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The study analyzed the effect of nitrogen (N) management and different sowing parameters of winter wheat on the flour quality, rheological properties of flour, and bread quality. Flour was obtained from winter wheat grain produced during a field experiment conducted in 2018–2021. The experiment involved three factors: (i) the sowing date (early (3–6 September), delayed by 14 days, and delayed by 28 days), (ii) sowing density (200, 300, and 400 live grains m−2), and (iii) split application of N fertilizer in spring (40 + 100, 70 + 70, and 100 + 40 kg ha−1 in the full tillering stage and the first node stage, respectively). A 28-day delay in sowing increased the total protein content of the flour, water absorption capacity of the flour, dough development time and stability, and degree of softening. When sowing was delayed by 14 or 28 days, the crumb density decreased without affecting the loaf volume. A sowing density of 400 grains m−2 had a positive impact on the flour color, dough stability, and loaf volume. The flour color and dough stability were enhanced when N was applied at 100 + 40 kg ha−1, respectively. In turn, the total protein content of flour peaked when it was applied at 40 + 100 kg N ha−1. The quality of flour improved when winter wheat was sown at a density of 400 live grains m−2 with a delay of 14 or 28 days and supplied with 100 kg N ha−1 in the full tillering stage and 40 kg N ha−1 in the first node stage. [ABSTRACT FROM AUTHOR]

During this study, an indoor experiment was conducted to determine the effect of mixed seeding rates of legumes used as green manure on the substrate fertilizer, growth characteristics, and bioactive compounds of baby leaf vegetables. The mixed seeding treatment was designed for milkvetch (Astragalus sinicus L.), tatsoi (Barassica rapa L.), kale (Brassica oleracea var. sabellica L.), and spinach (Spinacia oleracea L.) using five rates for each. Accordingly, a total of 15 treatments (3 baby leaf species × 5 mixed seeding rates) were constructed using a randomized complete block design with three replications for each treatment. During the baby leaf vegetable harvest, we evaluated the macronutrient levels (nitrogen, phosphorus, and potassium) in the substrate as well as the growth parameters and carotenoid contents. The substrate in the treatment mixed with milkvetch showed significantly higher levels of nitrogen, phosphorus, and potassium compared with those of tatsoi and kale sown alone (P ≤ 0.05). However, there were no significant differences in macronutrients observed in substrate-sown spinach with or without the milkvetch mixture. The growth and carotenoid levels of each baby leafy vegetable sown alone were significantly higher than those of each baby leafy vegetable sown with the mixed seeding treatment (P ≤ 0.05). Sowing the milkvetch-vegetable mixtures did not result in a significant increase in the growth and carotenoid levels of the three baby vegetables. The results showed that planting milkvetch with tatsoi and kale had a significant impact on substrate fertilization. However, regarding short-term vertical indoor farming, the growth and carotenoid responses of the three greens may be different. Nonetheless, we still believe that the combined interactions of legumes can provide long-term benefits by enhancing the biological functionality of the growing medium for balanced indoor agriculture production. [ABSTRACT FROM AUTHOR]

Exogenous selenium application could effectively improve the selenium absorption of crops affected by different climatic conditions due to changes in the planting environment and planting conditions. We planted maize at planting densities of 67,500 plants ha−1 (D1) and 75,000 plants ha−1 (D2). Five selenium fertilizer gradients of 0 mg m−2 (Se0), 7.5 mg m−2 (Se1), 15.0 mg m−2 (Se2), 22.5 mg m−2 (Se3), and 30.0 mg m−2 (Se4) were applied to investigate the response of the plants to selenium fertilizer application in terms of the gradient selenium absorption and substance accumulation. With the increase in the amount of selenium fertilizer applied, more of the selenium fertilizer will be absorbed and transported from the leaves to the grains, and the selenium content of the grains will gradually increase and exceed the selenium content of leaves. Under the D2 density in 2022, the selenium content of the grains under Se1, Se2, Se3, and Se4 treatments increased by 65.67%, 72.71%, and 250.53%, respectively, compared with that of Se0. A total of 260.55% of the plants showed a gradient of grain > leaf > cob > stalk from the Se2 treatment, and the overall selenium content of the plants increased first and then decreased. Under the D1 density, compared with the Se0, the dry matter mass of the Se1, Se2, Se3, and Se4 treatments significantly improved by 5.84%, 1.49%, and 14.26% in 2021, and significantly improved by 4.84%, 3.50%, and 2.85% in 2022. The 1000-grain weight under Se2, Se3, and Se4 treatments improved by 8.57%, 9.06%, and 15.56% compared to that under the Se0 treatment, and the yield per ha under the Se2, Se3, and Se4 treatments was 18.58%, 9.09%, and 21.42% higher than that under Se0 treatment, respectively. In addition, a reasonable combination of selenium application rate and density could improve the chlorophyll content and stem growth of dryland maize. This lays a foundation for the efficient application of selenium fertilizer and provides an important reference. [ABSTRACT FROM AUTHOR]

Seed‐based restoration of wetlands is often necessary to improve important ecosystem functions (e.g., invasion resistance and habitat provisioning) and meet society's need for wetland ecosystem services such as supporting recreational activities and improving water quality. However, persistent questions remain about the composition and sowing density of seed mixes needed to restore robust native wetland plant communities. In Great Salt Lake wetlands (Utah, USA), the revegetation of native species is crucial to recovering critical habitat and preventing reinvasion of the invasive, non‐native grass Phragmites australis and other invasive species (e.g., Typha spp.). In greenhouse and field experiments, we investigated the effects of seed mix composition and sowing density on plant community reassembly. We predicted that seed mixes containing native forb species with resource‐preempting traits (e.g., rapid seedling emergence and high aboveground growth rate) and high sowing densities (>5500 pure live seed m−2), would increase native plant light acquisition and establishment, thereby limiting invasive species. To our surprise, the effect of seed mix composition on native plant performance (cover and biomass) varied among the experiments, with distinct differences between plant functional groups arising. Native forb species had the highest performance in the greenhouse, but native grasses performed better in the field. Although multiple seed mix compositions show promise for establishing high native cover and biomass, these mixes may not always suppress invasive species. Interestingly, seed mix composition most often affected plant performance independent of sowing density. However, in one greenhouse experiment, we found that only slow‐growing mixes required a high sowing density to maximize native cover, an indication that the ideal sowing density may depend on the seed mix composition. Our research also supports the idea that in addition to reducing propagules of invasive species via appropriate management strategies, the application of higher sowing densities (>5500 pure live seed m−2) may lead to more favorable outcomes when a high density of invasive plant seeds remains or stressful field conditions are present. This research contributes to knowledge of plant community reestablishment in wetlands and demonstrates how seed‐based restoration strategies can catalyze native species revegetation and, in some situations, reduce the cover of invasive species. [ABSTRACT FROM AUTHOR]

