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The effects of soil management practices on soil organic matter changes within a productive vineyard in the Nitra viticulture area (Slovakia)

The effects of soil management practices on soil organic matter changes within a productive... Original paper DOI: 10.1515/agri-2016-0001 VLADIMÍR SIMANSKÝ*, NORA POLLÁKOVÁ Slovak University of Agriculture in Nitra, Slovak Republic SIMANSKÝ, V. POLLÁKOVÁ, N.: The effects of soil management practices on soil organic matter changes within a productive vineyard in the Nitra viticulture area (Slovakia). Agriculture (Ponohospodárstvo), vol. 62, 2016, no. 1, p. 1­9. Since understanding soil organic matter (SOM) content and quality is very important, in the present study we evaluated parameters of SOM including: carbon lility (L C ), lility index (LI), carbon pool index (CPI) and carbon management index (CMI) in the soil as well as in the water-stle aggregates (WSA) under different soil management practices in a commercial vineyard (estlished on Rendzic Leptosol in the Nitra viticulture area, Slovakia). Soil samples were taken in spring during the years 2008­2015 from the following treatments: G (grass, control), T (tillage and intensive cultivation), T+FYM (tillage + farmyard manure), G+NPK3 (grass + 3 rd intensity of fertilisation for vineyards), and G+NPK1 (grass + 1 st intensity of fertilisation for vineyards). The highest LI values in soil were found for the G+NPK3 and T+FYM fertilised treatments and the lowest for the unfertilised intensively tilled treatments. The CPI in the soil increased as follows: T < G+NPK3 < T+FYM < G+NPK1. The highest accumulation of carbon as well as decomposle organic matter occurred in G+NPK1 compared to other fertilised treatments, while intensive tillage caused a decrease. On average, the values of LI in WSA increased in the sequence G+NPK1 < T+FYM < G+NPK3 < T. Our results showed that the greatest SOM vulnerility to degradation was observed in the WSA under T treatment, and the greatest values of CPI in WSA were detected as a result of fertiliser application in 3 rd intensity for vineyards and farmyard manure application. Key words: index lility, carbon pool index, carbon management index, fertilisation, soil tillage, vineyard SOM represents a polyfunctional, uneven-aged, multicomponent continuum of destroyed plant residues, root exudates, microbial biomass, biomolecules, and humic substances. It has lifetimes varying from several hours or days through to millennia (Schepaschenko et al. 2013; Semenov et al. 2013). SOM content in the soils is influenced by several factors, such as climate, clay content and mineralogy and soil management techniques etc. (Stevenson 1982; Lugato & Berti 2008). Organic carbon content in the soil (SOC) is one of the qualitative parameters of the soil humus regime and long has been recognized as a key component of soil quality (Reeves 1997). SOC can be divided into lile and recalcitrant fractions based on the relative susceptibility to biological decomposition (McLauchlan & Hobbie 2004; Belay-Tedla et al. 2009). Lile SOC pools such as water-extractle organic C, hot water-soluble organic C, potassium permanganate oxidizle organic C, and organic C fractions of different oxidizility are considered to respond to agricultural management more rapidly than total organic C (Blair et al. 1995; Benbi et al. 2012). As such lile fractions of SOM are used as sensitive indicators for soil management and land use induced changes in soil quality (Kolá et al. 2011; Benbi doc. Ing. Vladimír Simanský, PhD. (* Corresponding author), Department of Soil Science, FAFR ­ SUA Nitra, 949 76 Nitra, Tr. A. Hlinku 2, Slovak Republic. E-mail: Vladimir.Simansky@uniag.sk doc. Ing. Nora Polláková, PhD., Department of Soil Science, FAFR ­ SUA Nitra, 949 76 Nitra, Tr. A. Hlinku 2, Slovak Republic. E-mail: Nora.Pollakova@uniag.sk et al. 2015; Shang et al. 2016). Small changes in total SOM are difficult to detect because of its high background levels and natural soil variility. For this reason Blair et al. (1995) recommended the use of the carbon lility (LC), lility index (LI), carbon pool index (CPI) and carbon management index (CMI) for the determination of smaller changes and changes over a short time period. These parameters have been rather quickly adopted and used for the evaluation of SOM changes (Szombathová 1999; 2010). However, data out LC, LI, CMI and CPI in individual size fractions of water-stle aggregates are very rare. In this study we evaluated the effect of different soil management practices on LC, LI, CPI and CMI parameters in (i) the soil and (ii) the water-stle aggregates. Finally, we investigated relationships between these parameters within both the soil and water-stle aggregates. soil management practices in a productive vineyard was initiated. This experimental design had been previously described by Simanský & Polláková (2014). Briefly, the treatments consisted of (1). G: as a control (in the rows and between vines rows, a mixture of the grass were sown), (2). T: tillage (in autumn tilth to a depth of 25 cm and intensive cultivation between vine rows during the growing season), (3). T+FYM: tillage + farmyard manure (ploughed farmyard manure at a dose of 40 t/ha in autumn 2005, 2009 and 2012), (4). G+NPK3: doses of NPK fertilisers in 3rd intensity for vineyards, this means 120 kg/ha of N, 55 kg/ha of P and 195 kg/ha of K kg/ha (Fecenko & Lozek 2000). The dose of nutrients was divided: 2/3 applied into the soil in the spring (bud burst) and 1/3 at flowering. The grass was sown in and between the vine rows. (5). G+NPK1: doses of NPK fertilisers in 1st intensity for vineyards, this means 80 kg/ha of N, 35 kg/ha of P and 135 kg/ha of K (Fecenko & Lozek 2000). The dose of nutrients was divided: 1/2 applied into the soil in the spring (bud burst) and 1/2 at flowering. The grass was sown in and between the vine rows. Sampling was done in the spring throughout the years 2008 ­ 2015. Soil samples were collected (0 ­ 20 cm layer) from 4 random locations within each treatment of different vineyard soil management practices. Soil