Water retention in soil can be understood as the water retained by the soil after it runs through the soil pores to join water bodies such as groundwater or surface streams. Pores in the soil can be defined as the air-spaces that exist in between soil particles.
Water retention is mainly dependant on the particle size of the soil. The finer the soil particles, the higher the chance that water molecules shall hold on to soil particles, such as in clay, as opposed to sandy soil, that has large and coarse particles that are not cohesive.
The water retention by soil is critical for plants and acts as the chief source of moisture for it in almost all habitats. Other than percolation through the soil, soil moisture can also deplete due to evaporation directly from the soil and by transpiration by plants.
As based on the size of the soil particles, there are four classificatory systems for the identification of soils (J. Mariamma, 2010) –
- US Bureau of Soil Classification
- International Classification
- M.I.T Classification
- Indian Standard Classification
The Indian Standard classificatory system was formulated originally for the classification of soils primarily for engineering purposes. This is because the draft for soil classification was prepared by the Soil Engineering Sectional Committee and was approved by the Civil Engineering Division Council.
The final draft was adopted by the Bureau of Indian Standards on December 19th, 1970. This system divides soils into three broad categories based on the properties of soil particles (Bureau of Indian Standards, 2004) –
i) Clay – the particles are microscopic to sub-microscopic and exhibit plasticity, allowing it to retain the most water.
ii) Silt – the particles are fine grains, but exhibit less plasticity, making this form retain lesser water.
iii) Sand and Gravel – aggregates of comparably larger particles that are coarse and loosely bound thus lacking cohesion. The least water retention is possible in this form of soil.
Different topographic and climactic patterns result in varied behaviour of soils and thus require a variety of approaches to analyze and implement soil management techniques for water retention. Soil can sometimes pose problems for not being as desired, and these problems can broadly be grouped under chemical and physical problems (National Agricultural University, NAU, 2013).
Chemical problems include high salinity or acidity in soils, along with the presence of other toxic chemicals such as phosphorous in soil (NAU, 2013). This problem becomes especially pertinent in agriculture where crop yield or productivity could dwindle due to chemicals used in the agricultural process such as pesticides and herbicides.
Among a large gamut of solutions and applications, the most common one is the use of ecologically beneficial green manure. Agricultural soil should also be frequently and properly drained to achieve effects such as the leaching of saline moisture in soils.
The physical problems can involve soil that is not able to contain much water due to lack of cohesion or due to a rigidity that can occur owing to encrustation, or a very clayey surface. Shallow depth of soil, soil that is too clayey, or the presence of hard opaque surfaces underneath can also present problems to water retention and there can be water-logging when too much water is added to soil.
These require artificial solutions to soil management that frequently involves the mixing of soil with other different forms of soil. Incorporating organic matter and regulating drainage are also frequently applied solutions.
There are various methods to enhancing the water retention capacity of soil. Some methods are more traditional, and also conventional, while some involve the utilization of technology. While most of technological investment regarding water retention in soils involves technologies for enumeration and generation of data, technological solutions can vary from simple, affordable, everyday solutions to solutions utilizing high-end technology.
Some of the simple solutions include application of organic solutions such as drought resistant crop varieties and organisms that increase the fertility of soil, management and design of irrigation according to soil properties, application of biochar – produced from biomass for low-cost carbon sequestration in soil – making soil less porous, use of the roots of plants that grip soil, and application of natural by-products such as poultry litter that provide greater cohesiveness to soil.
The solutions can also range towards using complex technologies such as mapping the global water cycle in relation to water retention in soil, and preparation of dietary fibres that have high water-holding capacity from food sources used in soil. There is however, a leaning in technological progress in engineering water retention in soil to introduce organic elements in the soil instead of inorganic matter.
Receive Daily Updates
Recent Posts
- Lowering Emissions by Accelerating Forest Finance (LEAF) Coalition, a collective of the United States, United Kingdom and Norway governments, came up with a $1 billion fund.
- LEAF is supported by transnational corporations (TNCs) like Unilever plc, Amazon.com, Inc, Nestle, Airbnb, Inc as well as Emergent, a US-based non-profit.
- The world lost more than 10 million hectares of primary tropical forest cover last year, an area roughly the size of Switzerland.
- Ending tropical and subtropical forest loss by 2030 is a crucial part of meeting global climate, biodiversity and sustainable development goals. Protecting tropical forests offers one of the biggest opportunities for climate action in the coming decade.
- Tropical forests are massive carbon sinks and by investing in their protection, public and private players are likely to stock up on their carbon credits.
- The LEAF coalition initiative is a step towards concretising the aims and objectives of the Reducing Emissions from Deforestation and Forest Degradation (REDD+) mechanism.
- REDD+ was created by the United Nations Framework Convention on Climate Change (UNFCCC). It monetised the value of carbon locked up in the tropical forests of most developing countries, thereby propelling these countries to help mitigate climate change.