Introduction: Oat (Avena nuda L.) and common vetch (Vicia sativa L.) intercropping in the northern regions of China has resulted in substantial production capabilities. However, there is currently a dearth of comprehensive research on whether this intercropping system can enhance productivity through increased sowing densities and underlying interspecies interaction mechanisms. Methods: A two-year field experiment was conducted in 2022 and 2023 to investigate the yield, biological efficiency, economic efficiency, and competition indicators of oats and common vetch in a high-density intercropping system. Two cropping patterns (monocropping and intercropping) and five sowing densities (D1: 4.5×106 plants ha-1; D2:5.4×106 plants ha-1; D3:6.3×106 plants ha-1; D4: 7.2×106 plants ha-1; andD5: 8.1×106 plants ha-1) were arranged in a randomizedblockdesign. Results: At the same sowing density, the intercropped oats exhibited greater grain yield than the monocultures. Increasing the oat sowing density significantly enhanced oat yield, with the D3 level in intercropping showing the highest yield increase, ranging from 30.98% to 31.85%, compared with the monoculture. The common vetch intercropping grain yield was maximized in the D2 treatment. The land equivalent ratio was maximized at the D2 level in both years and was significantly higher than D1, with the land equivalent coefficient, system productivity index, and percentage yield difference suggesting that increasing oat sowing densities improved the productivity of the intercropping system, with the best performance observed at the D2 level. For both years, the proportionate actual yield loss of oat was the highest at the D3 level; significantly surpassing D1, proportionate actual yield loss of common vetch and actual yield loss were the highest at level D2, both significantly surpassing D1. These indicates that appropriate densification contributes to the realization of the advantages of intercropping. With an increased oat sowing density, the economic benefits of the intercropping system were maximized at the D2 and D3 levels. Regarding intercropping competition, oat was the dominant crop under different sowing densities (Aggressivity for oat (AO)>0, relative crowding coefficient for oat (KO)>1, competition ratio for oat (CRO)>1), whereas common vetch was the inferior crop. Compared with the D1 level, the D2 level harmonized the aggressivity, competitive ratio, and relative crowding coefficients of oat and common vetch, significantly increasing crowding coefficient for common vetch (KV) and competition ratio for common vetch by 19.76% to 21.94% and 4.80% to 7.51%, respectively, while reducing KO and CRO. Discussion: This result suggests that in the intercropping of common vetch and oat in alpine regions, rational densification can harmonize interspecific competition and thus improve the biological efficiency and economic benefits of intercropping systems. [ABSTRACT FROM AUTHOR]

Atriplex nitens, which can easily grow in arid and saline conditions and produce high amounts of roughage and seed material, has been seen as an important advantage in both closing the forage deficit and bringing marginal areas into production. However, agronomic studies on the plant are limited, and there is no study revealing the effect of inter-row spacing on seed yield. For this purpose, for 2 years (2021-2022), a study was planned to determine the effect of inter-row spacings (22.5, 45.0 and 67.5 cm) on seed yield components in Atriplex nitens grown under unsoiled and rainfall conditions in Iğdır with arid climate. The study was established according to the randomized blocks experimental design with 3 replications. Some parameters showed significant differences according to inter-row spacing. The highest plant height (3.19 m), stem thickness (17.0 mm) and maturation time (192.3 days) were measured in the plots grown with 67.5 cm row spacing, and the highest seed yield (1315 kg/da), the highest stem yield (3970 kg/da) and the highest biological yield (5285 kg/da) in the plots grown with 22.5 cm row spacing. However, harvest index (28.94 - 29.36%) and bracteole thousand grain weight (10.71 - 11.49 g) were determined in the plots grown with 45.0 and 67.5 cm row spacings. When evaluated in terms of years, plant height was high in 2022, while maturation time, pericarp thousand grain weight and harvest index were found to be higher in 2021 when the amount of rainfall was high in the months corresponding to the generative phase of the plants. However, the other parameters examined were not affected by rainfall amounts that vary according to years. [ABSTRACT FROM AUTHOR]

This study was undertaken to examine the influence of the sowing date, sowing density, and split spring application of nitrogen (N) fertilizer on plant density, tillering, yield components, and grain yields of winter wheat (Triticum aestivum L.) grown in northeastern Poland between 2018 and 2021. The experiment had a split-plot design with three sowing dates (early (3–6 September), delayed by 14 days, and delayed by 28 days), three sowing densities (200, 300, and 400 live grains m−2), and three split spring N rates (40 + 100, 70 + 70, and 100 + 40 kg ha−1 applied in BBCH stages 22–25 and 30–31, respectively). The number of spikes m−2 increased by 11% on average when winter wheat was sown with a delay of 14 days (17–20 September) and 28 days (1–4 October). The number of spikes m−2 was highest when winter wheat was sown at 300 and 400 live grains m−2. The application of 100 + 40 kg N ha−1 (BBCH 22–25 and 30–31, respectively) increased the number of spikes m−2. An increase in sowing density from 200 to 300 to 400 live grains m−2 decreased the number of grains spike−1 by 5% and 7%, respectively. Thousand grain weight (TGW) increased by 1% and 2% when sowing was delayed by 14 (17–20 September) and 28 days (1–4 October), respectively. In northeastern Poland, grain yields peaked when winter wheat was sown between 17 September and 4 October (10.52–10.58 Mg ha−1). In late-sown winter wheat, grain yields increased due to a higher number of spikes m−2 and higher grain weight. The highest sowing density (400 live grains m−2) induced a greater increase in grain yields than the lowest sowing density (200 live grains m−2) (10.25 vs.10.02 Mg ha−1). In winter wheat sown at a density of 400 live grains m−2, the increase in grain yields resulted in a higher number of spikes m−2. Grain yields peaked in response to 100 kg N ha−1 applied in BBCH stages 22–25 and 40 kg N ha−1 applied in BBCH stages 30–31 (this split N rate increased the number of spikes m−2). In turn, the highest straw yield (6.23 Mg ha−1) was obtained when the second split of N fertilizer was applied in BBCH stages 30–31 (40 + 100 kg N ha−1). Straw yields decreased significantly (by 6%) when winter wheat was sown late (early October). Delayed sowing (mid-September and early October) increased the harvest index (HI) of winter wheat by 5–7%. Split spring N application influenced grain and straw yields, but it had no effect on the HI of winter wheat. [ABSTRACT FROM AUTHOR]

Copyright of Environmental & Social Management Journal / Revista de Gestão Social e Ambiental is the property of Environmental & Social Management Journal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract Seed‐based restoration of wetlands is often necessary to improve important ecosystem functions (e.g., invasion resistance and habitat provisioning) and meet society's need for wetland ecosystem services such as supporting recreational activities and improving water quality. However, persistent questions remain about the composition and sowing density of seed mixes needed to restore robust native wetland plant communities. In Great Salt Lake wetlands (Utah, USA), the revegetation of native species is crucial to recovering critical habitat and preventing reinvasion of the invasive, non‐native grass Phragmites australis and other invasive species (e.g., Typha spp.). In greenhouse and field experiments, we investigated the effects of seed mix composition and sowing density on plant community reassembly. We predicted that seed mixes containing native forb species with resource‐preempting traits (e.g., rapid seedling emergence and high aboveground growth rate) and high sowing densities (>5500 pure live seed m−2), would increase native plant light acquisition and establishment, thereby limiting invasive species. To our surprise, the effect of seed mix composition on native plant performance (cover and biomass) varied among the experiments, with distinct differences between plant functional groups arising. Native forb species had the highest performance in the greenhouse, but native grasses performed better in the field. Although multiple seed mix compositions show promise for establishing high native cover and biomass, these mixes may not always suppress invasive species. Interestingly, seed mix composition most often affected plant performance independent of sowing density. However, in one greenhouse experiment, we found that only slow‐growing mixes required a high sowing density to maximize native cover, an indication that the ideal sowing density may depend on the seed mix composition. Our research also supports the idea that in addition to reducing propagules of invasive species via appropriate management strategies, the application of higher sowing densities (>5500 pure live seed m−2) may lead to more favorable outcomes when a high density of invasive plant seeds remains or stressful field conditions are present. This research contributes to knowledge of plant community reestablishment in wetlands and demonstrates how seed‐based restoration strategies can catalyze native species revegetation and, in some situations, reduce the cover of invasive species.

