Is better minimum than standard mouldboard ploughing tillage from viewpoint of the pore-size distribution and soil water retention characteristic changes?

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

Biochar and biochar with N-fertilizer affect soil N2O emission in Haplic Luvisol

The benefits of biochar application are well described in tropical soils, however there is a dearth of information on its effects in agricultural temperate soils. An interesting and little explored interaction may occur in an intensive agriculture setting; biochar addition may modify the effect of commonplace N-fertilization.We conducted a field experiment to study the effects of biochar application at the rate of 0, 10 and 20 t ha−1 (B0, B10 and B20) in combination with 0, 40 and 80 kg N ha−1 of N-fertilizer (N0, N40, N80).We followed nitrous oxide (N2O) emissions, analysed a series of soil physicochemical properties and measured barley yield in a Haplic Luvisol in Central Europe. Seasonal cumulative N2O emissions from B10N0 and B20N0 treatments decreased by 27 and 25% respectively, when compared to B0N0. Cumulative N2O emissions from N40 and N80 combined with B10 and B20 were also lower by 21, 19 and 25, 32%, respectively compared to controls B0N40 and B0N80. Average pH was significantly increased by biochar addition. Increased soil pH and reduces NO−3 content seen in biochar treatments could be the two possible mechanisms responsible for reduced N2O emissions. There was a statistically significant increase of soil water content in B20N0 treatment compared to B0N0 control, possibly as a result of larger surface area and the presence of microspores having altered pore size distribution and water-holding capacity of the soil. Application of biochar at the rate of 10 t ha−1 had a positive effect on spring barley grain yield

Stability of soil aggregate in loamy soils of Slovakia

Stability of soil aggregates is affected by dozens different factors and their individual effects are hardly discernable. For this reason, we investigated the structure of the top layer (to a depth 0.2 m) of loamy soils (Haplic Fluvisol, Mollic Fluvisol and Calcaric Chernozem), at three sites (Šulekovo, Trakovice and Bučany) in the north-western part of the Danube Lowlands (Slovakia) in order to: (1) evaluate the differences in soil organic matter (SOM), texture, water-stable aggregates (WSA) and content of SOM in WSA; (2) determine the relationships between SOM, texture and WSA; and (3) identify the threshold limits for soil organic carbon (SOC) and the particle-size distributions for stabilization of water-stable macro-aggregates (WSAma). We found significant effects of a soil type on both SOM and WSA as well as on the content of SOM in WSA. When all loamy soils were assessed together, positive significant correlations were observed between size fractions of WSAma >2 mm and the content of SOC and hot-water soluble carbon (CHWD). The content of WSAma 1-0.25 mm and water-stable micro-aggregates (WSAmi) correlated negatively with SOC and CHWD. The quality of SOM was more important than its quantity for the stabilization of WSAma at size fractions 1-0.25 mm and WSAmi. The content of clay improved the aggregation in size fractions of WSAma >2 mm in the investigated top layer of loamy soils. The maximum WSAma content occurred where the ratio of organic carbon content in WSAma to that in soil was ~1.0. The threshold limits for clay and silt content for the formation of WSAma were ~20% and equal to 43%, respectively

The content and profile distribution of carbon and nitrogen fractions susceptible to acid hydrolysis in Haplic Chernozems and Mollic Fluvisols of western Slovakia