samples were then mixed together to form an average sample for each treatment. Samples were air-dried. Then, each of the samples was divided and one half of them were sieved through a 2 mm sieve for chemical analyses and the second half of samples were used for the determination of water-stle aggregates (WSA). MATERIAL AND METHODS The study was conducted at Drazovce (48°21'6.16"N; 18°3'37.33"E), a village located near Nitra city in the west of Slovakia. The area (vineyard) is located under the south-west side of the Tribec Mountain. In the 11th century, the southern slopes of the Zobor hills were deforested and vineyards were planted. Today the locality is used as a horticulture area and for growing wines. The climate is temperate with a mean annual rainfall of 550 mm and the mean annual temperature 10°C. The soil was classified as Rendzic Leptosol (WRB 2006) with a sandy loam texture developed on limestone and dolomite. Characteristics of the topsoil (0­30 cm) before the experiment in 2000 are presented in Tle 1. Before vineyard estlishment the locality was andoned. In the year 2000, the vines (Vitis vinifera L. cv. Chardonnay) had been planted and up to the year 2003 the vineyard was intensively cultivated in and between rows of the vine (mechanical removal of weeds). In 2003, a variety of grasses in following ratio Lolium perenne 50% + Poa pratensis 20% + Festuca rubra commutata 25% + Trifolium repens 5% were sown in and between rows of the vine. In the year 2006, the experimentation of different T a b l e 1 Characteristics of a Rendzic Leptosol at NitraDrazovce in the year 2000 Soil properties Rock fragments [%] Clay [g/kg] Silt [g/kg] Sand [g/kg] Organic carbon [g/kg] Base saturation [%] pH (in 1 mol/dm3 KCl) Means and standard deviation 8±1.6 101±12 330±18 569±23 17.0±1.6 99.3±0.01 7.18±0.08 Seven aggregate-size fractions (>5, 5­3, 3­2, 2­1, 1­0.5, 0.5­0.25 and <0.25 mm) were separated by the wet-sieving of the soil through the series of six sieves using the Baksheev method. The method for aggregate separation was adopted from Vadjunina and Korchagina (1986). In soil samples as well as in size fractions of WSA, the soil organic carbon (C org) and lile carbon (C L) contents were determined by Tyurin (Dziadowiec & Gonet 1999) and by Loginow (Loginow et al. 1987), respectively. On the base of determined C org and C L we calculated the following parameters of SOM: carbon lility (L C), lility index (LI), carbon pool index (CPI) and the carbon management index (CMI), as suggested Blair et al. (1995). In this research, the control (G) treatment was the reference and different soil management practices (T, T+FYM, G+NPK3 and G+NPK1) were used as treatments. Analysis of variance for SOM parameters were performed using Statgraphics Centurion XV.I statistical software (Statpoint Technologies, Inc., USA). The difference between the treatments was examined by one-way analysis of variance (ANOVA) and the LSD test (P < 0.05) was used for means comparison. Correlation analyses were used to assess the relationship between L C, LI, CPI and CMI in the soil and the same parameters of SOM in individual size fractions of water-stle aggregates. RESULTS AND DISCUSSION SOM in soil The values of carbon lility (LC) were not affected by soil management practices, however differences between treatments were observed. The content of LC increased on average in the following order: G+NPK1 = T < G < T+FYM < G+NPK3. We also evaluated the effect of different soil management practices on changes in SOM parameters such as: LI, CPI and CMI, which are used for determination of smaller changes and changes over a short time period (Blair et al. 1995; Szombathová 1999; Vieira et al. 2007). Higher values of LC and LI indicated that SOM was rapidly degradle by micro-organisms, otherwise, lower values of LI indicated SOM had greater stility and resistance to microbial degradation. The highest LI values were found for the G+NPK3, T+FYM and G+NPK1 fertilised treatments and the lowest for the unfertilised, intensively tilled treatments (Tle 2). Thus, higher doses of mineral fertilisers as well as organic amendment increased the amount of less stle forms of SOM, mainly by FYM addition, as well as by the promotion of root exudates excretion and the amount of grasses' residues, or through the decay of stle SOM due to high doses of NPK application (G+NPK3). Our findings are in agreement with Fröberg et al. (2013), Tong et al. (2014), who reported the impacts of mineral fertilisers and effect of manure on mineralization of SOM. Generally, T a b l e 2 Analyses of variance of soil organic matter parameters Parameters LC LI CPI Soil management G 0.150 ­ ­ T 0.149 0.807 T+FYM 0.166 1.014 G+NPK3 0.176 0.956 G+NPK1 0.149a 1.073 1.073b 0.831a 1.104b 1.184b ­ CMI 70.800a 113.700b 116.000b 116.100b G ­ control; T ­ tillage; T+FYM ­ tillage+farmyard manure; G+NPK3 ­ doses of NPK fertilisers in 3 rd intensity for vineyards; G+NPK1 ­ doses of NPK fertilisers in 1 st intensity for vineyards L C ­ carbon lility; LI ­ lility index; CPI ­ carbon pool index; CMI ­ carbon management index Different letters between columns (a, b) indicate that treatment means are significantly different at P < 0.05 according to LSD multiple-range test lile SOM is highly susceptible to mineralization. Our results non-significantly confirmed this fact by low value of CPI in G+NPK3 treatment. Conversely, intensive cultivation (T treatment) was responsible for microbial decomposition of SOM, since aeration caused by cultivation stimulated decomposition and the subsequent mineralization of both lile and also later stle forms of SOM (Prasad et al. 2016), which resulted in an overall decrease of SOM quantity. Subsequently we found then that the T treatment contained the lowest stock of Corg (13.0 g/kg), and also, significantly, the lowest value of CPI (0.807). When we expressed LI from Corg (Corg varied in different treatments: G = 17.4 g/kg, T = 13.0 g/kg, T a b l e 3 Analysis of variance of organic and lile carbon contents in size fractions of water-stle aggregates Parameters Size fraction of water-stle aggregates in mm WSAmi <0.25 0.25­0.5 0.5­1.0 