No-till Farming Systems Research Articles

Experience in implementation of the No-till farming system in the Belgorod region

The research was conducted in a forest-steppe zone of the municipality of “Korochan district” (Belgorod region). Typical and leached chernozem constituted the two types of soils, that were studied. The goal was to evaluate the main results of introduction of the No-till farming system, following the example of LLC “Meat Farms – Iskra”. It was found out that on average, throughout the years of 2018-2022, winter wheat was the most regular (24.5%), alongside sunflower (23.2%). Legumes prevalence was at 32.5% with soy (20.0%). Organic fertilizer wasn’t used in the process; however, the average dose of mineral fertilizers was 66 kg of the substance/ha, which is 42.4% lower than the average for Belgorod region. The usage of the system No-till yield the sunflower, soy and corn-beans, as well as winter wheat plantings corresponded to 2.21, 1.65, 6.35 and 4.43 t/ha, which is lower by 23.5, 20.7, 11.2,10.9% when compared with the average throughout Belgorod region. The quantity of organic substances in the arable layer of the soil underwent an increase of 0, 14%, the quantity of mobile forms of phosphorus and potassium went down by 12 and 28 mg/kg accordingly, the dose of acidic soils decreased by 8,7%. The amount of mobile forms of sulfur and microelements didn’t particularly change. The profitability of crop production using the No-till system was 82.3%, which is 1.29 times higher than the average of the Belgorod region.

Life Cycle Greenhouse Gas Emissions in Maize No-Till Agroecosystems in Southern Brazil Based on a Long-Term Experiment

Life Cycle Greenhouse Gas Emissions in Maize No-Till Agroecosystems in Southern Brazil Based on a Long-Term Experiment

The Effect of Furrow Opener and Disc Coulter Configurations on Seeding Performance under Different Residue Cover Densities

The performance of the no-till seeder is one of the most important factors that affect the success of the no-tillage. Striking the right balance between furrow opener design and residue cover is essential for optimizing seeding conditions and ensuring sustainable agricultural practices that promote both soil conservation and high-yield crop production. This study investigates the impact of residue cover on no-tillage maize seeding after wheat harvest, focusing on plant spacing, seeding depth, mean emergence time, and percent emergence. Trials with hoe-type and double-disc-type furrow openers, accompanied by plain- or ripple-disc-type coulters, were conducted in Antalya, Turkey. The results indicate that residue cover had no significant effect on mean plant spacing, but a higher residue cover increased spacing variation. The seeding depth in hoe-type furrow opener trials remained consistent, while double-disc-type furrow openers showed lower depths with 80% and 90% residue covers. The percentage of plant emergence and mean emergence time decreased as the residue cover increased in double-disc-type furrow opener trials. At 90% residue cover, PE decreased to 60%. The impact of disc coulters on hoe-type furrow openers was limited, but they increased seeding depth and MET in double-disc-type furrow openers. These findings can help optimize residue management for improved efficiency in no-till farming systems.

Effect of Leveling and Tillage Equipment on Soil Bulk Density and Yield of Maize

A field experiment was carried out to evaluate the effect of leveling and tillage equipment on the soil bulk density and the growth and production of maize. Three landscaping types of equipment, namely laser, pelvic, and grader equipment, and three tillage equipment, namely moldboard plow, chisel plow, and no-till farming system. Soil bulk density, practical productivity, plant height, weight of 100 seeds, number of seeds per ear, and the yield of maize were measured. The results can be summarized as follows: The interaction between the pelvic leveling equipment and the no-till farming system was superior in obtaining the lowest soil bulk density, while the interaction between the laser leveling equipment and chisel plow was superior in obtaining the highest plant height, the highest weight of 100 seeds stood 36.70 g, the highest number Seeds per ear stood 371.30 seeds per ear and the highest yield of the plant stood 6.36 tons ha-1 compared to the other interventions.

