Low Sowing Research Articles

96 Evaluating the impact of macroenvironment temperature on thermoregulatory and milk quality parameters in lactating sows and their litter

Abstract Farrowing facility macroenvironment temperatures (TMacro) are often maintained at the upper end of the thermoneutral zone (24–25°C) of lactating sows, which may result in heat stress and reduced milk quality and quantity. Therefore, the study objective was to evaluate the impact of TMacro on thermoregulatory and milk quality parameters in lactating sows and their litters. In two repetitions, 37 lactating sows (parity = 3.1 ± 1.7) and their litters (d 1 litter size = 12.0 ± 1.0) were housed within 1 of 3 farrowing rooms set to different TMacro: LOW (n = 12 sows and litters; 15.0 ± 0.4°C), MID (n = 13 sows and litters; 19.3 ± 0.2°C), and HIGH (n = 12 sows and litters; 24.6 ± 0.8°C). Lactating sows and litters were monitored from d 3 of lactation until weaning (19.8 ± 0.9 d of age). All litters were provided with a 0.34 × 1.52 m heating pad. Sow respiration rates (RR, breaths per minute, BPM) were measured daily at 0800, 1200, 1600 and 2000 h by counting the number of flank movements. Vaginal temperature (TV) was measured in all sows at 10-min intervals using implanted data loggers. One sentinel piglet from each litter was implanted with a temperature recording bolus at d 2 of age to monitor core body temperature in 15-min intervals. Milk samples were collected from all sows on d 6, 12, and 18 of lactation and analyzed for true protein %, total solid %, and fat %. Data were analyzed using PROC GLIMMIX. The litter was considered the experimental unit for piglet measures, and the sow was considered the experimental unit for sow measures. Respiration rates were greater (P < 0.01) for HIGH (48 ± 2 bpm) sows versus MID (33 ± 2 BPM) and LOW (27 ± 2 bpm) sows, but no differences were detected between MID and LOW sows. A TMacro treatment by lactation day effect was observed for TV (P = 0.02), where HOT sows had greater TV on lactation d 15 (+0.31°C), 18 (+0.43°C) and 19 (+0.34°C) versus MID and LOW sows. Piglet core body temperature was reduced (P < 0.01) in the HIGH (39.07 ± 0.06 °C) versus the MID (39.31 ± 0.06 °C) and LOW (39.33 ± 0.07 °C) treatment groups, but it was similar for MID and LOW litters. Fat % was reduced for COLD (6.15 ± 0.52%) versus MID (7.35 ± 0.50%) sows on d 12, but no differences were observed when compared with HIGH sows (6.97 ± 0.52%). In conclusion, the HIGH treatment resulted in physiological heat stress for lactating sows and lowered piglet core body temperature, but it had minimal effects on measures of milk quality.

ВЛИЯНИЕ ПРЕДПОСЕВНОЙ ОБРАБОТКИ СЕМЯН ЭЛЕКТРИЧЕСКИМ ПОЛЕМ НА УРОЖАЙНОСТЬ ЛЬНА-ДОЛГУНЦА И ЯРОВОЙ ПШЕНИЦЫ

Pre-sowing seed treatment is a mandatory agricultural method of increasing yields by increasing the energy and germination of seeds. Laboratory and field tests showed an increase in the yield and quality of flax and spring wheat seeds due to pre-sowing seed treatment with an electric field at the Sadko-1 electrophysical installation. (Research Purpose) The research purpose is selecting the treatment modes (the voltage acting on the seeds with a low-frequency electric field and the resting of the seeds after treatment) that increase the sowing properties of the seeds and yield and determining the economic efficiency of electrophysical technology of pre-sowing seed treatment in the cultivation of flax and spring wheat. (Materials and methods) Three batches of seeds of each crop were treated with an electric field of 2, 4 and 6 kilovolts per centimeter. After resting for 9 days, the seeds were sown into the soil. The field experiment included four options: control (without exposure to an electric field on seeds) and three options corresponding to exposure modes: 2, 4, and 6 kilovolts per centimeter. The area of the registered plot was 50 square meters. During the growth and development of crops, the field germination and preservation of plants before harvesting and the harvest of each plot were determined. (Results and discussion) During laboratory germination of treated seeds, an improvement in seed sowing qualities is observed: energy and germination, increase in the size and weight of seven-day seedlings. It was found that in the process of growth and development of crops, the effect of pre-sowing treatment is manifested in increasing field germination and preservation of plants before harvesting. (Conclusions) Pre-sowing treatment of flax seeds and spring wheat at the Sadko-1 installation contributed to an increase in the yield and quality of straw and flax grain. Economic calculations indicate the high profitability of the proposed technology. Due to processing in the electric field intensity mode of 6 kilovolts per centimeter, additional net profit of 1.87 thousand rubles per hectare was obtained when cultivating flax using mineral fertilizers, without the use of mineral fertilizers - 1.03 thousand rubles per hectare (in 2021 prices). The cost of seed treatment is ~ 50 rubles per hectare. Net profit due to pre-sowing electrophysical processing of wheat at 2 kilovolts per centimeter amounted to 2.86 thousand rubles per hectare. The presented method of seed treatment can be offered to farms as an element of resource-saving technologies, as well as for pre-sowing seed treatment of low sowing conditions.

