•Nitrogen use efficiency (NUE) decreased in general with increasing N level.•Yield increased from N1 to N2 and changed inconsistently from N2 to N3.•Medium N level (N2) is most suitable from the NUE ...and yield viewpoints.•Soil type and tillage systems have significant influence on soil physical properties.•Maize and winter wheat yields respond positively to a conservation tillage system.
The hypothesis that the optimal nitrogen rate for crop yield and nitrogen use efficiency (NUE) are affected by tillage treatment, crop type and soil properties (type) was evaluated by an experiment which include five different tillage treatments (CT-conventional, SS-subsoiling, CH-chiselling, DH-disk-harrowing and NT-no-till), three levels of nitrogen rates (N1-reduced, N2-optimal and N3-luxury), on two different soil types (Stagnosol and Gleysol) and with two different crops (maize and winter wheat). Soil and plant samples were taken from the first and second year in the second four-year crop rotation cycle. The highest value of soil compaction (ρb-bulk density and PD-packing density) as well as the lowest soil total porosity (P) was found, on average for all tillage treatments, on Gleysol in both experimental year in the root zone (20–40 cm). At all depths the highest values of ρb and PD were recorded for DH treatment on Gleysol and for soil porosity for NT treatment on Stagnosol. Grain yields, biomass, and harvest index of maize and winter wheat on both soil type respond positively to conservation tillage treatment, but with different significations. Soil cover crop residues were significantly affected by soil treatment and nitrogen fertilization (P < 0.01), and decreasing in the following order: NT > CH > SS > DH > CT on both soil types. The average NUE in general decreased successively under N1, N2 and N3 with respective NUEs on Stagnosol 58.5, 49.5 and 36.0 kg kg−1 for maize and 59.9, 45.3 and 35.9 kg kg−1 for winter wheat. Corresponding values on Gleysol were 78.5, 69.4, 52.0 kg kg−1 and 46.3, 51.3, 44.0 kg kg−1. The grain and biomass of winter wheat increased from N1 to N2, whereas from N2 to N3 they decreased, increased or remained almost the same depending on the tillage system and soil type. The effect of all the investigated tillage treatments on NUE and crop yield was variable depending on particular tillage system, crop type and soil type. The results indicate that, from the NUE and crop yield viewpoints, the N2 and N3 nitrogen rates are respectively most and least suitable on both soil types, depending on soil treatment. Irrespective of the nitrogen application rate and tillage treatments, the NUEs were the most comparable treatments higher in the more productive Gleysol (32.7–92.5 kg kg−1) than in Stagnosol (26.4-76.7 kg kg−1).
Konzervacijska poljoprivreda sa svojim temeljnim principima (trajna pokrovnost tla, minimalna obrada i plodored) jedan je od najučinkovitijih sustava za prilagodbu poljoprivredne proizvodnje ...nepovoljnim uvjetima klimatskih promjena. Brojne prednosti konzervacijske poljoprivrede dodatno su izražene integracijom pokrovnih usjeva u plodored. Pokrovni usjevi uvode se u inovativne sustave biljne proizvodnje u svrhu poboljšanja kemijskih, fizikalnih i bioloških svojstava tla uz pozitivan utjecaj na bioraznolikost i doprinos održivosti poljoprivredne proizvodnje. Cilj ovoga rada je pregledno prikazati neke od glavnih uloga pokrovnih usjeva u konzervacijskoj poljoprivredi s osvrtom na zaštitu tla od erozije, konzervaciju vode i hraniva te utjecaj na organsku tvar i strukturu tla.
Conservation agriculture with its basic principles (permanent soil cover, minimal soil disturbance and crop rotation) is one of the most effective tools for adapting agricultural production to the adverse conditions of climate change. The numerous advantages of conservation agriculture are further expressed by the integration of cover crops into the crop rotation. Cover crops are introduced into innovative plant production systems for the purpose of improving the chemical, physical and biological properties of the soil with a positive impact on biodiversity and contributing to the sustainability of agricultural production. The aim of this paper is to present some of the main roles of cover crops in conservation agriculture with emphasis on soil erosion protection, water and nutrient conservation, and the impact on organic matter and soil structure.
