unknown land

Land is the main resource of the planet and yet it is not preserved enough. Prof. Yosef Steinberger from Bar Ilan University, land expert and Israel's representative on environmental issues in the European market, has some ideas

The population of the earth is growing, today - 7 billion, in 2020 - 9.5 billion and in 2050 - 13 billion. Man occupies more and more space on the face of the earth and the available space is getting smaller and smaller; the amount of food consumed increases; The earth is getting warmer; The glaciers will melt and large areas will be covered with water - land will become a sought-after commodity. The land issue has recently occupied some of the best minds in the European community. The reason: many regions in Europe are undergoing a desertification process. The European community is aware of this and within the framework of the European market moves are being developed to stop the process. We spoke with Prof. Yosef Steinberger from the Faculty of Life Sciences at Bar-Ilan University who was recently awarded the Lifetime Achievement Award in the field of soil ecology by the International Society for Soil Ecology. Steinberger is the Israeli representative in the European market for science and technology in the field of earth systems sciences and environmental interface.

Prof. Steinberger, how do you define soil, what are its components and what are the interrelationships between them?

Soil consists of a physical, chemical and organic component, and the most important of all the different populations of creatures in it. They are responsible for its stability, for the constant supply of food materials, the decomposition of organic matter and its circulation, and other actions that most people are not aware of at all. The system as a whole consists of three components: the first component - the producers - are the only ones capable of utilizing the sun's energy to produce organic matter. These are the plants and various photosynthetic bacteria. The second component is the consumers - the creatures living on Earth, including humans, who use the organic material. And the third component is the decomposers - various bacteria and fungi that break down the organic matter that reaches the ground from the producers. They break it down into nutrients - nitrogen, carbon, phosphorus, sulfur and others - the components necessary to build plant cells, which are used to produce the organic matter. Thus the circle is closed.
During the decomposition of the organic matter that occurs in the soil, the decomposers secrete substances that stabilize the soil and together with other chemical components form aggregates (aggregates) of soil that stabilize it and give it resistance to environmental factors that cause it to disintegrate, such as floods, radiation and other environmental factors that also include human activity.

What is the state of knowledge about this "black box"?

It turns out that as of today, the knowledge accumulated on the ground is quite limited. We do not know the variety of species that live in the soil and affect its stability and do not understand their role. In many parts of the world there are serious problems with the stability of the soil that seriously damage its fertility and may lead to a lack of food in the long run. Other areas are undergoing a desertification process whose implications are no less serious. Due to the lack of knowledge in the field, the solutions given to problematic situations are not always optimal.

Can you give a concrete example that will represent the problematic in the field?

The number of examples is many, but I will briefly try to give an actual example to which I myself was exposed during a scientific tour that was organized in the southern countries of the former Soviet Union after the fall of the walls (Uzbekistan, Kazakhstan and Kyrgyzstan). During the tour of the field I learned a lot about the disaster that the "five-year" programs can bring. Lack of consideration of basic scientific rules and consideration of the needs of the local population resulted in excessive use of pesticides and chemical fertilizers. The results - the disappearance (drift) of the organic layer of the soil (in this case about 30 cm of the upper layer). The lack of fuel for heating houses affected the amount of organic matter in the agricultural areas - all of these together affected the amount of water from the source of the snow, there was a decrease in organic matter available for decomposition, as a result a decrease in biological activity in the soil, in nutrients from an organic source and worst of all - nitrogen poisoning in the population. Research cooperation and work in the field improved the situation dozens of times.

The desert is also in your field of business. How can the processes of desertification in the world be controlled or bypassed?

I am involved in two projects in this field in the European market. One is the restoration of arid areas and stopping desertification processes or bypassing them. In this regard, Israel has a significant contribution in regards to innovative technologies of growing in greenhouses and growing in brackish water. At the same time, the project people are developing aquaculture technologies. The second project deals with the development of new tools and the creation of uniform methods for identifying molecular sequences of bacteria in the soil. We know that bacteria are one of the key components of soil and are largely responsible for its fertility. If we can identify the bacteria and understand how they work, we can deal more effectively with problems in the soil.

Please give an example from one of your studies.

I am involved in research on environmental issues, in the study of natural systems and systems that suffer from human disturbances. One of the environmental issues that has been gaining momentum in recent decades is the effect of sex hormones on creatures in the soil and the disruption they cause to normal sexual development. Hormones and hormone-containing secretions are found in everything from swimming pools to the food industry, diapers, hospital products, and more. All these penetrate into the soil and drinking water. In recent years, it has been noticed that sex hormones found in the environment can interfere with the normal development of hormonal systems of organisms in nature. For example, they can change the mating of certain fish and in humans they recently discovered a reduction in the number of sperm cells in the males.

In the soil there are populations of microorganisms that know how to break down the hormones. We are looking for the creatures that can be used in the future to get rid of the substances harmful to the environment. We found that in the soil exposed to cow excrement containing sex hormones, a population of bacteria and single cells developed that was different from that found in unfertilized soil. These creatures feed on the estrogen and derive from it the energy necessary for their existence.

And what about the desert?

The significant climatic changes are expected to occur at the point of the seam between the Mediterranean region and the semi-arid region, since in the process of desertification, areas with a Mediterranean climate will turn into more arid regions. Because of this, the importance of research in these areas is great. In the laboratory, long-term studies are conducted with the aim of examining the effect of changes in the rainfall regime in space and time, on the structure and function of the population of microorganisms in the soil along a climatic gradient in Israel.

The issue of forestry is also important to the issue of desertification. The forests prevent soil erosion and weathering and thus prevent desertification processes at the same time as their contribution as a treasure habitat containing great biological diversity and as a cultural-tourism asset for the public in Israel. In the last decade, forest fires have increased in many parts of the world, including Israel, and in the laboratory we have been monitoring the condition of the soil and the decomposers living in it, in order to understand the effect of the fire and a sustainable forest interface, on the functioning of the soil.

It is important for me to point out that my branch studies are conducted by the students and my colleagues in the laboratory and collaborations with research colleagues in the US and Europe, China, Taiwan, Mexico, and more. We are the only laboratory in Israel and in the region as a whole that is involved in understanding the structure and function of the soil as a holistic system for all its components - chemical, physical and biological.