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The article presents the results of research on the optimization of the supply of maize plants with the main nutrients under different agrochemical loads in the Forest-Steppe. The aim of the research was to establish the effect of different doses of mineral fertilizers and by-products of the predecessor as fertilizers on the supply of plants with nitrogen, phosphorus and potassium and corn yield. The research was carried out during 2016-2019 on dark gray wooded soil of the Forest-Steppe with the use of field, chemical, calculation-weight and mathematical-statistical methods. It were found that long-term growing of agricultural crops for 30 years under different agrochemical loading in crop rotation on dark gray wooded soil of the Forest-Steppe led to the creation of different agrochemical backgrounds. According to the results of soil and plant diagnostics, it has been established that nitrogen is the limiting nutrient for growing corn. In the variants with application of increased (N180P120K180) and high (N240P120K240) norms of mineral fertilizers against the background of by-products of the predecessor (winter wheat straw), where the highest yield of corn is formed - 11.21-12.10 t / ha, mobile phosphorus content 20 cm layer of soil was very high, mobile potassium - high, easily hydrolyzed nitrogen - very low. In these variants, maize plants in stages BBCH 16, 19 and 65 accumulated the optimal amount of nitrogen, and the content of phosphorus and potassium showed optimal and high supply during the growing season for the application of mineral fertilizers in the norms above N60P45K60.According to the results of correlation and regression analysis, the decisive role of nitrogen and potassium in the formation of corn productivity was confirmed. Mathematical models have been constructed that make it possible to predict the level of maize yield depending on the content of chemical elements in the soil and plants at the early stages of BBCH development.

An increase in beet production at the present stage is possible only with the use of intensive technologies, where the integrated protection of crops from harmful organisms is of great social and economic importance. In the system of measures aimed at increasing the production of beetroots, an important place is the protection of sugar beets from diseases. Successful control of sugar beet diseases is an important reserve for increasing the yield and sugar content of root crops and improving their technological quality. A rather dangerous disease of sugar beet is the root eater, which is widespread throughout Ukraine, especially in the zone of sufficient moisture. Conducting studies to study the effect of certain agro technical measures, as more economically affordable, on the formation of harmful microorganisms that contribute to the development of root and other root diseases during the growing season, the effect of sugar beet concentration in crop rotation. In the experiments, various types of crop rotation were studied: grain-sowing, grain-cultivating (with green manure) and fruit-bearing. The technology for growing crops is generally accepted. Pesticides were not used in the experiments, with the exception of seed dressing. Studies have established that the main causative agent of the root in the conditions of the western forest-steppe of Ukraine are various species of fungi of the genus Fusarium i Aphanomyces cochliondes. The dominance of these pathogens among pathogens causes the most severe defeat of beets in the phase of the first pair of leaflets, as well as the death of plant diseases in a later period - after the formation of planting density. Studies have shown that the lowest prevalence of sugar beet diseases was observed at a saturation level of 17% when they were grown in one place after 5 years (the average degree of development of the root was 14.7%). The development of the disease increased with a decrease in the time of returning to the previous place of cultivation in the rotation. So, on average, over a three-year period, the reduction of this period to four to two years increased the degree of root beetle damage to 15.4-19.8%. At a one-year break and re-sowing, this indicator was 24.4% and 27.2%, respectively. Based on the results obtained, it can be argued that an increase in the concentration of sugar beets in the crop rotation leads to an increase in the distribution of the root.

Estimating soil nitrogen (N) mineralization is critical to balance fertilizer N requirements and their environmental impacts. In this study, net N mineralization was examined in soils under different crop rotations with each phase of the rotation present every year with biologically based incubations in 2011 and 2015. Net N mineralization was significantly different among treatments when the current crop was soybean, and the effect was dependent upon the previous crop and the cropping sequence. In particular, net increases in inorganic N were greater when the previous crop was winter wheat with or without red clover than if it were corn, and greater for the first year of soybean compared with the second year for rotations with two consecutive years of soybean in the 2011 incubation. However, cropping history did not influence net soil N mineralization when the current crop was corn, winter wheat, or winter wheat with red clover. In 2015, the presence of red clover in the rotation increased net N mineralization in all phases of the rotation. These results suggest both current and previous crops should be considered when estimating the N supplying capacity (net mineralization) of the soil. Net mineralizable N was found to be significantly correlated with total amino sugars (P

Adjusting nitrogen (N) fertilization and accounting for the legacy of past N fertilizer application (i.e., residual N) based on remote sensing estimation of crop nutritional status may increase resource efficiency and promote sustainable management of cropping systems. Our main goal was to evaluate the potential of hyperspectral airborne imagers and ground-level sensors for identifying N fertilizer rates and the residual N effect from the previous crop fertilization in a maize/wheat rotation. A two-season field trial that provided various combinations of N rates and residual N response was established in central Spain. Ground-level sensors and aerial hyperspectral images were used to calculate vegetation indices (VIs). In addition, the solar-induced chlorophyll fluorescence (SIF $_{760}$ ) was estimated by the Fraunhofer line-depth method using high-resolution hyperspectral imagery, and together with biophysical modeling, biochemical and biophysical constituents at canopy scales were retrieved. N uptake, N output, grain N concentration, and proximal sensors discriminated between different N fertilizer rates and identified the residual effect when it was relevant. Structural, photosynthetic pigments and short-wave infrared region (SWIR)-based VIs, together with SIF $_{760}$ and the chlorophyll a + b ( $C_{ab}$ ), biomass, and the leaf area index (LAI), performed similarly on N rate detection. However, the residual effect of nitrification inhibitors was only detected by the structural (NDVI and OSAVI), chlorophyll (CCCI and NDRE), blue/green, NIR-SWIR (N $_{850,1510}$ ) indices, SIF $_{760}$ , $C_{ab}$ , biomass, and the LAI. This study confirmed the ability of remote sensing to identify N rates at early growth stages and highlighted its potential to detect residual N in crop rotation.

Soybean cyst nematode (SCN; Heterodera glycines) is one of the devastating soybean pests worldwide, including in the United States. Resistant cultivars combined with crop rotation are the primary methods for managing this nematode. SCN is known to have genetically diverse populations and can develop new virulent forms over time due to the continuous planting of cultivars derived from same source of resistance. Thus, identifying novel SCN resistant sources is of paramount importance for soybean breeding for nematode resistance. In this study, we screened 149 early maturity soybean [Glycine max (L.)] accessions for resistance to SCN HG type 2.5.7, which is one of the prevalent virulent SCN populations in North Dakota. SCN white females were extracted from individual plants of each accession after 35 days of growth in greenhouse conditions. The females were counted to determine a female index (FI = [average number of females on a tested accession/average number of females in Barnes, a susceptible soybean check] × 100). The resistance response of each soybean accession was categorized as resistant, moderately resistant, moderately susceptible, and susceptible. Of the 149 soybean accessions tested, only 13 were resistant in both runs of the experiments. The majority of screened soybean accessions were susceptible or moderately susceptible to the SCN HG type 2.5.7. The resistant soybean accessions identified in this study have the potential to be used in breeding SCN-resistant cultivars after further elucidation of the resistance genes or loci.

The crop rotation system in organic farming is a determinant factor to accumulate and preserve soil organic matter (SOM), and in depth knowledge on its effects is still lacking. Tillage intensity in particular is crucial to maintain soil aggregates and protect SOM from degradation. The evolution of SOM was tested in two adjacent fields under two different rotation cropping systems (low-intensity tillage and high-intensity tillage), and the effect of a further cultivation of legume in both fields was evaluated using 13 carbon (C)-nuclear magnetic resonance (NMR) and elemental analysis of samples isolated through combined aggregate size and density fractionation. The two adjacent fields had been managed using the following organic farming methods for 13 seasons since 1998: i) alfalfa-based, with nitrogen (N) enrichment and low-frequency tillage with alfalfa (Medicago sativa) (9 seasons), winter wheat (Triticum durum) (3 seasons), and broad bean (Vicia faba) (1 season) and ii) cereal-based, with N depletion and annual tillage with barley (Hordeum vulgare) (7 seasons), sunflower (Helianthus annuus) (2 seasons), broad bean (Vicia faba) (3 seasons), and bare fallow (1 season). Soil sampling was carried out at the end of the 13-year rotation (T0, November 2011) and after winter wheat and chickpea cultivation in both fields over two subsequent years (T1, July 2013). Bulk organic C was significantly higher in the alfalfa-based system than in the cereal-based system at both T0 and T1, with SOM occluded in soil aggregates and associated with mineral particles. In terms of the macroaggregates heavy fraction at T0, the alfalfa-based field contained twice the organic C of that in the cereal-based field, as well as three times the organic C in the occluded particulate organic matter (POM). The occluded POM (oPOM) had a lower aryl/O-alkyl C ratio in the alfalfa-based system than in the cereal-based system, suggesting that oPOM undergoes a lower degree of decomposition during low-intensity management. The aryl/O-alkyl C ratios of the macro- and microaggregate oPOM decreased from T0 to T1 in the cereal-based system, suggesting increased protection of these fractions by soil aggregates. Thus, including legumes in crop rotation appears to positively affect the accumulation of SOM associated with mineral particles and within soil aggregates.