Earthworm richness in no-tillage farming systems and riparian forests in Southern and Southeastern Brazil

No-tillage (NT) is a soil conservation management practice that can sustain important earthworm populations due the maintenance of soil cover and absence of soil disturbance. Sites with NT can also support native earthworm species, but few studies have identified the earthworms collected under NT. Therefore, the present study evaluated earthworm diversity in 14 sites under NT and seven with riparian forest (RF) in Atlantic Forest located in Rolândia, Cambé, Toledo (Paraná), Coxilha, Sarandi (Rio Grande do Sul) and Itaí (São Paulo). The earthworms were collected by handsorting using quantitative and qualitative methods. The 1471 individuals collected were classified into 23 species belonging to five families: Glossoscolex sp.71, sp.72, sp.73 and sp.74, Fimoscolex sp.23 sp.24 and sp.25 (Glossoscolecidae); Pontoscolex corethrurus, Urobenus brasiliensis (Rhinodrilidae); Haplodrilus sp.1 and sp.2, Ocnerodrilidae sp.1, sp.15, sp.16, sp.48, sp.49 and sp.50 (Ocnerodrilidae); Amynthas gracilis, Metaphire californica (Megascolecidae); Dichogaster affinis, D. gracilis, D. bolaui and D. saliens (Benhamiidae). Of the total, 15 were native and eight were exotic species. In general NT sites had higher species richness than the forest sites (except at Itaí), mainly due to the invasion of NT fields by exotic species, particularly Ocnerodrilidae sp.1 and Dichogaster spp. Six of the seven forests had native species, but only four NT fields had native earthworms, and these were generally found in low abundance.

Prediction of Single Disc Seeding System Forces, Using a Semi-Analytical and Discrete Element Method (DEM) Considering Rotation Effects

Disc seeders are commonly used in no-till farming systems, and their performance evaluation generally rely on expensive and time-consuming field experiments. Mathematical models can help speed up force-related evaluations and improve the understanding of soil-disc interactions, to assist the performance optimisation processes. Previous analytical force prediction models of disc blades have not accounted for the free rotation aspect of the disc blade. This paper develops an analytical force prediction model from the wide blade failure theory adapted to suit rotating flat disc blades operating at different sweep and tilt angles and compares predictions with Discrete Element Method (DEM) simulations. To validate the two models, experiments were performed on a remoulded sandy soil condition using a rotating flat disc set at two tilt angles of 0° and 20°, and four sweep angles of 6, 26, 45 and 90° the 3-dimensional force components of draught, vertical and side forces were measured. Results showed a higher coefficient of determination (R2 = 0.95) was obtained with analytical model predictions compared to DEM predictions (R2 = 0.85) for their agreement with the test results. It was found that both the developed analytical approach and the DEM model can be used to predict tillage forces at different sweep and tilt angles acting on a rotating flat disc blade.

ДО ПИТАННЯ ІСТОРІЇ ВИНИКНЕННЯ ТА ЕВОЛЮЦІЇ ВИГІННОЇ СИСТЕМИ ЗЕМЛЕРОБСТВА

Summary The purpose of the research is to make a comprehensive historical-scientific analysis of the process of formation of the scientific and practical foundations of the cropping (multi-field-grass) system of agriculture, to find out the prerequisites for its emergence and to establish the patterns of development of its components. The research methods are historical-scientific, dialectical-logical, bibliographic-statistical, problem-chronological, which contributed to the comprehensive analysis of the research subject, which is based on the principles of multifactoriality, comprehensiveness, historicism and scientific objectivity of knowledge. Research results. Many years of research by scientists of the Bilotserki National University convincingly proved that the very low productivity of cattle breeding due to the constant shortage of fodder, and of low quality, and an excessively large share of steam (usually 1/3-1/2 of the entire area of arable land) under the steam farming system were the main reasons the emergence of a fallow (multi-field-grass) system of agriculture on the territory of Ukraine. In the estates of the nobles of the Black Earth belt, this system often arose from virgin or fallow land as a transitional form from primitive to interactive farming systems. Conclusion. It was noted that the yield system was gradually transformed into an improved grain crop by reducing the share of the area under perennial grasses and the growth under grain crops. The improved grain system, in turn, is transformed into a crop rotation (grain-grass rowing system) by replacing clean pairs with busy ones, as well as introducing row crops into crop rotations. Analyzing the data, it can be stated that in Ukraine, the no-till farming system was not very widespread in its pure form, but its individual components (multi-pollinated - grass, soil protection, fodder crop rotations) are successfully used even today in combination with crop rotations of other systems. V.O. is deservedly considered a pioneer of experimental field grass seeding and the creator of an improved grain system with a four-field crop rotation. Levshina, and the founders of field grass sowing on a large economic scale were D.M. Poltoratskyi and I.I.Samarin. Key words: evolution, system of farming (agriculture), crop rotation, culture, steam, tillage, soil, fertility, fertilizers.

