Measurement of degradation on under-utilized natural turf

The role of turf serving animal husbandry is significantly declining with the decreasing number of grazing livestock in Hungary. Accordingly, the area of under-utilized or non-utilized turfs is increasing. At the University of Debrecen, Institutes for Agricultural Research and Educational Farm, Karcag Research Institute we studied four types of turf utilization in three repetitions on a salt meadow with Alopecurus pratensis. As a result of the performed examinations, we identified the composition of the flora structure on the investigated area and we measured carbon-dioxide circulation and soil moisture.


INTRODUCTION
Turf cultivation occupies 11% of agricultural area in our country (799.3 thousand ha) (Central Statistical Office, 2018), which should mean considerable forage base, but turf is the serving branch of grazing livestock and with the loss of its income and prestige this branch has gone into crisis (Vinczeffy, 1993). Beside these, the turf area in our country is gradually decreasing (Harcsa et al., 2008;2011). Vinczeffy (1993) found that the natural, species-rich turfs is also decreasing because of tree plantations and building. More and more often extreme weather conditions also affect the turf culture . It is very important the fact that the turf uses 840 litre water for producing 1 kg dry matter without any nutrition (Barcsák et al., 1978;Szemán, 2006). Beside the decreasing tendency of turfs, most of our turfs are nature reservations (Molnár and Csízi, 2015). Because of this, so agrotechnical and utilization technologies must be applied in turf culture which can reach yield surplus and this can compensate yield loss caused by discarding nutrition resupply and irrigation (Dér et al., 2003;Bajnok et al., 2011).
Therefore, new concepts have been introduced into turf culture discipline (Szemán, 2006;Harcsa, 2009), these are the following: fertile turf, abandoned turf and fallow turf. Fertile turf is suitable for agricultural aims. The abandoned turf is at the beginning of the failure process. With the progress of succession, the fellow turf appears, where the valuable components of the turf are suppressed because of discarding utilization.
Yield of degraded turf is used, but because of inefficient methods the proportion of valuable turf components is gradually decreasing or missing, so the worthless species are dominant (Szente et al., 1998;Stefler et al., 2000;Magyar, 2009). The inefficient utilization has two types: over-utilization, in case of over-grazing load the turf becomes thinner and weeds avoided by livestock can spread in free places (Szente et al., 1998;Magyar, 2009;Czóbel et al., 2012). In case of under-utilization Penszka et al. (2015;2016) and Pápay (2016) wrote that succession processes endanger the life and survival of valuable turf components. Because of Williems and Bik, (1998), Török et al. (2007) in European mountain turfs under-utilization is also a problem Stefler et al. (2000) and Halász (2018) confirmed that not only the overload, but the lack of utilization lead to turf degradation. According to Nagy (2001) on non-utilized areas the mother hay becomes old, sprouting is very moderate and the big size dicotyledonous weeds can dominate. Barcsák et al. (1978) state that flora components of non-utilized turfs change into an unfavourable direction, so the processes of natural succession boom, while Vinczeffy (1993) determined that because of the inefficient turf utilization these areas can become sea weed. Because of discarding to mow on the meadows reeds form (Szabó et al., 2010), on the dry turfs bushes and forest formation starts (Bajor et al., 2016;Hanson and Fogelfors, 2000;Kozák, 2011;Szentes et al., 2011;. Erdős et al. (2013;2014a;2014b) found that with scrub formation species richness of turfs is decreasing. If the traditional turf treatment ceases, (Bakker and Berendse, 1999) on the under-utilized areas the amount of flammable grass moor will grow (Ryser et al., 1995), which increases the risk of grass fires (Brockway et al., 2006;Ónodi et al., 2008). Da Ronch et al. (2002) investigated the consequences of ceasing utilization and determined that the number flora species decreased to one fourth. Tóth et al. (2002) investigated the flora on bound soil, natural turfs which are similar to our experimental area and they observed that species richness decreases form grazing through mowing to zero utilization. According to Kahmen et al. (2002), for the adequate treatment the valuable species disappear on the area and at the same time the spread of competitor species threaten the survival of natural turfs (Isselstein et al., 2005). The consequence of the decreasing flora diversity is the poor fauna, too (Barcsák et al., 1978;Bartha et al., 2014). Furthermore, foreign species appear, which causes the ruin of the natural condition (Ferrer and Broca, 1999). Perevolotsky and Seligman (1998) state that the undergrazing leads to "green desert". When the area becomes an impermeable bushy, the species richness of the area decreases and the danger of the wildfire increases on Mediterranean and dry areas because of water shortage. At the same time, Margóczi (2003) found that for preserving vegetation utilized and non-utilized areas are needed. According to Molnár and Csízi (2015), where there is pastored grazing method, the grazing from well to well can be a solution to terminate overgrazing near quarters and moor on far steppes. Nowadays, moor is a bigger problem on turfs than overgrazing because of decreasing number of grazing livestock. The dense grass moor blocks the germination of the valuable turf components, suppress the shorter species (fescues, Trifolium species), the worthless plants spread such as Elymus repens, and weeds can ripen seeds for instance Daucus carota, Cichorium intybus). In addition, on the under-utilized turfs the Glareola pratincola and the Alauda arvensis nestle, but their stocks are suppressed. In the past, moor turfs could be used because in spring grazing could be started earlier with using young grass growing on the moor turf from the previous year. The moor turf used as meadow was burnt with quick fire at the end of winter and a good meadow was gained (Baskay- Tóth, 1962).