Context Cropping in the Queensland Murray–Darling and Fitzroy Basins has precursors for secondary salinity – high soil salt loads and increased drainage after clearing. Aims To measure changes in deep drainage, for key tillage, traffic, and cropping systems. Methods Steady-state and transient chloride (Cl) mass-balance were applied to Cl profiles from four tillage and crop rotation trials and one controlled traffic trial in southern and central Queensland, to determine deep drainage below the root zone. Key results Large downward movement of Cl occurred after clearing. Deep drainage from transient Cl balance for cropping was a small proportion of rainfall but considerably higher than under native vegetation. Deep drainage was consistently greater under zero than conventional tillage, for both winter and summer cropping. For example, deep drainage was greatest for zero tillage (∼45 mm/year) and least for conventional, stubble mulch, and reduced tillage (2–6.3 mm/year) at the highest-rainfall site (677 mm/year). Deep drainage was 12.7 and 7.9 mm/year for zero and conventional tillage, respectively, at the lowest-rainfall site (497 mm/year). Drainage under continuous wheat conventional tillage was more than twice that where some summer crops were included. At Billa Billa, continuous wheat had greater deep drainage by three to five times than continuous sorghum for three of four tillage systems. No drainage was detected during 6 years of opportunity cropping. A pasture legume ley had only 1.7 mm/year of deep drainage. Deep drainage was less for compacted than non-compacted treatments (23.3 vs 38.2 mm/year). Conclusion and implications Increased deep drainage with zero tillage and controlled traffic can be reduced using summer crops, particularly opportunity cropping where crops are planted when soil water is sufficient, and ley pastures.

We explored how long-term agricultural practices affect arbuscular mycorrhizal (AM) fungal traits and community structure. We sampled soil and roots from a 26-year-old field experiment comprising 16 replicated treatments, in which we manipulated tillage intensity (moldboard vs. chisel plow), fertilization (organic vs. mineral) and crop rotation (continuous barley vs barley-forage rotations) in a factorial design (N = 64). We measured AM fungal community-aggregated traits, namely the abundance of vesicles, arbuscules, extraradical mycelium (ERM) and spores. We characterized root-borne and soil-borne AM communities using Illumina sequencing. Crop rotation was the main factor controlling AM fungal traits, with more arbuscules and ERM found in forage rotation plots, and more vesicles and spores found in continuous barley plots. Members of the Glomeraceae family were preferentially associated with continuous barley whereas the Gigasporaceae and Diversisporaceae families were overrepresented in the first stage of crop rotation. Trait-based and phylogenic filtering of AM fungal communities allowed us to speculate on different life history strategies among taxonomic families. AM community structure in soil responded to fertilizer type, whereas root-borne communities responded to crop rotation. We found the first evidence of temporal niche partitioning as a potential driver of coexistence among AM fungal taxa, resulting in higher species richness (i.e. storage effects). Crop rotation scheme strongly influences functional traits and coexistence of AM fungi, more so than soil disturbance intensity or fertilization regime. Future work is required to understand the implications of these shifts in AM fungal community structure for crop productivity.

Crop rotations and the inclusion of cover crops and green manures are primary tools in the sustainable management of soil-borne diseases in crop production systems. Crop rotations can reduce soil-borne disease through three general mechanisms: (1) serving as a break in the host-pathogen cycle; (2) by altering the soil physical, chemical, or biological characteristics to stimulate microbial activity and diversity; or (3) directly inhibiting pathogens through the release of suppressive or toxic compounds or the enhancement of specific antagonists. Brassicas, sudangrass, and related plant types are disease-suppressive crops well-known for their biofumigation potential but also have other effects on soil microbiology that are important in disease suppression. The efficacy of rotations for reducing soil-borne diseases is dependent on several factors, including crop type, rotation length, rotation sequence, and use of the crop (as full-season rotation, cover crop, or green manure). Years of field research with Brassica and non-Brassica rotation crops in potato cropping systems in Maine have documented the efficacy of Brassica green manures for the reduction of multiple soil-borne diseases. However, they have also indicated that these crops can provide disease control even when not incorporated as green manures and that other non-biofumigant crops (such as barley, ryegrass, and buckwheat) can also be effective in disease suppression. In general, all crops provided better disease control when used as green manure vs. as a cover crop, but the addition of a cover crop can improve control provided by most rotation crops. In long-term cropping system trials, rotations incorporating multiple soil health management practices, such as longer rotations, disease-suppressive rotation crops, cover crops, and green manures, and/or organic amendments have resulted in greater yield and microbial activity and fewer disease problems than standard rotations. These results indicate that improved cropping systems may enhance productivity, sustainability, and economic viability.

A pineapple-banana rotation was studied as a model system to investigate the potential emergence of a fungal-mediated disease-suppression in a soil highly infested with the pathogen Fusarium oxysporum causing the banana wilt disease. By using both field and pot experiments, the pineapple-banana rotation system resulted in a significant decrease of the pathogen number and next-stubble banana disease incidence (P

Despite being native to semi-arid environments, safflower (Carthamus tinctorius L.) growth, seed yield, and physiological responses under contrasting temperature and moisture conditions typically occurring in semi-arid regions are not fully understood. Thus, three field experiments and a greenhouse study were conducted to study the growth, yield, and physiological attributes of six safflower genotypes under different environmental conditions. Spring-sown and summer-sown plants were subjected to contrasting environmental conditions in two 4-replicate randomized complete block design (RCBD) field experiments. In the third field experiment (a 3-replicate split plot RCBD) and the greenhouse study (a 3-replicate RCBD), the safflower genotypes were subjected to different irrigation regimes of no stress to severe drought. Spring-sown safflower outperformed the summer-sown crop in terms of seed filling rate (SFR) by 93%, seeds head−1 by 62%, 1000-seeds weight by 30%, seed yield by 53%, oil concentration by 16% and protein concentrations by 22%. Plant dry mass (PDM) for the summer-sown safflower was 25% greater than the spring-sown one. In contrast to a 21% increase in seed protein concentration, severe drought led to notable decreases in leaf chlorophyll a (chl-a), chl-b and total chlorophyll (chl-tot) concentrations, leaf area, relative water content (RWC), catalase (CAT) and ascorbate peroxidase (APX) activities, membrane stability index (MSI), oil concentration, yield components and consequently seed yield (36%) and PDM (34%). Genotype Kouseh tended to maintain its seed yield and quality across the environmental conditions, potentiating this under-utilized crop as an alternative to be endorsed in crop rotations of semi-arid climates.

Dwindling water resources appear to become a great challenge threatening the future of sustainable rice cultivation as it consumes substantial amount of water available in agricultural farming par se. Ostensibly being a water-guzzling crop, aerobic rice could be a viable option requiring less irrigation water than conventional farming, instead. However, grain yield penalty while grown continuously is becoming a strong demerit for sustainable aerobic rice cultivation. A better understanding of the causes and concerns vis-a-vis alleviation mechanism suggested a long term field experiment studying rotational sequences with different non-rice crops in a system perspective mode. Thus, the current field study was conducted for consecutive five years exploring the potentiality of aerobic rice based crop rotations with maize, ground nut and green gram in view of promoting soil health resiliency for arresting grain yield decline during 2013–14 to 2017–18. The study revealed a perceptible depletion in soil quality parameters at the end of last year/5th year accounting around 2.70% soil organic carbon, 1.70% available nitrogen, 1.60% available phosphorus, 1.39% available potassium, 2.75% iron and 1.35% zinc as compared those in the 1st year of the study. Even the situations also aggravated root nematode populations, especially rice root knot (Meloidogyne graminicola) and root rot nematode (Hirschmanniella oryzae) that inhibited usual root growth pronouncing less volume (26.50 cc plant−1) and density (0.54 g cc−1). As a result, drastic depression in usual growth and development of continuously grown aerobic rice caused more than 50% grain yield (2.04 t ha−1) decline at the 5th year compared to that (4.30 t ha−1) at the initial 1st year. However, no detrimental impacts were visualized on rice while grown in yearly rotation with non-rice crops; instead, grain yield increased significantly, especially in rotation with groundnut or green gram (4.40–4.46 t ha−1). Additionally, rice grain protein content (6.92–7.0%) also enhanced as compared that (6.36%) at pure aerobic rice stands. Thus, implication of this current study could have far reaching consequences ensuring aerobic rice cultivation sustainable in a rotational sequence with ground nut/green gram even under the apprehension of irrigation water deficiency.

