Take this for example…Over the past 50 years, at the

southern edge of the Sahara, an area the size of Somalia has become desert. The same fate now threatens more than one-third of the African continent.

Process # 3 –-- “Salinization & Nutrient Loss”

Soil salinization is the concentration of salts in the surface or near surface of soils. Human induced salinization is a major problem in dry lands and is often associated with large-scale irrigation.

What happens is that…When dry lands are irrigated, the water

evaporates quickly, leaving behind previously dissolved salts. These salts can collect, since there is little rain to flush the system. The salt in the soil inhibits the uptake of water by plant roots and the soil can no longer sustain a vegetative cover.

Any idea on what causes it?

Physical Processes: Erosion Desertification Crusting Compaction Anaerobism Environmental Pollution

_______________________________________Chemical Processes:

Acidification Leaching Salinization Decrease In Cation Retention Capacity Fertility Depletion

Biological Processes:

Biological Processes: Eutrophication Of Surface Water Contamination Of Groundwater Eemissions of trace gases

(CO2, CH4, N2O, NOx) from terrestrial/aquatic ecosystems to the

atmosphere_______________________________________Land Quality_______________________________________Land Use_______________________________________Soil Structure

Its Effects On Soil… We often assume that land degradation only affects soil fertility. However, the effects of land degradation often more significantly affect receiving water courses (rivers, wetlands and lakes) since soil, along with nutrients and contaminants associated with soil, are delivered in large quantities to environments that respond detrimentally to their input.

Therefore… ----- Land

degradation has potentially disastrous effects on lakes and reservoirs that are designed to alleviate flooding, provide irrigation, and generate hydroelectricity.

Accelerated soil erosion by wind and water Soil acidification or alkalinisation Salination Destruction of soil structure including loss of organic matter Derelict Soil

In other words…The main outcome of land degradation is a

substantial reduction in the productivity of the land.

On the other hand, land degradation results to a big problem towards productivity…

Especially the Croplands…

According To Statistics…The worldwide amount of cropland per

capita has declined due to population growth. North America and the former USSR have substantially more cropland per capita than the rest of the world.

Meanwhile…

Severe land degradation affects a significant portion of the earth's arable lands, decreasing the wealth and economic development of nations. Land degradation cancels out gains advanced by improved crop yields and reduced population growth.

• Unless land rehabilitation measures are effective a downward eco-social spiral is created when marginal lands are nutrient depleted by unsustainable land management practices resulting in lost soil resilience leading to soil degradation and permanent damage.

TRENDS OF LAND TRENDS OF LAND DEGRADATIONDEGRADATION

This is all nothing but just a short view on land degradation as well as how it affected the countries even from the past until now…

Though sad to say that no developing country has installed a system for monitoring soil quality at a national scale.Existing assessments are based on consultation with experts, extrapolation from case studies,field experiments and other micro studies, or inferences from land use pattern.

During the last half-century the global extent of agriculture has

increased vastly at the expense of natural forests, rangelands, wetlands, and even deserts.

• GLASOD STUDY…

It is the most influential assessment of aggregate land degradation, in which 250 experts contributed assessments of land degradation in their countries since the mid1940’s .

The results suggest that about 560 million ha of farmland had been degraded – or 38% of the total. Within specific agro-ecological environments, experimental data from plot and field scale allowsoil degradation processes to be observed with greater precision.

The data underlying these results are, however, limited to a few experimental plots, and the basis for extrapolation to farmers’ fields is weak.

A review of 16 studies to assess the global extent, rate, and effects of soil degradation concluded that soil quality on three quarters of the world’s agricultural lands has been fairly stable over the last fifty years, but that on the remaining share land degradation is widespread and has accelerated.

Soil Monitoring Equipment…

To be used for research on land degradation.

Temperate lands, for example, are generally more resilient to degradation, but are also associated with societies that have more resources for investing in maintaining and rehabilitating land quality – and for developing alternative sources of livelihood for their citizens.

Thus, the areas for prime concern are the tropical and subtropical marginal lands, which have low physical resilience to land degradation, and are also associated with societies in which property rights are weakly defined, information systems are weak, and managerial capacity is low.