During this study, an indoor experiment was conducted to determine the effect of mixed seeding rates of legumes used as green manure on the substrate fertilizer, growth characteristics, and bioactive compounds of baby leaf vegetables. The mixed seeding treatment was designed for milkvetch (Astragalus sinicus L.), tatsoi (Barassica rapa L.), kale (Brassica oleracea var. sabellica L.), and spinach (Spinacia oleracea L.) using five rates for each. Accordingly, a total of 15 treatments (3 baby leaf species × 5 mixed seeding rates) were constructed using a randomized complete block design with three replications for each treatment. During the baby leaf vegetable harvest, we evaluated the macronutrient levels (nitrogen, phosphorus, and potassium) in the substrate as well as the growth parameters and carotenoid contents. The substrate in the treatment mixed with milkvetch showed significantly higher levels of nitrogen, phosphorus, and potassium compared with those of tatsoi and kale sown alone (P ≤ 0.05). However, there were no significant differences in macronutrients observed in substrate-sown spinach with or without the milkvetch mixture. The growth and carotenoid levels of each baby leafy vegetable sown alone were significantly higher than those of each baby leafy vegetable sown with the mixed seeding treatment (P ≤ 0.05). Sowing the milkvetch–vegetable mixtures did not result in a significant increase in the growth and carotenoid levels of the three baby vegetables. The results showed that planting milkvetch with tatsoi and kale had a significant impact on substrate fertilization. However, regarding short-term vertical indoor farming, the growth and carotenoid responses of the three greens may be different. Nonetheless, we still believe that the combined interactions of legumes can provide long-term benefits by enhancing the biological functionality of the growing medium for balanced indoor agriculture production.

Copyright of COMU Journal of Agriculture Faculty / ÇOMÜ Ziraat Fakültesi Dergisi is the property of Canakkale Onsekiz Mart University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In the context of the Chinese government's policy guidance, there is black soil protection and ecological environment protection. The purpose of this paper is to solve the problem that the soil ecology of the black soil in Northeast China is changing year by year, and it is necessary to explore the sowing and fertilization strategy under the new situation; most Chinese growers rely excessively on their personal experience in the process of soybean sowing and fertilization. In this study, we used "Heihe 43" soybeans and used regression experimental design methods to analyze the effects of planting density, nitrogen, phosphorus, and potassium fertilizer application on soybean yield and to determine the optimal planting density and fertilizer ratios. The study reveals that the optimal soybean planting density in Northeast China is 45.37 × 104 plants/ha, with nitrogen at 98.4 kg/ha, phosphorus at 218.96 kg/ha, and potash at 47.62 kg/ha. Under these conditions, soybean yields can reach 3816.67 kg/ha. This study can provide a theoretical method for decision-making to obtain the optimal planting density and fertilizer ratio for different regions of the farming system. [ABSTRACT FROM AUTHOR]

Napier grass (Pennisetum purpureum Schumach) comprises up to 80% of the cattle diet in many tropical and subtropical regions and is used primarily by smallholder farmers. Despite the grass’s high yield, resulting animal productivity from this grass is low. One of the key reasons for the low animal productivity of Napier grass is its low nutritive value under current management. Taken together, previous work has shown the current yield, crude protein (CP), and metabolisable energy (ME) of Napier grass to be 26 t dry matter (DM)/ha/year, 96 g/kg DM, and 8.7 MJ/kg DM, respectively, ranging from 2 to 86 t DM/ha/year, 9 to 257 g CP/kg DM, and 5.9 to 10.8 MJ ME/kg DM, respectively, suggesting an opportunity for significant improvement on both yield and nutritive value of this grass. The DM yield and nutritive value of this grass are inversely related, indicating a trade-off between yield and quality; however, this trade-off could be minimised by increasing sowing density and harvesting frequency. Available literature shows that this simple management strategy of increasing sowing density (50 cm × 40 cm) and harvesting frequency (11–12 harvests/year) provides 71 t DM/ha with 135 g/kg DM CP and 10.8 MJ ME/kg DM. This quality of Napier grass has the potential to increase both milk and meat production substantially in the tropics and subtropics, and the farmers will likely find this simple management acceptable due to the high yield obtained through this management. However, there is a paucity of work in this field. Therefore, management strategies to improve the nutritive value of Napier grass are required to increase milk and meat production in the tropics and subtropics and in doing so improve the food security of more than half of the global population living in these regions. [ABSTRACT FROM AUTHOR]

The study analyzed the effect of nitrogen (N) management and different sowing parameters of winter wheat on the flour quality, rheological properties of flour, and bread quality. Flour was obtained from winter wheat grain produced during a field experiment conducted in 2018–2021. The experiment involved three factors: (i) the sowing date (early (3–6 September), delayed by 14 days, and delayed by 28 days), (ii) sowing density (200, 300, and 400 live grains m−2), and (iii) split application of N fertilizer in spring (40 + 100, 70 + 70, and 100 + 40 kg ha−1 in the full tillering stage and the first node stage, respectively). A 28-day delay in sowing increased the total protein content of the flour, water absorption capacity of the flour, dough development time and stability, and degree of softening. When sowing was delayed by 14 or 28 days, the crumb density decreased without affecting the loaf volume. A sowing density of 400 grains m−2 had a positive impact on the flour color, dough stability, and loaf volume. The flour color and dough stability were enhanced when N was applied at 100 + 40 kg ha−1, respectively. In turn, the total protein content of flour peaked when it was applied at 40 + 100 kg N ha−1. The quality of flour improved when winter wheat was sown at a density of 400 live grains m−2 with a delay of 14 or 28 days and supplied with 100 kg N ha−1 in the full tillering stage and 40 kg N ha−1 in the first node stage.

Exogenous selenium application could effectively improve the selenium absorption of crops affected by different climatic conditions due to changes in the planting environment and planting conditions. We planted maize at planting densities of 67,500 plants ha−1 (D1) and 75,000 plants ha−1 (D2). Five selenium fertilizer gradients of 0 mg m−2 (Se0), 7.5 mg m−2 (Se1), 15.0 mg m−2 (Se2), 22.5 mg m−2 (Se3), and 30.0 mg m−2 (Se4) were applied to investigate the response of the plants to selenium fertilizer application in terms of the gradient selenium absorption and substance accumulation. With the increase in the amount of selenium fertilizer applied, more of the selenium fertilizer will be absorbed and transported from the leaves to the grains, and the selenium content of the grains will gradually increase and exceed the selenium content of leaves. Under the D2 density in 2022, the selenium content of the grains under Se1, Se2, Se3, and Se4 treatments increased by 65.67%, 72.71%, and 250.53%, respectively, compared with that of Se0. A total of 260.55% of the plants showed a gradient of grain > leaf > cob > stalk from the Se2 treatment, and the overall selenium content of the plants increased first and then decreased. Under the D1 density, compared with the Se0, the dry matter mass of the Se1, Se2, Se3, and Se4 treatments significantly improved by 5.84%, 1.49%, and 14.26% in 2021, and significantly improved by 4.84%, 3.50%, and 2.85% in 2022. The 1000-grain weight under Se2, Se3, and Se4 treatments improved by 8.57%, 9.06%, and 15.56% compared to that under the Se0 treatment, and the yield per ha under the Se2, Se3, and Se4 treatments was 18.58%, 9.09%, and 21.42% higher than that under Se0 treatment, respectively. In addition, a reasonable combination of selenium application rate and density could improve the chlorophyll content and stem growth of dryland maize. This lays a foundation for the efficient application of selenium fertilizer and provides an important reference.