Nitrous Oxide Emissions from a Long-Term Integrated Crop–Livestock System with Two Levels of P and K Fertilization

Nitrous oxide (N2O) emissions resulting from nitrogen (N) fertilization have been documented. However, no data on the effects of other nutrients, such as phosphate (P) and potassium (K), on N2O emissions in integrated crop–livestock systems are available so far. In the 2015/2016 and 2016/2017 growing seasons, we measured N2O emissions from a long-term system, established in 1991 in the Cerrado biome (a tropical savanna ecoregion in Brazil), fertilized with two P and K levels. The studied no-tillage farming systems consisted of continuous crops fertilized with half of the recommended P and K rates (CC-F1), continuous crops at the recommended P and K rates (CC-F2), an integrated crop–livestock system with half of the recommended P and K rates (ICL-F1), and an integrated crop–livestock at the recommended P and K rates (ICL-F2). The cumulative N2O emissions (603 days) and soil chemical properties were analyzed as a 2 × 2 factorial design (long-term agricultural systems x fertilization). The cumulative N2O emissions from CC-F2 and ICL-F1 were 2.74 and 1.12 kg N ha−1, respectively. The yield-scaled N2O emissions from soybean were 55.5% lower from ICL-F1 than from CC-F2 in the 2015/2016 growing season. For off-season sorghum, the mean yield-scaled N2O emissions were 216 mg N2O m−2 kg−1 (in a range from 79.83 to 363.52 mg N2O m−2 kg−1, for ICL-F2 and CC-F1, respectively). The absence of pasture and the presence of soybean and sorghum promoted the highest cumulative N2O emissions, favored by the recommended rate in relation to half of the P and K. In the total evaluation period (603 days), the presence of grazed land in the years prior to this study and land fertilized with half the recommended P and K rates in an integrated crop–livestock system reduced the resulting cumulative N2O emissions by 59%. Thus, we conclude that crop–livestock systems can be beneficial in reducing P and K applications and also in mitigating N2O emissions in comparison with continuous cropping systems fertilized with the full recommended P and K rates. In view of the global fertilizer crisis, this aspect is extremely relevant for agriculture in Brazil and around the world.

Commercial classification and physicochemical characterization of beets from a no-till vegetable planting system under different densities of corn stover

The cultivation of sugar beet (Beta vulgaris L.) for table or horticultural purposes is largely carried out in the conventional way which is characterized by intense mechanization causing soil degradation and high labor costs. New cultivation techniques are being employed in the production of vegetables aiming to ensure improvements in environmental and economic conditions, such as the no-till farming system. Thus, the objective of this work was to evaluate the vegetable classification and physicochemical characteristics of beets from different corn planting densities. The experiment was conducted in the period from October 2018 to June 2019 in the municipality of Nova Laranjeiras (PR). Corn was used as a cover plant and the vegetable used was beet cultivar Early Wonder Tall Top. The experimental design used was in interspersed blocks in unifactorial scheme (corn densities 40, 60, 80, 100 thousand plants/ha and control) with four blocks, with plots 3.60 m long and 1.20 m wide. The parameters evaluated 60 days after planting were: commercial classification (class, group, subgroup, category), length, diameter, mass, pulp firmness, soluble solids, titratable acidity, pH and ratio, phenolic compounds. Of which the variables that were not significant at 0.5 probability were length, category (defects), firmness, subgroup (flesh color), soluble solids and phenolic compounds. It is concluded that high densities of corn as mulch for SPDH of sugar beet crop negatively affect the grade and physicochemical characterization of the products.