Lc WSAma 1.0­2.0 2.0­3.0 3.0­5.0 >5.0 WSAmi <0.25 0.25­0.5 0.5­1.0 LI WSAma 1.0­2.0 2.0­3.0 3.0­5.0 >5.0 WSAmi <0.25 0.25­0.5 0.5­1.0 CPI WSAma 1.0­2.0 2.0­3.0 3.0­5.0 >5.0 WSAmi <0.25 0.25­0.5 0.5­1.0 CMI WSAma 1.0­2.0 2.0­3.0 3.0­5.0 >5.0 Treatments G 0.147 0.140 T 0.197 T+FYM 0.176 G+NPK3 0.197 G+NPK1 0.154 0.164a 0.173a 0.130a 0.146a 0.134a 0.133 1.077a 1.124a 1.254a 1.061a 1.127a 0.989a 1.109a 1.053b 1.098 1.035 1.062 1.094 1.126a 1.030a 112.8a 118.8a 122.6a 119.1a 117.2a 109.7a 117.0a 0.143a 0.183a 0.159 0.177a 0.151 0.164a 0.176 0.130a 0.132a 0.139 ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ 0.192b 0.166a 0.159 0.159a 0.150a 0.152 0.149a 0.147a 0.168 0.128a 0.169b 1.372 1.155 1.292 0.162 1.232 1.099 1.159 0.162 1.369 1.316 1.147 1.295a 1.262a 1.164a 1.556b 1.293 1.178 1.165 1.453a 0.824 1.110a 1.354a 1.038 1.274b 1.329a 1.061 1.017 0.915a 0.891 1.165b 1.127 1.087 0.955a 1.019 1.173b 1.209 1.056 1.167 1.098a 1.087 1.334b 1.439 1.191 1.134 117.2a 119.7a 99.6 131.9a 146.6a 122.8 140.9 197.5 143.4a 126.3a 132.9 133.5 151.5 146.6a 122.9 171.9 149.7a 121.5a 131.2a 148.7a 152.9a G ­ control; T ­ tillage; T+FYM ­ tillage+farmyard manure; G+NPK3 ­ doses of NPK fertilisers in 3 rd intensity for vineyards; G+NPK1 ­ doses of NPK fertilisers in 1 st intensity for vineyards L C ­ carbon lility; LI ­ lility index; CPI ­ carbon pool index; CMI ­ carbon management index WSA mi ­ water-stle micro-aggregates; WSA ma ­ water-stle macroaggregates Different letters between columns (a, b) indicate that treatment means are significantly different at P < 0.05 according to LSD multiple-range test T+FYM = 17.4 g/kg, G+NPK3 = 16.8 g/kg, in G+NPK1 = 18.4 g/kg), the most intense mineralization was observed in G+NPK3 < T+FYM < T < G+NPK1. Using Blair et al. (1995) and Conteh et al. (1999) recommendation of the use of CPI for determination of SOM content, we found the lower the CPI value is, the more soil degradation is intensified in terms of reduction of soil organic matter content. Soil CPI increased in the following order: T < G+NPK3 < T+FYM < G+NPK1. However, CPI was lower in T treatment by 18%, 26% and 33% than in G+NPK3, T+FYM and G+NPK1, respectively. We also calculated the values of CMI in the soil to examine the impact of soil management practices. Usually, lower values of CMI indicate more intensive changes in the content of organic matter due to soil management practices and more carbon released from the soil stock (Blair et al. 1995). In our study, when considering CMI indices, the most intense change was caused as a result of intensive cultivation. The highest accumulation of carbon as well as decomposle organic matter occurred in G+NPK1 (Tle 2), while intensive tillage caused decreases in not only SOM content, but also the percentage of its lile forms, since these were quickly mineralized due to cultivation. SOM in water-stle aggregates Soil management practices in the vineyard had a statistically significant influence on LC in WSA. The largest values of LC in water-stle micro-aggregates (WSAmi) were found for the T, G+NPK3, then T+FYM and G+NPK1, whilst the smallest influence was seen for the G. The highest statistically significant difference of the LC in WSAmi was observed between the control and treatment with added fertilisers in 3rd intensity for vineyards as well as tillage treatment. Carbon lility indices in greater sized (water-stle macro-aggregates) WSAma (> 3mm) copied this trend as was also seen in LC in WSAmi of the investigated soil treatments. In size fractions of WSAma 1­2 mm and >5 mm the highest differences were observed between the control and tilled treatment. In all treatments, except G+NPK1, higher values of LC were determined in WSAmi than WSAma, which indicated higher proportions of lile carbon were in micro-aggregates. This means that micro-aggregates were more sensitive to the microbial decomposition than macro-aggregates. This is surprising because previous literature reports the opposite finding. Peth et al. (2008) and Kögel-Knner et al. (2008) reported that SOM inside of micro-aggregates is more stile due to better physical protection and physico-chemical protection. On average, the values of LI in WSA increased in the sequence G+NPK1 (1.11±0.08) < T+FYM (1.22±0.10) < G+NPK3 (1.30±0.11) < T (1.33±0.15). The largest differences (statistically significant) were found between treatments T and G+NPK1 in fractions of WSAma 1­2 mm and between the G+NPK3 and G+NPK1 in fractions of WSAma 3­5 mm. Lobe et al. (2001) reported that the largest content of total carbon (60­90%) is found in small macro-aggregates and that micro-aggregates up to 40% may decrease carbon supply as a result of cultivation compared with meadows. Our results showed that the greatest vulnerility to degradation of organic matter was observed in the micro-aggregates (the greatest Lc and LI values) and also macro-aggregates (the greatest average LC and LI values) under intense cultivation of vine rows, which indirectly confirmed the findings of Lobe et al. (2001). The highest values of the CPI in WSAma were detected as a result of farmyard manure application (Tle 3). The results point to the fact that SOM is degraded not only in the soil but also in the WSA, especially due to intensive soil cultivation, which confirmed findings of several studies (Khorramdel et al. 2013; dollahi et al. 2014), and also as a result of the application of high doses of fertilisers to the soil (Yang et al. 2011). Results obtained in this study showed, that the greatest enrichment in C in WSA occurred in the T+FYM treatment, the depletion in C in T treatments, whereas in G+NPK1 and G+NPK3 treatments the values were almost the same. In T treatment, the average CPI in macro-aggregates was lower than 1, what means a decreasing trend of organic carbon. In T treatment in addition to macro-aggregates, the CPI value was not lower than 1 also in micro-aggregates, which means that the microbial decomposition of organic matter occurred at the level of micro-aggregates, which may gradually result in the collapse of soil structure. Moreover, the lility of organic matter (LC) was the greatest just in T