Assessment of Soil Structure Under Monoculture of Vines
Long-term impact of vine growing on the soil structure stability was studied in three wine-growing areas of Slovakia. In Leptosols, the highest content of water-stable aggregates was determined. This soil type had the lowest vulnerability of soil structure as well. In Chernozems, the highest stability of soil structure was determined, while on the other hand, in Fluvisols, soil structure had the highest vulnerability. Between rows of vines in comparison to rows of vines a more favourable soil structure was determined. In vineyards, the soil structure state depends on the quantity and stability of soil organic matter, as well as particle size distribution.
The effect of different fire severity on the changes of the soil organic matter (SOM) and soil structure was evaluated. Soil samples were collected (May 2010) in the locality of Nitra-Dražovce (Slovakia) from the following plots: 1) control (unburned place), 2) low severity of fire and 3) higher severity of fire. The results showed that the content of water-stable microaggregates (WSAmi) increased by 20% in the area with a low severity of fire, but on the other hand, it decreased by 42% in the area with the higher severity of fire in comparison to control. The higher severity of fire resulted in a decrease of smaller size fractions of water-stable macroaggregates (WSAma) (0.5−0.25) and a low severity of fire resulted in the decrease of WSAma 2−0.5 mm. On the other hand, the content of WSAma in the size fraction >5 mm was higher by 54% and by 32% in the lower and higher severity of fire, respectively, than in unburned soil. The higher severity of fire had a more positive effect on increases of the structure coefficient and coefficient of aggregate stability, as well as on the decrease of the vulnerability coefficient compared to the low severity of fire. After burning, the contents of soil organic carbon (Corg) and labile carbon were significantly increased by the severity of fire. However, the low severity of fire affected more markedly the increase of hot water-soluble and cold water-soluble carbon than the higher severity of fire. After burning and due to the severity of fire, both the carbon of humic and carbon of fulvic acids ratios and SOM stability increased. The parameters of SOM due to fire significantly increased also in WSA with the least changes in WSAmi. The results showed that a low severity of fire increased Corg mainly in WSAma >2mm and WSAmi, whereas high severity fire increased Corg content in the smaller fraction of WSAma.
Quantity and quality of soil organic matter (SOM) is very important from view point of sustainable agriculture; therefore, during the years 1994–2011, the influence of different soil management practices on changes in SOM parameters in loamy Haplic Luvisol was evaluated in a field experiment in the locality of Dolná Malanta. The field experiment included two types of soil tillage – (1) conventional tillage (CT) and (2) reduced tillage (RT) – and also two treatments of fertilisation – (1) crop residues together with added NPK (nitrogen, phosphorus and potassium) fertilisers (CR + NPK) and (2) added NPK fertilisers. Contents of humic substances (HS) and fulvic acids (FA) under RT increased by 1.6% and 4.4%, respectively, compared to CT during the years 1994–2011. On the other hand, contents of humic acids (HA), HA-to-FA ratios, colour quotient of HS and colour quotient of HA under CT increased by 2.0%, 2.5%, 1.8% and 2.3%, respectively, compared to RT. In CT and RT, HS declined at an average speed of 0.33% and 0.53% per year, respectively. In CR + NPK treatments and application, only NPK fertiliser caused a decline of HS at an average speed of 0.52% and 0.33 % per year, respectively. In CT, RT and CR + NPK treatments, the linear trends (statistical significant) in decline of FA were observed. All in all, the CT had a slightly better effect on the quality of SOM, whilst the stability of SOM was improved by RT. Applications of mineral fertilisers along with crop residues resulted in better quality but lower stability of SOM.
We investigated the role of Mn oxides on the soil structure (contents of dry and water-stable aggregates) of sandy soil under a controlled long-term fertilisation experiment. We examined two experiments: a 94-year-term experiment with: no fertilisers, NPK fertilisers, and CaNPK fertilisers; and a 25-year-term experiment that included: farmyard manure and no mineral fertilisation, farmyard manure + NPK fertilisers, and farmyard manure + CaNPK fertilisers. The results showed that in the 94-year-term trial, Mn oxides were increased in CaNPK treatment. In the 25-year-term experiment, the farmyard manure combined with NPK decreased total Mn and its oxides. In the 94-year-term experiment, the content of dry-sieved macro-aggregates (DSAma) and water-stable macro-aggregates increased due to fertilisation. The result of our study suggests that Mn oxides had positive effects mainly on higher size classes of DSAma and did not have any effect on water-stable aggregate contents.
