Stop The Burning
Soil WAR
Soil Fertility & Erosion - World Agricultural Report
The World Bank and the United Nations initiated a unique international scientific process to evaluate the state of global agriculture, its history and future: the International Assessment of Agricultural Knowledge, Science and Technology for Development (IAASTD), commonly known as the World Agriculture Report. More than 400 scientists, stemming from all continents and a broad spectrum of disciplines, worked together for four years with the aim of answering the following question:
“How can we reduce hunger and poverty, improve rural livelihoods and facilitate equitable, environmentally, socially and economically sustainable development through the generation of, access to, and use of agricultural knowledge, science and technology?"
Click on the link for the full results of the study
One handful of healthy soil contains more micro-organisms than there are people living on earth. The thin layer of topsoil, that we walk on and through which plants send their roots, is the result of enduring, age-old processes of decomposition, transformation and accretion through countless organisms. Most of these organisms are microscopic and at present we only know a fraction of them. Since the transition from hunter-gathering lifestyles to settled agricultural societies, human civilisations have time and again learnt from painful experience that healthy soils are more fragile than they might appear. The long-term fertility of a soil, its resilience and capacity to regenerate form the foundation of all forms of agriculture which is built on a very sensitive base.
Errors in the management and care of soils often become visible when it is too late to avoid the consequences. Some proven methods are no longer adequate to meet the demand of a growing world population for fertile soil. These include slash and burn agriculture, which was traditionally used to convert forest areas into arable land for are restricted period of time, thereby adding nutrients to the soil, as well as the practice of leaving land fallow for several years to enable soils to regenerate. Some of the world's most vulnerable farmlands are tropical areas, where most of the organic matter is found on and above the surface, overlying a very thin topsoil layer, as well as the oldest soils in the world in the subtropical, dry plains of Africa. European soils, on the contrary, are deeper and richer in organic matter and for this reason more resilient.
Building up, maintaining and conserving the fertility of different soil types around the world in the face of diverse climatic conditions is the biggest challenge to agriculture today. The key to soil fertility lies mostly in it's humus content. The wide variety of essential nutrients can only be available if soils contain a sufficient proportion of decomposed organic matter. And only then can these nutrients dissolve in the water and be absorbed by the plant. Generations of farmers and soil scientists from different backgrounds have been researching and experimenting with tilth, the optimum soil condition for the cultivation of plants. Animal and human manure, nitrogen-fixing leguminous plants, mulching techniques, composting and adequate crop rotation can all play an important role. Equally important factors for soil fertility are the preparation and protection of the soil structure, root penetration, aeration, water absorption and storage, wind protection, run-off prevention, and terracing. To be truly healthy, soil also needs to be teeming with a wide variety of soil-dwelling organisms, as well as the right combination of micro organisms and fungi.
Over the past hundred years, the sophistication of localised adaptive soil conservation and land use has suffered, because these skills have increasingly been replaced by the generalised use of synthetic mineral fertilisers. These fertilisers are easily applied, are seemingly inexhaustible and have replaced the long-term conservation and building-up of soil fertility. Each year, more than a 100 million tonnes of synthetic nitrogen fertiliser are manufactured using the eponymous Haber-Bosch industrial process for making ammonia, developed by German chemists Fritz Haber and Carl Bosch. Since the process only works at high temperatures and pressure it requires large energy inputs, making agriculture in general and soil fertility in particular dependent on the oil price.
The boost in nutrients, provided by nitrogen fertilisers, made possible the steep increase in agricultural production over the past century and enabled the current overproduction. However, it has the same fatal effect on soils as a drug: the natural soil fertility and especially the humus formation are both affected. Soils are depleting and leaching faster; soil acidification is accelerating; or the soils need higher doses of mineral fertilisers. At the same time, mineral fertilisers tempt farmers to abandon the more time-consuming, knowledge-based and labour-intensive methods of conserving soil fertility. Or they are compelled to do so for economic reasons. Without the introduction of industrially produced mineral fertilisers, farmers would not have been able to specialise in just a few crops, have monocultures or give up animal husbandry.