treatment (Tle 3), indicating greater susceptibility of organic matter to decomposition. Although organic matter lility (LC) means the biodegradility of lile organic matter forms, the cultivation without organic and mineral fertilisers added, considerly accelerated the decrease of Corg ­ when in control treatment Corg was 17.4 g/kg, and in T treatment 13.0 g/kg. Generally, lile (active) forms of organic matter are precursors of the stle (passive, slow) forms of SOM. When soil lacks lile organic matter, soil micro-organisms gradually use as a source of nutrients and energy more stle forms of SOM, and the result is a slow, gradual decrease of organic matter in the soil (Brady & Weil 1999). Surprising finding was revealed that the largest changes in stocks of SOM in all soil management practices occurred in WSAmi T a b l e 4 Correlation between SOM parameters in soil and water-stle aggregates Soil management SOM parameters in soil LC Together LI CPI CMI G T T+FYM G+NPK3 G+NPK1 T T+FYM G+NPK3 G+NPK1 T T+FYM G+NPK3 G+NPK1 T T+FYM G+NPK3 G+NPK1 Size fractions of water-stle aggregates >5 n.s. n.s. 0.398+ n.s. n.s. 5­ 3 n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. 0.750+ 0.734 n.s. n.s. n.s. n.s. n.s. n.s. 3­ 2 n.s. n.s. 0.379+ n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. 2­ 1 LC n.s. LI n.s. CPI n.s. CMI n.s. LC n.s. n.s. n.s. n.s. n.s. LI n.s. n.s. n.s. n.s. CPI n.s. n.s. n.s. n.s. CMI n.s. n.s. n.s. n.s. 1­ 0.5 n.s. n.s. 0.384+ n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. 0.717+ n.s. n.s. n.s. 0.5­ 0.25 n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. 0.739+ n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. <0.25 n.s. n.s. 0.358+ n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. LC n.s. n.s. n.s. n.s. n.s. LI n.s. n.s. n.s. 0.806+ CPI n.s. n.s. n.s. n.s. CMI 0.723+ n.s. n.s. P 0.05; n.s. ­ non-significant G ­ control; T ­ tillage; T+FYM ­ tillage+farmyard manure; G+NPK3 ­ doses of NPK fertilisers in 3 rd intensity for vineyards; G+NPK1 ­ doses of NPK fertilisers in 1 st intensity for vineyards L C ­ carbon lility; LI ­ lility index; CPI ­ carbon pool index; CMI ­ carbon management index compared to WSAma. For example, Six et al. (2004) reported that macro-aggregates are less stle due to intensive soil cultivation and therefore break-up into micro-aggregates. Thus, significant changes in the carbon content, particularly in the largest fractions WSAma recorded by Gale et al. (2000), are not consistent with our findings (Tle 3). In the WSA we also calculated CMI indices depending on the soil management practices in vineyard. Overall, smaller CMI values, indicating minor changes in the content and quality of organic matter due to land management, were recorded more in WSAmi than WSAma (except G+NPK3). The lowest value of CMI in WSAmi was determined in G+NPK1 and T treatments (Tle 3). One-way ANOVA analysis did not confirm significant differences between treatments in contents of WSAma. The largest accumulation of SOM was detected in the size fraction of WSAma > 5 mm due to application of farmyard manure and application of fertilisers in 3rd intensity for vineyards, but also due to intensive cultivation of vine rows. In G+NPK1, the highest accumulation of SOM was observed in size fraction of WSAma 5­3 mm. Correlations between SOM parameters in soil and in WSA Correlation coefficients between SOM parameters in soil and in WSA are shown in Tle 4. When the LC and LI values were assessed together regardless of soil management practices, no correlation was recorded. However, the value of LI in soil positively correlated with LI in WSAma 0.5­0.25 mm, but only under T treatment. This means that intensive cultivation between vine rows can increase the lility of carbon in smaller macro-aggregates. Statistically significant positive correlations were observed between CPI in soil and CPI in WSA (together), and this effect was stronger in size fractions of 5­3 mm, 2­1 mm and 0.5­0.25 mm. As the CPI values were assessed with relation to soil management practices, we detected a positive significant correlation between CPI in soil and CPI in WSAma in size fractions of >5 mm and 5­3 mm under intensive cultivated rows of vine, and in fractions of 5­3 mm in treatments with ploughed farmyard manure (Tle 4). Statistically significant positive correlation was observed between CMI in soil and CMI in WSAma 1­0.5 mm, if the CMI values were assessed together, regardless of soil management practices in the vineyard. Evaluating CMI values in relation to soil management practices, we only detected positive significant correlation between CMI in soil and CMI in WSAma in size fractions of 1­0.5 mm under T treatment and > 5mm in T+FYM treatment (Tle 4). CONCLUSIONS This study indicates that the highest accumulation of carbon, as well decomposle organic matter in soil, occurred in treatments with the application of fertilisers in 1-st intensity for vineyards compared other fertilised treatment, while intensive tillage caused the decrease not only of total SOM content, but also its lile forms, which were quickly mineralized due to cultivation. Similarly, the greatest vulnerility of organic matter to degradation was observed in the WSA under T treatment, however, the highest accumulation of SOM in WSA were detected as a result of farmyard manure application. Results further showed that between CPI in soil and WSA there were significant relationships if all soil management practices were assessed together. When soil management practices in a vineyard have been assessed separately, there were clear relationships between CPI in soil and higher size fraction of water-stle macro-aggregates. Acknowledgements. We thank Matthew Evans (Brackley Northants, England) for help with improving the editorial presentation of this paper. Project supported by the Scientific Grant Agency of the Ministry of Education, Science, Research and Sport of the Slovak Republic and the Slovak Academy of Sciences (No. 1/0604/16). http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Agriculture de Gruyter

The effects of soil management practices on soil organic matter changes within a productive vineyard in the Nitra viticulture area (Slovakia)

