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Tillage practices govern crop quality and quantity through soil nutrient availability and crop root systems. A deeper knowledge of the impact of conservation tillage on soil chemical characteristics (such as pH, soil organic carbon, macro and micronutrient storage and distribution) is required for both the promotion of agricultural sustainability and environmental preservation. This study assesses the changes in soil features and properties in the context of a long-field experiment with different tillage systems and straw management practices. Research findings revealed that compared with conventional tillage (CT) conservative tillage with partial straw retention (MT) and no-tillage with straw mulching (NT) substantially boosted the organic carbon (OC) (by 6–19%), total nitrogen (TN) (by 2–12%), and available potassium content (AK) (by 2–5%), in 0–30 cm soil depth. However, the stratification trend was observed for available macro and micronutrient content (Zn, Fe, Mn) in both conservative management practices. The concentration of Cu indicates a constant pattern through a 0–30 cm soil profile with a higher concentration under MT (1.41 mg kg−1) compared to NT (1.10 mg kg−1). In particular, the results failed to establish if conservation tillage can increase the total phosphorus (TP) and potassium content (TK), where only in surface 0–10 cm an increase was observed. This research also suggested that the X-ray fluorescence analysis (XRF) of total micronutrient content (Zn, Cu, Fe, Mn) is minimal or unpredictable with no substantial differences between the tillage systems and straw return management practices. These findings suggest that conservation tillage in north-eastern Romania might be optimal to maintain soil quality status and sustain high yields. [ABSTRACT FROM AUTHOR]

During the last decades, notillage has started to be used on more and more areas, being a conservative tillage system practiced in many farms in the country. The aim of this study was to quantify the effects of the no-tillage system on the physical properties of the soil compared to the conventional system, in a plateau area with cambic chernozem soil under the current climatic conditions in the north-east of Romania, in order to implement it in agricultural practice of the studied area. The soil samples were taken in natural and undisturbed conditions for bulk density and moisture content, soil penetration resistance was determined using the Eijkelkamp penetrologger. The status of soil compaction, the various porosity categories, and the soil moisture content were all determined based on field and laboratory analysis. Measurements performed at a depth of 0-40 cm showed a lower bulk density in the conventional system, and in terms of variation in values from sowing to harvesting, there was a maximum increase of 18% in the 10-20 cm soil layer, an intermediate of 10% in the topsoil and 20-30 cm layers, and a minimum of 1% in the 30-40 cm layer. Total porosity, which reflects soil pore volume, is inversely correlated with bulk density, which means that under conventional tillage practices, soil macropore volume (>0.05 cm) was higher (47.79-60.82% v/v) than under no-tillage practices (45.90-50.79% v/v) for 0-40 cm depth at the sowing time. The results confirm that the no-tillage system conserves more water in the soil under current climatic conditions. [ABSTRACT FROM AUTHOR]

The long-term experiment was carried out during 2005-2018, with samples collected on the experimental farm of the University of Agricultural Sciences and Veterinary Medicine in the city of Iasi (47'07' N latitude, 27'30' E longitude). The soil under investigation is classified as Cambic Chernozem (WRB) with a clay-loamy texture. Initial physical characteristics of the soil on 0-20 cm depth were: bulk density 1.33 g.cm-3, pH (1:2.5) 6.23, clay 364.2 g.kg-1, silt 263.2 g.kg-1, loam 372.6 g.kg-1, humus 2.95%. In the last 5 years a continuous maize cropping system was used. The tillage treatments included: (1) No-till: direct drilling in untilled soil with a disc drill without previous removal of residues, using a FABIMAG FG01 seeder (NT); (2) a reduced system using a chisel at 22-25 cm depth, after harvest without overturning the furrow (RT); (3) moldboard ploughing after harvest to a soil depth of 28-30 cm (CT). The crumbled and loosened soil was turned over and thereby residues were fully incorporated into the soil. After the harvest of pre-crop, stubble breaking (disking to the depth 10 cm) was used. Seedbed preparation was applied using a compactor after chisel and conventional tillage. In spring the weeds were suppressed by total herbicides before seeding. Crop-specific fertilization was performed according to good agricultural practice. Combine harvest was performed in October (between 5th and 28th) using a Wintersteiger Delta Plot Combine. Tillage systems affected soil penetration resistance (PR) under maize crop only for certain soil depths. At 0-5 cm depth, the highest value (0.78 MPa) was recorded on no-till system, whilst in the case of the other two variants the values ranged from 0.56 to 0.61 MPa. In CT variant at 30-40 cm, we noticed a compacted layer (2.54 MPa) indicating the existence of hardpan. [ABSTRACT FROM AUTHOR]

X-ray computed tomography is one of the modern techniques used for soil structure visualization and quantification. The aim of this study was to investigate the effects of different tillage systems on soil porosity. Soil samples were collected from the field, on 0-30 cm depth, within the Experimental Farm of the Agricultural University of Iasi, North East of Romania, from a long term experiment with three tillage systems: V1 - chisel, V2 - no-till, V3 - plough at 30 cm. Aggregates were scanned using a SkyScan 1172 microCT and then the reconstructed 3D images were analyzed, in order to investigate pore volume and pore size class distribution. The results of the porosity analysis revealed significant differences between the variants taken into study. Regarding the solid surface area the tillage systems determined very different values of this parameter in soil. Pore size class distribution also showed clear differences between the variants. X-ray CT proved to be a useful tool for soil analysis, in order to have a detailed view of the pore network. [ABSTRACT FROM AUTHOR]

Climatic evolution from Romania, with trend toward heating and aridity, requires the application of new tillage variants, which ensure both soil fertility conservation and high yields. Winter wheat is a very important crop, but the more frequent droughts from August-September, determine great difficulties for seedbed preparation and good sowing. One of the most used indices for physical state characterization, with direct influence on soil air and water permeability, plant root development and microbiological processes is bulk density (BD). In order to emphasize the effect of conventional and conservative tillage on soil compaction degree, expressed by BD values, undisturbed samples were collected on 0-30 cm depth, from 10 to 10 cm, at sowing, during vegetation and at harvest of the winter wheat crop. The highest values were recorded for HDH 3.85+Vibromix and HDH 3.85+VRH and the lowest for the Plow+Combigerm variant. [ABSTRACT FROM AUTHOR]

Rapeseed crop has a very important role in world economy, being the third largest source of vegetable oil after palm and soybeans. It is very sensitive to soil compaction, because root growth, water and nutrient absorption are achieved with difficulty. The seedbed preparation ensures the lumps shredding, weed control, land leveling, introduction of fertilizers in soil and, essentially, creating a layer of loose soil, favorable for seed germination. The last tillage done before sowing has direct effects on the quality and quantity of the yield. The tillage activities by their nature must modify soil properties towards biological plant requirements without damaging its physical condition. The qualitative indices determined for the seedbed preparation are average depth of soil mobilization (Da), soil crumbling degree (Dsc), soil loosening degree (Dsl), soil leveling degree (Dls) and weed control degree (Dwc). The paper present the effect of soil tillage on seedbed qualitative indices for the rapeseed crop. The experiments were carried out at the Research and Development Agricultural Station, Secuieni, Neamt County, between 2012 and 2014. The results show that different tillage systems influenced the quality of the seedbed, with higher values for the conventional Plough+Combigerm variant and lower for the minimum tillage one, Disc+Vibromix. [ABSTRACT FROM AUTHOR]