Conservation tillage (CT) is an effective tool for maintaining crop productivity under adverse climate conditions, while its adoption is conditioned by the possible negative response of crop weed. ...Research with CT and liming (L) was conducted at different experimental sites on acid soils (ES 1 and ES 2) to determine the maize weediness and yield. The tillage treatments used were ST (conventional tillage), CTD (deep loosening), CTS (shallow loosening), and liming; Ly (CaO) and Ln (no CaO). The weediness assessment was conducted at the V7 and R5 maize growth stages. Weed density (WD), biomass (WB), weed coverage (WC), and species density (WSN) were determined. The highest WD was recorded on ES 2 in V7, and WB, WC, and WSN were significantly higher at CTS in R5 compared to ST. Liming affected the decrease of WD and WC in V7 and WB, WC, and WSN in R5. The average maize yield on ES 2 was 36% higher compared to ES 1. CTS resulted with the highest yield at ES 1, while at ES 2, it was similar to ST. Liming application significantly increased the maize yield. The given results indicated the positive impact of CT and L on crop productivity in different agroecological conditions, despite the increased weediness.
Effects of soil tillage (CTconventional, SS-subsoiling, CH-chiselling, DH-disk-harrowing and NT-no-till) and nitrogen rate (reduced N1, optimal N2 and luxury N3) on yield and yield components of ...maize and winter wheat in two different agricultural subregions of Croatia (Magadenovac and Cacinci site), were studied in the years 2013–2014 as part of a long-term experiment. Maize yield and yield components were influenced by site properties, tillage and nitrogen treatments. The highest yields and yield components were recorded at the Magadenovac site with N2 and N3. The lowest values of the yield and yield components of maize were recorded on NT and were significantly lower than CT, SS, CH and DH, among which no significant differences were recorded. Winter wheat yield and yield components were affected by site properties and nitrogen rates while soil tillage treatments only had an influence on grain and straw yield and plant height. Winter wheat achieved maximum yield and yield components on a N3 and N2 and at the Magadenovac site. Winter wheat grain yield decreased in the following order: SS > DH > CH > NT > CT. The obtained results indicate the importance of optimal nitrogen fertilization and the possibility of the implementation of conservation tillage for maize and winter wheat production in different agroecological conditions.
Biochar, a carbon-rich material, is highlighted to improve soil fertility, simultaneously mitigating climate change by carbon sequestration. Combined with mineral fertilizer, it can increase ...weediness, the major source of yield loss in agricultural production. Research with biochar was conducted in Eastern Croatia in 2016, with the aim to investigate the influence of biochar and mineral fertilizer on weed infestation and winter wheat yield. Field experiments were set up as a split-plot where biochar (B) was the main factor and fertilization was the sub factor. The main treatments were: B0 (control without biochar), B1-5 t ha−1, B2-10 t ha−1 and B3-15 t ha−1. Fertilization sublevels were F0) without fertilizer and F1) optimal dose of fertilizer. Weediness was determined by counting and measuring aboveground biomass. The treatments with the greatest effect on weediness were B3 and F1 in the winter wheat tillering stage. In the winter wheat ripening stage, treatment B3 obtained the highest weediness and F1 significantly reduced weed density. Biochar treatment B3 increased winter wheat yield by 77% in relation to the control. The application of biochar combined with fertilization affected the level of weediness depending on agroecological conditions, but with a significant increase in yield.
Seed dormancy is a major impediment for the production of Salvia officinalis L. (sage) seedlings. This study aims to test seed priming methods to break the dormancy of sage seeds in controlled ...conditions. Seeds were subjected to four treatments respectively hydropriming, magneto-priming, electro-priming and control with no seed priming techniques. During germination development stage all parameters were registered according to BBCH (Biologische Bundesanstalt, Bundessortenamt und CHemische Industrie) standardized scale. Daily assessments were made, germination indices were calculated, new germination secondary stages were observed and described, and daily range for each secondary stage were obtained. All priming methods had different effect on sage seeds. The hydropriming treatment was the most effective with 70% seeds germinated in 10 days. Sage seeds from magneto-priming determine more than 50% seeds to germinate in only 8 days. Control and electropriming treatment showed a similar value of seed germination, set around 64-65%. In control, electro- and hydropriming treatments are necessary 6 days for the achievement of more than 50% seed germination, while for magneto-priming are necessary 8 days. Hydropriming has the highest germination index, significantly higher than control and magneto-priming. During the germination, hydropriming shows a gradual transition of seeds from one BBCH sub-stage to another, while electro- and magneto-priming induce a heterogenous variation through the entire process. Overall, the hydropriming treatment registered better results of sage germination compared to the control treatment.