Agriculture , Volume 62 (1) – Apr 1, 2016

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de Gruyter
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1338-4376
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DOI
10.1515/agri-2016-0001
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Abstract

Original paper DOI: 10.1515/agri-2016-0001 VLADIMÍR SIMANSKÝ*, NORA POLLÁKOVÁ Slovak University of Agriculture in Nitra, Slovak Republic SIMANSKÝ, V. POLLÁKOVÁ, N.: The effects of soil management practices on soil organic matter changes within a productive vineyard in the Nitra viticulture area (Slovakia). Agriculture (Ponohospodárstvo), vol. 62, 2016, no. 1, p. 1­9. Since understanding soil organic matter (SOM) content and quality is very important, in the present study we evaluated parameters of SOM including: carbon lility (L C ), lility index (LI), carbon pool index (CPI) and carbon management index (CMI) in the soil as well as in the water-stle aggregates (WSA) under different soil management practices in a commercial vineyard (estlished on Rendzic Leptosol in the Nitra viticulture area, Slovakia). Soil samples were taken in spring during the years 2008­2015 from the following treatments: G (grass, control), T (tillage and intensive cultivation), T+FYM (tillage + farmyard manure), G+NPK3 (grass + 3 rd intensity of fertilisation for vineyards), and G+NPK1 (grass + 1 st intensity of fertilisation for vineyards). The highest LI values in soil were found for the G+NPK3 and T+FYM fertilised treatments and the lowest for the unfertilised intensively tilled treatments. The CPI in the soil increased as follows: T < G+NPK3 < T+FYM < G+NPK1. The highest accumulation of carbon as well as decomposle organic matter occurred in G+NPK1 compared to other fertilised treatments, while intensive tillage caused a decrease. On average, the values of LI in WSA increased in the sequence G+NPK1 < T+FYM < G+NPK3 < T. Our results showed that the greatest SOM vulnerility to degradation was observed in the WSA under T treatment, and the greatest values of CPI in WSA were detected as a result of fertiliser application in 3 rd intensity for vineyards and farmyard manure application. Key words: index lility, carbon pool index, carbon management index, fertilisation, soil tillage, vineyard SOM represents a polyfunctional, uneven-aged, multicomponent continuum of destroyed plant residues, root exudates, microbial biomass, biomolecules, and humic substances. It has lifetimes varying from several hours or days through to millennia (Schepaschenko et al. 2013; Semenov et al. 2013). SOM content in the soils is influenced by several factors, such as climate, clay content and mineralogy and soil management techniques etc. (Stevenson 1982; Lugato & Berti 2008). Organic carbon content in the soil (SOC) is one of the qualitative parameters of the soil humus regime and long has been recognized as a key component of soil quality (Reeves 1997). SOC can be divided into lile and recalcitrant fractions based on the relative susceptibility to biological decomposition (McLauchlan & Hobbie 2004; Belay-Tedla et al. 2009). Lile SOC pools such as water-extractle organic C, hot water-soluble organic C, potassium permanganate oxidizle organic C, and organic C fractions of different oxidizility are considered to respond to agricultural management more rapidly than total organic C (Blair et al. 1995; Benbi et al. 2012). As such lile fractions of SOM are used as sensitive indicators for soil management and land use induced changes in soil quality (Kolá et al. 2011; Benbi doc. Ing. Vladimír Simanský, PhD. (* Corresponding author), Department of Soil Science, FAFR ­ SUA Nitra, 949 76 Nitra, Tr. A. Hlinku 2, Slovak Republic. E-mail: Vladimir.Simansky@uniag.sk doc. Ing. Nora Polláková, PhD., Department of Soil Science, FAFR ­ SUA Nitra, 949 76 Nitra, Tr. A. Hlinku 2, Slovak Republic. E-mail: Nora.Pollakova@uniag.sk et al. 2015; Shang et al. 2016). Small changes in total SOM are difficult to detect because of its high background levels and natural soil variility. For this reason Blair et al. (1995) recommended the use of the carbon lility (LC), lility index (LI), carbon pool index (CPI) and carbon management index (CMI) for the determination of smaller changes and changes over a short time period. These parameters have been rather quickly adopted and used for the evaluation of SOM changes (Szombathová 1999; 2010). However, data out LC, LI, CMI and CPI in individual size fractions of water-stle aggregates are very rare. In this study we evaluated the effect of different soil management practices on LC, LI, CPI and CMI parameters in (i) the soil and (ii) the water-stle aggregates. Finally, we investigated relationships between these parameters within both the soil and water-stle aggregates. soil management practices in a productive vineyard was initiated. This experimental design had been previously described by Simanský & Polláková (2014). Briefly, the treatments consisted of (1). G: as a control (in the rows and between vines rows, a mixture of the grass were sown), (2). T: tillage (in autumn tilth to a depth of 25 cm and intensive cultivation between vine rows during the growing season), (3). T+FYM: tillage + farmyard manure (ploughed farmyard manure at a dose of 40 t/ha in autumn 2005, 2009 and 2012), (4). G+NPK3: doses of NPK fertilisers in 3rd intensity for vineyards, this means 120 kg/ha of N, 55 kg/ha of P and 195 kg/ha of K kg/ha (Fecenko & Lozek 2000). The dose of nutrients was divided: 2/3 applied into the soil in the spring (bud burst) and 1/3 at flowering. The grass was sown in and between the vine rows. (5). G+NPK1: doses of NPK fertilisers in 1st intensity for vineyards, this means 80 kg/ha of N, 35 kg/ha of P and 135 kg/ha of K (Fecenko & Lozek 2000). The dose of nutrients was divided: 1/2 applied into the soil in the spring (bud burst) and 1/2 at flowering. The grass was sown in and between the vine rows. Sampling was done in the spring throughout the years 2008 ­ 2015. Soil samples were collected (0 ­ 20 cm layer) from 4 random