The knowledge of the impacts of the management practices used in each agricultural production system on the ecological interactions between commercial crops and weed populations can assist in the development of specific and sustainable integrated management strategies. This study aimed to assess weed communities in soybean in succession to second-crop corn and production systems with crop diversification in Northern Paraná State. The study was conducted during three agricultural years (2014/2017). Six treatments were setup: 1 –corn/soybean, corn/soybean, and corn/soybean), 2 – white oat/soybean, rye/corn, and wheat/soybean, 3 –oat + rye/soybean, oat + radish/corn, and congo grass/soybean, 4 – canola/corn, crambe/corn, and safflower/soybean, 5 –buckwheat/ radish/corn, bean/soybean, and buckwheat/oat/soybean, and 6 –wheat/corn + congo grass, canola/corn, and bean/soybean. The relative importance value index of each weed species and the soil cover (soil, straw, and weeds) were assessed. The experimental design consisted of randomized blocks with four replications of 300 m2 (20 × 15 m). The production systems white oat/soybean, rye/corn, and wheat/soybean; buckwheat/radish/corn, bean/soybean, buckwheat/oat/soybean; and wheat/corn+congo grass, canola/corn, bean/soybean had a suppressive effect on the species Commelina benghalensis. Euphorbia heterophylla and Digitaria horizontalis were the species most adapted to the assessed production systems. Seeds remaining from crambe and radish cultivations became volunteer plants in subsequent cultivations. O conhecimento dos impactos dos manejos empregados em cada sistema de produção agrícola sobre as interações ecológicas entre as culturas comerciais e as populações das plantas daninhas pode auxiliar no desenvolvimento de estratégias de manejo integrado específicos e sustentáveis. O objetivo do trabalho foi avaliar comunidades de plantas daninhas na soja em sucessão ao milho segunda safra e sistemas de produção com diversificação de culturas no Norte do Estado do Paraná. O estudo foi realizado durante três anos agrícolas (2014/2017). Foram instalados seis tratamentos: 1 (milho/soja, milho/soja, milho/soja); 2 (aveia branca/soja, centeio/milho, trigo/soja); 3 (aveia + centeio/soja, aveia + nabo/milho, braquiária/soja); 4 (canola/milho, crambe/milho, cártamo/soja); 5 (mourisco/nabo/milho, feijão/soja, mourisco/aveia/soja) e 6 (trigo/milho + braquiária, canola/milho, feijão/soja). Foram avaliados o índice de valor de importância relativa de cada espécie de planta daninha e a cobertura do solo (solo, palha e plantas daninhas). O delineamento experimental foi de blocos ao acaso com quatro repetições de 300 m2 (20 m x 15 m). Os sistemas de produção: aveia branca/soja, centeio/milho, trigo/soja; mourisco/nabo/milho, feijão/soja, mourisco/aveia/soja e trigo/milho+braquiária, canola/milho, feijão/soja tiveram efeito supressor na espécie Commelina benghalensis. Euphorbia heterophylla e Digitaria horizontalis foram às espécies mais adaptadas aos sistemas de produção avaliados. As sementes remanescentes dos cultivos de crambe e nabo tornaram-se plantas voluntárias nos cultivos subsequentes.

The article presents the most common rice pests in the conditions of the Kyzylorda region in 2020. In this regard, a scale for assessing the species composition and intensity of damage to rice pests found in the region was presented, as well as data on crop rotation. In Kazakhstan, the Kyzylorda region is one of the largest rice fields and is one of the most favorable rice growing regions. In general, in the territory of the region during the growing season, the temperature above +10°C ranges from 3700-4100°C. Many changes in the process of its growth depend on the temperature of the air, soil and water in the crop. With an increase in temperature, the growth rate of rice accelerates, the distance between the stages of development is reduced, thereby accelerating the entire growing season of rice. Therefore, the heat reserves determine how suitable a particular land is for sowing rice. Based on the temperature conditions in it, you can also predict the quality and yield of future rice. In the Kyzylorda region, rice varieties Coral, Avangard, Solnechny, Ushtobe and Kuban are widespread. The volume of rice cultivation is growing every year, and it will have to use saline lands for culture. Due to the violation of the water regime in rice fields, elements of some agricultural activities taking place in rice fields go wrong, as a result of which the yield decreases by 35-70%, and losses from pests and diseases reach from 15% to 30%.The death of the shore fly 20 days after the treatment of rice seeds with the treatment of Yunta, k. s. -1.5 l / t and 1.75 l/t (insecticide) was 55.6-63.6%, the biological efficiency on the rice mosquito was 57.0 – 63.0%; these indicators are higher than in the version of Rich 350 k.s.-1.0 l / ha (standard).

Powdery scab, caused by Spongospora subterranea, is an important potato disease. Greenhouse experiments in 2017/18 and 2018/19 on (very susceptible) ‘Agria’ seed tubers assessed if field-collected soils had different powdery scab-suppressive capabilities and identified factors involved in disease suppression. 2017/18: 12 geographically diverse soils with either S. subterranea added at planting or not added; 2018/19: six single-type soils used, to determine if powdery scab suppression was ‘general’, or ‘specific’ (transferable; possibly involving microorganisms), and if suppression was associated with soil physical, chemical, or biological factors (bacteria/fungi). For both seasons, S. subterranea soil ammendment increased scab severity on harvested tubers in all soils but one. Powdery scab severity (percent tubers with > 5% surface area covered by scabs) ranged from 0 to 39%. Soil texture, pH, soil organic matter and nutrient contents were associated with powdery scab incidence for some soils but not others. Effects of previous crop rotations on powdery scab were variable: one soil with three recent previous potato crops in rotation was disease-suppressive. All 2018/19 soils displayed some microbe-mediated disease suppression, three being more suppressive than others. Two had possible ‘specific’ Spongospora suppression (less disease when added to the conducive soil). Thus Spongospora-suppressive soils are present in New Zealand, and abiotic and biotic soil factors influenced incidence/severity of powdery scab of potato.

The work reflects the analysis of changes in the productivity of crops of crop rotation during the long-term use of fertilizer systems in a stationary experiment for the period from VI to VIII rotation (1999-2001 - 2016-2018). The influence of various doses of nitrogen, phosphorus and nitrogen-phosphorus fertilizers on the change in the content of nitrate nitrogen and mobile phosphorus in the conditions of the southern chernozem for the specified period of research was determined. The responsiveness of crop rotation crops to the application of nitrogen, phosphorus, and nitrogen-phosphorus fertilizers in minimum, medium and high doses has been established.

The management and environmental impacts influence agricultural production, diseases, in turn, can interfere and cause damage to the crop at different times and parts of the plant, due to economic loss, it is necessary to use disease control methods. To maintain sustainable agricultural production, disease management is necessary. Many methods are adopted in agriculture during its development, and led to the implementation of various production systems, including the no-till system, which helped boost production. However, no-tillage was found to have several soil conservation problems, making it necessary to adopt another practice in this system, which is crop rotation, which emerged as a sustainable means of soil conservation, bringing several benefits. Crop rotation is the planned and orderly alternation of different crops in a given period of time and in the same area, making the development and survival of pests and pathogens that affect crops difficult. Along with sustainable disease management using biological control and methods plant-based, allowed for better disease management in agriculture and provided a more sustainable production environment. Crop rotation is important in disease control because it can be a preventive practice to provide diversity to the system through breakage cycles. The control of these diseases can be done through the biological control of pests and plant extracts.

Increasing climatic pressures such as drought and flooding challenge agricultural systems and their management globally. How agricultural soils respond to soil water extremes will influence biogeochemical cycles of carbon and nitrogen in these systems. We investigated the response of soils from long-term agricultural field sites under varying crop rotational complexity to either drought or flooding stress. Focusing on these contrasting stressors separately, we investigated soil heterotrophic respiration during single and repeated stress cycles in soils from four different sites along a precipitation gradient (Colorado, MAP 421 mm; South Dakota, MAP 580 mm; Michigan, MAP 893 mm; Maryland, MAP 1192 mm); each site had two crop rotational complexity treatments. At the driest (Colorado) and wettest (Maryland) of these sites, we also analyzed microbial biomass, six potential enzyme activities, and N2O production during and after individual and repeated stress cycles. In general, we found site specific responses to soil water extremes, irrespective of crop rotational complexity and precipitation history. Drought usually caused more severe changes in respiration rates and potential enzyme activities than flooding. All soils returned to control levels for most measured parameters as soon as soils returned to control water levels following drought or flood stress, suggesting that the investigated soils were highly resilient to the applied stresses. The lack of sustained responses following the removal of the stressors may be because they are well in the range of natural in situ soil water fluctuations at the investigated sites. Without the inclusion of plants in our experiment, we found that irrespective of crop rotation complexity, soil and microbial properties in the investigated agricultural soils were more resistant to flooding but highly resilient to drought and flooding during single or repeated stress pulses.

