Interview with Professor Oļģerts Nikodemus, Faculty of Geography and Earth Sciences, University of Latvia

Your name also appears on the covers of books about soil issues!

That is true! Soil research and related issues are one of the areas I work in! I have been interested in soil ever since I enrolled in the Faculty of Geography at the University of Latvia. Currently, thanks to the new colleagues who have joined us, I believe we are in a leading position regarding soil issues in Latvia.

The Zemgale Plain and the regional acclaim as Latvia's breadbasket. Can we still say that?

Zemgale is still the most fertile region in Latvia! Quite a while ago – around the year 2000, when many agricultural areas were being bought up by the Danes – I heard a good description of the region: “If you sell us (the Danes) the whole of Zemgale, we will feed half of Europe!” Productivity in Zemgale's fields is very high, certainly above the European average!

If we talk about current soil protection issues, the amount of organic matter in agricultural land is decreasing! This is observed throughout Latvia, not just in Zemgale! The explanation is simple: even in Zemgale, the primary crops grown are cereals, from which, when the harvest is collected, there are not enough organic residues left behind that could then be worked into the soil. Some of the existing organic matter is used by plants, some leaches away – that is a natural process. We have few farms in Zemgale and, consequently, little manure. The result of these processes is that the amount of organic matter in the soil is decreasing. Latvia is located in a climatic zone where the soil requires regular agrotechnical replenishment of organic matter. We do not have black earth steppes like in Ukraine, where the humus layer can reach 3 metres! With intensive farming, there is nowhere for organic matter to come from. It is possible for a farmer to plough green manure into the ground, but is the farmer prepared to “remove” the field from production for a certain period? In the short term, it will not be economically profitable, but in the long term, there will certainly be benefits!

Another observed problem is soil compaction. The agricultural machinery used is heavy and leaves consequences on the physical properties of the soil. Good examples, where a farmer purchases machinery so that the pressure on the soil is lower, are certainly to be commended! Looking at it overall, the situation is slowly improving, but soil compaction as a problem is quite topical! Other important issues that have been looked at less in Latvia include research on pesticide residues in the soil: what of the chemicals used in the past has remained and persisted in the soil.

Have you encountered the peculiar “Soviet legacy”: stocks of unsuitable chemicals buried in forests or bushes or otherwise hidden away?

We have not found any! Back in the day, together with geologists, we carried out geochemical mapping of the territory in Latvia, which resulted in the compilation of geochemical maps. Understandably, this work was not overly detailed, but we did not find places where anyone had buried or otherwise hidden old loads of mineral fertilisers or DDT. Most of the pesticides and mineral fertilisers from the Soviet years were collected and taken for disposal at the Gardene landfill near Dobele.

Pesticides are often referred to as a bogeyman, having been used in the wrong place and time, and under the wrong conditions…

When talking about pesticides, the question is one: how we use them! It is clearly not right to act as I recently observed in Kurzeme: a farmer is spraying a field with Roundup, while next to it is an apple orchard where beautiful apples can be seen on the branches… In small doses, the pesticide will, of course, also end up on the apples. Control and understanding of pesticide use are insufficient. It still happens that before harvesting cereals, in order to destroy weeds, so that the harvest would be cleaner and the grain easier to dry, the field is sprayed with the same Roundup… That is unacceptable!

Speaking of the amount of organic matter in the soil, I was surprised this summer by the fact that natural grasslands and meadows often like lean soil, even though we often call a bright meadow lush, which makes one think of rich soil!

In theory, we read: “many biodiverse grasslands grow in relatively poor soils.” In the current EU planning period, there was a condition that if a farmer does not keep livestock that could “graze down” the grass, and there is nowhere to put the hay, the grass mown in biodiverse grasslands must not be mulched! The mown grass must definitely be removed from the field in question so that the soil, as the grass decays, does not become richer! There is a contradiction here! From the soil protection point of view, organic matter is necessary to ensure soil fertility, but biodiversity in this case asks for soil that is as poor as possible. In this case, the “interests” should be reconciled.

It must be remembered that from the 1930s to the present day, rural residents grazed livestock closer to homes or farms! Manure was also taken to the nearest (not distant) fields. In more remote places, they mowed hay but did not graze animals. Biodiversity was more pronounced in more remote places, not close to houses or barns.

In my opinion, one of the most important factors for biodiversity is the possibility to mow valuable meadows, for example, twice. In the Soviet years, this happened because the area of backyard farms was not large, and rural people, when preparing hay, mowed in almost every gully, in meadows in the middle of the forest, that is, wherever hay could be obtained. They mowed with a tractor, and in many places, they used scythes or horse-drawn mowers. Now it is different, because it is not economically profitable to mow steep slopes, waterlogged meadows, or floodplains. These territories, if I may say so, are being lost to biodiversity because they tend not to be maintained!

So biodiversity does not exist in isolation from humans…

In Latvia's natural conditions, grasslands are created and preserved by people. Geographers strongly dispute the view of the World Wide Fund for Nature that some meadows were formed thanks to large herbivorous animals. If we look at geochronology – how vegetation has historically changed in the territory of Latvia – it is very difficult to find a period when animals were the decisive factor in the formation of meadow vegetation.