PSX-18 Determining the Optimal Macroenvironment Temperature to Improve Lactating Sow and Piglet Productivity

Abstract Pre-weaned piglets prefer higher temperatures than lactating sows. To address this, swine producers use heating lamps or pads in combination with maintaining farrowing room macroenvironment temperatures at the upper end of the thermoneutral zone (24-25℃) of the lactating sow. This may inadvertently cause thermal stress for lactating sows resulting in decreased feed consumption, and ultimately, reduced milk production and litter growth. Therefore, the objective was to determine the sow level macroenvironment temperature that would improve both sow and litter productivity. In two repetitions, 37 lactating sows (parity = 3.1 ± 1.7) and their litters (d 1 litter size = 12.0 ± 1.0) were housed within 1 of 3 farrowing rooms set to different macroenvironment temperatures: LOW (n = 12 sows and litters; 15.0 ± 0.4℃), MID (n = 13 sows and litters; 19.3 ± 0.2℃), and HIGH (n = 12 sows and litters; 24.6 ± 0.8℃). Lactating sows and their litters were on trial from the onset of farrowing until weaning (19.8 ± 0.9 d of age). Individual farrowing crate temperatures were recorded throughout the trial in 0.14 s intervals using thermocouples mounted at sow head height. Piglets were provided a 0.34 x 1.52 m heating pad with a verified steady state of 35.0℃. Sow body weight (BW) was recorded at 24 h post-farrowing and at weaning, and piglet weights were measured on d 1, 7, 14 and at weaning to determine average daily BW gain (ADG). Liveborn piglet mortality was recorded throughout the trial. Sow feed intake (FI) was recorded daily from d 1 post-farrowing until weaning. The sow was considered the experimental unit for sow level measures and the litter was considered the experimental unit for piglet measures. Data were analyzed using PROC GLIMMIX in SAS 9.4 and using GLM in JMP 15. Regression models were used to determine the optimal macroenvironment temperature to improve sow FI and piglet ADG. Sow FI was greater (P < 0.01) for LOW (7.91 ± 0.38 kg) and MID (7.32 ± 0.37 kg) versus HIGH (6.37 ± 0.39 kg) sows, but similar for LOW and MID sows. Piglet ADG was greater from d 1 to weaning (P < 0.01) for LOW (0.25 ± 0.01 kg) and MID (0.26 ± 0.01 kg) versus HIGH (0.21 ± 0.01 kg) piglets, but similar for LOW and MID piglets. Pre-weaning mortality was similar (P = 0.32; 15.6%) among all treatments. A quadratic effect was observed (P < 0.01) where sow FI was maximized at a macroenvironment temperature of 17.2℃. A cubic effect was observed (P < 0.01) where piglet ADG was greatest at 17.0℃. In summary, these data have implications towards housing lactating sows and their litters at lower macroenvironment temperatures to improve growth performance.

273 Longitudinal Investigation of Nutrient Intervention During Gilts Development on Sow Reproductive Performance and Longevity