The physical properties of Luvisols under vineyards of the Nitra wine-growing area (Slovakia) were evaluated in the paper. Soil samples were taken from two selected localities (Nitra - Dražovce, Vráble). The obtained results showed that in the soil profile of Dražovce, the average contents of non-capillary pores, capillary pores and semi-capillary pores to the total porosity were equal to 26.1, 64.4 and 9.4%, respectively, and in the soil profile of Vráble - 22.3, 75.6 and 2.1%, respectively. In the Dražovce locality, the average content of aggregate stability index (Sw) decreased in the following order: abandoned vineyard > grassy strip between the vineyard rows > intensively cultivated rows of vineyard. In contrast, in the Vráble locality, higher average contents of Sw were determined in intensively cultivated rows of vineyard in comparison to grassy strip between the vineyard rows. The lowest average value of vulnerability coefficient (Kv) was observed in abandoned vineyard (Dražovce locality) and in both localities in grassy strip between the vineyard rows. Intensive cultivation of the vineyard rows resulted in higher vulnerability of soil structure. The values of maximum capillary capacity were almost the same in both soil profiles of Luvisols. A higher content of soil moisture was observed in the soil profile in the Vráble locality (33.6±2.50) in comparison to the Dražovce locality (30.6±5.44). Higher content of storage moisture was determined in the Vráble locality (2,684 l m-2) in comparison to the Dražovce locality (2,450 l m-2).
An interaction between the slope position and type of soil management practices could be one of the most important factor affecting several soil properties including soil structure. Therefore, we evaluated selected soil properties including soil structure parameters in relation to slope gradient and soil management practices between Trakovice and Bučany villages (western Slovakia). The sampling sites were located in two adjacent, gently sloping fields with a NW-SE orientation. The sites also differ in soil management type: Field No. 1 was used as arable land with intensive cultivation (IC) of crops, while a greening system (GS) had been established on Field No. 2. Soil samples were taken from five geomorphological zones at each slope: summit, shoulder, back-slope, toe slope and flat terrain under the slope. Results showed that soil pH, content of soil organic matter (SOM) and carbonates depended on land use of the slopes. In GS, the water-stable macro-aggregates (WSAma) 0.5–3 mm (favourable size fraction) displayed statistical significant quadratic polynomial trend along the slope gradient. In IC the values of mean weight diameter of dry sieved aggregates (MWDd) decreased significantly along the slope gradient, while in GS the opposite trend was observed. In IC significant correlations between carbonates content (r=-0.775, P<0.01), humic acids (HA) content (r=0.654, P<0.05), colour quotients of humic substances (r=-0.706, P<0.05), colour quotients of HA (r=-0.723, P<0.05) and MWDd were determined. In GS higher content of carbonates was followed by a decrease in content WSAma, MWDd, mean weight diameter of wet sieved aggregates (MWDw) and stability index of aggregates. At the same time stabile and labile soil organic matter improved soil structure parameters in GS.
At present time exists a lot of soil tillage practices with different effects on soil productivity, therefore the effects of two tillage systems (conventional: CT, and miminum: MT) and two different soil types (Chernozem and Mollic Fluvisol) on soil physical quality indicators and water availability were evaluated in an on-farm study in the Krakovany (Danube Lowland, Slovakia). We evaluated pore-size distributions and selected hydro-physical properties (capillary rise, maximum capillary water capacity and retention water capacity). The total porosity (P) on average by 23% and by 14%, non-capillary pores (Pn) by 271% and by 114% and semicapillary pores by 102% and by 192% were significantly greater for CT than MT in Chernozem and in Mollic Fluvisol, respectively. The content of capillary pores (Pc) was significantly greater for MT than CT on average by 13% and 8% in Chernozem and in Mollic Fluvisol, respectively. The average content of capillary rise (ΘCR), maximum capillary water capacity (ΘMCWC) and retention water capacity (ΘRWC) were higher by 6, 10 and 13% under MT than CT in soil profile of Chernozem. The same effect of soil tillage systems in Mollic Fluvisol was not observed. In Chernozem under MT with increased P, ΘCR significantly increased, however, under CT, the ΘCR significantly decreased. At the same time we determined negative correlations between Pn and soil water retention characteristics under CT. Higher content of Pc resulted in higher values of capillary rise, maximum capillary water capacity and retention water capacity in both soil types under both tillage systems.