Meadows and fields are more associated with what is read in books about clearing woodland and settlers…

Recently, we have been conducting research on these historical processes – slash-and-burn agriculture – we look for charcoal or coal remains in the soil. With the help of archaeologists, we determine not only the age of the coal but also the tree species. Slash-and-burn agriculture is attributable to cereals. When the clearings were abandoned, they were replaced by shrubland (busch land in German). Cattle were grazed between the bushes, which often still happens today – especially when grazing beef cattle. When they started mowing the grass, meadows appeared!

Climate change and Latvian soil. Is there anything observable?

Natural changes in the soil happen slowly, even very slowly! The only exception is if something is suddenly and strongly influenced by humans! At present, significant changes in the soil are very difficult to detect. Scientists have only found that soil microorganisms, which react more quickly to environmental changes, are changing.

A little about the mentioned geochemical mapping (research) – what does it show?

In the vicinity of large cities, a number of chemical elements have been found in the topsoil, the amount of which is increased in these territories! It cannot be said that this is dangerous! The level of pollution with heavy metals in Latvia is generally low and not dangerous. Except for individual cases, for example, former Soviet army deployment sites, which can be considered a “local phenomenon”. Mapping showed that there are many places in Latvia (in fact – in most of Latvia) where there is a lack of selenium (Se) in the soil. For example, if a farmer raises sheep in this territory and there is not enough Se (it is not absorbed through the grass), the element must be injected into the lambs to reduce mortality. The lack of Se is natural, related to the deposits from which the soil in the respective territory was formed. It is similar with potassium (K), which is lacking, for example, in the coastal lowland, which should be paid attention to. The results obtained in mapping are valuable in land use policy, but, unfortunately, they are little taken into account.

On soil research issues, farmers in Latvia turn more to the State Plant Protection Service, for example, to draw up soil fertilisation maps. Foreigners who want to buy land in Latvia often come to us. I must say, the Germans and Danes often do not understand our soil classification and land value and often ask us to explain soil maps or map symbols.

Climate, like a blanket pulled in different directions. Is it not too exaggerated and loud?

Alarmists are needed, because if you only chirp, you might not be heard! I do not use the term climate change – it would be more accurate to say – climate variability. It is clear: man affects the climate with his actions! It is not yet clear how natural processes affect this variability and how much importance human activity has! We can look at the not-so-distant past, for example: the Little Ice Age, when it was much colder here and you could walk across the ice to Sweden. That was not so long ago – 200–300 years before us! If we take into account the shift in the Earth's axis, there is a possibility that it will soon become colder again.

In climate processes, as scientifically modelled and proven, the impact of human economic activity is also felt, but we must think – what is Latvia's influence in these processes on a global scale! For example, forest fires in South America, Africa and Russia this year; a major fire disaster in one country affects the situation on Earth much more than all of Latvia's industry and transport combined! At the same time, “purely” politically, we cannot say that this is not topical for Latvia.

What are we doing too much or too little of in Latvia?

It is difficult for me to answer this question, but in nature, balance is very important or, in the case of humans, compromise! This can be achieved in different ways.

For example, forestry and biodiversity. A topical theme at the moment is the reduction of tree-cutting diameters. In my opinion, one should not measure everything with one yardstick and “cut” everything the same way. For example, the cutting diameter could not be reduced for all spruce stands, but for spruce stands in peatlands and stands in former agricultural lands, where the timber life cycle could be very short (even 40 years), while in historical forest lands it (the diameter) would remain the previous one. In my opinion, that would be a reasonable solution, because spruce in former agricultural lands is mostly “finished off” by root rot – I see no reason why not to saw faster. Former agricultural lands, understandably, are quite fertile. By accelerating the cycle of spruce stands, we reduce soil fertility and at the same time reduce the possibility of root rot. This is roughly how I see the system working in the future. Similarly for meadows and biodiversity: the human is always smarter than the “official” solution seekers. For example, the farmer does not need hay, it would have to be taken away, which is not economically profitable, and the solution is found: the meadow must be ploughed! Biodiversity is lost, the climate is affected and… Policy must be smarter, not habitual: we all “cut” the same way because the regulations foresee it!

Mires in Latvia. Is it necessary to restore drained mires?

As much as nature has given us, that is how much there is – not too much, not too little! In some European countries, there is a theory in force that mires become overgrown with pines due to their drainage. Research carried out in Latvia shows that drainage is not the most significant cause for mires “becoming overgrown with pines”. (During the research, about 1000 pine trees were cut down in both drained and undrained mires and their annual rings were studied.) This shows that there were two periods in Latvia – in the 60s and 80s of the last century – when we had a relative drought (little precipitation), during which the mire's overgrowth with pines developed very rapidly. The direct influence of humans and drainage ditches on the mire extends about 150–200 m from the edge of the ditch! In the Ance mire, where drainage has not been carried out, pine trees also grow. Our conclusion: the influence of drainage on mires is strongly exaggerated, and in cases of “restoration of the hydrological regime”, we often go against natural processes. If we study peat and its composition, it can be seen that very often the sphagnum peat layer is replaced by a tree layer and then sphagnum is seen again. Therefore, in the previously determined period, there were also more trees in the mire! Therefore, when planning various management measures in grasslands, forests, or mires, it is important to accurately find out and understand the processes in nature.

Photographs by Toms Grīnbergs (University of Latvia Press Centre) and zemeunvalsts.lv were used