The studies on the content and profile distribution of carbon and nitrogen fractions of varied susceptibility to acid hydrolysis were performed in arable Haplic Chernozems and Mollic Fluvisols at four locations near Krakovany, Slovakia. The soils were sampled every 10 cm and analyzed, including the content of total organic carbon (TOC) and nitrogen (TN) and fractions of these elements after sequential extraction in 0.25 mol dm-3 KCl, 0.25 mol dm-3 H2SO4 and 2.5 mol dm-3 H 2SO4. Based on extractions, the content of easy hydrolyzable (EHC), hardly hydrolyzable (HHC) and nonhydrolyzable carbon (NHC) and the content of ammonium nitrogen (NH4-N), nitrate nitrogen (NO3-N), dissolved organic nitrogen (DON), easy hydrolyzable nitrogen (EHN), hardly hydrolyzable nitrogen (HHN) and nonhydrolyzable nitrogen (NHN) was calculated. Mollic Fluvisols were more abundant in TOC and TN as compared to Haplic Chernozems. The content of carbon and nitrogen fractions varied among the soils, showing correlations with the total content of these elements. A low contribution of EHC and HHC in TOC and NO3-N, EHN, HHN in TN and a large share of nonhydrolyzable fractions of these elements were characteristic features of the studied soils. In general, trends in HHC (as % of TOC) and NO3-N, NH4-N, EHN (as % of TN), increasing with depth with a simultaneous decrease of NHN were observed. A-horizons of Haplic Chernozems were characterized by a higher contribution of EHN, NH4-N and NO3-N in TN, but a lower share of NHN as compared to Mollic Fluvisols

Stability of soil aggregate in loamy soils of Slovakia

Stability of soil aggregates is affected by dozens different factors and their individual effects are hardly discernable. For this reason, we investigated the structure of the top layer (to a depth 0.2 m) of loamy soils (Haplic Fluvisol, Mollic Fluvisol and Calcaric Chernozem), at three sites (Šulekovo, Trakovice and Bučany) in the north-western part of the Danube Lowlands (Slovakia) in order to: (1) evaluate the differences in soil organic matter (SOM), texture, water-stable aggregates (WSA) and content of SOM in WSA; (2) determine the relationships between SOM, texture and WSA; and (3) identify the threshold limits for soil organic carbon (SOC) and the particle-size distributions for stabilization of water-stable macro-aggregates (WSAma). We found significant effects of a soil type on both SOM and WSA as well as on the content of SOM in WSA. When all loamy soils were assessed together, positive significant correlations were observed between size fractions of WSAma >2 mm and the content of SOC and hot-water soluble carbon (CHWD). The content of WSAma 1-0.25 mm and water-stable micro-aggregates (WSAmi) correlated negatively with SOC and CHWD. The quality of SOM was more important than its quantity for the stabilization of WSAma at size fractions 1-0.25 mm and WSAmi. The content of clay improved the aggregation in size fractions of WSAma >2 mm in the investigated top layer of loamy soils. The maximum WSAma content occurred where the ratio of organic carbon content in WSAma to that in soil was ~1.0. The threshold limits for clay and silt content for the formation of WSAma were ~20% and equal to 43%, respectively

Impact of foliar application of the biostimulator Mg-Titanit on the formation of winter oilseed rape phytomass and its titanium content

The objective of the following three-year small-plot experiments was to determine the impact of a dose and application date of the biostimulator Mg-Tytanit (MgTi) on the formation of winter oilseed rape phytomass and its titanium cont ent. In the trial the biostimulant Mg-Tytanit containing 8.5 g of titanium in 1 liter was used. The experiment consisted of 5 treatments: 0 – control treatment without MgTi; 2xTi0.2 – two applications of MgTi in the dose of 0.2 dm3 ha-1; 3xTi0.2 – three applications of MgTi in the dose of 0.2 dm3 ha-1; 2xTi0.4 – two applications of MgTi in the dose of 0.4 dm3 ha-1; 3xTi0.4 – three applications of MgTi in the dose of 0.4 dm3 ha-1. The BS was applied in spring during two or three different growth stages: BBCH 50, BBCH 59, BBCH 66. The first plant sampling was carried out shortly before the first application of BS (BBCH 50). The second, third and fourth sampling were taken 2 – 3 weeks after the application of Mg-Tytanit (BBCH 59, BBCH 66, BBCH 71). The results showed that the biostimulator MgTi, regardless of its dose and application date, resulted in a higher weight of the aerial and underground phytomass. All the MgTi applications had impact on the winter oilseed rape yield increase. The seed yield was increased by 0.3 to 0.63 t ha-1. Higher yields were achieved in the treatments where MgTi was applied three times in comparison with the treatments, where it was used twice. The oil content in rape seeds was increased significantly only if MgTi was used in the total doses 0.8 and 1.2 dm3 ha-1 in the single application dose 0.4 dm3 ha-1. The oil content value was increased by 0.94 % and by 0.82 %. The oil production per hectare was increased after each use of MgTi, i.e. regardeless of the dose and date of its application. The highest Ti content in the aerial phytomass was 68.5 mg kg-1 and in the underground phytomass it was 247.1 mg kg-1