Ecological strategy of using agricultural land in Ukraine

The article is devoted to the problem aspects of agricultural land use in Ukraine. Analysed influence on using of agricultural land such factors as systems of farming, global warming, uneven precipitation distribution by months and deficit of humus in the soil. Considered such system of farming as traditional, organic, No-Till and made conclusion about a harmfulness of traditional farming system on ecology. Analysed the influence of organic and No-Till farming systems on preservation of moisture in the soil under condition of increasing of air temperature and uneven distribution of precipitation by months. Made conclusion that in contrast to traditional farming system, organic farming system is able to improve a state of ecosystem, in particular a biological variability, biological cycles and biological soil activity. It is a possible by using cultural, biological and mechanic methods when cultivating the land in opposite to synthetic materials. So, organic farming is not only a system of agricultural production, but also is a complex approach for supporting of sustainable development of agriculture. The advantage of organic farming is a possibility for adaptation to many climate zones and local conditions.

What are the effects of irrigation rates and cropping systems on the soybean agronomic traits?

The irregularity and uneven distribution of rainfall may restrict the potential productive development of soybeans, causing numerous losses to farmers. The use of irrigation systems in hydrically heterogeneous areas are important measures that should be adopted during the crop cycle. Furthermore, the implementation of conservationist strategies, such as crop rotation or intercropping and no-till (NT) farming systems, can minimize the damage caused by water deficit. Therefore, the present study aimed to evaluate the soybean yield under different irrigation sheets and cropping systems in the extreme west of São Paulo. A completely randomized design was used, with 10 repetitions, in a subdivided plot scheme. The treatments were composed of different cropping systems in the plots, with four levels (conventional system; NT, using Urochloa brizantha cv Paiaguás; U. brizantha cv Piatã; and U. ruziziensis cv Ruziziensis), and different irrigation scheduling in the subplots, with three levels of irrigation scheduling (0%, 70% and 100%) based on reference evapotranspiration (ETo). Irrigation rates of 70% and 100% ETo in the conventional system provided higher grain yields under the climatic conditions in which the experiment was conducted. However, the continuity of long-term research is necessary, since NT is incipient, and have been implemented only two years ago. This is a relatively short period to observe the advantages of this cultivation system and for its consolidation process. Thus, the Brachiaria residual dry mass showed similar behavior in NT at the irrigation levels evaluated.

Taxonomic structure of the southern chernozem under application of biological preparations and different farming systems

The study of the taxonomic structure of the southern chernozem under influence of microbial preparations and various farming systems in the conditions of the southern steppe zone has been carried out. Metagenomic analysis of the microbiome of southern chernozem showed the presence of 174 genera representatives of prokaryotes, among which 17 are dominant, representing more than 1%. Farming systems cause changes in the taxonomic structure of the microbiome in comparison with virgin soil in the steppe zone. The influence of microbial preparations of complex action on the qualitative and quantitative composition of the microbiome of southern chernozem and increasing under no-till farming system has been established. The maximum content of water-soluble organic matter was found in virgin soil, which has higher amount of plant residues, up to 491 mg/kg of soil. Under the influence of farming systems its amount decreased in 4.2-8.5 times. The use of a complex of microbial preparations in the southern chernozem contributed to an increase in the amount of water-soluble fraction of humus depending on the farming system: 1.7 times with the conventional farming system and 3 times with no-till compared to the control without CMP.