locations within each treatment of different vineyard soil management practices. Soil samples were then mixed together to form an average sample for each treatment. Samples were air-dried. Then, each of the samples was divided and one half of them were sieved through a 2 mm sieve for chemical analyses and the second half of samples were used for the determination of water-stle aggregates (WSA). MATERIAL AND METHODS The study was conducted at Drazovce (48°21'6.16"N; 18°3'37.33"E), a village located near Nitra city in the west of Slovakia. The area (vineyard) is located under the south-west side of the Tribec Mountain. In the 11th century, the southern slopes of the Zobor hills were deforested and vineyards were planted. Today the locality is used as a horticulture area and for growing wines. The climate is temperate with a mean annual rainfall of 550 mm and the mean annual temperature 10°C. The soil was classified as Rendzic Leptosol (WRB 2006) with a sandy loam texture developed on limestone and dolomite. Characteristics of the topsoil (0­30 cm) before the experiment in 2000 are presented in Tle 1. Before vineyard estlishment the locality was andoned. In the year 2000, the vines (Vitis vinifera L. cv. Chardonnay) had been planted and up to the year 2003 the vineyard was intensively cultivated in and between rows of the vine (mechanical removal of weeds). In 2003, a variety of grasses in following ratio Lolium perenne 50% + Poa pratensis 20% + Festuca rubra commutata 25% + Trifolium repens 5% were sown in and between rows of the vine. In the year 2006, the experimentation of different T a b l e 1 Characteristics of a Rendzic Leptosol at NitraDrazovce in the year 2000 Soil properties Rock fragments [%] Clay [g/kg] Silt [g/kg] Sand [g/kg] Organic carbon [g/kg] Base saturation [%] pH (in 1 mol/dm3 KCl) Means and standard deviation 8±1.6 101±12 330±18 569±23 17.0±1.6 99.3±0.01 7.18±0.08 Seven aggregate-size fractions (>5, 5­3, 3­2, 2­1, 1­0.5, 0.5­0.25 and <0.25 mm) were separated by the wet-sieving of the soil through the series of six sieves using the Baksheev method. The method for aggregate separation was adopted from Vadjunina and Korchagina (1986). In soil samples as well as in size fractions of WSA, the soil organic carbon (C org) and lile carbon (C L) contents were determined by Tyurin (Dziadowiec & Gonet 1999) and by Loginow (Loginow et al. 1987), respectively. On the base of determined C org and C L we calculated the following parameters of SOM: carbon lility (L C), lility index (LI), carbon pool index (CPI) and the carbon management index (CMI), as suggested Blair et al. (1995). In this research, the control (G) treatment was the reference and different soil management practices (T, T+FYM, G+NPK3 and G+NPK1) were used as treatments. Analysis of variance for SOM parameters were performed using Statgraphics Centurion XV.I statistical software (Statpoint Technologies, Inc., USA). The difference between the treatments was examined by one-way analysis of variance (ANOVA) and the LSD test (P < 0.05) was used for means comparison. Correlation analyses were used to assess the relationship between L C, LI, CPI and CMI in the soil and the same parameters of SOM in individual size fractions of water-stle aggregates. RESULTS AND DISCUSSION SOM in soil The values of carbon lility (LC) were not affected by soil management practices, however differences between treatments were observed. The content of LC increased on average in the following order: G+NPK1 = T < G < T+FYM < G+NPK3. We also evaluated the effect of different soil management practices on changes in SOM parameters such as: LI, CPI and CMI, which are used for determination of smaller changes and changes over a short time period (Blair et al. 1995; Szombathová 1999; Vieira et al. 2007). Higher values of LC and LI indicated that SOM was rapidly degradle by micro-organisms, otherwise, lower values of LI indicated SOM had greater stility and resistance to microbial degradation. The highest LI values were found for the G+NPK3, T+FYM and G+NPK1 fertilised treatments and the lowest for the unfertilised, intensively tilled treatments (Tle 2). Thus, higher doses of mineral fertilisers as well as organic amendment increased the amount of less stle forms of SOM, mainly by FYM addition, as well as by the promotion of root exudates excretion and the amount of grasses' residues, or through the decay of stle SOM due to high doses of NPK application (G+NPK3). Our findings are in agreement with Fröberg et al. (2013), Tong et al. (2014), who reported the impacts of mineral fertilisers and effect of manure on mineralization of SOM. Generally, T a b l e 2 Analyses of variance of soil organic matter parameters Parameters LC LI CPI Soil management G 0.150 ­ ­ T 0.149 0.807 T+FYM 0.166 1.014 G+NPK3 0.176 0.956 G+NPK1 0.149a 1.073 1.073b 0.831a 1.104b 1.184b ­ CMI 70.800a 113.700b 116.000b 116.100b G ­ control; T ­ tillage; T+FYM ­ tillage+farmyard manure; G+NPK3 ­ doses of NPK fertilisers in 3 rd intensity for vineyards; G+NPK1 ­ doses of NPK fertilisers in 1 st intensity for vineyards L C ­ carbon lility; LI ­ lility index; CPI ­ carbon pool index; CMI ­ carbon management index Different letters between columns (a, b) indicate that treatment means are significantly different at P < 0.05 according to LSD multiple-range test lile SOM is highly susceptible to mineralization. Our results non-significantly confirmed this fact by low value of CPI in G+NPK3 treatment. Conversely, intensive cultivation (T treatment) was responsible for microbial decomposition of SOM, since aeration caused by cultivation stimulated decomposition and the subsequent mineralization of both lile and also later stle forms of SOM (Prasad et al. 2016), which resulted in an overall decrease of SOM quantity. Subsequently we found then that the T treatment contained the lowest stock of Corg (13.0 g/kg), and also, significantly, the lowest value of CPI (0.807). When we expressed LI from Corg (Corg varied in different treatments: G = 17.4 g/kg, T = 13.0 g/kg, T a b l e 3 Analysis of variance of organic and lile carbon contents in size fractions of water-stle aggregates