Napier grass (Pennisetum purpureum Schumach) comprises up to 80% of the cattle diet in many tropical and subtropical regions and is used primarily by smallholder farmers. Despite the grass’s high yield, resulting animal productivity from this grass is low. One of the key reasons for the low animal productivity of Napier grass is its low nutritive value under current management. Taken together, previous work has shown the current yield, crude protein (CP), and metabolisable energy (ME) of Napier grass to be 26 t dry matter (DM)/ha/year, 96 g/kg DM, and 8.7 MJ/kg DM, respectively, ranging from 2 to 86 t DM/ha/year, 9 to 257 g CP/kg DM, and 5.9 to 10.8 MJ ME/kg DM, respectively, suggesting an opportunity for significant improvement on both yield and nutritive value of this grass. The DM yield and nutritive value of this grass are inversely related, indicating a trade-off between yield and quality; however, this trade-off could be minimised by increasing sowing density and harvesting frequency. Available literature shows that this simple management strategy of increasing sowing density (50 cm × 40 cm) and harvesting frequency (11–12 harvests/year) provides 71 t DM/ha with 135 g/kg DM CP and 10.8 MJ ME/kg DM. This quality of Napier grass has the potential to increase both milk and meat production substantially in the tropics and subtropics, and the farmers will likely find this simple management acceptable due to the high yield obtained through this management. However, there is a paucity of work in this field. Therefore, management strategies to improve the nutritive value of Napier grass are required to increase milk and meat production in the tropics and subtropics and in doing so improve the food security of more than half of the global population living in these regions.

This research aims to evaluate the impact of durum-wheat sowing density on wetting front advancement and water infiltration rate along the furrow length. In addition, durum wheat yield and furrow irrigation performance under the different sowing densities were assessed. For that purpose, a field experiment was conducted under semi-arid conditions in Tunisia using four durum-wheat sowing densities: SD1 (250 seeds m−2), SD2 (350 seeds m−2), SD3 (450 seeds m−2) and SD0 (bare soil). The results reveal that water front advancement tends to be inversely proportional to sowing density. In fact, under the SD3 treatment, both irrigation duration and applied water volume increased about twofold compared to those recorded under SD0, resulting in an increasing soil infiltration rate. Furthermore, the two-point method performed well in estimating water front advancement, with an R2 value close to 1. Regarding durum wheat yield, values varied between 3.5 and 4.9 t ha−1 with the highest value attributed to the SD3 treatment. Meanwhile, higher irrigation water productivity was recorded under SD1. Considering irrigation performance indicators, the results indicate that distribution uniformity (DU) increases with increasing sowing density. Moreover, the lowest application efficiency values (75%) were recorded under the SD0 and SD3 treatments as compared to 82% for SD2 and 80% for SD1. [ABSTRACT FROM AUTHOR]

The key to high-yielding peanut cultivation is the optimization of agricultural production practices. Regulating single-seed precise sowing (SSPS) density and paclobutrazol (Pbz) application concentration are effective practices that increase peanut yield by improving plant architecture, lodging resistance, and photosynthetic characteristics. Therefore, we conducted a two-factor field optimization experiment for the sowing density (D1: 1.95 × 105 plants ha−1, D2: 2.40 × 105 plants ha−1, D3: 2.85 × 105 plants ha−1, and D4: 3.30 × 105 plants ha−1) and Pbz application concentration (P0: 0 mg L−1 and P1: 100 mg L−1). The objective was to optimize agricultural production practices and provide a theoretical basis for high-yielding peanut cultivation by evaluating the effects of sowing density and Pbz application on plant architecture, lodging resistance, photosynthetic characteristics, and yield. The results showed that at the same Pbz application concentration, increasing sowing density increased lodging percentage and reduced leaf photosynthetic capacity. At the same sowing density, Pbz application reduced lodging percentage by decreasing plant height (PH), improving lignin biosynthesis-related enzyme activities, and enhancing stem puncture strength (SPS) and breaking strength (SBS). The paclobutrazol-induced alterations in plant architecture and lodging resistance improved light transmission at the middle and bottom leaf strata, resulting in the increase in relative chlorophyll content and net photosynthetic rate (Pn) of leaves. Furthermore, D3P1 treatment had the highest peanut yield among all treatments. In summary, the production strategy combining the sowing density of 2.85 × 105 plants ha−1 with the application of 100 mg L−1 Pbz was found to be the optimal agricultural production practice for giving full play to production potential and achieving higher peanut yield.

This study was undertaken to examine the influence of the sowing date, sowing density, and split spring application of nitrogen (N) fertilizer on plant density, tillering, yield components, and grain yields of winter wheat (Triticum aestivum L.) grown in northeastern Poland between 2018 and 2021. The experiment had a split-plot design with three sowing dates (early (3–6 September), delayed by 14 days, and delayed by 28 days), three sowing densities (200, 300, and 400 live grains m−2), and three split spring N rates (40 + 100, 70 + 70, and 100 + 40 kg ha−1 applied in BBCH stages 22–25 and 30–31, respectively). The number of spikes m−2 increased by 11% on average when winter wheat was sown with a delay of 14 days (17–20 September) and 28 days (1–4 October). The number of spikes m−2 was highest when winter wheat was sown at 300 and 400 live grains m−2. The application of 100 + 40 kg N ha−1 (BBCH 22–25 and 30–31, respectively) increased the number of spikes m−2. An increase in sowing density from 200 to 300 to 400 live grains m−2 decreased the number of grains spike−1 by 5% and 7%, respectively. Thousand grain weight (TGW) increased by 1% and 2% when sowing was delayed by 14 (17–20 September) and 28 days (1–4 October), respectively. In northeastern Poland, grain yields peaked when winter wheat was sown between 17 September and 4 October (10.52–10.58 Mg ha−1). In late-sown winter wheat, grain yields increased due to a higher number of spikes m−2 and higher grain weight. The highest sowing density (400 live grains m−2) induced a greater increase in grain yields than the lowest sowing density (200 live grains m−2) (10.25 vs.10.02 Mg ha−1). In winter wheat sown at a density of 400 live grains m−2, the increase in grain yields resulted in a higher number of spikes m−2. Grain yields peaked in response to 100 kg N ha−1 applied in BBCH stages 22–25 and 40 kg N ha−1 applied in BBCH stages 30–31 (this split N rate increased the number of spikes m−2). In turn, the highest straw yield (6.23 Mg ha−1) was obtained when the second split of N fertilizer was applied in BBCH stages 30–31 (40 + 100 kg N ha−1). Straw yields decreased significantly (by 6%) when winter wheat was sown late (early October). Delayed sowing (mid-September and early October) increased the harvest index (HI) of winter wheat by 5–7%. Split spring N application influenced grain and straw yields, but it had no effect on the HI of winter wheat.

The article focuses on the cultivation of hemp (Cannabis sativa L.) for seed production, specifically examining the effects of different seeding densities and herbicidal control on weed infestation, plant characteristics, and nutrient content in the seeds. Hemp is a versatile plant known for its fiber and oil production, including health-promoting cannabinoids. The study utilizes a Romanian monoecious variety called Secuieni Jubileu, which has low THC content and is suitable for seed cultivation. The experiment compares three treatments: sowing at a density of 20 kg ha-1 with herbicide, sowing at a density of 30 kg ha-1 with herbicide, and sowing at a density of 30 kg ha-1 without herbicide. The results indicate significant differences in weed density among the treatments, with herbicide application and higher seeding density reducing weed populations. Plant height, number of leaves, and seed fraction also varied significantly among the treatments, with higher seeding density (30 kg ha-1) resulting in higher plants, decreased leaf number and with the predominant fraction of 2.5 mm in the seeds. The experimental factor also significantly differentiated the macro- and micronutrient content of hemp seeds. Nutrient content analysis revealed variations in nitrogen, potassium, phosphorus, and magnesium levels in the hemp seeds, depending on the experimental treatments. Overall, the study highlights the importance of seeding density and herbicidal control in hemp cultivation for seed production. The findings suggest that higher seeding density can effectively suppress weed growth, whereas the yield and the high ratio of seed fraction at 2.8 mm is attributed to herbicide control and seed density of 20 kg ha-1. The research contributes to the understanding of optimal cultivation practices for hemp seed production, aiming to support stable, efficient, and profitable agricultural production in the field. [ABSTRACT FROM AUTHOR]