The damage caused by insect pest is the continual factor for the reduction of rice production. To date, 232 rice insect pest species are identified in Bangladesh and more than 100 species of insects are considered pests in rice production systems globally, but only about 20 - 33 species can cause significant economic loss. The major goal of this study is to explore all the possible ways of developed and proposed technologies for rice insect pests management and minimize economic losses. Insect pests cause 20% average yield loss in Asia where more than 90% of the world's rice is produced. In Bangladesh, outbreak of several insects such as rice hispa, leafroller, gallmidge, stem borers and brown planthopper (BPH) occurs as severe forms. Based on previous reports, yield loss can reach upto 62% in an outbreak situation due to hispa infestation. However, BPH can cause 44% yield loss in severe infestested field. To overcome the outbreaks in odd years and to keep the loss upto 5%, it is necessary to take some preventive measures such as planting of resistant or tolerant variety, stop insecticide spraying at early establishment of rice, establish early warning and forecasting system, avoid cultivation of susceptible variety and following crop rotation. Subsequent quick management options such as insecticidal treatment for specific insect pest should also be broadcasted through variety of information systems. Advanced genomic tool can be used to develop genetically modified insect and plants for sustainable pest management. In addition, to stipulate farmers not use insecticides at early crop stgae and minimize general annualized loss, some interventions including training rice farmers, regular field monitoring, digitalization in correct insect pests identification and their management (example; BRRI rice doctor mobile app), and demonstration in farmers field. Each technology itself solely or combination of two or more or all the packages can combat the insect pests, save natural enemies, harvest expected yield and contribute to safe food production in Bangladesh. Bangladesh Rice J. 25 (1) : 1-22, 2021

Mucuna (Stizolobium pruriens) is widely used in agriculture as a green allowance and in crop rotation, due to its ability to fix nitrogen and recover degraded areas; without embargo, there is a slow and uneven germination. This study used some classical methods, together with the use of low-frequency ultrasound to accelerate and homogenize the germination and emergence of the seeds. The experiment was carried out at the Plant Tissue Cultivation Laboratory of the Ilha Solteira Campus, São Paulo, Brazil. The design used was a completely randomized one, with five replications, in a 3x6 factorial scheme, the factors being: three pre-treatments for latency break: mechanical scarification, thermal scarification, and without scarification with six levels of ultrasound exposure: 0, 1, 2, 3, 5, 8 min, totaling 18 treatments. For eight days the germination and the initial stages of the seedlings were controlled. The method without scarification subjected to 4.5 min of ultrasound can become an excellent alternative, since it presented greater germination vigor, while 3.14 min of exposure to ultrasound were enough to improve the emergence speed, regardless of the method used in the preparation of seeds. In conclusion, only with the use of low-frequency ultrasound, it is possible to improve both the germination speed index and the germination vigor, without the need for additional treatments.

Agriculture is composed of many factors that alter its production, are of an environmental and management nature, and in terms of management, pests and diseases are of great importance, as they cause a lot of damage to the crop, at different times, and the control of these is essential. pests and diseases to ensure that the plant can reach its production potential. With the concern for a more sustainable production, agriculture has diversified through transformations in the technological and information scopes, which helped to increase the production of production systems. However, only biological and plant-based controls did not guarantee such a large control of pests and diseases, and to complement the control, and to reduce the use of chemicals in agriculture, cultural control was used. This cultural control, together with its sustainable management of pests and diseases, using biological control methods and the base of plant origin, brought new forms of pest and disease control, helping in management, and providing a more sustainable production environment. In addition to these benefits, cultural control is of great importance in the control of pests and diseases, as its control comes as a preventive practice, providing a diversity of the system, and a better control of pests and diseases by breaking cycles, culture, pests and diseases.

Reduced tillage is considered as one of the main tools to save biological diversity; however, it increases pressure of diseases, including wheat leaf blotches. The aim of present study was to clarify the impact of reduced soil tillage on the development of winter wheat leaf blotches in different schemes of crop rotation. The impact of different growing technologies on the severity of winter wheat disease was evaluated in a two-factorial experiment: A – soil tillage system, and B – different combinations of wheat pre-pre-crop and pre-crop (wheat, oilseed rape, barley and faba beans). Diseases were assessed every 10 days approximately and total impact of diseases was evaluated by calculating AUDPC (Area under Diseases Progress Curve). Tan spot, caused by Pyrenophora tritici-repentis was dominated disease over the long period, regardless of meteorological conditions. Development of Septoria leaf blotch was not influenced by neither crop rotation nor soil tillage. The level of tan spot was essentially higher after wheat, regardless of the pre-pre-crop. Reduced soil tillage promoted severity of tan spot. Ploughing mitigated effect of previous crops and differences in tan spot level were insignificant. Despite many positive effects of conservation tillage, increasing of fungicide treatment could be necessary, in conditions, when the tan spot is most devastating and widespread wheat disease.

The article presents the results of studies of the quantitative and specific composition of soil micromycetes in potato cultivation, depending on the intensity of irrigation in the north-east of Kazakhstan. During their growth in the soil, plants actively interact with its microflora, while microorganisms can have both positive and negative effects. Micromycetes produce mycotoxins that accumulate in food and, when ingested, cause liver damage and cancer. Some mycotoxins persist in the ground for a long time, and with improper agricultural processing, they accumulate in it, and are also removed from it to adjacent environments (surface reservoirs). As a result of the conducted studies, indicators of the quantitative and specific composition of fungi were obtained, antagonist fungi and toxin-forming species were identified. According to the results of the mycological analysis of soil samples, 39 isolates were isolated. During the study, the accumulation of toxin-forming species was found to be 43−54 % in all the studied variants. In the soil, when using irrigation, there are both pathogenic (18.1-50.0%) and saprophytic (50.0-81.9%) species of micromycetes, as well as toxin-forming species of fungi (46.2-55.6%) , which can cause different effects on the resistance of plants to potato diseases. The greatest number of pathogenic fungi, as well as toxin-forming fungi, was found when using limited watering of potatoes. The greatest number of pathogenic fungal species was observed in the variants with moderate irrigation −38.5 % (genera Fusarium − 30.8 %, Penicillium − 7.7 %), as well as in the variant with maximum irrigation – 50.0 % (genus Fusarium – 39.0%, from the genera Gliocladium and Aspergillus − 5.5%). Thus, the use of crop rotations and repeated fungicidal treatments carried out when growing potatoes does not guarantee the absence of pathogenic microorganisms in the soil, and the use of intensive watering provokes a stronger development of pathogenic microflora. New approaches to integrated potato protection are required.

The influence of growth regulators with retardant properties (TseTseTse 750, Reggi, and Messidor) and seeding rates (5.0, 5.5, and 6.0 mln germinating seeds/ha) on the growth and development of winter wheat of the Nemchinovskaya 17 variety under the conditions of sod-podzolic soils of the western part of the Moscow oblast’ was studied. Experiments during 2013 – 2017 were laid in the link of the crop rotation of black fallow–winter wheat. On average, over the years of research, the greatest photosynthetic potential was accumulated in the variant with a seeding rate of 550 pcs/m 2 and the use of the growth regulator Messidor — 1727 thousand m 2 · day/ha. The largest dry mass was accumulated in the variants without growth regulators, then with the TseTseTse 750 growth regulator, then in the variants with the Reggi growth regulator. The smallest dry biomass was accumulated in the variants with the use of the growth regulator Messidor. The highest biological yield of winter wheat was formed in the variant with a seeding rate of 550 pcs/m 2 and the use of the growth regulator Messidor — 8.58 tons/ha. The lowest biological yield of winter wheat was noted in the variant with a seeding rate of 500 pcs/m 2 and without the use of growth regulators — 7.22 tons/ha. The highest grain quality indicators were noted in the variant of winter wheat of the Nemchinovskaya 17 variety with the Reggi growth regulator treatment of 1.5 liter/ha, where, on average, over 5 years, according to the experimental variants, the protein content was 16.4%, and the gluten content was 37.6%.

Aim. To identify the effect of biological preparations applied with or without nitrogen fertilizers for crop by-product, their incorporation into the soil on the decomposition of plant residues and composition of mobile humus substances in typical slightly eroded chernozem.Materials and Methods. The study was carried out in the field experimental station of Kursk FARC in the cycles of cereal and cereal-row crop rotations in variants with by-product treated with biopreparations; with applied biopreparations + nitrogen fertilizers; with applied nitrogen fertilizers and without biopreparations. To study decomposition the content of unhumified organic matter was determined in the topsoil by the monolith method after by-product incorporation into the soil and 3045 days after their decomposition. Simultaneously the composition of mobile humus substances in the soil was determined.Results. The decomposition of crop by-product and after harvesting and root residues mixed with it in the soil and treated with biopreparations or nitrogen mineral fertilizers was studied for the first time. The peculiarities of the effect of the factors studied on the degree of plant residue decomposition and the composition of mobile humus substances were shown.Conclusion. It was determined that treating the by-product of barley, buckwheat and sunflower with bioproducts, both with applied nitrogen fertilizers and without them, contributed to the increase in the degree of plant residue decomposition as compared with the control and nitrogen mineral fertilizer application. In the years which are favourable according to hydrothermal conditions the improved quality of mobile humus substances of the soil influenced by biopreparations are noted and under extreme conditions the tendency to the improvement of their quality is observed.