Abstract The objective of this study was to evaluate the dietary nutrient level and vitamin D source during gilt development on sow reproductive performance and longevity. Three groups of gilts (n = 60 in each group, PIC Camborough) were received at 9 weeks of age (average BW: 21.2 ± 0.67 kg) and assigned to one of four dietary treatments. Treatments comprised two levels of dietary nutrients (Adeq: optimal growing diets that exceed NRC 2012 recommendations or Low: moderate slow growing diet that SID lys and ME levels were gradually reduced by 0.03% and 0 kcal/kg, 0.15% and 146 kcal/kg, and 0.15% and 150 kcal/kg, respectively) and two sources of vitamin D [StD: 1653 IU cholecalciferol/kg or HyD: 500 IU cholecalciferol/kg + 50 mcg calcifediol (ROVIMIX HY-D DSM Nutritional Products North America)] during development phase 1 (22 to 57 kg), 2 (57 to 91 kg), and 3 (91 until breeding). Dietary nutrient level treatment was withdrawn during gestation and lactation stages, while sows remained on their vitamin D treatments through three reproduction cycles. Replacement gilts (n = 12 in each cycle) were handled and treated the same as the initial three groups of gilts and introduced to each group at the end of each cycle. Gilts fed Low diets had decreased ADG (P = 0.01), lighter BW (P < 0.01), increased ADFI (P < 0.01), and poorer feed efficiency during development (P < 0.01) when compared with gilts fed Adeq. Gilts fed Low were lighter (149.8 kg) than the Adeq (153.9 kg) fed gilts. Sows fed Low diets during their development had reduced number of stillborn (P < 0.01), 0.79 more pigs born alive (P = 0.10), and weaned a total of 238 more pigs than Adeq sows (2,127 vs 1,889, P < 0.01). Numerically greater lactation intake allowed sows developed using Low diets to have greater backfat at weaning compared with those developed using Adeq diets (weaning backfat: 13.0 vs 11.9 mm, P = 0.03). Gilts and sows fed HyD had significantly greater born alive litter weight (P = 0.03) due to numerical greater born alive (14.2 vs 13.47, P = 0.14) but average born alive piglet BW (P = 0.86) was not different. Piglets from sows fed HyD_Low diets had greater preweaning mortality compared with piglets from sows fed StD_Low diets because of greater number of pigs born alive observed in HyD_Low sows (1.323.vs.1,143, P = 0.02). Interestingly, a total of 5 sows that were culled due to lameness were all from the first cycle and StD treatment. Moreover, the percentage of sows rebred tended to be greater in sows fed HyD diets (P=0.08). These data indicate that the level of dietary nutrients fed during gilt's development and feeding HyD continuously from gilt development through subsequent reproductive phases, modulated reproductive performance.

Agronomic performance of summer forage crops on a Waikato dry-stock farm

Forage crops options are required by dry-stock farmers to fill summer feed gaps. This trial compared a brassica monoculture with simple and hyper-diverse mixtures containing up to 21 forage species sown in October on a Waikato dry-stock farm. Two of the twelve treatments were established at paddock scale. Species included rape, oats, plantain and red clover. Seedling emergence was assessed four weeks after sowing and herbage production, metabolisable energy and botanical composition in mid-January. Rape was common in all mixtures for the provision of high-quality forage. Oats suppressed rape production, even at low sowing rates (<13 kg/ha), and reduced weed ingress. Plantain, sown at <2 kg/ha, contributed negligible dry matter in mid-January but provided ground cover and additional forage by late February. Red clover failed to establish. Most diverse treatments provided a similar energy yield (MJ ME/ha) to rape. Simple mixtures and hyperdiverse mixtures were similar for most metrics. Results at plot and paddock scale were consistent for the energy yield effects. When these data were combined withproduction costs, the energy costs were similar for most treatments. The most promising was a rape dominant mixture, with high energy yield, low weed abundance and low energy costs.

Yield Loss and Integrated Disease Control of Rhizoctonia solani AG2-1 Using Seed Treatment and Sowing Rate of Oilseed Rape.

Rhizoctonia solani anastomosis group (AG) 2-1 is an ubiquitous soilborne pathogen causing severe damping-off of oilseed rape (OSR). In the absence of varietal resistance to AG2-1, there are limited methods for integrated disease management. The objectives of these field studies were to quantify yield losses due to AG2-1 and to determine the effectiveness of integrated control using sedaxane, fludioxonil, and metalaxyl-M applied as seed treatment on two OSR genotypes at a sowing rate of 40 (low) or 80 (high) seeds m-2. Crop assessments of green area index (GAI), vigor, and cabbage stem flea beetle (CSFB) Psylliodes chrysocephala damage were carried out at GS16, while pathogen DNA in soil was quantified using real-time PCR at GS32. Yield and seed weight losses of 41 and 18%, respectively, were associated with reduced establishment, GAI, vigor, and delayed development and flowering of OSR. Seed treatment reduced AG2-1 DNA in soil by 80%, resulting in a 94, 16, and 64% increase of establishment, thousand seed weight (TSW), and yield, respectively. Seed treatment also mitigated the effects of AG2-1 on delaying plant development, resulting in increased uniformity of crop flowering. OSR plants infected with AG2-1 suffered 27% more damage by the CSFB, indicating positive pathogen-pest interaction at the expense of the OSR host. Optimum control of AG2-1 infection was achieved by integrating low sowing rate and seed treatment. However, under dual pest and pathogen attack, high sowing rates should be combined with the use of seed treatment to mitigate seedling death and delayed development caused by AG2-1 and CSFB damage.