Unraveling microbiomes and functions associated with strategic tillage, stubble, and fertilizer management

Occasional one-time tillage (strategic tillage, ST) is an effective tool for managing weeds and crop diseases in no-till and conversative farming systems. However, there is limited understanding of the impacts of ST on soil microbiome and their associated soil processes, particularly in dryland agriculture. This study aims to quantify the effect of one-off ST - after three years - on soil microbiomes and functions in a long-term no-till farming system under crop stubble and fertilizer management practices. The results showed that ST had marginal effects on microbial richness and diversity, enzyme activities, and catabolic function, but significantly affected the abundance of some microbial taxa (Actinobacteria, Firmicutes, Verrucomicrobia, Basidiomycota and Ascomycota) that are relevant to carbon (C) degradation. Stubble retention, regardless of tillage and fertilizer management, mainly increased the abundance of copiotrophs such as Proteobacteria (e.g., Rhizobiales) and Actinobacteria (e.g., Streptomyces and Micromonosporaceae), and affected Ascomycota and Basidiomycota. Among the management practices, stubble retention was the main factor that contributed to increased richness and diversity of the soil bacterial and fungal community. Supplementary fertilizer application, regardless of tillage and stubble management had minimal impact on bacterial and fungal richness and diversity, enzyme activity and catabolic function. The variation in bacterial community structure was influenced mainly by soil pH (c.a. 10%), while only a small but significant effect (< 7%; P = 0.001) was attributed to tillage and stubble management. Wheat grain yields ranged between 5 and 5.3 t ha-1 and were not affected by tillage, stubble, nor fertilizer management practices. Similarly, these management practices did not influence total soil C or nitrogen concentrations. Our findings show that strategic tillage, when used to address specific constraints in no-till systems in dryland agriculture, does not have a significant effect on total soil C, microbial ecology nor catabolic function.

Improvement of Maize Productivity and N Use Efficiency in a No-Tillage Irrigated Farming System: Effect of Cropping Sequence and Fertilization Management.

The sequence of the preceding crops in a no-tillage farming system, could interact with the integrated use of mineral and organic nitrogen (N) sources in a way that improves the growth and productivity of the terminal maize crop, meanwhile, enhancing its N use efficiency (NUE). In the current study, six legume-cereal crop sequences, including faba bean, soybean, Egyptian clover, wheat, and maize were evaluated along two experimental rotations that ended up by planting the terminal maize crop. In addition, the effects of applying variable mineral nitrogen (MN) rates with and without the incorporation of farmyard manure (FYM) on the productive performance of maize and its NUE were tested. The field experiments were conducted in a no-tillage irrigated farming system in Northern Egypt, a location that is characterized by its arid, Mediterranean climate. Results revealed that increasing the legume component in the evaluated crop sequences, up to 75%, resulted in improved maize ear leaf area, 1000-grain weight, and harvest index, thus, a higher final grain yield, with the inclusion of Egyptian clover was slightly better than faba bean. Comparing the crop sequences with 50% legume contribution uncovered the positive effects of soybean preceding crop on the terminal maize crop. Substituting 25% of the applied MN with FYM resulted in similar maize yields to the application of the equivalent 100% MN rates. The fertilizer treatments significantly interacted with the crop sequences in determining the maize grain yield, where the highest legume crop contribution in the crop sequence (75%) equalized the effects of the different fertilizer treatments on maize grain yield. The integrated use of FYM with MN in maize fertilization improved the NUE compared to the application of MN alone. Comparing fertilization treatments with similar MN content, with and without FYM, revealed that the difference in NUE was attributed to the additional amount of FYM. In similar conditions to the current study, it is recommended to grow faba bean two years before maize, while Egyptian clover could be grown directly preceding maize growth, with frequent inclusion of soybean in the sequence, this could be combined with the application of an average of 200 kg MN ha−1 in addition to FYM.