Goal. Based on the results to substantiate the need for a significant increase in legume crops in Ukraine on the basis of analysis of food and feed indicators of their seeds, the impact on soil quality and the environment. Material and methods. Field – determination of features of growth and development of plants, elements of seed productivity; biometric and measuring-weight – accounting of yield and total biomass; biochemical – determination of protein, fat and other components of seeds; statistical – variation, regression and analysis of variance. Results and discussion. The significant nutritional value of legume seeds, which is rich in high-quality protein with a high content of essential amino acids, isoflavones, essential micronutrients, is substantiated. It is distinguished by high taste, quickly swells and boils, has a pleasant aroma. This group of crops is able to fix nitrogen from the air, provide for their own needs and leave a significant amount of it in the soil for subsequent crop rotations. Legumes should be considered in the crop rotation system together with winter wheat as fallow crops. Their synergistic effect on subsequent crop rotations is explained by the peculiarity of the microflora of the root zone, where symbiotic and free-living bacteria are concentrated. Observations indicate the need to increase crops of pea, chickpea and lentil in Ukraine, as there are all the necessary conditions - adapted to insufficient moisture varieties, developed technology for their cultivation, accumulated positive experience for obtaining high yields. Conclusions. Based on our own results and analysis of the experience of many countries around the world revealed the importance of legumes for our country. Their role in providing high-quality food, improving soil quality, increasing the country’s export potential is noted

Fungal diseases represent a widely spread natural phenomenon affecting many of wild and domesticated plants. In nature, all plant species forms plant communities of a mixed character, and the spatial pattern of dominant species is usually irregular and spotted. Some species are impregnable to a certain infection, which provides a kind of natural barrier to the infection spread within the natural community. Under the agricultural environment, when the single plant species may occupy a huge area, the species-specific parasite takes a great advantage to develop focal outbreaks and fast spreading of the infection within the area. The concentration of vulnerable plants and the absence of natural barriers within the agricultural areas provokes outbreaks of fungal diseases, that may have highly harmful consequences and result in significant yield losses. One of the purposes of the satellite optical data is an operative, cost-effective diagnostic and, in combination with climatic datasets and crop rotation information, a prognosis of fungal disease appearance and severity. In this paper, we describe the system of prognostic and monitoring measures to control the fungal diseases of wheat in Central Kazakhstan with special attention to septoria leaf blotch. The prognostic procedure provides a map of the probability of septoria leaf blotch appearance. The prognosis takes into consideration the combination of three main variables: the model of ecological niche for Septoria, the presence of wheat residue, and Vegetation Condition Index counted for the late spring (May) of the current year. The new spectral index, introduced in this paper, is the core component of monitoring activity. The index is sensitive to septoria leaf blotch severity at middle to late (stages 8-11, accordingly Feekes growth stages) periods of wheat development. Several other indices (RETA, VSDI, vegetation indices) may be of help in providing information on the spatial unevenness of wheat crops that may indicate the presence of fungal infection.

In agroecosystems, temporal diversification creates a sequence of short-lived habitats through time. Crop species as well as the diversity of crops grown in sequence might affect soil biodiversity and nutrient cycling processes. In the present study, we focused on a long-term crop rotation established in 2006 in Lower Saxony, Germany on a Luvisol. Winter wheat (WW) and silage maize (SM) were grown in continuous cultivation as well as in rotations. WW rotations span up to six years (including silage maize, sugar beet, winter rape and/or grain pea). Over two years, microbial biomass carbon (MBC) as well as kinetics (Michaelis-Menten Vmax and Km) of extracellular hydrolytic enzymes (β-glucosidase (BG), N-acetyl-β-glucosaminidase (NAG) and acid phosphomonoesterase (AP)) were measured in topsoil (0–10 cm depth) three times during the growing season. Continuous wheat increased soil microbial parameters compared to continuous maize as indicated by the higher microbial biomass to soil organic carbon ratio and higher potential enzymes activities involved in the C- and N-cycles (Vmax of BG and NAG). The efficiency of these enzymes was lowest in continuous maize (highest Km of BG and NAG). Maize and sugar beet as preceding crop of WW significantly decreased MBC in the 1st year but not in the 2nd year WW. Sugar beet decreased BG activity as well as its substrate affinity (increased Km). The effect of sugar beet on MBC and enzyme kinetics depended on the preceding crop and lessened with grain pea as the preceding crop. Soil microorganisms in the wheat phase benefited from winter rape as the preceding crop, shown by an increased biomass and efficiency to turn over chitin and peptidoglycan (decreased Km of NAG). Differences between cultivated crops, cropping history and fluctuations within the year in soil microbial biomass and enzyme kinetics are shown.

Over the past decades, intensive farming has operated under conditions of progressive degradation of the soil cover, maintaining production levels only at the expense of inadequate expenditure of non-renewable energy resources. The soils have acquired irreversible excessive compaction in the sub-arable part of the profile, and the dehumification has acquired a threatening status. The humus content in the soils of Ukraine decreased by almost 25%, and the average annual losses amount to 0.6-0.7 t/ha. Therefore, the search for ways to guarantee the reproduction of soil organic matter, reliable control and restoration of the optimal humus status is extremely relevant. The purpose of the study is to activate natural nitrogen-fixing systems using a mix of green manure and by-products of agricultural crops of short-term leguminous crop rotation. Field experiments were conducted on light grey soils during 2018-2020 in the experimental field of Polissia National University in a leguminous short-term rotation system. This study uses general scientific methods to establish the area of research, plan and lay experiments, conduct observations and analysis; visual – during the implementation of phenological observations; field – to study the relationship with abiotic factors; physiological – to determine the symbiotic effectiveness of preparations of biological origin. The technology of growing agricultural crops in leguminous crop rotation, which ensures the supply of raw materials of organic origin and the accumulation of air nitrogen by root nodule bacteria, has been theoretically substantiated and improved. It is established that one hectare of crop rotation area receives 6.8 tonnes of dry organic raw materials, which corresponds to 78.3 kg/ha of biological nitrogen. It is found out that inoculation of soybean seeds with a preparation of biological origin – Optimise 400, and treatment of soybean crops at BBCH microstages 60-63 with a complex microfertiliser on a chelated basis Nanovit Super+Magnesium Sulphate contributes to the active development of nodule bacteria, the number and weight of which is 81-89 pcs per plant and 510-572 kg/ha. Thus, the active symbiotic potential was 34.2-38.9 thousand kg/day. It is proved that during the growing season soybeans generate 357-400 kg/ha of biological nitrogen in the air, which provides a seed yield of 2.96-2.64 t/ha and leaves 117-160 kg/ha of nitrogen in the soil. The practical value of this study lies in the possibility of enriching the soil with organic matter and the biological form of nitrogen

We studied the influence of various methods and systems of the primary soil tillage on the yields of seeds, vegetable oil and protein of soybean and spring rapeseed at the All-Russian Rapeseed Research Institute (Lipetsk, Lipetsk region) in 2015–2018. In the field crop rotation (soybeans, winter wheat, spring rapeseed and barley), four systems of the primary soil tillage have been carried out, these are conventionally referred to as: moldboard-surface tillage, moldboardsurface tillage with deep loosening, moldboardsurface tillage with shallow loosening and minimal treatment (subsurface). The soil at the experimental field was leached, heavy clay loam chernozem. The weather conditions during the vegetative period varied according to the years of the research, which affected the seed yield and quality of soybean and spring rapeseed. We revealed the largest and relatively equal yields of seeds, vegetable oil and protein per a hectare of soybean and spring rapeseed was provided by moldboard-surface tillage (plowing under soybean and rapeseed, surface tillage for winter wheat and barley) and moldboard-surface tillage with deep loosening (deep subsurface loosening under soybean, plowing under spring rapeseed and surface tillage under winter wheat and barley), and the lowest yield was obtained using minimal soil treatment (chisel plowing under spring rapeseed and surface tillage under soybean and cereal crops). The quality of seed yield of oil crops in the studied experimental variants was practically equal. At the same time, in general, during the experimental period, the yield and the total yields of vegetable oil and protein of spring rapeseed were significantly higher than those of soybean.

Plant diseases cause serious economic losses (5–15%/up to 25%) in all sorts of economic crop plants irrespective of cash, industrial, horticultural, ornamental, food, fodder, fibre, spices, plantation, aromatic and medicinal plants and forest trees especially in the tropics and subtropics. Farmers, due to lack of expertise, can neither identify the pathogens nor manage them. They are ignorant of varied symptoms produced by the diseases and the mode of field spread of these diseases. Knowledge of the disease cycle and use of resistant varieties are essential for developing effective management strategy against the diseases. Rigorous field training of students/village workers/farmers is the most important pedagogical aspect to ensure sustainability of Indian agriculture. In order to put a long term check on yield/quality losses by overcoming farmer’s ignorance, there is a need to ensure availability of resistant varieties and effective but simple methods of vector control. Intensive training of the farmers through frequent field visits enables them to recognize incidence of the disease and to understand the epidemiological facet of the disease too. Bio agents occurring naturally within the host's environment and crop rotation practices are also helpful. Emphasis is needed to train students in various methods of pathogen detection and to coach a large number of farmer’s team to help them recognize and manage the disease in field. Generally limited number of important diseases and pests affect any crop plant which does not exceed 4–6 and 15–20 respectively in all regions.

