| Biography | |
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 Prof. M. E. Asadi Golestan Agricultural and natural resources research and education center, Iran |
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| Title: Healthy soils with conservation agriculture systems | |
| Abstract: Soil is the network of interacting living organisms within the earth's surface layer, which support life above ground – plants and animals, including humans. Soil form the skin of the Earth. Soil consists of a variable, and often complex, mixture of organic matter, sand, silt and clay particles. Soil is our life support system. Soils provide anchorage for plant roots, while holding water and nutrients. Soils are home to myriad microorganisms that fix nitrogen and decompose organic matter, and armies of microscopic animals as well as earthworms and termites. Earthworms as macro fauna are considered as soil engineers because of their effects on soil properties and their influence on the availability of resources for other organisms, including microorganisms and plants. Soil plays a vital role in the Earth’s ecosystem. Without soil human life would be very difficult. Soil filters the rainwater and regulates the discharge of excess rainwater, preventing flooding; it is capable of storing large amounts of organic carbon; it buffers against pollutants, including CO2. Soil protects groundwater quality. Many people don’t realize that soil, especially healthy soil, is full of life. Millions of species and billions of organisms make up a complex and diverse mix of microscopic and macroscopic life that represents the greatest concentration of biomass anywhere on the planet. Bacteria, algae, microscopic insects, earthworms, beetles, ants, mites, and fungi are among them. Altogether, their value has been estimated at $1.5 trillion a year worldwide. What these low-lying creatures lack in size, they make up for in numbers. Consider bacteria, the soil microbes with the highestnumbers. For example, you can fit 40 million of them on the end of one pin. In fact, there are more soil microorganisms (microbes for short) in a teaspoonful of soil than there are people on the earth. These microbes, which make up only one-half of one percent of the total soil mass, are the yeasts, algae, protozoa, bacteria, nematodes, and fungi that process soil into rich, dark, stable humus. The healthiest soils are those with a diversity and abundance of life. Farmers who adapted conservation agriculture (CA) approach understand that tillage, the turning of the soil that has been the standard for growing crops for years and years, is disruptive to soil microbes and destructive to the soil system and its very structure. Instead, they disturb the soil as little as possible, generally using specially designed planters that can sow seed into unplowed soils, even though crop residues. CA farmers grow a diversity of living plants in the soil as much of the time as practical, covering the soil and offering food to soil microbes through living roots. Those soil organisms, in turn, cycle nutrients back to the plant, allowing it to grow and flourish. It’s a natural, symbiotic system that leads to healthy soils and more sustainable and profitable agriculture. Tillage is the main cause of soil disturbance. In the minds of many, a freshly tilled field means it’s ready for the next planting. But soil scientists can prove that tillage generally isn’t good. When soil is tilled, the top 20 centimeters of the soil is often disturbed and even inverted.The plowing and disking implements often make a compaction zone in the soil at the lower depth of the implement, which limits root growth and water infiltration. CA-based crop management technology recommends, when practical, leaving the previous year’s crop residues on the soil surface as well as growing a cover crop between cash crops to provide more surface and subsurface biomass to improve soil health. Tillage destroys the soil’s pore space which is a critical part of how water gets into the soil (infiltration). When we till the soil, we destroy the soil aggregates creating a tighter soil where water infiltration and soil water storage for the plants are severely reduced. Instead of water going deep into the soil for the plant to use, the water runs off the soil surface taking valuable topsoil with it. CA-farming practices that involve minimal soil disturbance, permanent soil cover and the use of crop rotation to simultaneously maintain and boost yields, reduce costs for farmers – especially by saving fuel for the soil tillage – increase soil quality, reduce soil erosion and improve biological activity, all while increasing agricultural productivity, especially by increasing resilience to drought. Unplowed fields that retain crop residues are better at capturing and holding moisture, often raising yields with less water. CA is a conservation practice that can save on irrigation, labor and fuel costs. Studies show a producer can save at least 30% of water consumption per hectare by changing from conventional tillage to CA. It’s a sound investment for the environment and the farmer. In the last few years, the term ‘soil health’ has replaced ‘tilth.’ Soil health includes the properties mentioned above, but also includes soil temperature, water content, soil faunal populations, pH, fertility, and nutrient cycling. USDA’s Natural Resources Conservation Service defines soil health as ‘the capacity of a specific kind of soil to function, within natural or managed ecosystem boundaries, to sustain plant and animal productivity, maintain or enhance water and air quality, and support human health and habitation. There are four key soil health concepts to remember when trying to develop a healthy soil. They are: 1- Disturb the soil as little aspossible; 2- Increase diversity by using crop rotation; 3- Keep living roots in the soil as many days as possible throughout the year; and 4- Keep the soil covered as much as possible. Disturbances such as tillage introduce an abundance of oxygen to the soil that accelerates the action of bacteria that process organic matter. This leads to rapid oxidation of organic matter (OM) and an overall loss of OM in the soil as it is decayed and released into the atmosphere as carbon dioxide (CO2). Conventional tillage systems that disturb the soil multiple times a year cause the soil biological system to be dominated by a bacterial community. Removing tillage and minimizing disturbance allows the fungal, micro-arthropod, protozoa, nematode and earthworm populations to come into balance with their environment and produce a more diverse biological community. Processing of OM becomes more consistent throughout the year with CA practices and OM levels will actually begin to increase. In this lecture we will provide some examples and case studies from adoption and practices of CA in developed and developing countries especially Asian countries who got good results in terms of healthy soils. | |
| Biography: Mr. Mohammad Esmaeil Asadi, an Iranian citizen, finished my Ph.D degree in Integrated Water Resources Management, at Asian Institute of Technology (AIT), Thailand in Aug 2001. Currently I am working as a principle research scientist in Golestan Agricultural and Natural Resources Research and Education Center (GANRREC) that is governmental center which is situated in Golestan Province north part of Iran near Caspian Sea. My research interests are as follows: 1- Irrigation/drainage systems design, development and performance evaluation 2- Conservation Agriculture (CA), Soil and water management of upland crops 3- Development/validation/applications of water management, and crop models 4- Precision Farming 5- Climate change, agrometeorology and cropwatch In addition, I am an official instructor of CA courses for experts and researchers in Ministry of Agriculture of Iran. I am also instructor of some courses like irrigation systems, soil water and plant relationship, climatology, water quality and so on in national universities (2002-2017). Moreover, as a senior researcher of GANRREC from 1989 to 2017, I had followed a well balanced approach in discharging my 3 functions such as teaching, research and outreach activities. My academic functions include teaching regular soil and water courses per year. The regular courses include Irrigation and Drainage Engineering and Management; Land and Water Conservation, water quality, climatology and so on. From 2012 to present, I have handled CA courses at all over the country for farmers, experts and researchers. On the research side, I have conducted sponsored research projects in Iran related to CA, soil erosion, irrigation management and non-point source (NPS) pollution monitoring and modeling. I had also supervised/graduated 8 Doctoral and 15 Master advisees at national universities of Iran and Malaysia. The outputs from these research undertakings are reflected in my 4 published books, 15 International Journal papers and 30 International Conference papers published since finishing my doctoral degree in 2001. Google Scholar shows that as of June 2017, I had more than 200 citations with H Index of 7. | |