Pesticides in a case study on no-tillage farming systems and surrounding forest patches in Brazil

With the growing global concern on pesticide management, the relationship between its environmental recalcitrance, food security and human health has never been more relevant. Pesticides residues are known to cause significant environmental contamination. Here, we present a case study on long-term no-tillage farming systems in Brazil, where Glyphosate (GLY) has been applied for more than 35 years. GLY and its main breakdown product, aminomethylphosphonic acid (AMPA) were determined in topsoil (0–10 cm) samples from no-tillage fields and nearby subtropical secondary forests by high-performance liquid chromatography coupled with a fluorescence detector. In addition, the presence of carbamates, organochlorines, organophosphates and triazines were also screened for. GLY and AMPA were present in all soil samples, reaching values higher than those described for soils so far in the literature. A significant decrease for AMPA was observed only between the secondary forest and the farm's middle slope for site B. GLY and AMPA were observed respectively at peak concentrations of 66.38 and 26.03 mg/kg soil. GLY was strongly associated with forest soil properties, while AMPA associated more with no-tillage soil properties. Soil texture was a significant factor contributing to discrimination of the results as clay and sand contents affect GLY and AMPA retention in soils. This was the first study to report DDT and metabolites in consolidated no-tillage soils in Brazil (a pesticide fully banned since 2009). Based on human risk assessment conducted herein and the potential risk of GLY to local soil communities, this study offers a baseline for future studies on potential adverse effects on soil biota, and mechanistic studies.

Is no-till farming more or less efficient than till farming?: the case of tobacco farms in East Lombok, Indonesia

No-till farming is farming technics that could better conserve the fertility of the farmland than till farming. Technically, it is greatly linked with the global sustainable agriculture framework. However, it needs to be economically sound for adoption by farmers. Scientific analysis of this aspect is rarely reported in the literature, accessible to the authors. This paper attempts to fill the gap by taking as a case study: the efficiency of tobacco Virginia farms in East Lombok (Indonesia), involving 15 no-till farming farmers and 15 till farming farmers as the sample. This sample was randomly selected from the population of Virginia farmers in purposively selected two villages in the research areas. Data collection was carried out during 2018 planting session using an individual structural interview technique. Farm efficiency was measured as Return to Cost (R/C) ratio. The significance of the efficiency difference between no-till and till farming was analyzed using a t-test. The analysis found that the R/C ratio of Virginia tobacco farms using no-till farming system (mean = 2.21) was significantly lower at 95% degree of confidence than the R/C ratio of virginal tobacco farms using till farming system (mean=3.47). In spite of this significant difference, the value of the R/C ratio was larger than one, indicating each of the systems was financially feasible. This explained the adoption of no-till farming by some of the Virginia tobacco farmers in the study areas. However, the wider adoption of the no-till farming system needed some improvements to reduce farm cost and increase revenue.

Relationship between resistance and tolerance of crown rot in bread wheat

Crown rot of wheat and barley is a serious disease caused by the fungus Fusarium pseudograminearum; a stubble-borne pathogen common in no-till farming systems in many wheat growing regions. Evidence suggests that partial resistance and a degree of tolerance exists in wheat. To assess the relationship between resistance and tolerance, 207 wheat genotypes developed from the same population including parents and check cultivars, were evaluated in the field under crown rot pressure in yield loss experiments. Yield loss was determined in replicated, inoculated and un-inoculated paired plots in 2014 and 2015 and resistance assessed by the extent of stem browning on plants sampled from the same plots grown at Narrabri in northwestern NSW. The population was genotyped using a high-density 90 K SNP array and a genome wide association analysis conducted to identify QTLs for both tolerance and resistance. Transgressive segregation was observed for crown rot resistance and tolerance in the population. Forty-three QTLs were associated with resistance and tolerance traits and 8 previously reported QTLs were confirmed. Comparison of linked marker positions indicated that QTL for yield in the presence of crown rot inoculum located on chromosomes 2B, 2D, 4B, 6A and 6B were previously unreported. Stem browning was effective in determining resistance only and was not associated with tolerance, determined as yield under crown rot pressure or yield loss.