Effects of Restoration Years on Vegetation and Soil Characteristics under Different Artificial Measures in Alpine Mining Areas, West China

In view of the problem of sustainable restoration of vegetation in alpine mining areas, vegetation communities and physical and chemical properties of soil under different artificial restoration measures (i.e., grass monoculture, sowing quantity and topsoil replacement) were investigated for five consecutive years (2016–2020) in the sloped eastern area of a northern slag mound in the Jiangcang mining area of the Muli coalfield in Qinghai, China. The results showed that the vegetation characteristics of different sowing treatments with different kinds of grass species, such as Elymus nutans, Poa pratensis cv. Qinghai and Poa crymophila cv. Qinghai, were significantly different (p < 0.05). The content of soil available nitrogen and phosphorus was significantly different among different grass species (p < 0.05). Vegetation coverage and ramet density of sowing treatment five were significantly higher than those of a lower sowing quantity (p < 0.05). There was no significant difference in the vegetation characteristics among different grass species treatments five years after the restoration (p > 0.05). There was no significant difference in vegetation height of different soil covering treatments (p > 0.05). In the early stage of restoration, vegetation coverage and ramet density in TR2 (resurfacing soil 10 cm) and TR3 (resurfacing soil 15 cm) were significantly higher than those without treatment. Soil N, P and organic matter under the treatments of TR1 (resurfacing soil 5 cm), TR2 and TR3 were significantly higher than those in CK (p < 0.05) in the early stage of restoration, but there was no significant difference in soil N, P and organic matter after five years of restoration. Overall, the vegetation and soil characteristics showed a trend of increase first and then decrease during the 5-year restoration period under different artificial measures. There were significant differences in the vegetation and soil characteristics among different treatments in the second year of restoration (p < 0.05), but there was no significant difference between the first year and the fifth year of restoration, which indicated that vegetation and soil began to degrade after five years of restoration, and substrate nutrients in the mining waste soil could only support the short-term restoration of vegetation. Therefore, it is necessary to target matrix nutrients in future vegetation restoration in alpine mining areas.

Генетические и агротехнологические особенности формирования посевных качеств овса при различном уровне минерального питания

Abstract. The purpose is to study the genetic and agrotechnological features of the formation of the sowing qualities of oat grain at various agricultural backgrounds in the forest-steppe of the Trans-Urals. Materials and methods. The research was carried out on an experimental field located in the forest-steppe zone of the Trans-Urals. The object of the study were three varieties of oats, which were sown on different agricultural grounds, ensuring the formation of yields from 3.0 to 6.0 t/ha of grain. The mass of 1000 grains, the proportion of fine grains, germination energy and laboratory germination were determined. Results. On the natural agricultural background, the Talisman and Otrada varieties form a yield of 1.41 and 1.85 t/ha with a fraction of fine grain (< 2.0 mm) up to 11 %. In the Foma variety on the natural agricultural background, this indicator was 7.5 %. The introduction of mineral fertilizers for the planned yield from 3.0 to 5.0 t/ha reduces the amount of fine grain only in the Talisman and Foma varieties. Grain with high sowing qualities is formed on a natural agricultural background and when fertilizers are applied to the planned yield of 3.0 t/ha. The grain obtained on such variants had 72–76 % germination energy and 91-93% laboratory germination. Grain obtained at a high and very high agricultural background had low sowing indicators: germination energy and laboratory germination reached minimum values: 57–59 and 61–63 %, respectively. It was found that the mass of 1000 grains depends on fertilizers by 23.4 % and 30.0 % on the weather conditions of the growing season. Varietal characteristics account for 9.6 %. Laboratory germination of the studied varieties by 86.8 % depends on the level of mineral nutrition. Scientific novelty. For the first time for the Northern Trans-Urals, an optimal level of agricultural background has been established, providing maximum yield of oat grain with high sowing qualities. Recommendations. In the forest-steppe zone of the Trans-Urals, the cultivation of oats for seed purposes is recommended in fields with an average or increased agricultural background, designed to obtain yields of 3.0 and 4.0 t/ha.