Hemp fibers produced by different extraction techniques that were cultivated in the Portuguese districts of Bragança and Mirandela under various nitrogen fertilization and planting density conditions are examined and mechanically described in this paper. The objective of this study is to evaluate the influence of sowing density, nitrogen fertilization, sample location, and extraction method in order to improve the mechanical properties of hemp fibers. To achieve this, we determined the modulus of elasticity, the tensile strength, and the density. The mean value for the modulus of elasticity was 92.44 ± 7.44 GPa, the mean of tensile strength was 564.98 ± 167.03 MPa, and the mean of the density was 1.64 ± 0.24 g cm−3. We performed a statistical analysis of all parameters using ANOVA and found that the retting method had the greatest influence among all parameters. The associated effects of nitrogen fertilization and sowing density revealed an important influence on tensile strength and specific tensile strength, respectively. [ABSTRACT FROM AUTHOR]

Influence of agroclimatic conditions on active substances content in hemp cultivated in the South-East Baltic region Abstract: Due to legal regulations prohibiting cultivation of cannabis (Cannabis indica Lam.) in many countries, industrial hemp (Cannabis sativa L.) remains the main source of active substances with potential application in the pharmaceutical industry. To assess the possibility of using the varieties of industrial hemp for this goal, and their adaptation to the habitat conditions and the agricultural technology appropriate for them, we investigated three monoecious varieties of hemp (‘Futura 75,’ ‘KC Dora’ and ‘Tygra’) at different sowing densities (60 germinating seeds·1 m2 or 180 germinating seeds·1 m2) and nitrogen fertilization levels (0, 30, 60, 90 kg·ha−1). In none of the tested hemp varieties registered as fibrous did the concentration of Δ9-THC exceed 0.2%, satisfying the requirements of European legislation for industrial hemp varieties. The tested varieties did not differ significantly in the cannabidiol (CBD) and Δ9- tetrahydrocannabinol (Δ9 -THC) content in the dry matter of inflorescences. Agronomic factors such as sowing density or nitrogen fertilization did not modify the content of CBD and Δ9-THC. This result is very helpful for farmers, because it allows them to select hemp varieties of dual-purpose production (stems and inflorescences or stems and seeds) adapted to the South-East Baltic environment.

The study aims to investigate industrial hemp growing potential in the Nordic-Baltic region, to assess the impact of various agrotechnological measures on macro: calcium, magnesium, potassium, phosphorus, and micronutrient: boron, iron, manganese, copper, zinc accumulation in hemp seeds, and to determine biologically active compounds and beneficial elements: elements cobalt, aluminum, sodium accumulation trends. Obtained results indicate that hemp seeds are rich in K (0.69–0.90%) followed by P (0.41–0.51%), Mg (0.42–0.46%), and Ca (0.10–0.19%). It was determined that Fe (181–334 mg/kg) was the main abundant microelement followed by Mn (58–81 mg/kg), Zn (55–68 mg/kg), Cu (13–20 mg/kg), and B (7–16 mg/kg) independently from applied agrotechnological measures. The amount of biologically active compounds ranged from 6.55 to 12.39 mg/gRUE and from 2.52 to 4.74 mg/gRUE, respectively, for TPC and TFC. A significant amount of beneficial elements Al (6.0–12.6 mg/kg) and Na (0.90–16.1 mg/kg) except Co were obtained. Results presented in this study indicate that seeds of industrial hemp grown in the Nordic-Baltic region could be considered as an important source of essential minerals and biologically active compounds.

The sowing date and density are considered to be the main factors affecting crop yield. The determination of the sowing date and sowing density, however, is fraught with uncertainty due to the influence of climatic conditions, topography, variety and other factors. Therefore, it is necessary to find a comprehensive consideration of these factors to guide the production of winter rapeseed. A reliable crop model could be a crucial tool to investigate the response of rapeseed growth to changes in the sowing date and density. At present, few studies related to rapeseed model simulation have been reported, especially in the comprehensive evaluation of the effects of sowing date and density factors on rapeseed development and production. This study aimed to evaluate the performance of the AquaCrop model for winter rapeseed development and yield simulation under various sowing dates and densities, and to optimize the sowing date and density for agricultural high-efficient production in the Jianghuai Plain. Two years of experiments were carried out in the rapeseed growing season in 2020 and 2021. The model parameters were fully calibrated and the simulation performances in different treatments of sowing dates and densities were evaluated. The results indicated that the capability of the AquaCrop model to interpret crop development for different sowing dates was superior to that of sowing densities. For rapeseed canopy development, the RMSE for three sowing dates and densities scenarios were 7–22% and 16–23%, respectively. The simulated biomass and grain yield for different sowing dates treatments (RMSE: 0.8–2.1 t·ha−1, Pe: 0–35.3%) were generally better than those of different densities treatments (RMSE: 0.7–3.9 t·ha−1, Pe: 8.2–90%). Compared with other sowing densities, higher overestimation errors of the biomass and yield were observed for the low-density treatment. Adequate agreement for crop evapotranspiration simulation was achieved, with an R2 of 0.79 and RMSE of 26 mm. Combining the simulation results and field data, the optimal sowing scheme for achieving a steadily high yield in the Jianghuai Plain of east China was determined to be sowing in October and a sowing density of 25.0–37.5 plant·m−2. The study demonstrates the great potential of the AquaCrop model to optimize rapeseed sowing patterns and provides a technical means guidance for the formulation of local winter rapeseed production. [ABSTRACT FROM AUTHOR]

In the context of the Chinese government’s policy guidance, there is black soil protection and ecological environment protection. The purpose of this paper is to solve the problem that the soil ecology of the black soil in Northeast China is changing year by year, and it is necessary to explore the sowing and fertilization strategy under the new situation; most Chinese growers rely excessively on their personal experience in the process of soybean sowing and fertilization. In this study, we used “Heihe 43” soybeans and used regression experimental design methods to analyze the effects of planting density, nitrogen, phosphorus, and potassium fertilizer application on soybean yield and to determine the optimal planting density and fertilizer ratios. The study reveals that the optimal soybean planting density in Northeast China is 45.37 × 104 plants/ha, with nitrogen at 98.4 kg/ha, phosphorus at 218.96 kg/ha, and potash at 47.62 kg/ha. Under these conditions, soybean yields can reach 3816.67 kg/ha. This study can provide a theoretical method for decision-making to obtain the optimal planting density and fertilizer ratio for different regions of the farming system.

Wheat is a grass, originally from the Fertile Crescent region of the Near East, but now cultivated worldwide. The paper presents the results obtained in the last two years of experience, about the influence of sowing technology on the ponderal features of the winter wheat seeds. The experimental parcels were laid down in a randomized complete block design with three replications in the pedo-climatic conditions of Timişoara. The purpose of the research is to determine the influence of some sowing links on the thousand grain mass and hectoliter mass. The average data obtained after two years of study indicate an increase of about 2 % of the thousand grain mass and hectoliter mass on the second sowing period (16-31 October)and a distinctive decrease of 2-3% on the fourth sowing period(16-30 November). During the two years of experience the row distance and the sowing density had a negative impact on both thousand grain mass and hectoliter mass in both variants compared with the control variant, the difference being statistical significant.