- It is a unique initiative as it seeks to help developing countries in battling the double-edged sword of development versus ecological commitment.
- The initiative comes at a crucial time. The tropics have lost close to 12.2 million hectares (mha) of tree cover last year according to global estimates released by Global Forest Watch.
- Of this, a loss of 4.2 mha occurred within humid tropical primary forests alone. It should come as no surprise that most of these lost forests were located in the developing countries of Latin America, Africa and South Asia.
- Brazil has fared dismally on the parameter of ‘annual primary forest loss’ among all countries. It has lost 1.7 mha of primary forests that are rich storehouse of carbon. India’s estimated loss in 2020 stands at 20.8 kilo hectares.
- Between 2002-2020, Brazil’s total area of humid primary forest reduced by 7.7 per cent while India’s reduced by 3.4 per cent.
- Although the loss in India is not as drastic as in Brazil, its position is nevertheless precarious. For India, this loss is equivalent to 951 metric tonnes worth carbon dioxide emissions released in the atmosphere.
- It is important to draw comparisons between Brazil and India as both countries have adopted a rather lackadaisical attitude towards deforestation-induced climate change. The Brazilian government hardly did anything to control the massive fires that gutted the Amazon rainforest in 2019.
- It is mostly around May that forest fires peak in India. However, this year India, witnessed massive forest fires in early March in states like Odisha, Uttarakhand, Madhya Pradesh and Mizoram among others.
- The European Union’s Copernicus Atmospheric Monitoring Service claimed that 0.2 metric tonnes of carbon was emitted in the Uttarakhand forest fires.
- Implementation of the LEAF Coalition plan will help pump in fresh rigour among developing countries like India, that are reluctant to recognise the contributions of their forest dwelling populations in mitigating climate change.
- With the deadline for proposal submission fast approaching, India needs to act swiftly on a revised strategy.
- Although India has pledged to carry out its REDD+ commitments, it is impossible to do so without seeking knowledge from its forest dwelling population.
Context:-
At the recently concluded Leaders’ Summit on Climate in April 2021, Lowering Emissions by Accelerating Forest Finance (LEAF) Coalition, a collective of the United States, United Kingdom and Norway governments, came up with a $1 billion fund plan that shall be offered to countries committed to arrest the decline of their tropical forests by 2030.
[wptelegram-join-channel link=”https://t.me/s/upsctree” text=”Join @upsctree on Telegram”]What is LEAF Coalition?
Why LEAF Coalition?
Brazil & India
According to the UN-REDD programme, after the energy sector, deforestation accounts for massive carbon emissions — close to 11 per cent — in the atmosphere. Rapid urbanisation and commercialisation of forest produce are the main causes behind rampant deforestation across tropical forests.
Tribes, Forests and Government
Disregarding climate change as a valid excuse for the fires, Indian government officials were quick to lay the blame for deforestation on activities of forest dwellers and even labelled them “mischievous elements” and “unwanted elements”.
Policy makers around the world have emphasised the role of indigenous tribes and local communities in checking deforestation. These communities depend on forests for their survival as well as livelihood. Hence, they understand the need to protect forests. However, by posing legitimate environmental concerns as obstacles to real development, governments of developing countries swiftly avoid protection of forests and rights of forest dwellers.
For instance, the Government of India has not been forthcoming in recognising the socio-economic, civil, political or even cultural rights of forest dwellers. According to data from the Union Ministry of Tribal Affairs in December, 2020 over 55 per cent of this population has still not been granted either individual or community ownership of their lands.
To make matters worse, the government has undertaken systematic and sustained measures to render the landmark Scheduled Tribes and Other Traditional Forest Dwellers (Recognition of Forest Rights) Act, 2006 ineffective in its implementation. The Act had sought to legitimise claims of forest dwellers on occupied forest land.
Various government decisions have seriously undermined the position of indigenous people within India. These include proposing amendments to the obsolete Indian Forest Act, 1927 that give forest officials the power to take away forest dwellers’ rights and to even use firearms with impunity.
There is also the Supreme Court’s order of February, 2019 directing state governments to evict illegal encroachers of forest land or millions of forest dwellers inhabiting forests since generations as a measure to conserve wildlife. Finally, there is the lack of data on novel coronavirus disease (COVID-19) deaths among the forest dwelling population;
Tardy administration, insufficient supervision, apathetic attitude and a lack of political intent defeat the cause of forest dwelling populations in India, thereby directly affecting efforts at arresting deforestation.
Way Forward
Tuntiak Katan, a global indigenous leader from Ecuador and general coordinator of the Global Alliance of Territorial Communities, aptly indicated the next steps at the Climate Summit:
“The first step is recognition of land rights. The second step is the recognition of the contributions of local communities and indigenous communities, meaning the contributions of indigenous peoples.We also need recognition of traditional knowledge practices in order to fight climate change”
Perhaps India can begin by taking the first step.