The current paper has presented the results of the estimation of productivity of the winter wheat varieties ‘Krasa Dona’, ‘Polina’ and ‘Yubiley Dona’ when using liquid complex fertilizers ‘Strada N + Mono Sulfur (S)’, ‘Strada P + Mono Sulfur (S)’ and ‘Diform Silicon-potassium’. The treatment of winter wheat plants was carried out in the form of foliar top-dressings in the stages of tillering and stem extension. The study was carried out on the basis of the FSBSI “Agri- cultural Research Center “Donskoy” in 2019-2020. The trials were laid in the crop rotation of the laboratory for primary seed production and seed study. The purpose was to study the effect of liquid complex fertilizers on the productivity of the studied winter wheat varieties. When using fertilizers for all varieties, there was a tendency to an increase in the density of the productive stand on 18-61 pcs/m2 in comparison with the control. The variety ‘Krasa Dona’ showed the best indicators of the traits ‘number of grains per head’, ‘grain weight per head’ and ‘1000 grain weight’ being fertilized with ‘Strada N + S’ (43 pcs., 2.19 g and 45.7 g) and ‘Diform Silicon-potassium’ (46 pcs., 2.30 g and 46.5 g). The variety ‘Polina’ showed good results after being treated with ‘Strada P + S’ (48 pcs., 2.30 g and 42.1 g) and ‘Diform Silicon-potassium’ (51 pcs., 2.43 g and 42.4 g). The variety ‘Yubiley Dona’ showed the greatest increase of the trait ‘number of grains’ with the fertilizer ‘Diform Silicon-potassium’. The trait ‘1000 grains weight’ had an increase of 2.3 g, and ‘grain weight per head’ was 0.29 g. The treatment with fertilizers did not affect the trait ‘plant height’. The highest productivity of the variety ‘Krasa Dona’ was obtained when being fertilized with ‘Strada N + S’ (9.4 t / ha) and ‘Diforma Silicon-potassium’ (9.5 t/ha); the productivity of the variety ‘Polina’ increased after ‘Strada P + S’ (8.8 t/ha) and ‘Diform Silicon-potassium’ (9.1 t/ha), and the productivity of the variety ‘Yubiley Dona’ increased after ‘Diform Silicon-potassium’ (8.9 t/ha). The maximum economic effect (19080 rubles/ha) with 9.5 t/ha of productivity was obtained from the variety ‘Krasa Dona’ after the treatment with the fertilizer ‘Diform Silicon-potassium’. The experimental results have shown that the use of complex fertilizers has a positive effect on the productivity of winter wheat plants.

The article summarizes the results of 1990-2012 research conducted during the stationary experiment on leached heavy loam chernozem in the Republic of Mordovia. The objects of the study are two crop rotations (grain-grass-fallow and grain-grass crop rotations) where alfalfa of the VEGA 87 variety was used as a bean component, smooth brome (Bromus inermis) Penza 1 was used as a grain component. It has been established that mineral fertilizers in grain-grass-fallow crop rotations with legumes increased productivity by 0.34-0.55, with cereals – by 0.31-0.73 tons of feed units/ha. That provided to get additional income from 1.19 to 1.40 and 1.09 to 1.47 rub/rub, respectively. Recommended doses of mineral fertilizers against soil liming by 0.5 hydrolytic acidity (h.a,) were N22-39P42K52, for grain-grass-fallow crop rotation with alfalfa and N27-71P42K52. with smooth brome. In the grain-grass crop rotation with legume and cereal components the payback of 1 kg active ingredient (a.i.) of complete mineral fertilizer was 6.13 and 6.17 kg feed units, additional income was 2.00 and 1.99 rub/rub, the productivity increased by 0.86-1.08 and 0.84-1.22 tons of feed units/ha, respectively. The payback of 1 kg of a. i. nitrogen as part of a complete mineral fertilizer in this crop rotation averaged 13.04 kg feed units versus 11.5 kg in legumes. Recommended doses of mineral fertilizers were N26-87P46K65 against the background of liming of the soil by 0.5-1.0 h. a. In crop rotation with smooth brome phosphorus-potash fertilizers should not be applied due to the low additional income (0.97-1.07 rub/rub).

The advent of ‘conservation agriculture’ (CA) farming using zero- or no-tillage practices and an accompanying change in crop rotations in the last 10–15 years has potentially led to less disturbance of mouse burrows and increased cover and food supply. Given the irregular outbreaks of mice in grain cropping regions in Australia and the damage they cause, it is important to understand when and where mouse populations increase so that management strategies can be improved. We utilised a 20-year long-term mouse population data set collected prior to the introduction of CA farming practices and a more recent 8-year data set after CA to compare changes in mouse population abundance in a typical dryland grain cropping system in north-western Victoria, Australia. Mouse trapping data were used to compare abundance in crop and margin habitats during crop growth and non-crop (fallow) periods before (‘conventional’) and after introduction of CA. Mice are now resident year-round within crops and stubble and appear to only spill over into margin habitats. Previously developed recommendations for mouse management that include their control while in margin habitats may no longer be valid.

Background: Legume crop rotation in sugarcane cropping systems can improve soil health and fertility. However, their impacts on soil microbial community composition and function have not been clearly understood to date. Aims: This study aimed to assess responses of soil biochemical properties and composition of microbial communities driving C and N transformations in soils to different legume crop rotations and crop residue management practices. Methods: We investigated the effects of two rotational legume crops (soybean and peanut) and six different crop residue management practices on soil physicochemical and microbial properties as well as biological activities including C and N mineralisation, nitrification capacity and denitrification potential, in a subtropical sugarcane cropping system. Results: Incorporating high-N soybean crop residues into soil significantly increased soil mineral N content in the first month compared to no-till; no significant tillage effects were recorded with low-N peanut residues. Both crop residues increased soil microbial biomass C, C mineralisation capacity and nitrification capacity. However, bacterial and archaeal composition and abundances of 16S rRNA and nitrification genes were not affected. Spraying a nitrification inhibitor (DMPG) onto the crop residues before tillage significantly suppressed soil nitrification capacity. Conclusions: Compared to peanut rotation, soybean rotation could supply significantly more N for the following sugarcane crop due to its much higher crop residue N inputs and faster N mineralisation. Spraying legume residues with DMPG before tillage may provide an effective strategy to inhibit NO3 - formation and thus reduce the risk of NO3 - losses through leaching or denitrification.

Crop rotation is an important management tactic that farmers use to manage crop production and reduce pests and diseases. Long-term crop rotations may select groups of microbes that form beneficial or pathogenic associations with the following crops, which could explain observed crop yield differences with different crop sequences. To test this hypothesis, we used two locations each with four long-term (12–14-year), replicated, rotation treatments: continuous corn (CCC), corn/corn/soybean (SCC), corn/soybean (CSC), and soybean/corn (SCS). Afterwards, soybean was planted, and yield and soil health indicators, bulk soil microbiome, and soybean root-associated microbiome were assessed. Soybean yields, as well as soil protein, and POXC as soil health indicators were higher following CCC than in the other three treatments at both locations. A bacterial taxon in family JG30-KF-AS9 was enriched in CCC, whereas Microvirga, Rhodomicrobium, and Micromonosporaceae were enriched in SCS. Several ascomycetes explain lowered yield as soybean pathogens in SCS. Surprisingly, Tumularia, Pyrenochaetopsis and Schizothecium were enriched in soybean roots after CCC, suggesting corn pathogens colonizing soybean roots as nonpathogens. Our finding of associations between soil health indicators related to microbiomes and soybean yield has wide-ranging implications, opening the possibility of manipulating microbiomes to improve crop yield potential.

This article is devoted to the study of the effect of nitrate nitrogen content in the soil on its biological activity on crops cultivated in the system of six-field crop rotation and mono-crops, as well as the effect of nitrate nitrogen and soil bioactivity on the yield of field crops (corn for silage, peas, millet and barley) in crop rotations and mono-crops. Field experiments were carried out on a long-term plot and the results are objective from the point of view of the data on the yield of field crops, soil bioactivity and the content of nitrate nitrogen on the crops were obtained in various weather conditions, including suitable and very dry years. Very dry years are considered when the hydrothermal index is 0.6 or less, they accounted for 68% of the total number of research years. The question of the forecrop influence and the nutritional background on the field crop yield, the content of nitrate nitrogen and the biological activity of the soil is considered. The lowest biological activity of the soil is noted in the variant with permanent barley sowing on unfertilized background - 6.0 %, on fertilized background - 6.1%. As a result of the research, it was found that the yield of corn for silage is higher in mono-crops compared to crop rotation. Millet slightly reacts to application of mineral fertilizers, and when cultivated in monoculture, it reduces yield. The usage of mineral fertilizers increases the content of nitrate nitrogen and the biological activity of the soil in all variants of the experiment.