Sunflower is one of the pioneer crops cultivated in salt-affected arid areas. The influences of sowing density on the growth performance of this crop under fertigation conditions have not been well studied. This study arranged four sowing density treatments, 41,667, 35,714, 31,250, and 27,778 plants ha−1, marked as D30, D35, D40, and D45, respectively, to reveal the relationships between soil salinity, growth performance, and sowing density under drip fertigation conditions. The results showed that the electrical conductivity of saturated paste extracts (ECe) decreased during the growing seasons but increased on the topsoil during the non-growing seasons in all of the treatments. The sowing densities had remarkable influences on the ECe in the 0–40 cm soil layer (ECe-40). The average ECe-40 during the two seasons for treatments D30–D45 correspondingly decreased by 7.0%, 33.9%, 11.1%, and 15.8% when compared to the original value. The soil pH in the 0–40 cm soil layer during the two seasons for treatments D30–D45 correspondingly decreased by −0.03, 0.20, 0.20, and 0.27 when compared to the original value. Increasing the spacing in the rows could promote the stem diameter, plant biomass, and proportion of biomass allocated underground. The yield and related yield components in this experiment under fertigation were significantly higher than those under surface irrigation. A sowing density between 31,250 and 35,714 plants ha−1 could ensure both the high yield and high morphological quality of the seeds, which could be recommended for sunflower cultivation under drip fertigation conditions. [ABSTRACT FROM AUTHOR]

The study aims to investigate industrial hemp growing potential in the Nordic-Baltic region, to assess the impact of various agrotechnological measures on macro: calcium, magnesium, potassium, phosphorus, and micronutrient: boron, iron, manganese, copper, zinc accumulation in hemp seeds, and to determine biologically active compounds and beneficial elements: elements cobalt, aluminum, sodium accumulation trends. Obtained results indicate that hemp seeds are rich in K (0.69-0.90%) followed by P (0.41-0.51%), Mg (0.42-0.46%), and Ca (0.10-0.19%). It was determined that Fe (181-334 mg/kg) was the main abundant microelement followed by Mn (58-81 mg/kg), Zn (55-68 mg/kg), Cu (13-20 mg/kg), and B (7-16 mg/kg) independently from applied agrotechnological measures. The amount of biologically active compounds ranged from 6.55 to 12.39 mg/gRUE and from 2.52 to 4.74 mg/gRUE, respectively, for TPC and TFC. A significant amount of beneficial elements Al (6.0-12.6 mg/kg) and Na (0.90-16.1 mg/kg) except Co were obtained. Results presented in this study indicate that seeds of industrial hemp grown in the Nordic-Baltic region could be considered as an important source of essential minerals and biologically active compounds. [ABSTRACT FROM AUTHOR]

Influence of agroclimatic conditions on active substances content in hemp cultivated in the South-East Baltic region Abstract: Due to legal regulations prohibiting cultivation of cannabis (Cannabis indica Lam.) in many countries, industrial hemp (Cannabis sativa L.) remains the main source of active substances with potential application in the pharmaceutical industry. To assess the possibility of using the varieties of industrial hemp for this goal, and their adaptation to the habitat conditions and the agricultural technology appropriate for them, we investigated three monoecious varieties of hemp ('Futura 75,' 'KC Dora' and 'Tygra') at different sowing densities (60 germinating seeds·1 m2 or 180 germinating seeds·1 m2) and nitrogen fertilization levels (0, 30, 60, 90 kg·ha−1). In none of the tested hemp varieties registered as fibrous did the concentration of Δ9-THC exceed 0.2%, satisfying the requirements of European legislation for industrial hemp varieties. The tested varieties did not differ significantly in the cannabidiol (CBD) and Δ9- tetrahydrocannabinol (Δ9 -THC) content in the dry matter of inflorescences. Agronomic factors such as sowing density or nitrogen fertilization did not modify the content of CBD and Δ9-THC. This result is very helpful for farmers, because it allows them to select hemp varieties of dual-purpose production (stems and inflorescences or stems and seeds) adapted to the South-East Baltic environment. [ABSTRACT FROM AUTHOR]

Sowing native seeds is a common approach to reintroduce native plants to degraded systems. However, this method is often overlooked in wetland restoration despite the immense global loss of diverse native wetland vegetation. Developing guiding principles for seed‐based wetland restoration is critical to maximize native plant recovery, particularly in previously invaded wetlands. Doing so requires a comprehensive understanding of how restoration manipulations, and their interactions, influence wetland plant community assembly. With a focus on the invader Phragmites australis, we established a series of mesocosm experiments to assess how native sowing density, invader propagule pressure, abiotic filters (water and nutrients), and native sowing timing (i.e., priority effects) interact to influence plant community cover and biomass in wetland habitats. Increasing the density of native seeds yielded higher native cover and biomass, but P. australis suppression with increasing sowing densities was minimal. Rather, community outcomes were largely driven by invader propagule pressure: P. australis densities of ≤500 seeds/m2 maintained high native cover and biomass. Low‐water conditions increased the susceptibility of P. australis to dominance by native competitors. Early sowing of native seeds showed a large and significant benefit to native cover and biomass, regardless of native sowing density, suggesting that priority effects can be an effective restoration manipulation to enhance native plant establishment. Given the urgent wetland restoration need combined with the limited studies on seed‐based wetland restoration, these findings provide guidance on restoration manipulations that are grounded in ecological theory to improve seed‐based wetland restoration outcomes. [ABSTRACT FROM AUTHOR]

Intercropping, i.e., growing several species in the same field for a major part of their growing periods, often improves yield and weed control, but their performance greatly varies across situations. The aim of this study was to evaluate the effects of bi-species legume–cereal intercrops on weed dynamics and their impact on crop production, in the absence of nitrogen or water stress, via simulations with F lor S ys. This individual-based 3D model simulates daily crop–weed seed and plant dynamics over the years, from cropping system and pedoclimate, focusing on competition for light. The study tested seven species proportions in two species mixtures (wheat–faba bean and barley–pea) and nine spatial sowing patterns in three species mixtures (triticale–faba bean, wheat–faba bean, wheat–pea), in both cases comparing the intercrops with the corresponding sole crops (controls). Intercrops and controls were inserted into rotations and simulated over 30 years and repeated with 10 climate scenarios from South-Western France, either with or without weeds. The simulations showed that: (1) the intercrops that best controlled weeds were barley–pea and triticale–faba bean, (2) the spatial pattern alternating one cereal row with one legume row as well as the 67 %-cereal–33 %-legume and 100 %-cereal–50 %-legume species proportions were those that maximised yields and minimised losses due to weeds, (3) the weed biomass in intercrop was greater than or equal to that of the sole cereal, and less than that of the sole legume, and (4) legumes benefitted more from intercropping than cereals because cereals are more competitive against weeds. Intercrop yield was best when combining species with contrasting shading responses (etiolated with stockier plants, leafy with stemmier plants) but early and good plant emergence was essential, particularly for weed suppression. • 4 legume–cereal intercrops were simulated with 7 proportions or 9 sowing patterns. • Intercrops suppressed weeds better than legumes, but not always as well as cereals. • Yields and weed control were best when alternating 1 cereal row with 1 legume row. • 67 %-cereal–33 %-legume and 100 %-cereal–50 %-legume species proportions were best. • Combining stocky with etiolated plants and leafy with stemmy plants increased yield. [ABSTRACT FROM AUTHOR]

This research aims to evaluate the impact of durum-wheat sowing density on wetting front advancement and water infiltration rate along the furrow length. In addition, durum wheat yield and furrow irrigation performance under the different sowing densities were assessed. For that purpose, a field experiment was conducted under semi-arid conditions in Tunisia using four durum-wheat sowing densities: SD1 (250 seeds m−2), SD2 (350 seeds m−2), SD3 (450 seeds m−2) and SD0 (bare soil). The results reveal that water front advancement tends to be inversely proportional to sowing density. In fact, under the SD3 treatment, both irrigation duration and applied water volume increased about twofold compared to those recorded under SD0, resulting in an increasing soil infiltration rate. Furthermore, the two-point method performed well in estimating water front advancement, with an R2 value close to 1. Regarding durum wheat yield, values varied between 3.5 and 4.9 t ha−1 with the highest value attributed to the SD3 treatment. Meanwhile, higher irrigation water productivity was recorded under SD1. Considering irrigation performance indicators, the results indicate that distribution uniformity (DU) increases with increasing sowing density. Moreover, the lowest application efficiency values (75%) were recorded under the SD0 and SD3 treatments as compared to 82% for SD2 and 80% for SD1.