World agriculture is likely to expand in area to cater

for population growth and increased demand for food

and industrial crops._______________________________________Continued degradation of existing lands

will also raise the land clearing rate. Under current

technologies and practices this will have high local

costs, but is lesslikely to lead to large agricultural

commodity price increases – or to threaten global food

supplies within the next couple of decades.

VITAL VITAL STATISTICSSTATISTICS

The following are some of the research works done on land degradation…

Table 1 :

Estimates of all degraded lands (in million km2) in dry areas (Dregne and Chou, 1994)

Table 2 :

Estimates of the global extent (in million km2) of land degradation (Oldeman, 1994)

Table 3 :

Vulnerability to desertification and wind and water erosion (Eswaran and Reich, 1998). Only arid, semi-arid, and sub-humid areas (in million km2) are considered according to the definition of UNEP. Estimates of water erosion include humid areas.

Table 4 :

Vegetation degradation in pastoral areas of Australia (Woods, 1983; Mabbutt, 1992)

Table 5 :

Land degradation on cropland in Australia (Woods, 1983; Mabbutt, 1992)

Table 6 :

Cumulative soil loss and runoff in relation to crop yield in three ASIALAND Sloping Lands Network countries (Sajjapongse, 1998)

Table 7 :

Relationship between yield of sisal and soil fertility (0–20 cm depth) decline in Tanga region of Tanzania (Hartemink, 1995)

Table 8 :

Estimates of vulnerability to desertification in some Asian countries

Table 9 :

Matrix for risk assessment of human-induced desertification. 1 = low risk; 2, 3 = moderate risk; 4, 5, 6 = high risk; 7, 8, 9 = very high risk. (After Reich et al., 1999.)

Table 10:

Land area (1,000 km2) of Africa in risk classes. (After Reich et al., 1999.)

Table 11 :

Rates of return on activities to reduce land degradation

Table 12 :

Benefit Cost Ratios of approaches to reducing land degradation

OPINIONS ON OPINIONS ON THE MATTERTHE MATTER

Come on! Read it. I know you want to…

WAYS OF WAYS OF PREVENTIONPREVENTION

It is like what they say:“Prevention is better than a cure.”

So, in order to prevent land degradation, let us keep in mind the following:

Lake shores with homes on them featuring large grass lawns are a huge source of land degradation as well. Allowing for a natural riparian area (native plants in a protective barrier) can slow degradation from tides or wake and save the property.

Impermeable surfaces (urban settings) allow for an increase of surface runoff from rain and other water sources as well. This increases the velocity and quantity of water which might have previously infiltrated into the ground. The result is a reduction of soils and a scarred landscape. Planting natural vegetation or creating ground water infiltration caches helps.

Off road travel does not help when tracks are not followed. Hence vegetation needs protection...

--- Ex: plants and trees.

THE SUMMARYTHE SUMMARY

Just to sum things up so your mind won’t get out of control 0_o, here’s…

Concept Map

Key points to remember are:

Degradation of land includes soil erosion, salinization, nutrient depletion, and desertification. The rate of degradation has increased dramatically with growth in human populations and technology. 

Severe land damage accompanies large scale agriculture. Restoration is very problematical. 

Continued loss of arable land will jeopardize our ability to feed the world population. 

Land degradation is worldwide - both developed and developing countries. 

REFERENCEShttp://en.wikipedia.org/wiki/Land_degradationhttp://www.globalchange.umich.edu/globalchange2/current/lectures/land_deg/land_deg.htmlhttp://soils.usda.gov/use/worldsoils/papers/land-degradation-overview.htmlhttp://www.aae.wisc.edu/coxhead/papers/CCC-April7.pdfhttp://images.search.yahoo.com/images

“I saw all the people hustling early in the morning to go into the factories and the stores and the office buildings, to do their job, to get their check. But ultimately it’s not office buildings or jobs that give us our checks. It’s the soil. The soil is what gives us the real income that supports us all…” --- Ed Begley, Jr.