Parameters Size fraction of water-stle aggregates in mm WSAmi <0.25 0.25­0.5 0.5­1.0 Lc WSAma 1.0­2.0 2.0­3.0 3.0­5.0 >5.0 WSAmi <0.25 0.25­0.5 0.5­1.0 LI WSAma 1.0­2.0 2.0­3.0 3.0­5.0 >5.0 WSAmi <0.25 0.25­0.5 0.5­1.0 CPI WSAma 1.0­2.0 2.0­3.0 3.0­5.0 >5.0 WSAmi <0.25 0.25­0.5 0.5­1.0 CMI WSAma 1.0­2.0 2.0­3.0 3.0­5.0 >5.0 Treatments G 0.147 0.140 T 0.197 T+FYM 0.176 G+NPK3 0.197 G+NPK1 0.154 0.164a 0.173a 0.130a 0.146a 0.134a 0.133 1.077a 1.124a 1.254a 1.061a 1.127a 0.989a 1.109a 1.053b 1.098 1.035 1.062 1.094 1.126a 1.030a 112.8a 118.8a 122.6a 119.1a 117.2a 109.7a 117.0a 0.143a 0.183a 0.159 0.177a 0.151 0.164a 0.176 0.130a 0.132a 0.139 ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ 0.192b 0.166a 0.159 0.159a 0.150a 0.152 0.149a 0.147a 0.168 0.128a 0.169b 1.372 1.155 1.292 0.162 1.232 1.099 1.159 0.162 1.369 1.316 1.147 1.295a 1.262a 1.164a 1.556b 1.293 1.178 1.165 1.453a 0.824 1.110a 1.354a 1.038 1.274b 1.329a 1.061 1.017 0.915a 0.891 1.165b 1.127 1.087 0.955a 1.019 1.173b 1.209 1.056 1.167 1.098a 1.087 1.334b 1.439 1.191 1.134 117.2a 119.7a 99.6 131.9a 146.6a 122.8 140.9 197.5 143.4a 126.3a 132.9 133.5 151.5 146.6a 122.9 171.9 149.7a 121.5a 131.2a 148.7a 152.9a G ­ control; T ­ tillage; T+FYM ­ tillage+farmyard manure; G+NPK3 ­ doses of NPK fertilisers in 3 rd intensity for vineyards; G+NPK1 ­ doses of NPK fertilisers in 1 st intensity for vineyards L C ­ carbon lility; LI ­ lility index; CPI ­ carbon pool index; CMI ­ carbon management index WSA mi ­ water-stle micro-aggregates; WSA ma ­ water-stle macroaggregates Different letters between columns (a, b) indicate that treatment means are significantly different at P < 0.05 according to LSD multiple-range test T+FYM = 17.4 g/kg, G+NPK3 = 16.8 g/kg, in G+NPK1 = 18.4 g/kg), the most intense mineralization was observed in G+NPK3 < T+FYM < T < G+NPK1. Using Blair et al. (1995) and Conteh et al. (1999) recommendation of the use of CPI for determination of SOM content, we found the lower the CPI value is, the more soil degradation is intensified in terms of reduction of soil organic matter content. Soil CPI increased in the following order: T < G+NPK3 < T+FYM < G+NPK1. However, CPI was lower in T treatment by 18%, 26% and 33% than in G+NPK3, T+FYM and G+NPK1, respectively. We also calculated the values of CMI in the soil to examine the impact of soil management practices. Usually, lower values of CMI indicate more intensive changes in the content of organic matter due to soil management practices and more carbon released from the soil stock (Blair et al. 1995). In our study, when considering CMI indices, the most intense change was caused as a result of intensive cultivation. The highest accumulation of carbon as well as decomposle organic matter occurred in G+NPK1 (Tle 2), while intensive tillage caused decreases in not only SOM content, but also the percentage of its lile forms, since these were quickly mineralized due to cultivation. SOM in water-stle aggregates Soil management practices in the vineyard had a statistically significant influence on LC in WSA. The largest values of LC in water-stle micro-aggregates (WSAmi) were found for the T, G+NPK3, then T+FYM and G+NPK1, whilst the smallest influence was seen for the G. The highest statistically significant difference of the LC in WSAmi was observed between the control and treatment with added fertilisers in 3rd intensity for vineyards as well as tillage treatment. Carbon lility indices in greater sized (water-stle macro-aggregates) WSAma (> 3mm) copied this trend as was also seen in LC in WSAmi of the investigated soil treatments. In size fractions of WSAma 1­2 mm and >5 mm the highest differences were observed between the control and tilled treatment. In all treatments, except G+NPK1, higher values of LC were determined in WSAmi than WSAma, which indicated higher proportions of lile carbon were in micro-aggregates. This means that micro-aggregates were more sensitive to the microbial decomposition than macro-aggregates. This is surprising because previous literature reports the opposite finding. Peth et al. (2008) and Kögel-Knner et al. (2008) reported that SOM inside of micro-aggregates is more stile due to better physical protection and physico-chemical protection. On average, the values of LI in WSA increased in the sequence G+NPK1 (1.11±0.08) < T+FYM (1.22±0.10) < G+NPK3 (1.30±0.11) < T (1.33±0.15). The largest differences (statistically significant) were found between treatments T and G+NPK1 in fractions of WSAma 1­2 mm and between the G+NPK3 and G+NPK1 in fractions of WSAma 3­5 mm. Lobe et al. (2001) reported that the largest content of total carbon (60­90%) is found in small macro-aggregates and that micro-aggregates up to 40% may decrease carbon supply as a result of cultivation compared with meadows. Our results showed that the greatest vulnerility to degradation of organic matter was observed in the micro-aggregates (the greatest Lc and LI values) and also macro-aggregates (the greatest average LC and LI values) under intense cultivation of vine rows, which indirectly confirmed the findings of Lobe et al. (2001). The highest values of the CPI in WSAma were detected as a result of farmyard manure application (Tle 3). The results point to the fact that SOM is degraded not only in the soil but also in the WSA, especially due to intensive soil cultivation, which confirmed findings of several studies (Khorramdel et al. 2013; dollahi et al. 2014), and also as a result of the application of high doses of fertilisers to the soil (Yang et al. 2011). Results obtained in this study showed, that the greatest enrichment in C in WSA occurred in the T+FYM treatment, the depletion in C in T treatments, whereas in G+NPK1 and G+NPK3 treatments the values were almost the same. In T treatment, the average CPI in macro-aggregates was lower than 1, what means a decreasing trend of organic carbon. In T treatment in addition to macro-aggregates, the CPI value was not lower than 1 also in micro-aggregates, which means that the microbial decomposition of organic matter occurred at the level of micro-aggregates, which may gradually result in the collapse of