About Water

Yvonne Baskin in her book “The Work of Nature” states that the earth possesses the only liquid water in the solar system. She explains that life sprang from the waters of ancient oceans, and that humans live intricately bound to processes of water. The water that bathes the earth’s surface provides habitat to many organisms, and essential sustenance to all.

She reminds us that our Palaeozoic ancestors crawled from the seas 400 million years ago, yet our fellow creatures and we still carry within our tissues a remnant of those early oceans. Like most organisms, humans are two thirds of water, and we must consume roughly two litters a day to flush and replenish our vital processes.

In her opinion, the continual renewal and cycling of water through plants and animals and across the landscape is essential to the productivity of the lands, lakes, and coastal waters from where we harvest our food.

She says that the fresh water rivers, lakes and reservoirs contain less than half of one percent of the planet’s fresh water. Fortunately for life on earth, the ocean is a reservoir of fresh water. 

Yvonne explains that water is breathed out pure and fresh from the evaporation of oceans, from the open waters and soils of the continents, and by the life processes of plants and animals, a great exhalation of water vapour powered by the energy of the sun. This vapour cools and condenses into clouds, rains out and makes its way back toward the sea.

It is her opinion that the most grandiose attempts by humans to modify the water cycle are dams, reservoirs, and diversion channels that have radically altered the quality and flow patterns of most of the earth’s major rivers. The global climate changes that human civilization has set in motion by unrestrained emissions of greenhouse gases may cause a major redistribution of the earth’s rainfall.

She says that of the 113,50 cubic kilometres of rain that strike the land each year, two- thirds evaporates directly from wet leaves and soil or gets dawn up by plant roots and transpired back to the atmosphere, as crops, meadows, and forests grow. The remaining water percolates through the soil into underground aquifers or runs off cross the surface to join the ocean, replenishing lakes, rivers and other aquatic habitats along the way and creating a vast arterial system that connects alpine forests to coastal marshes.

She alerts us to the fact that in croplands around the world, water logging and salinization of   soils are major causes of deterioration. That one-third of the world’s food is now produced on artificially irrigated lands, and one third to one half of those fields suffer moderate to serious salt problems because wasteful amounts of water – are pumped up into poorly drained soils. 

She tells us that when rivers run grey with mud or lakes are filled with pond scum, it often means someone upstream has ravaged forests, packed too many cattle onto the range or cleared sloping land for crops.

She informs us that results clearly show that neither maize nor grasses can duplicate the services of the original forest. The forest lets virtually none of its soil or water escape and sustains a lush productivity year round.

She alerts us to the fact that the destruction of the forest for a few years worth of unsustainable grain crops is a tragic trade. And that the sediments flow, are only half the problems created by modern agriculture. Since the mid-twentieth century, chemical fertilizers have powered an enormous increase in world food production and are not intricately linked to agriculture. 

She states that between 1950 and 1989, for example, the world’s farmers increased their annual fertilizer use from 14 million tons to 143 million tons. Too much of this fertilizer, however, never contributes to crop growth. 

The consequences of the use of these fertilizers are invisible to farmers, often showing up far downstream in rivers, lakes, and coastal waters. One of the major fertilizer ingredients, phosphorus, binds to soil particles and is carried away with surface runoff. Nitrate, is highly water-soluble and leaches from nitrogen fertilizers, animal wastes, and organic matter. This causes serious pollutants in drinking water supplies. They have been linked with increases in lymphatic cancer, and, at high levels in drinking water, nitrates can cause a type of anaemia in infants.  

She tells us that in the tropics as well as in temperate streams, overhanging vegetation may    supply the bulk of the organic matter that fuel the aquatic communities below. The black water rivers of Amazonia, for instance, are both acidified and tinted dark by organic substances leached from decomposing leaf litter and from soils of annually flooded forests. 

She says that the acidified water discourages the growth of aquatic plants like algae or water hyacinths. The few fish species that make a living in black water rely on beetles, fruit, seeds and other materials that happen to tumble into the water from the tropical forest overhead. When these forests are cut, the aquatic community’s lifeline is also severed, and little can survive in the rivers.

She explains us that downstream in the tropics, along river deltas and lagoons, flooded mangrove forests perform many of the same roles that trees along temperate streams do: sopping up nutrients and sediments that run off the land, stabilizing shorelines, creating habitats that nurture aquatic organisms, and sometimes supplying much of the organic matter that    supports the food chain in nearby coastal waters.  

She tells us that researchers are studding and putting into practice a system that they believe can work in order to prevent further ecological destruction -ecological restoration is a notion that degraded lands can be restored to a fully functional and self-sustaining condition and that the ecological damage can be undone and natural landscapes recreated. 

Some improvements have been verified in prairies where ecologists have put this system into practice. The structure and water holding capacity of the soils have improved dramatically.  

The author tells us that multi-crop agriculture has also been put into practice. The question for researches is weather multi crop systems involving only two or three species can achieve the same yield as monocultures without sacrificing the sustainability that diversity provides. Studies so far show that the right combination of species in the right setting can consistently yield more together then the same species grown singly on the same plot. Not only do multi-crop systems often match the output of monocultures; more important, they may provide steadier yields through good and bad years while requiring fewer artificial resources to defend or nurture them. 

This strategy involves combining a cereal grain with a nitrogen-fixing legume, such as inter-planting rows of corn between rows of clover. The clover supplies nitrogen, provides living mulch, protects soil and water, and creates habitat for insects that prey on crop pests.

Plant diversity in a field not only lowers the risk of complete crop failure but also preserves a level of natural pest control that helps reduce losses to insects. It can also help sustain productivity by preventing soil deterioration. In any multi-crop system, of course boosting output depends on picking the right combination of species.

Around the world new strategies have arouse in order to prevent further ecological destruction: 

Researches say that by practising organic farming many harmful situations can be avoided. Organic farming consists in a production system, which avoids or excludes the use of synthetically compounded fertilizers, pesticides, growth regulators, and livestock feed additives.

This system relies upon crop rotations, crop residues, animal manures, legumes, green manures, farm organic wastes, mechanical cultivation, mineral-bearing rocks, and aspects of biological pest control to maintain soil productivity, to supply plant nutrients, and to control insects, weeds and other pests.

Sustainable Agriculture is also being put into practice. It is a philosophy based on human goals and on understanding the long - term impact of our activities on the environment and on other species. Use of this philosophy guides our application of prior experience and the latest scientific advances to create integrated, resource conserving, equitable farming systems. These systems reduce environmental degradation, maintain agricultural productivity, promote economic viability in both short and long term and maintain stable rural communities and quality of life.

According to researches the first aspect of sustainable agriculture is the understanding that a respect for life, which protects its various forms, and recognizes their right to exist, is not only desirable but also necessary to human survival. A second aspect requires that the farming system does not put life in jeopardy; its methods do not deplete the soil or the water, or place farmers in situations where they themselves are depleted, either in numbers or in the quality of their lives.

Sustainable agriculture is:

-          Environmentally sound

-          Economically viable

      -          Socially acceptable