К вопросу о совершенствовании технических средств для предпосевной СВЧ обработки семенного зерна

Pre-sowing processing of the seed material is one of the most important stages for the formation of a sustainable yield of grain. Low sowing qualities of seeds, contamination with pathogenic spores have a negative impact on the yield. Pre-sowing chemical treatment of seeds undoubtedly has a positive effect in most cases, but at the same time it negatively affects the environment and beneficial soil microorganisms. Electrophysical methods of pre-sowing treatment are environmentally safe and can be used as comprehensive measures to protect and stimulate plants. In spite of the fact that a large number of works are devoted to electrophysical methods of pre-sowing treatment, the results obtained are ambiguous, and the technical means used need to be improved. The article presents the positive results of the vibration impact on the uniformity of irradiation with an ultrahigh frequency electromagnetic field. These results indicate that the vibrofluidized layer formed in the irradiation chamber contributes to a more uniform grain heating, compared with heating statica lly located grain. The article also presents the results of the ultrahigh frequency electromagnetic field impact on the sowing qualities of spring oats grain and its contamination with pathogens. Thus, processing grain ensures the destruction of spores of certain diseases with a slight decrease in germination ability and germination energy. The results show that the use of electrophysical methods should solve a compromise problem, while observing the level of temperature impact in order to preserve the vital functions of the embryo. Keywords: PRE-SOWING TREATMENT, ELECTROMAGNETIC FIELD, MICROWAVE, SOWING QUALITIES, GERMINATION ABILITY, GERMINATION ENERGY, VIBRATION, UNIFORMITY OF PROCESSING

Improving wheat yield by optimizing seeding and fertilizer rates based on precipitation in the summer fallow season in drylands of the Loess Plateau

Precipitation has been recognized as the dominant factor driving crop grain yields and large yield variations in drylands, which suggests that some agricultural management practices can be optimized to achieve high yields and benefits. In this study, we investigated 804 farmers' wheat fields from 2015 to 2018 in the dryland area of the Loess Plateau in China and analyzed the relationships between wheat yield and the influence factors (including precipitation, wheat sowing rate, fertilizer inputs, and soil nutrients) to propose optimized agricultural management practices for wheat production. The results showed that wheat grain yield followed a linear plateau pattern relative to the precipitation in the summer fallow season, with a yield of 5344 kg ha−1 obtained at a precipitation of 203 mm. In the L203 group (precipitation in the summer fallow season less than 203 mm), the Low-yield subgroup (0–33th in grain yield group (in order from low to high)) had a lower sowing rate, kernel weight, kernel number and spike number than the High-yield subgroup (68–100th in grain yield group); different levels of phosphorous (P) and potassium (K) fertilizer overuse were found among the three yield subgroups. However, in the H203 group (precipitation in the summer fallow season greater than 203 mm), differences in only kernel and spike numbers and nitrogen (N) fertilizer application rate were observed among the Low-, Moderate-, and High-yield subgroups. Additionally, there were no differences in the soil organic matter (SOM), total N or pH in the three subgroups in either L203 or H203, but significant differences in soil mineral N, available P and K were observed among the three subgroups (except mineral N in L203). Based on these results, the wheat sowing rate and fertilizer input rates can be optimized to increase wheat yield and farmers’ income and promote agricultural management for dryland wheat production on the Loess Plateau.

Ефективність заходів підтримання продуктивності лучних травостоїв довготривалого використання

Goal. To establish the influence of the system of fertilizers and annual improvement of fodder lands of long-term use by the method of sowing seeds with low norms on grass yield and fodder nutrition. Methods. Field — to establish the biometric data, laboratory — to make agrochemical analysis of feed, and statistical. Results. According to the results of scientific research during 2016–2020, a positive impact was established of annual improvement of fodder lands of long-term use on botanical composition, yield and fodder quality by low sowing rates of grasses. Thus, the number of shoots per unit area increased on average on 10% — from 1922 to 2108 pieces/m2. In the structural composition, the share of the bean component in pasture use was up to 35, in raw — up to 43%. The negative influence of intensive fertilizer system on the structural composition of grass mixtures (reduction of bean component by 43–69%) was established. On average over the years of research, the yield of grass mixtures for pasture use was 14.1–23.9 t/ha of green or 3.2–5.5 t/ha of dry matter, feed units — 2.15–3.61, digestible protein — 0.32–0.71 t/ha; for raw material use — 31.7–51.0 t/ha of green or 7.0–11.0 t/ha of dry mass, feed units — 4.32–7.18, digestible protein — 0.54–0.86 t/ha, depending on fertilizer and composition of grass mixtures. With the use of organo-mineral fertilizer Ecoplant the number of shoots per unit area increased by 6–9%, with the application of complex mineral fertilizer N16R16K16 — by 6–32%, and with intensive fertilizer system — by 8–24%. Yields increased by 18–28%, 49–56 and 13–25%, respectively, depending on the group of maturity of grass mixtures and the direction of their use. The annual improvement contributes to a more balanced supply of feed from them during the growing season. It is established that the most economically feasible is the system of fertilization with complex fertilizers in the norm of N16P16K16, which allows reducing the cost of green fodder by 7.6–33.4%. Conclusions. Annual improvement of forage lands by small sowing rates of components in the conditions of climate change promotes full-fledged restoration of grassland. The use of complex mineral fertilizers in the dose of N16P16K16 helps to reduce the cost of green fodder by 33.4%.