soil structure. Moreover, the lility of organic matter (LC) was the greatest just in T treatment (Tle 3), indicating greater susceptibility of organic matter to decomposition. Although organic matter lility (LC) means the biodegradility of lile organic matter forms, the cultivation without organic and mineral fertilisers added, considerly accelerated the decrease of Corg ­ when in control treatment Corg was 17.4 g/kg, and in T treatment 13.0 g/kg. Generally, lile (active) forms of organic matter are precursors of the stle (passive, slow) forms of SOM. When soil lacks lile organic matter, soil micro-organisms gradually use as a source of nutrients and energy more stle forms of SOM, and the result is a slow, gradual decrease of organic matter in the soil (Brady & Weil 1999). Surprising finding was revealed that the largest changes in stocks of SOM in all soil management practices occurred in WSAmi T a b l e 4 Correlation between SOM parameters in soil and water-stle aggregates Soil management SOM parameters in soil LC Together LI CPI CMI G T T+FYM G+NPK3 G+NPK1 T T+FYM G+NPK3 G+NPK1 T T+FYM G+NPK3 G+NPK1 T T+FYM G+NPK3 G+NPK1 Size fractions of water-stle aggregates >5 n.s. n.s. 0.398+ n.s. n.s. 5­ 3 n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. 0.750+ 0.734 n.s. n.s. n.s. n.s. n.s. n.s. 3­ 2 n.s. n.s. 0.379+ n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. 2­ 1 LC n.s. LI n.s. CPI n.s. CMI n.s. LC n.s. n.s. n.s. n.s. n.s. LI n.s. n.s. n.s. n.s. CPI n.s. n.s. n.s. n.s. CMI n.s. n.s. n.s. n.s. 1­ 0.5 n.s. n.s. 0.384+ n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. 0.717+ n.s. n.s. n.s. 0.5­ 0.25 n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. 0.739+ n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. <0.25 n.s. n.s. 0.358+ n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. LC n.s. n.s. n.s. n.s. n.s. LI n.s. n.s. n.s. 0.806+ CPI n.s. n.s. n.s. n.s. CMI 0.723+ n.s. n.s. P 0.05; n.s. ­ non-significant G ­ control; T ­ tillage; T+FYM ­ tillage+farmyard manure; G+NPK3 ­ doses of NPK fertilisers in 3 rd intensity for vineyards; G+NPK1 ­ doses of NPK fertilisers in 1 st intensity for vineyards L C ­ carbon lility; LI ­ lility index; CPI ­ carbon pool index; CMI ­ carbon management index compared to WSAma. For example, Six et al. (2004) reported that macro-aggregates are less stle due to intensive soil cultivation and therefore break-up into micro-aggregates. Thus, significant changes in the carbon content, particularly in the largest fractions WSAma recorded by Gale et al. (2000), are not consistent with our findings (Tle 3). In the WSA we also calculated CMI indices depending on the soil management practices in vineyard. Overall, smaller CMI values, indicating minor changes in the content and quality of organic matter due to land management, were recorded more in WSAmi than WSAma (except G+NPK3). The lowest value of CMI in WSAmi was determined in G+NPK1 and T treatments (Tle 3). One-way ANOVA analysis did not confirm significant differences between treatments in contents of WSAma. The largest accumulation of SOM was detected in the size fraction of WSAma > 5 mm due to application of farmyard manure and application of fertilisers in 3rd intensity for vineyards, but also due to intensive cultivation of vine rows. In G+NPK1, the highest accumulation of SOM was observed in size fraction of WSAma 5­3 mm. Correlations between SOM parameters in soil and in WSA Correlation coefficients between SOM parameters in soil and in WSA are shown in Tle 4. When the LC and LI values were assessed together regardless of soil management practices, no correlation was recorded. However, the value of LI in soil positively correlated with LI in WSAma 0.5­0.25 mm, but only under T treatment. This means that intensive cultivation between vine rows can increase the lility of carbon in smaller macro-aggregates. Statistically significant positive correlations were observed between CPI in soil and CPI in WSA (together), and this effect was stronger in size fractions of 5­3 mm, 2­1 mm and 0.5­0.25 mm. As the CPI values were assessed with relation to soil management practices, we detected a positive significant correlation between CPI in soil and CPI in WSAma in size fractions of >5 mm and 5­3 mm under intensive cultivated rows of vine, and in fractions of 5­3 mm in treatments with ploughed farmyard manure (Tle 4). Statistically significant positive correlation was observed between CMI in soil and CMI in WSAma 1­0.5 mm, if the CMI values were assessed together, regardless of soil management practices in the vineyard. Evaluating CMI values in relation to soil management practices, we only detected positive significant correlation between CMI in soil and CMI in WSAma in size fractions of 1­0.5 mm under T treatment and > 5mm in T+FYM treatment (Tle 4). CONCLUSIONS This study indicates that the highest accumulation of carbon, as well decomposle organic matter in soil, occurred in treatments with the application of fertilisers in 1-st intensity for vineyards compared other fertilised treatment, while intensive tillage caused the decrease not only of total SOM content, but also its lile forms, which were quickly mineralized due to cultivation. Similarly, the greatest vulnerility of organic matter to degradation was observed in the WSA under T treatment, however, the highest accumulation of SOM in WSA were detected as a result of farmyard manure application. Results further showed that between CPI in soil and WSA there were significant relationships if all soil management practices were assessed together. When soil management practices in a vineyard have been assessed separately, there were clear relationships between CPI in soil and higher size fraction of water-stle macro-aggregates. Acknowledgements. We thank Matthew Evans (Brackley Northants, England) for help with improving the editorial presentation of this paper. Project supported by the Scientific Grant Agency of the Ministry of Education, Science, Research and Sport of the Slovak Republic and the Slovak Academy of Sciences (No. 1/0604/16).

Journal

Agriculturede Gruyter

Published: Apr 1, 2016

References