Crop multi-model ensembles (MME) have proven to be effective in increasing the accuracy of simulations in modelling experiments. However, the ability of MME to capture crop responses to changes in sowing dates and densities has not yet been investigated. These management interventions are some of the main levers for adapting cropping systems to climate change. Here, we explore the performance of a MME of 29 wheat crop models to predict the effect of changing sowing dates and rates on yield and yield components, on two sites located in a high-yielding environment in New Zealand. The experiment was conducted for 6 years and provided 50 combinations of sowing date, sowing density and growing season. We show that the MME simulates seasonal growth of wheat well under standard sowing conditions, but fails under early sowing and high sowing rates. The comparison between observed and simulated in-season fraction of intercepted photosynthetically active radiation (FIPAR) for early sown wheat shows that the MME does not capture the decrease of crop above ground biomass during winter months due to senescence. Models need to better account for tiller competition for light, nutrients, and water during vegetative growth, and early tiller senescence and tiller mortality, which are exacerbated by early sowing, high sowing densities, and warmer winter temperatures. [ABSTRACT FROM AUTHOR]

Oat has been gaining renewed interest due to its role in a healthy human diet, in animal feed, and as a source of high value compounds with industrial applications. Nitrogen fertilization and planting density are two of the most important crop management practices that affect the formation of yield components and final yield of oat. A 2 year 3 × 5 factorial field experiment was conducted to investigate the effects of nitrogen (N) fertilizer and planting density on the flag leaf photosynthetic characteristics, grain yield, and yield components under rainfed conditions. The experiment consisted of three sowing densities (60, 180, and 300 kg·ha−1) and five nitrogen fertilizer rates (0, 45, 90, 135, and 180 kg·ha−1). Results showed that the grain yield was significantly (p < 0.05) correlated with the leaf net photosynthesis rate (Pn), stomatal conductance (Gs), intercellular CO2 concentration (Ci), transpiration rate (Tr), water-use efficiency (WUE), stomatal limitation value (Ls), chlorophyll content (SPAD value), leaf area index (LAI), panicle length, number of spikelets per panicle (NSP), number of grains per panicle (NGP), weight of grains per panicle (WGP), and 1000-kernel weight. Among the yield components, grain yield was driven by number of spikelets per panicle (NSP) and number of grains per panicle (NGP) at low (or high) planting density with low N supply, whereas, at high N supply, 1000-kernel weight was also an important factor for yield. Nitrogen fertilizer and sowing density had significant (p < 0.05) effects on the flag leaf photosynthetic characteristics, grain yield, and yield components of oat. The yield components increased and then decreased with the increase in nitrogen fertilizer, while they decreased with the increase in planting density. The maximum values (p < 0.05) of grain yield were observed in the nitrogen fertilization of 90 kg·ha−1 and sowing density of 180 kg·ha−1 treatment in both growing seasons, mainly contributing to the improved leaf photosynthesis traits (Pn, Gs, Tr, Ls, SPAD, and LAI). The combination of nitrogen fertilization of 90 kg·ha−1 and sowing density of 180 kg·ha−1 is suitable for oat production on a cool semiarid plateau or other agroecozones with similar environmental conditions. [ABSTRACT FROM AUTHOR]

Appropriate agrotechnical measures make it possible to optimise plant cultivation and obtain yields of the highest quality with an appropriate economic production index. The aim of the study was to evaluate different sowing density and row spacing on the morphological and mechanical properties of white lupine (Lupinus albus L.) seeds. The field experiment was conducted at the Experimental Station for Variety Evaluation in Przecław (50°11'25.2" N, 21°28'55.0" E). The experiment was established at two row spacings (15 cm and 30 cm) and three sowing densities (60, 75, 90 plants per m²). Mechanical parameters evaluated included destructive force FD (N), relative deformation DR (%) and destructive energy ED (mJ). Seed morphological properties such as weight, length and width were also assessed. Sphericity was also calculated. In the present study, improvements in the mechanical properties of the seeds were obtained by increasing the plant density per unit area of the experiment. In the case of morphological characteristics, only the weight of the analysed lupine seeds changed significantly as a result of row spacing. On the other hand, sowing density did not significantly affect morphological traits. of white lupine seeds. Apart from the spacing and sowing density of plants, the weather conditions in particular years of research were an important factor determining the properties of seeds. Determining the optimum sowing density and row spacing in the field contributes to the optimisation of the production process. Quasi-static mechanical tests are often used to obtain reasonable data on the physical properties of plant materials. [ABSTRACT FROM AUTHOR]

Pea is one of the most important legumes grown in the world. The seeds are used for food production and animal feed. The problem with its cultivation is the low yield and sensitivity to the course of the weather. The important factor is to determine the optimal sowing rate and row spacing, especially for new cultivars of pea. Therefore, research was undertaken to assess the effect of row spacing and sowing density on selected physiological parameters, yielding, and structural elements of peas cv. 'Batuta' in Poland. The results of the research showed that the row spacing and sowing density determine the values of plant physiological parameters, yield of pea seeds and protein content. The increase in plant density in the canopy caused a decrease in the measured parameters of chlorophyll fluorescence, such as maximum quantum yield of photosystem II (Fv/Fm) and maximum quantum yield of primary photochemistry (Fv/F0) and performance index (PI). The leaf area index (LAI) was lower with a wider row spacing. Row spacing and plant density determined yield of pea seeds, number of pods and seeds per plant and weight of seeds per plant. Wider row spacing resulted in a decrease in the protein content in seeds, while an increase in sowing density from 70 to 110 m² caused its increase. The course of the weather during the vegetation period of plants significantly influenced the obtained results. [ABSTRACT FROM AUTHOR]

Mechanized transplanting of rapeseed (Brassica napus L.) blanket seedling is an effective strategy to cope with the seasonal conflict and large labor cost in rapeseed production. The sowing density is a key factor to cultivate high-quality seedlings suitable for mechanized transplanting. An experiment was conducted to investigate the effects of different sowing density levels of 638, 696, 754, 812, 870 and 928 seeds per tray (referred as D1, D2, D3, D4, D5 and D6, respectively) on agronomic traits and survival rate after mechanized transplanting of two rapeseed cultivars (Zheyouza108 and Heza17) in 2020 and 2021. The results showed that high sowing density increased plant height but decreased leaf area, collar diameter, biomass accumulation, the ratio of root to shoot and seedling fullness. These negative effects jointly decreased the seedling rate and survival rate after mechanized transplanting. However, the seedlings under D1 and D2 posed a great plant survival rate of more than 95% after mechanized transplanting, suggesting that the seedlings under the two densities were perfect for mechanized transplanting. In addition, hierarchical analysis grouped D1 and D2 into the same class, indicating that their seedling qualities were not significantly different, though the blanket seedlings under D1 outperformed those under D2 in some traits. A sowing density of 696 seeds per tray (D2) is then recommended in this study, altogether considering its high-quality seedlings suitable for mechanized transplanting, and economically, fewer seedling trays required. [ABSTRACT FROM AUTHOR]

White sweet clover (Melilotus albus) cultivation, despite its many positive features such as the high yield of green mass, as well as protein content, is currently not widespread. This study aimed to determine the effect of the different sowing densities (500, 1000, and 1500 seeds per m2) and harvesting at different growth stages (before budding, budding, and full flowering) on the quality of fodder from the white sweet clover (Adela variety). The field experiment was carried out in the years 2018–2020 in a split-plot design. Plant biometric measurements, green and dry yield, the content of total protein, crude fat, crude fiber, ash, macro and microelements, and coumarin content were determined. The results show that an increase in the sowing density significantly increased the plant population after emergence and green and dry matter. However, it does not affect the total protein, crude fat, crude fiber, ash, macro and microelements, and coumarin content. Harvesting plants at the flowering stage increased plant height and green fodder yield. Plants harvested at the prebudding phase were characterized by the highest share of leaves (40.3%) and were the most abundant in protein (21.7%) and minerals (ash content 12.71%). Unfortunately, sweet clover at this growth stage contained the highest level of coumarin, which limits its use in animal feed. [ABSTRACT FROM AUTHOR]