Reducing competition in forage maize intercropped with tall fescue through herbicides, plant types, and sowing density

Forage maize is the predominant crop in the intensive dairy farming regions of Europe. This crop, however, is associated with considerable nitrate leaching and decreasing soil organic matter concentrations. Catch crops installed after maize harvest can usually only be sown late in the growing season in North-West Europe to tackle these problems efficiently. Intercropping maize with grass species such as tall fescue has the potential to result in a timely developed grass sward before the winter, capable of assimilating important quantities of carbon and soil residual nitrogen and to buildup soil organic matter. Yet, the intercropped grass might compete with the maize for water and nutrients. Here, we report, for the first time, the effect of (i) herbicide combinations, (ii) tall fescue sowing density and method, (iii) tall fescue morphotype, and (iv) the maize maturity group on the functioning of forage maize intercropped with tall fescue. We assessed maize and intercropped tall fescue yields and studied the N uptake and the effect on soil residual nitrate of the intercropped grass. We found that every kg dry matter ha−1 of tall fescue aboveground dry matter, present at the end of the autumn, came at a cost of 1.4 kg dry matter ha−1 of maize dry matter yield. Herbicide treatments can regulate grass-maize competition, whereas lower sowing densities of the intercropped grass or different sowing methods of the intercropped grass had no effects. Despite the superior winter growth of the Mediterranean tall fescue morphotype compared to the continental tall fescue, the reduction in soil residual nitrate was similar for both morphotypes. We demonstrate that tall fescue intercropped in maize can be an alternative to cover crops installed after the harvest of maize, to reduce nitrate leaching, and to compensate for the soil organic matter losses associated with forage maize production.

Yield performance of oat cultivars in response to sowing dates and densities

Adjustment of seeding density oriented by genotype and conditions of the growing environment may favor growth, development and yield performance of the oat crop. This study aimed to evaluate the growth, lodging, yield components, and grain yield of oat cultivars grown at different sowing dates and densities. Two independent experiments were conducted at two sowing dates (May 5 and June 24) in Londrina-PR under a randomized block design in a 4 × 2 factorial scheme, with four replications. Treatments consisted of four sowing densities (180, 240, 300, and 360 viable seeds m−2) and two cultivars (IPR Afrodite and IPR Artemis). Plant height, number of panicles.m−2, number of spikelets per panicle, number of grains per spikelet, number of grains per panicle, thousand-grain weight, plant lodging, and grain yield were evaluated. The data were submitted to the analysis of joint variance for sowing dates, separately for the cultivars. The averages of sowing dates were compared by the F test and densities submitted to polynomial regression analysis up to 2nd degree, at 5% probability. The first sowing date favors most yield components and grain yield of the cultivars IPR Afrodite and IPR Artemis. In contrast, the number of panicles m−2 was reduced during this growing season for both cultivars. The late sowing date for the IPR Artemis cultivar resulted in a high percentage of lodging at all evaluated densities. However, this phenomenon is more intense at higher sowing densities during the first sowing date. Yield components and grain yield varied according to sowing dates and densities and the cultivar. The highest grain yield of the cultivar IPR Afrodite at the first sowing date was achieved with a lower sowing density than in the later date. However, the highest grain yield of the IPR Artemis cultivar was achieved at density of 280 viable seeds m−2, regardless of the growing season.