MATERIALS AND METHODS
On the turf area number 01712/1 of the University of Debrecen, Institutes for Agricultural Research and Educational Farm, Karcag investigations have been done since 2009. The area of the salt meadow with foxtails (Agrosti-Alopecuretum pratensis) belongs to the Natura2000 environmental regulations, so extensive meadow culture (one mowing a year, then grazing after grass) has been done since 1987. The area is 83 m above the sea level, the average amount of precipitation in the past 50 years is 503,4 mm. In the investigation period, the total amount of precipitation was 353 mm. The features of the months according to Vinczeffy (1993) climatic index were the following: in March desert (0.032), in April dry (0.122), in May a bit rainy (0.254), in June drought (0.095), in July drought (0.088), in August desert (0.020), and in September semi-desert (0.079) weather. The soil type is medium meadow solonec. At the beginning of the experiment we settled 4 treatments in 3 repetitions, the area of the parcels were net 30 m 2 : "Ősgyep" (ancient lawn) zero treatment since 2009 (sign: A/Ő); "Mulcsozás" (mulching) stem-crushing in 3. decade of May since 2009 and mulch stays on the area (sign: A/M); "Egyoldalú kaszálás" (one-sided mowing) one mowing a year in 3. decade of May phytomass removal (sign: A/E); "Legeltetett-Kontroll" (Grazing control) mowing in 3. decade of May, hay removal, grazing after grass in August with sheep (sign: A/L).
In our experiment we done the following methods: coenological monitoring, carbon-dioxide emission measurement, soil moisture measurement and soil temperature measurement.
Monitoring plants was done on 24 th May 2019 with the quadrate method by Balázs (Balázs, 1949). Its point is that we represented the occurrent plant species within the investigated quadrate or area with dominant value by Balázs (DB). After monitoring plant covering the plant species were classified into categories of Social Behaviour Types by Borhidi (Borhidi, 1993).
The measurement of CO2 emission depends on the moisture content and temperature of the soil and the air temperature, so at the same time of the measure we measured the air temperature, the moisture and temperature of the upper 10 cm layer of the soil. For measuring the moisture and the temperature of the soil, SMT-100 device was used, which measures dielectric conductivity of the soil in 0-10 cm deep and calculates the moisture in volume percentage. At the same time of this it measures the temperature of the layer, the results can be read on the screen of a hand data collector. The measurements were done in three repetitions. The data were analysed with descriptive statistic in Microsoft Office Excel.

Results of coenological observation and Social Behaviour Types by Borhidi (SBT) in 2019
On the investigated area plant covering was monitored with quadrate method by Balázs (DB) and it was characterized with Social Behaviour Types categories by Borhidi, the results are shown in Table 1.
In "Mulching" treatment Elymus repens, Vicia tetrasperma, Alopecurus pratensis and Poa pratensis occured in every three parcels. Rosa canina leans over form ancient lawn parcels. Uncovered areas occured in every three repetitions.
By One-sided mowing" treatment, Potentilla argentea, Vicia tetrasperma, Alopecurus pratensis and Poa pratensis occure in every three parcels. There are also uncovered areas in every three parcels.
Social behaviour types (SBT) of plant species based on their role in the association. SBT shows natural and disturbing state of the association between the plant and the habitat, from its proportion we can conclude natural state, regeneration and difference from natural state of the association (Borhidi, 1993).

Measurement results of carbon-dioxide emission, soil moisture and soil temperature in 2019
Measurement of carbon-dioxide emission, soil moisture and soil temperature were done in the grazing season, the results are shown in Table 2. Table 2 Results of measurement Carbon-dioxide emission (kg×m -2 ×h-1 ), soil moisture (%), soil temperature (°C) in 2019 (Karcag)
Values on 11 th September 2019 are very important and require further measurements, because they can forecast the states caused by drought of climatic change on different utilized turfs. July in 2019 was droughty based on climatic index, while August was semi-desert. At the beginning of September 22.2 mm precipitation fell. In paradox way, there were higher values of soil moisture by "One-sided mowing" and "Grazing control" treatments than by "Ancient lawn" and "Mulching" treatments. It is possible that moor phytomass holds the small amount of precipitation falls after the longer dry period, so it cannot leak into the soil. By measuring carbon-dioxide emission, we found that there were higher values by "Mulching" and "Ancient lawn" treatments than on "One-sided mowing" and "Grazing control" areas. Our results were similar to those of Kovács (2014), Zsembeli et al. (2015) and Birkás (2017). On the areas covered with mulch and moor there is larger microbiological activity, because moor and mulch are degradable and get into the soil as organic material, which results higher carbon-dioxide emission even in drought if the soil moisture is not optimal for microbial activity. By measuring soil temperature, the values were higher by "Mulching" and "Ancient lawn" treatments than on "One-sided mowing" and "Grazing control" areas, which increase microbiological activity in the soil.

CONCLUSION
In our study, we found that succession process (shrub) has been increasing since the beginning of the survey (10 years) on the zero utilised area.
In 2019, because of droughty year non-covered areas were found with coenological investigation by Balázs in every parcel. Plants were classified into Social Behaviour Types by Borhidi and we concluded that natural competitors and stress tolerant species are in higher proportion in treatments than ruderal species, which signs the stability of the natural turf association. By measuring soil moisture, we found that the little precipitation falls after droughty period remains in mulch and moor, so by these treatments after a longer dry period smaller moisture value is expected. In similar cases (whose frequency will possibly increase) on parcels covered with moor phytomass the carbondioxide emission is the highest because of the extra degrading organic material. The confirm of this tendency requires further identifications.

ACKNOWLEDGEMENT
The study is the result of EFOP-3.6.2-16-2017-00001, "Complex country economy and sustainability development research, service system in the Carpathian Basin" project.