Linum usitatisimum L. is the most important crop in Russia for the production of high-quality oil with low cost (review)

Oil crops play an important role in providing society with food, livestock feed, industry and raw materials and are of great importance for economically stable agricultural production. The purpose of this review article was to show the importance of the agricultural crop of oil flax and its oil seeds for various types of industries, the possibility of expanding its cultivation areas in Russia, as well as a way to reduce the cost of production. The article provides overview information on studies conducted on oilseed flax (Linum usitatisimum L.), on the possibility of using its products in food, technical industry, medicine, for the production of biodiesel, in crop production and fodder production. High resistance to abiotic and biotic factors put oil flax in a number of crops that can be cultivated everywhere; however, its yield, oil content and cost in different regions of Russia and the world are very different. This question has not been sufficiently studied in the literature. This review focuses on modern research by both foreign and Russian scientists. The possibilities of cultivating Linum usitatisimum L. in Russia according to the modern no-till farming system (direct sowing technology, zero technology, technology without tillage) and the directions of its oil use are shown, which indicates their relevance and high demand in various fields of human activity. Oil flax is a unique natural and biological resource that has rational and environmental benefits in cultivation.

Marker-assisted recurrent selection improves the crown rot resistance of bread wheat

Crown rot of wheat and barley is a serious disease caused by the fungus Fusarium pseudograminearum, a stubble-borne pathogen common in no-till farming systems in water-limited grain growing regions. Marker assisted recurrent selection (MARS) was used to more effectively pyramid minor genes controlling plant response to crown rot disease. Two populations comprising 475 genotypes were phenotyped for adult plant resistance and genotyped using a 9K SNP array. A genome-wide association study (GWAS) was used to estimate quantitative trait locus (QTL) effects as more than two parents were recombined in each population. A total of 23 significant and unique marker-trait associations (MTAs) were identified in both populations. A Kompetitive allele-specific PCR (KASP) assay was developed and used to genotype the progeny and parents of each recombination cycle. Following two cycles of recombination among progeny, up to 22 markers of a possible 23 were recombined. Two hundred ninety-seven double haploid-derived lines representing both cycles of recombination, the original parents, parents selected from the base population and local cultivars were evaluated for crown rot resistance in 2016 and 2017 in the field under crown rot inoculation pressure. A significant and positive response to each cycle of recurrent selection was observed. MARS was an effective breeding strategy for combining many QTLs of small effect for crown rot resistance in wheat.

Dynamics of soil aggregation and organic carbon fractions over 23 years of no-till management

Evaluation of aggregate formation in no-till farming systems and the effects on soil organic matter can provide relevant insights into soil carbon storage, nutrient cycling, and soil susceptibility to erosion. However, there is little information on the soil aggregate formation pathways in no-till systems. This study aimed to investigate the effect of no-tillage duration on soil aggregates and soil organic matter compared with undisturbed soil in the rainy and dry season. The following experimental sites were analyzed: NT7 (no-till management for 7 years), NT14 (no-till management for 14 years), NT23 (no-till management for 23 years) and AF, a preserved fragment of Atlantic Forest (reference area). Aggregate formation pathway was analysed/described according to the morphological pattern using a stereo microscope (LEICA M125), in magnification ranges between 20x and 40 × . Physical fractionation of organic matter was carried out by granulometric size separation, and humic substances were separated into humic acid, fulvic acid, and humin fractions by differential solubility. No-till management affected the dynamics of soil aggregation and organic matter fractions. In the long term, no-till farming reduced biological aggregation (52.5 ± 4.5 % in AF to 19.2 ± 3.1 % in NT23), and increased physicochemical aggregation (21,2 ± 2.1 % in AF to 47.2 ± 5.1 % in NT23), may be because the traffic-induced compaction resulting from seeding. However, over the years, no-till farming increased soil particulate organic carbon (POC), mineral-associated organic matter (MAOM) and humin contents because of the constant input of crop residues to surface layers. Our results suggest that the morphological classification analysis of soil aggregates was sensitive to changes in land use over time, consisting as an indicator practical, affordable, repeatable, and easily understood and interpreted, which may be used to ascertain changes in physical soil conditions.