Reduced crop density increases floral resources to pollinators without affecting crop yield in organic and conventional fields

Abstract Effective weed control in agricultural crop fields increases yields, but simultaneously reduces floral resources for pollinators because many weed species provide pollen and nectar. Consequently, efforts to enhance crop yields on organic farms by using effective weed control methods risk compromising positive effects of organic farming on pollinating insects. Thus, it is important to find management strategies that alleviate the trade‐off between crop yields and flowering weeds on organic farms. We investigated the relationship between cereal yields, flowering weeds and bumblebees on organic and conventional arable land. We also investigated the potential of adjusting crop sowing density to benefit flowering weed species richness and floral resources to bumblebees without affecting crop yield. Floral resources and species richness of flowering weeds were higher in organic compared to conventional fields and were negatively related to crop yield in organic but not conventional fields (where the variation of floral resources and flowering weed species richness was comparatively low). Bumblebee species richness was higher in organic compared to conventional fields, and abundance was twice as high in organic as in conventional fields, but not significantly so. Yields in organic fields were two thirds of those in conventional fields. When simultaneously testing the effect of farming type (organic vs. conventional), crop yield and floral resources, only floral resources were related significantly to bumblebee abundance and species richness. A lower sowing density of the crop increased floral resources without negatively affecting crop yield. Synthesis and applications. We show that organic farming practices in cereals benefit bumblebees by allowing more flowering weeds, but at a cost in terms of lower yields. However, adjusting crop sowing density provides an opportunity to attain increased floral resources without negatively affecting crop yields. Thus, by increasing floral resources, adjusting crop sowing density may contribute to supporting high bumblebee densities, which in turn sustain pollination services to wild plants and insect‐pollinated crops, such as oilseed rape and field beans, in agricultural landscapes. We suggest that sowing strategies have the potential to contribute to ecological intensification by supporting organisms that provide ecosystem services to agriculture.

Smooth Golden Fleece and Prickly Golden Fleece as Potential New Vegetables for the Ready-to-Eat Production Chain

Smooth golden fleece (Urospermum dalechampii (L.) F.W. Schmidt) and prickly golden fleece (Urospermum picroides (L.) Scop. ex F.W. Schmid) are two wild edible plants used in traditional cuisine and folk medicine. In this research, the domestication of both species was tested for the first time using a floating system and two plant densities (412 and 824 plants m−2) to evaluate yield and quality. Some quality traits were also compared in cultivated plants and wild ones gathered in grasslands. The results show that both species are suitable for cultivation, although prickly golden fleece showed highest total phenols (132 mg 100 g−1 fresh weight—f.w.) and total antioxidant activity (0.19 mg 100 g−1 f.w.). At low sowing density, smooth golden fleece showed a nitrate content of about 7200 mg kg−1 f.w., 38% higher than plants of the same species grown at high density and plants of prickly golden fleece. These results suggest that high density can be used to optimize yield in two harvests. By permitting modulation of nutrients and a product without soil residues, the floating system used in this study proved suitable for growing U. dalechhampii and U. picroides as new vegetables for the ready-to-eat production chain.

Effect of sowing pattern and density on the quality of one-year-old Austrian pine bareroot seedlings

Austrian pine (Pinus nigra Arnold) seedlings are frequently used for afforestation/reforestation and restoration practice in Serbia. Indeed, the seedlings of various stock types are produced by almost all forest nurseries in Serbia and bareroot seedlings are mostly common. The aim of this study is to analyze the method of sowing and sowing density on some morphological characteristics and quality of one-year-old Austrian pine seedlings. Sowing in rows and random sowing across all seedbed space were performed. In both cases, the sowing density (R1 - 8 g m-1, R2 - 40 g m-2) and half of the recommended sowing density (S1 - 4 g m-1, S2 - 20 g m-2) were applied. Seedlings from both treatments had average height and root collar diameter values in the range of 4.91 to 5.73 cm, and 1.25 to 2.34 mm, respectively. Observed characteristics of seedlings (height - H, root collar diameter - RCD, root length - RL, dry weight of shoot - SDW, root - RDW and seedlings - SLDW, sturdiness coefficient - SQ and quality index - QI) were conditioned by treatment (One-Way ANOVA, p<0.05). Shoot to root ration was similar at seedlings of all treatments and ranged from 1.33 to 1.63. In both cases, decreased density produced better results. The combination of lower sowing density (20 g m-2) and sowing in all seedbed areas (S2) provided the best seedlings with QI - 0.21.

Evaluation of the Productivity of New Spring Cereal Mixture to Optimize Cultivation under Different Soil Conditions

The aim of the study was to evaluate grain yields, protein yields, and net metabolic energy yields of different combinations of spring types of barley, oat, and wheat arranged in 10 mixtures and grown under different soil types. Naked cultivars of barley and oat were used. The three-year field experiment was conducted at the Agricultural Advisory Centre in Szepietowo, Poland. The study showed that the major factor determining yields of the mixtures was soil quality. Within the better soil (Albic Luvisols), the highest yield was achieved by a mixture of covered barley and wheat and by a mixture of covered barley with covered oats and wheat, but only in treatments with lower sowing density. Moreover, on the better soil, significantly higher protein yields were obtained for mixtures of barley (covered or naked grains) with wheat as compared to the mixture of covered barley with covered oats, or the mixture of covered barley with naked oats and wheat. The highest yields of net metabolic energy, regardless of soil type, were obtained from a mixture of naked barley with wheat, while the lowest from a mixture of covered barley with naked oats and wheat. Mixed sowings increase biodiversity of canopies, which allows a better use of production space. They also increase health and the productivity of plants.