Impact of foliar application of the biostimulator Mg-Titanit on the formation of winter oilseed rape phytomass and its titanium content

The objective of the following three-year small-plot experiments was to determine the impact of a dose and application date of the biostimulator Mg-Tytanit (MgTi) on the formation of winter oilseed rape phytomass and its titanium cont ent. In the trial the biostimulant Mg-Tytanit containing 8.5 g of titanium in 1 liter was used. The experiment consisted of 5 treatments: 0 – control treatment without MgTi; 2xTi0.2 – two applications of MgTi in the dose of 0.2 dm3 ha-1; 3xTi0.2 – three applications of MgTi in the dose of 0.2 dm3 ha-1; 2xTi0.4 – two applications of MgTi in the dose of 0.4 dm3 ha-1; 3xTi0.4 – three applications of MgTi in the dose of 0.4 dm3 ha-1. The BS was applied in spring during two or three different growth stages: BBCH 50, BBCH 59, BBCH 66. The first plant sampling was carried out shortly before the first application of BS (BBCH 50). The second, third and fourth sampling were taken 2 – 3 weeks after the application of Mg-Tytanit (BBCH 59, BBCH 66, BBCH 71). The results showed that the biostimulator MgTi, regardless of its dose and application date, resulted in a higher weight of the aerial and underground phytomass. All the MgTi applications had impact on the winter oilseed rape yield increase. The seed yield was increased by 0.3 to 0.63 t ha-1. Higher yields were achieved in the treatments where MgTi was applied three times in comparison with the treatments, where it was used twice. The oil content in rape seeds was increased significantly only if MgTi was used in the total doses 0.8 and 1.2 dm3 ha-1 in the single application dose 0.4 dm3 ha-1. The oil content value was increased by 0.94 % and by 0.82 %. The oil production per hectare was increased after each use of MgTi, i.e. regardeless of the dose and date of its application. The highest Ti content in the aerial phytomass was 68.5 mg kg-1 and in the underground phytomass it was 247.1 mg kg-1

The importance of initial application and reapplication of biochar in the context of soil structure improvement

It was shown that the use of biochar provides many benefits to agriculture by improving the whole complex of soil properties, including soil structure. However, the diverse range of biochar effects depends on its physicochemical properties, its application rates, soil initial properties etc. The impacts of biochar, mainly its reapplication to soils and its interaction with nitrogen in relation to water-stable aggregates (WSA) did not receive much attention to date. The aims of the study were: (1) to evaluate the effect of initial application (in spring 2014) and reapplication (in spring 2018) of different biochar rates (B0, B10 and B20 t ha−1) as well as application of biochar with N-fertilizer (40 to 240 kg N ha−1 depending on the requirement of the cultivated crop) on the content of WSA as one of the most important indicators of soil structure quality, (2) to assess the interrelationships between the contents of soil organic matter (SOM) and WSA. The study was conducted in 2017–2019 as part of the field experiment with biochar on Haplic Luvisol at the experimental station of SUA in Nitra, Slovakia. Results showed that initial application as well as reapplication of biochar improved soil structure. The most favorable changes in soil structure were found in N0B20B treatment (with biochar reapplication) at which a significantly higher content of water-stable macro-aggregates (WSAma) (+15%) as well as content of WSAma size fractions of > 5 mm, 5–3 mm, 3–2 mm and 2–1 mm (+72%, +65%, +57% and +64%, respectively) was observed compared to the control. An increase in SOM content, due to both, initial biochar application and its reapplication, significantly supported the stability of soil aggregates, while organic matter including humic substances composition did not