BACKGROUND: The redlegged earth mite, Halotydeus destructor Tucker, is a destructive and economically important pest of winter grain crops and pastures in Australia. It is largely controlled by pesticides, but this mite has evolved resistance to pyrethroid and organophosphate chemicals. A national Resistance Management Strategy has been developed for pro-active management to delay further resistance evolution, though its success is reliant on a detailed understanding of the incidence, patterns of spread, current distribution and the nature of resistance in the field. Here, we report on a long-term resistance surveillance program undertaken between 2006 and 2019 informed by resistance risk forecasting. RESULTS: By mapping the Australian distribution of resistance through time, we show that resistance is present across three Australian states and covers more than 3000 km. This current range includes a recently identified population exhibiting organophosphate resistance representing the most easterly location of resistance in H. destructor. Using field history information, we identify associations for the first time between crop management practices employed by farmers and the presence of pyrethroid resistance. Management strategies that could minimise the risk of further resistance include limiting local spread of resistance through farm hygiene practices, crop rotations and reducing pesticide usage. CONCLUSION: This study highlights the challenges of resistance in H. destructor but also indicates how quantitative resistance risk analysis can be developed to target field surveillance and delay further resistance. The management strategies highlighted in this study can help maintain the effectiveness of control options but will depend on farmer engagement and adoption. This article is protected by copyright. All rights reserved.

Corn (Zea mays L.) is one of the main source of feed and food resources. The importance of this culture in the world economy continues to grow. In Ukraine corn is an export-oriented crop of universal purpose and high potential. Based on the results of research in the ninth rotation of long-term stationary experiment, it was found that in the Western Forest-Steppe in four-field crop rotation on Albic Stagnic Luvisol the highest productivity of corn 73 t . ha–1 is formed by organo-mineral fertilizing system with systematic joint application of 10 t . ha–1 manure, N65Р68К68 on the background of periodic liming with 1.0 n CaCO3 by hydrolytic acidity. It is shown that long-term unilateral application of mineral fertilizer system (more than 50 years) on acidic soil along with the accumulation of nitrogen compounds increases the acidity and content of mobile aluminum compounds, leads to blocking the activity of enzyme systems, reducing absorption and transformation of nutrients and in consequence the formation of low-yield corn at the level of control without fertilizers.

Due to widespread adoption of no-till management and use of glyphosate-resistant transgenic crops, glyphosate is the most widely used herbicide worldwide. However, its effect on soil microbial communities is inconsistent. We studied the effects of glyphosate, tillage, and crop rotation on the diversity and composition of soil bacterial communities in wheat (Triticum turgidum var. durum Desf.) rhizosphere after 6 and 7 yr of glyphosate applications. In a 2 × 2 × 2 factorial design, there were two crop rotation treatments: continuous wheat (W–W) and wheat in rotation with field pea (Pisum sativum L.) (P–W); two tillage treatments: minimum tillage (MT) and no-till (NT); and two glyphosate treatments: no application or pre-seeding application at the recommended rate. None of the treatments affected wheat rhizobacterial α-diversity or the relative abundances of most bacterial groups. The most abundant phyla were Proteobacteria (25.1% relative abundance), Actinobacteria (21.7%), Acidobacteria (8.7%), Bacteroidetes (5.9%), Firmicutes (1.4%), Armatimonadetes (1.3%), and Verrucomicrobia (1.2%). Glyphosate reduced the relative abundance of Alphaproteobacteria in W–W rotation but increased it in P–W rotation, and it reduced the relative abundance of Opitutus spp. The W–W rotation had greater relative abundances of the classes Bacilli (Firmicutes) and Gammaproteobacteria, and genera Bacillus and Opitutus (Verrucomicrobia), than the P–W rotation. Compared with MT, NT increased the relative abundance of the phylum candidate division WPS-1, but it reduced that of Phenylobacterium spp. in W–W rotation. These treatment effects probably had implications for soil functioning, including nutrient cycling and biological disease/pest control.

The effect of organic and inorganic fertilizers, as well as their combinations, on soil fertility and productivity is studied on the soddy podzolic light loamy soils in the stationary field experiment. The highest efficiency of combined application of organic (80 t/ha of peat–manure compost) and inorganic (NPK) fertilizers is determined in a six-field fodder crop rotation. The positive effect of the organic and organic–inorganic fertilizer system on the soil’s organic matter content, a decrease in exchange and hydrolytic acidity, and an increase in the mobile phosphorus content is found. A decrease in exchangeable potassium in the soil is observed due to its high removal by crops. It is determined that the above fertilizer systems contributed not only to an increase in the yield of crops in rotation but also their quality. The content of starch and vitamin C increased in potato tubers and crude protein increased in annual and perennial grasses.

The Century model was used to simulate soil C and N cycling and crop produc- tion dynamics in an ongoing field experiment in Uruguay (started in 1963). The model was calibrated using observed data from three treatments (crop or crop–pasture rotations) and validated with a fourth treatment. The model correctly predicted the impact of different treatments on microbial biomass, N mineralization, soil respi- ration, and crop yields. The model and observed data show that soil respiration, N mineralization, soil C, and crop yields increase with increasing plant-derived C inputs caused by increasing the frequency of pastures in the rotations. This is one of the first papers that show the strong positive correlation of observed soil C with plant C soil inputs to field-observed microbial biomass, soil respiration, and N mineralization. The results also showed that reducing tillage and transitioning to a no-till system increased soil C and reduced soil erosion. The main path of soil C losses was het- erotrophic microbial respiration, which accounted for 66% of the total C lost in a continuous crop rotation and no fertilizers, 71% in a continuous crop rotation with fertilizers, and 86% in a crop–pasture rotation with fertilizers. Model results from a degraded cropping system showed that adding grass–clover (Trifolium spp.) pastures greatly increased plant production and soil C, whereas reducing the frequency of grass–clover pastures in high-fertility cropping systems from 50% of the time to 25% reduces crop yields and soil C. Including cover crops substantially increases crop production and maintains soil C in high-fertility and degraded cropping systems.

We studied the effects of 7-crop rotations and continuous - monocropping systems on soil microorganism and its feedback. The results showed that absolute abundance of soil bacteria (Pseudomonas and Bacillus) in tomato - celery - cucumber - cabbage and cucumber - tomato - cucumber - cabbage rotation were significantly higher than control (CK). Absolute abundance of soil fungi in tomato - celery - cucumber - cabbage, kidney bean - celery - cucumber - cabbage, cucumber - kidney bean - cucumber - cabbage and cucumber - tomato - cucumber - cabbage rotation were significantly higher than CK. Dry weight of cucumber seedlings was significantly positively correlated with bacterial (Pseudomonas and Bacillus) abundance, and negatively correlated with fungal count. The results of inoculation with Fusarium oxysporum f.sp. cucumerinum showed that plant dry weight of cucumber seedlings in tomato - celery - cucumber - cabbage, cucumber - kidney bean - cucumber - cabbage, cucumber - tomato - cucumber - cabbage rotation soil was significantly higher than other treatments, and their disease index was significantly lower than other treatments. There was no significant difference in dry weight of cucumber seedlings in rotation and CK in the soil sterilization test. The results of plant - soil feedback experiment showed that soil microbial changes caused by different rotation patterns had a positive feedback effect on growth of cucumber seedlings.

Verticillium wilt is a disastrous disease in cotton‐growing regions in China. As a common management method, cotton rotation with cereal crops is used to minimize the loss caused by Verticillium dahliae. However, the correlation between soil microbiome and the control of Verticillium wilt under a crop rotation system is unclear. Therefore, three cropping systems (fallow, cotton continuous cropping, and cotton–maize rotation) were designed and applied for three generations under greenhouse conditions to investigate the different responses of the soil microbial community. The soil used in this study was taken from a long‐term cotton continuous cropping field and inoculated with V. dahliae before use. Our results showed that the diversity of the soil bacterial community was increased under cotton–maize rotation, while the diversity of the fungal community was obviously decreased. Meanwhile, the structure and composition of the bacterial communities were similar even under the different cropping systems, but they differed in the soil fungal communities. Through microbial network interaction analysis, we found that Verticillium interacted with 17 bacterial genera, among which Terrabacter had the highest correlation with Verticillium. Furthermore, eight fungal and eight bacterial species were significantly correlated with V. dahliae. Collectively, this work aimed to study the interactions among V. dahliae, the soil microbiome, and plant hosts, and elucidate the relationship between crop rotation and soil microbiome, providing a new theoretical basis to screen the biological agents that may contribute to Verticillium wilt control., The effect of crop rotation on the soil fungal community is greater than that on the bacterial community, and the interaction between Verticillium dahliae and soil microbiome provides a theoretical basis for Verticillium wilt control.