In this paper we investigate the effects of biochar alone and its reapplication and combination with N-fertilizer (1) on the soil pH, and (2) sorption parameters. The soil samples were taken during growing period in 2018 from plots with different biochar (first application in 2014 – A, reapplication in 2018 – B) at application rates: 0 t.ha−1 (B0 control), 10 t.ha−1 (B10) and 20 t.ha−1 (B20) and different nitrogen fertilization: N0 (no nitrogen) and N40 (40 kg.ha−1). Our results showed that the first application of biochar at the rate of 20 t.ha−1 (B20A) without N-fertilizer significantly increased the values of soil pH in H2O, soil pH in KCl, the sum of base cations (SBC) and cation exchange capacity (CEC) compared to control (B0). Similar effects were observed also after reapplication of biochar (B10B). All investigated parameters in fertilized control treatment (B0N40) were worst and the first application, as well as the reapplication of biochar with N, caused significant increase of soil pH in H2O, soil pH in KCl, SBC, CEC, BS and decrease of hydrolytic acidity.
Agroecosystem crop residues are considered to be a primary resource of organic substances, and are subject to the different transformation processes in the soil environment. The decomposition processes of organic substance can be also regulated by the application of the different biopreparations. The decomposition of organic substances in soil also causes changes in nitrogen content and its forms. It is essential for farmers to know about these processes in order flexibly to regulate and affect the transformation processes of the applied crop residues via the biopreparations directly in the production conditions. The changes of content and forms of nitrogen and its calculated parameters in Haplic Luvisol influenced by the applied crop residues (wheat – WR, rape – RR) and biopreparations (Betaliq, Trichomil) were monitored in the small-pot experiment carried out at the Department of Soil Science (FAFR, SUA-Nitra). The laboratory experiments were established for the incubation period 4, 7, 14, 28, 60, 90 and 180 days. The applied crop residues had statistically significant impact on the contents of total nitrogen (Nt) and potentially mineralizable nitrogen (Npot) and inorganic forms N, similarly also the values of labile nitrogen (LN) and nitrogen pool index (NPI). The biopreparations affected statistically significantly the average values Npot, LN, nitrogen lability index (NLI) and nitrogen management index (NMI). During the incubation period, the contents Npot and values LN and other calculated indexes of nitrogen fluctuated significantly.
The effect of different doses of NPK fertilizer on the changes in quantity and quality of soil organic matter (SOM) in Rendzic Leptosol was evaluated. Soil samples were taken from three treatments of different fertilization: (1) control - without fertilization, (2) NPK 1 - doses of NPK fertilizer in 1st degree intensity for vine, and (3) NPK 3 - doses of NPK fertilizer in 3rd degree intensity for vine in the vineyard. Soil samples were collected in years 2008-2011 during the spring. The higher dose of NPK fertilizer (3rd degree intensity of vineyards fertilization) was responsible for the higher content of labile carbon (by 21% in 0-0.3 m and by 11% as average of the two depths 0-0.3 m and 0.3-0.6 m). However, by application of a higher dose of NPK (1.39%) in comparison to no fertilizer treatment (1.35%) or NPK 1 (1.35%) the tendency of total organic carbon content increase and hot-water soluble carbon decrease were determined. Fertilization had a negative effect on SOM stability. Intensity of fertilization affected the changes in quantity and quality of SOM; therefore it is very important to pay attention to the quantity and quality of organic matter in productive vineyards.