Climate change (CC) is undoubtedly induced and accelerated by human activity and can pose a serious threat to mankind by reducing food production. Significant weather aberrations in form of the ...uneven precipitation pattern, more frequent and intense occurrence of temperature fluctuations accompanied by changes in wind intensity and frequency, amount of clouds, intensity and quality of sunlight can be expected. Maybe the most vulnerable sector affected by CC is agriculture. So, it is important to mitigate and adapt to a new situation through different and most adaptable agricultural strategies. Accordingly, scientists, experts, politicians, decisionmakers, and others increasingly emphasize the need for further development of sustainable agricultural production, whose management will be compatible with different ecosystems (agroecosystem compliance with global ecosystems), while simultaneously restoring degraded agricultural land. One of the best solutions for sustainable agricultural production, under CC conditions, can be Conservation agriculture. Climate change is not only an abstraction, which is why one of the most important roles of conservation agriculture today is its ability to adapt and mitigate these changes. The basis of conservation agriculture production is in management set on three fundamental postulates, which contextually unify climate-soil-plant, while respecting agroecological and socio-economic differences.
A stationary field experiment of a reduced soil tillage was implemented at a Hypogley (Hypogleyic soils A–Gso–Gr soil horizon sequence) soil type of Eastern Croatia during three seasons and set up as ...a split-plot randomized block design in four repetitions. The tillage systems (TS) were as follows: 1) conventional tillage, i.e., plowing at 30 cm (CT), 2) disking up 10-12 cm (DT), 3) soil loosening up to 35 cm (LT), 4) no-tillage (NT). The experiment was designed to compare the penetration resistance (PR), soil moisture (SM), and bulk density (BD) at different TSs and soil depths. A cone penetrometer was used to measure the PR with 10 prods per TS, accompanied with a measurement of SM with a soil auger on every 10 cm, with four samples up to a 40-cm depth. The BD was determined by metal cylinders on every 10 cm up to a 30-cm depth, being weighed and dried thereafter to obtain an absolutely dry sample, and then calculated using absolutely a dry soil sample mass (m_s) and the soil volume (V). The PR and SM were significantly influenced by the TS and soil depth. The CT had the significantly lowest PR at all depths, while the DT has manifested a significantly higher PR at a soil depth amounting to 10 to 20 cm. The PR on NT were significantly diverse from the CT at all soil depths. The BD varied significantly concerning the TS and the soil depth. Subsequent to the three years, the CT had a significantly smaller BD at a depth amounting from 0 to 10 cm, and a significantly higher BD at 20- to 30-cm depth, compared to reduce the TS.
Stacionarni poljski pokus reducirane obrade tla proveden je u istočnoj Hrvatskoj na hipogleju tijekom triju sezona. Pokus je postavljen kao randomizirani blok-sustav u četiri ponavljanja. Sustavi obrade tla (TS) bili su sljedeći: 1) konvencionalna obrada tla oranjem na 30 cm (CT); 2) tanjuranje na 10–12 cm (DT); 3) rahljenje tla na 35 cm (LT); 4) no-tillage (NT). U eksperimentu su praćeni otpori tla (PR), vlaga tla (SM) i volumna gustoća tla (BD) na različitim TS-ovima i dubinama tla. Konusni penetrometar korišten je za mjerenje PR-a s 10 uboda po TS-u, praćeno sondiranjem za SM na svakih 10 cm, s četirima uzorcima do 40 cm dubine. BD je određen metalnim cilindrima na svakih 10 cm do 30 cm dubine. Izvagani uzorak je osušen do apsolutno suhoga uzorka, a zatim izračunan BD koristeći se apsolutno suhom masom uzorka tla (m_s) i volumena tla (V). PR i SM su bili pod značajnim utjecajem TS-a i dubine tla. CT je imao najniži PR na svim dubinama, DT je pokazao značajno veći PR na dubini tla od 10 do 20 cm u odnosu na CT. PR na NT bio je značajno različit od CT-a na svim dubinama tla. BD se znatno razlikovao po TS-u i dubini tla. Nakon tri godine CT je imao signifikantno manji BD na dubini 0-10 cm te signifikantno veći BD na dubini 20-30 cm u odnosu prema reduciranim sustavima obrade tla.
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