Assessing the Ability of Durum Wheat-Thinopyrum ponticum Recombinant Lines to Suppress Naturally Occurring Weeds under Different Sowing Densities

The use of synthetic chemicals in cropping systems is becoming more controversial and highly debated worldwide, owing to its impacts on the environment, food safety, and human health. For this reason, sustainable crop management strategies are gaining increasing interest. In this perspective, agronomic practices and use of disease-resistant and competitive genotypes represent valuable tools in the hands of farmers. The competitive ability of two durum wheat-Thinopyrum ponticum recombinant lines (named R5 and R112), carrying effective resistance genes towards main rust diseases and enhanced yield-related traits in their alien chromosome segments, was investigated in comparison with that of a widely grown commercial cultivar (Tirex), under two sowing densities (250 and 350 seeds m−2), in the presence or absence of weeds. Yield-related traits and specific attributes that confer competitive ability were recorded in two subsequent seasons. R5 was the most weed-suppressive genotype, whereas Tirex was the least competitive. R112 was the best yield performer under favorable weather conditions (5.6 t ha−1), while it suffered the presence of weeds in the drier year (−38% grain yield). Although 350 seeds m−2 appeared to be the most effective sowing density for suppression of weeds (−16% weed biomass), adoption of the lower density can optimize grain yield and limit weed infestation in dry seasons. A suitable combination of sowing density and genotype choice can improve yield performance. R112 required the higher sowing rate to maximize grain yield (+43% as compared to the lower sowing rate), while R5 proved to be a density-neutral genotype.

Effect of Row Spacing, Sowing Density, and Harvest Time on Floret Yield and Yield Components of Two Safflower Cultivars Grown in Southwestern Germany

The current demand for safflower florets (Carthamus tinctorius L.) in the food-coloring industry, especially in Europe, is rising. The present production, mainly located in China, is not sufficient. Unlike for the production of seeds, there are currently no recommendations for the cultivation of safflower for floret production in Germany. Therefore, field experiments were conducted at the experimental station Ihinger Hof, Southwestern Germany, in 2017 and 2018. The aim was to evaluate yield and yield parameters, such as number of capitula, floret yield, and carthamidin content for (i) two cultivars grown with (ii) two row spacing (12 and 33 cm) using (iii) two sowing densities (40 and 75 plants m−2), and (iv) five harvest dates. Results showed that lower sowing densities resulted in a significantly larger number of branches and capitula per plant and higher yields of florets and carthamidin. Harvesting two to three weeks after flowering resulted in the significantly highest floret and carthamidin yields. More capitula per plant, higher carthamidin contents, and higher floret and carthamidin yields were obtained with the Chinese cultivar. In general, yields of flowering florets (2.30–468.96 kg ha−1), carthamidin contents (2.53–8.29%), and carthamidin yields (0.04–37.86 kg ha−1) were comparable to or higher than in other studies. In conclusion, this study showed that safflower has great potential for the production of florets in Southwest Germany, for the food-color industry.

Reduced crop sowing density improves performance of rare arable weed species more effectively than reduced fertilisation

AbstractCharacteristic arable weed species of dryland cereal fields have undergone significant declines, due to agricultural intensification, to the point that some of them are considered rare. Crop edges host higher abundances of arable weed species, therefore they may act as a refuge for the conservation of these rare arable species. Using mesocosms, we experimentally tested how conditions at field edges (i.e. lower sowing densities and less intensive fertiliser applications) operate on the growth (biomass and height) and reproduction (reproductive biomass and flower onset) of six rare arable species. We found the rare arable species achieved lower biomass when growing with wheat compared with growing alone, and biomass of most of species was lower under high wheat sowing density than under low sowing density. In contrast, fertiliser application affected only two of the six arable species tested, especially when they were growing alone. Although the time to flowering was not affected by the conditions tested, reproductive biomass showed the same trends as overall biomass. These results indicate that conservation of rare arable species must primarily consider reductions in crop competition to increase their biomass and reproductive ability.