Made available in DSpace on 2021-06-25T10:24:09Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-05-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Knowledge of the ecological survival niches of Curtobacterium flaccumfaciens pv. flaccumfaciens (Cff), the causal agent of bean bacterial wilt, is essential for the efficient disease management. Our study evaluated the survival of Cff in the phyllospheres and rhizospheres of barley, black oat, canola, common bean, forage turnip, maize, pearl millet, ryegrass, sorghum, soybean, sunflower, velvet bean, wheat and white oat planted in a greenhouse. The aerial parts of the plants were inoculated by spraying a bacterial suspension (107 CFU.mL−1) from the strain Feij. 2628A, which is resistant to rifampicin and pathogenic to common bean. The soil of the pots was infested with 200 mL of the same suspension. Cff survival was evaluated every seven days for 70 days, and the survival periods were confirmed by selecting strains from all samples and performing PCR with specific primers. Cff survived for at least seven days in the phyllosphere, and 21 days in the rhizosphere of all evaluated crops. Based on our results, barley, black oat, canola, forage turnip, maize, pearl millet, ryegrass, sorghum, soybean, sunflower, velvet bean, wheat and white oat can be potential asymptomatic hosts for Cff, and their cultivation in succession with common bean is not recommended in areas with a history of bacterial wilt occurrence. Department of Plant Protection São Paulo State University (Unesp) School of Agriculture, Avenida Universitária, 3780 Department of Plant Protection São Paulo State University (Unesp) School of Agriculture, Avenida Universitária, 3780 CAPES: 001

Made available in DSpace on 2021-06-25T10:53:33Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-01 Aims: Xanthomonas campestris pv. campestris (Xcc) survival was evaluated in the phyllosphere and rhizosphere of 20 crop species, as well as in the rhizosphere of cabbage cultivated in six soil types. Methods: The crops aerial parts were inoculated, and the rhizosphere soil was infested with bacterial suspension (107 CFU.mL−1) of 3098C Xcc strain, which is rifampicin-resistant and pathogenic to brassica plants. Xcc recovery from the samples was performed in a semi-selective culture medium. Results: The highest average survival periods of Xcc in the phyllosphere were obtained from cabbage (70 days), tomato (67 days), wheat and pumpkin (63 days), black oat and radish (56 days) and sweet pepper (49 days). Low Xcc survival occurred in the rhizosphere of most crops evaluated when compared to the soil in the absence of plants. The highest average period of survival in the rhizosphere was observed for cabbage (53 days). Survival periods in lettuce, pumpkin, wheat and mustard ranged from 21 to 28 days. In the rhizosphere of cabbage cultivated in six soils, survival periods ranged from 8 to 17 days. Conclusions: Sunflower, carrot, zucchini, spinach, sunn hemp, sorghum, maize and chive are recommended for rotating systems with brassicas because Xcc showed low survival in the phyllosphere and rhizosphere of these crops. Departamento de Proteção Vegetal Faculdade de Ciências Agronômicas (FCA) Universidade Estadual Paulista “Júlio de Mesquita Filho” (UNESP), Avenida Universitária, 3780 Departamento de Produção e Melhoramento Vegetal Faculdade de Ciências Agronômicas (FCA) Universidade Estadual Paulista “Júlio de Mesquita Filho” (UNESP), Avenida Universitária, 3780 Departamento de Proteção Vegetal Faculdade de Ciências Agronômicas (FCA) Universidade Estadual Paulista “Júlio de Mesquita Filho” (UNESP), Avenida Universitária, 3780 Departamento de Produção e Melhoramento Vegetal Faculdade de Ciências Agronômicas (FCA) Universidade Estadual Paulista “Júlio de Mesquita Filho” (UNESP), Avenida Universitária, 3780

Long-term fertilization and crop rotation can influence both organic C sequestration as well as the C composition of soils and the more resistant organic C compounds contained in humic acid (HA). This study examined the effects of fertilization and cropping type (monoculture corn (MC) and Kentucky bluegrass sod (KBS) and corn-oat-alfalfa-alfalfa rotation (RC)) on the HA composition of soil from a 52-year field study in southern Ontario, Canada. Humic acid samples were extracted from soil, and elemental analysis, infrared spectroscopy, solid state 13C nuclear magnetic resonance spectra, and electron paramagnetic resonance methods were used to determine the influence of the cropping type on the characteristics of HA. Both fertilization and cropping type affected the chemical characteristics of HA. Fertilization led to a 5.9% increase in C, a 7.6% decrease in O, and lower O/C and (N + O)/C ratios in HA as compared to the corresponding non-fertilized treatments. Rotation resulted in a lower proportion of C (48.1%) and a greater (N + O)/C ratio (0.7) relative to monoculture cropping. Infrared spectroscopy analysis showed that HA contained more C-O groups in fertilized soil than in non-fertilized soil under MC and KBS. Fertilization increased the O-alkyl-C, phenolic-C, and free radical contents of HA relative to non-fertilization treatments. Rotation decreased the aliphatic and carboxyl groups and increased the O-alkyl, carbohydrate, aryl, and phenolic groups and free radicals, relative to MC and KBS. Both long-term crop rotation and fertilization dramatically modified the soil HA composition. Significant relationships were observed between the molecular composition of HA and soil organic C. Hence, humic acid characterization could be used as an indicator of the long-term sustainability of crop management practices.

The Australian canola industry was established in the 1970s and has expanded since that time, particularly in the last two decades. This review addresses the changes in farming practices since the year 2000 and the epidemiological and management consequences for blackleg, caused by the fungus Leptosphaeria maculans, the main disease impacting Brassica napus production. To help understand the change in production practices, a survey of over 100 growers and agronomists was conducted. Modern management practices include increased crop residue retention, frequency of canola in crop sequences, number of resistance genes in cultivars, use of hybrids and fungicides as well as earlier sowing and flowering times. While some of the changes identified in the survey and in this review increase the risk and severity of disease, including new symptoms like upper canopy infection, others provide novel strategies for control. Keeping these changes in mind, a set of research priorities towards long term sustainable management of blackleg disease are identified.

Nothopassalora personata is a cosmopolitan plant pathogenic fungus that causes late leaf spot (LLS) of peanut, the main foliar diseases of this crop. The disease emerged during the last decade in the USA and Argentina. Severely affected plants are early defoliated and yield is decreased by 40–50%. During the last decades, effective LLS management worldwide has been achieved using chemical fungicides, which may negatively affect human and animal health as well as the natural stasis of the soil native microbiota. This review provides an updated view of the new research conducted to understand and effectively manage the disease, based mainly on host plant resistance judicious use of fungicides together with other cultural practices such as crop rotation. Breeding for resistance remains challenging, but new SNPs markers for leaf spot diseases have been mapped and may be useful for improving host resistance which can reduce reliance on fungicides, especially after the ban of chlorothalonil in the E.U. Biocontrol using bacterial and fungal agents open new possibilities to reduce the use of chemical fungicides.

Made available in DSpace on 2021-06-25T10:49:00Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-03-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) A crop rotation system can reduce phytopathogen inoculum, and consequently reduce the incidence and severity of disease. Bean bacterial wilt is an important disease and several crops can act as inoculum sources for Curtobacterium flaccumfaciens pv. flaccumfaciens (Cff). The aim was to evaluate the influence of crop rotation systems on 10 common bean cultivars against bacterial wilt. Experiments were located in two different areas in Brazil (2012), cultivated under a no-tillage system and with a history of the disease. The evaluated rotation systems were black oat, wheat and fallow followed by common bean. After harvest, 10 dry bean cultivars were sown, together with a fallow area. Disease incidence and severity were assessed at 45, 60 and 80 days after sowing. Also evaluated were four agronomical parameters: pod numbers, grain numbers, total weight of grains per plant and weight of 100 grains. Epiphytic and endophytic colonization by Cff was evaluated in black oat and wheat, and in crop debris. The rotation systems significantly influenced the incidence and severity of bacterial wilt in common bean cultivars in both areas and negatively affected the four agronomic parameters. The cultivars BRS Campeiro, BRS Estilo, IPR Tuiuiú, IPR Tangará and IPR Campos Gerais presented low severity and incidence of the disease and higher productivity. Cff strains were recovered from black oat, wheat and crop debris. Our results reinforce the importance of planting non-Cff host crops in rotation systems with common bean, as well as planting cultivars with a level of resistance to bacterial wilt. Departamento de Proteção Vegetal Faculdade de Ciências Agronômicas (FCA) Universidade Estadual Paulista “Júlio de Mesquita Filho” (UNESP), Avenida Universitária, 3780 Departamento de Proteção Vegetal Faculdade de Ciências Agronômicas (FCA) Universidade Estadual Paulista “Júlio de Mesquita Filho” (UNESP), Avenida Universitária, 3780