The IAASTD makes the case for an intensive relearning of this knowledge for both industrial and small-scale agriculture, as well as its re-application in agricultural research. The report calls for refraining from all forms of agriculture and soil management that disregard the fundamental value of fertile soils. This includes over-fertilisation, the overexploitation of sensitive soils, and exposure to water and wind erosion, which can be prevented for example with a stock of trees or hedges. Other harmful practices include the use of heavy machinery which can lead to soil compaction, as can deep or unnecessary tillage with a plough. But soils are also threatened by the sealing of fertile land close to cities in industrial regions.
Monoculture
Plants need more than just sunlight and water in order to grow. They require a variety of different nutrients. In natural environments. Plants obtain most necessary nutrients from minerals found within the soil. When trees and shrubs shed their leaves or plants die, they fall to the ground, decompose, and release nutrients back into the soil, making them available for new plants. In this way, nutrients are "recycled" with each generation.
On farms, the nutrient cycle is different. Since crops are continually harvested, there is no steady supply of decaying plant material to replenish nutrient levels within the soil. Instead, nutrients must be restored by adding fertilizers to the soil.
Traditionally, agricultural soils were fertilized using livestock manure and urea, which is rich in nutrients and organic matter. Farmers also practiced crop rotation, regularly alternating the types of crop grown in various fields and periodically allowing fields to remain unplanted. This process enables organic matter to accumulate and decompose, thus restoring nutrients to the soil.
However, industrial agriculture has dramatically altered all that. Today, industrial farms no longer raise animals and crops together. Instead, livestock are raised in enormous concentrated operations, and crops are mass-produced on separate farms. Although the former generate tremendous amounts of manure, it’s too costly to transport it to other cropland for use as fertilizer.
Instead, today’s large-scale industrial farms depend on synthetic, manmade chemical fertilizers to support high-intensity monocrop systems. Unfortunately, synthetic fertilizers are often over-applied to cropland. In fact, it’s estimated that only about half of all fertilizers are actually absorbed by plants; the remaining chemicals pollute the atmosphere, soils and waterways.
As to the enormous amount of manure generated it also causes significant pollution problems. In order to avoid the expense of treating or transporting this animal manure, it is typically stored in huge open-air pits, or "lagoons," and eventually the untreated liquid manure is sprayed onto surrounding land.
Nutrient pollution damages aquatic ecosystems by stimulating the rapid growth of algae. This reduces the aesthetic and recreational values of waterways, and harms many other living organisms. When the algae die, the process of decomposition uses oxygen dissolved within the water - this oxygen depletion eventually kills fish and other aquatic organisms.
Sustainable nutrient management techniques allow farmers to maintain healthy, productive soil for crops without degrading the environment.
Small-scale sustainable farms are able to recycle nutrients by fertilizing their crops using compost and manure produced naturally by their livestock. Sustainable farms only raise small numbers of animals, creating enough manure to fertilize crops without polluting the environment or jeopardizing human health.
This enables sustainable farms to avoid using harmful synthetic fertilizers. Natural fertilizers, made of organic materials such as manure and compost, have been shown to cause much less pollution than synthetic fertilizers. One ten-year study of maize fields revealed that fields treated with synthetic fertilizers released 60% more nitrates into groundwater than fields treated with natural fertilizers.
Sustainable farmers have also increased nutrient levels in the soil by growing cover crops such as rye, buckwheat, hairy vetch, clover, cowpeas, millet and forage sorghums. When planted after harvests and chopped into mulch, cover crops help add organic matter and nutrients to fields, thereby reducing the amount of fertilizer required to grow additional crops in the future.
They help soil retain moisture, decrease water runoff, prevent crusting and increase the long-term accumulation of organic matter. They are also able to retain more oxygen since they aren’t compacted by the heavy machinery used in conventional systems.