About half of all barley areas are concentrated in the North Caucasus, where grain production has historically specialized in its use for fodder purposes. However, for brewing, it is not so much the quantity but rather the quality of barley grain as a raw material that is important. This work is devoted to comparing the parameters of the density of sowing seeds with different levels of mineral nutrition, depending on their size, taking into account their influence on the brewing qualities of barley grain, malt, and beer wort in the foothill zone of the Kabardino-Balkarian Republic (Russia). The conducted studies allowed establishing that both in winter and spring varieties, an increase in the density of sowing from 450 to 550 seeds/m2 was accompanied by a slight decrease in grain size. The extractivity was noticeably higher against the nitrogen, phosphorus, and potassium background in both forms of barley. It was determined that as the density of sowing increased, the solubility of malt protein decreased. It negatively correlated with the protein content in malt, i.e. as the density of sowing increased, malt contained more protein, but the degree of protein transition to wort decreased. It has been established that the best quality of malting barley and wort grains are noted at a stem density of 500 seeds/m2 against the nitrogen, phosphorus, and potassium background. [ABSTRACT FROM AUTHOR]

Selection of appropriate sowing density is an important yield enhancing management decision in maize (Zea mays L.) production particularly in rainfed conditions. This study aimed at evaluating the optimum stand densities (OSDs) of 10 recently released maize varieties under different crop management decisions and environments. Ten maize varieties of varying characteristics were planted in the Northern Guinea Savanna of Nigeria across 30 farmer's fields in the rainy seasons of 2016 and 2017 under three stand densities: 2.6, 5.3, and 6.6 plants m−2. Grain yield and yield components were greatest under the high density in both years across all locations. The intermediate maturing varieties produced higher grain yields compared to the early and late maturing varieties in both years and locations. The environmental indices from the Factor Analytic Model showed 20% of the fields were optimal, 28.3% moderate, 31.7% poor, and 20% were very poor environments. Increasing planting density did not significantly affect the grain yield of the varieties in very poor environments. A linear increase in grain yield was observed in moderate and optimum environments with every increase in stand density for all varieties except Sammaz 32, however, optimum planting densities could not be reached for all the varieties. Therefore, tropical maize varieties should be planted under specific densities that account for environmental and management conditions to maximize yield.

In this paper, we investigate the effect of seeding density on several morphological features such as plant height, height of the production ears, ear length, ear diameter, leaf area, and LAI (leaf area index). Inference is based on a series of three-year two-factor experiments with two hybrid maize varieties – SY Cooky and Drim "stay-green" type – and 5 sowing densities: 6, 7, 8, 9 and 10 plants per m2. The "stay-green" maize variety had production cobs significantly higher on the plant, and had a thicker cob and a larger leaf assimilation area than the conventional variety. Increasing maize sowing density from 6 to 10 plants m−2 resulted in a linear decrease in cob length and diameter, while it increased the LAI. Significantly higher chlorophyll content, expressed in SPAD units, was found in the "stay-green" hybrid at the BBCH 67 stage in a wet (2012) and drier year (2014), compared with the traditional variety. This may indicate that such a variety is more tolerant to stress conditions. [ABSTRACT FROM AUTHOR]

A study was carried out to determine the effect of sowing density on the yield of maize of two different varieties. The field experiment was carried out in 2012–2014 at the Department of Agronomy of Poznań University of Life Sciences. The first-order factor was the variety: SY Cooky and Drim "stay-green"; the second-order factor was sowing density: 6, 7, 8, 9, 10 plants per m2. Weather conditions during the maize growing seasons significantly influenced the values of the studied traits. Significantly the lowest green mass yield of maize was obtained at the sowing density of 6 plants m−2, and the highest for 10 plants m−2. The "stay-green" variety significantly responded to an increase in sowing density with reduced fresh weight of leaf blades of a single plant compared with the conventional variety. This indicated highly effective photosynthesis with a lower plant density per unit area, which is also the basis for effective absorption of solar radiation for these maize varieties. [ABSTRACT FROM AUTHOR]

The sowing date and density are considered to be the main factors affecting crop yield. The determination of the sowing date and sowing density, however, is fraught with uncertainty due to the influence of climatic conditions, topography, variety and other factors. Therefore, it is necessary to find a comprehensive consideration of these factors to guide the production of winter rapeseed. A reliable crop model could be a crucial tool to investigate the response of rapeseed growth to changes in the sowing date and density. At present, few studies related to rapeseed model simulation have been reported, especially in the comprehensive evaluation of the effects of sowing date and density factors on rapeseed development and production. This study aimed to evaluate the performance of the AquaCrop model for winter rapeseed development and yield simulation under various sowing dates and densities, and to optimize the sowing date and density for agricultural high-efficient production in the Jianghuai Plain. Two years of experiments were carried out in the rapeseed growing season in 2020 and 2021. The model parameters were fully calibrated and the simulation performances in different treatments of sowing dates and densities were evaluated. The results indicated that the capability of the AquaCrop model to interpret crop development for different sowing dates was superior to that of sowing densities. For rapeseed canopy development, the RMSE for three sowing dates and densities scenarios were 7–22% and 16–23%, respectively. The simulated biomass and grain yield for different sowing dates treatments (RMSE: 0.8–2.1 t·ha−1, Pe: 0–35.3%) were generally better than those of different densities treatments (RMSE: 0.7–3.9 t·ha−1, Pe: 8.2–90%). Compared with other sowing densities, higher overestimation errors of the biomass and yield were observed for the low-density treatment. Adequate agreement for crop evapotranspiration simulation was achieved, with an R2 of 0.79 and RMSE of 26 mm. Combining the simulation results and field data, the optimal sowing scheme for achieving a steadily high yield in the Jianghuai Plain of east China was determined to be sowing in October and a sowing density of 25.0–37.5 plant·m−2. The study demonstrates the great potential of the AquaCrop model to optimize rapeseed sowing patterns and provides a technical means guidance for the formulation of local winter rapeseed production.

Sunflower is one of the pioneer crops cultivated in salt-affected arid areas. The influences of sowing density on the growth performance of this crop under fertigation conditions have not been well studied. This study arranged four sowing density treatments, 41,667, 35,714, 31,250, and 27,778 plants ha−1, marked as D30, D35, D40, and D45, respectively, to reveal the relationships between soil salinity, growth performance, and sowing density under drip fertigation conditions. The results showed that the electrical conductivity of saturated paste extracts (ECe) decreased during the growing seasons but increased on the topsoil during the non-growing seasons in all of the treatments. The sowing densities had remarkable influences on the ECe in the 0–40 cm soil layer (ECe-40). The average ECe-40 during the two seasons for treatments D30–D45 correspondingly decreased by 7.0%, 33.9%, 11.1%, and 15.8% when compared to the original value. The soil pH in the 0–40 cm soil layer during the two seasons for treatments D30–D45 correspondingly decreased by −0.03, 0.20, 0.20, and 0.27 when compared to the original value. Increasing the spacing in the rows could promote the stem diameter, plant biomass, and proportion of biomass allocated underground. The yield and related yield components in this experiment under fertigation were significantly higher than those under surface irrigation. A sowing density between 31,250 and 35,714 plants ha−1 could ensure both the high yield and high morphological quality of the seeds, which could be recommended for sunflower cultivation under drip fertigation conditions.

Oat has been gaining renewed interest due to its role in a healthy human diet, in animal feed, and as a source of high value compounds with industrial applications. Nitrogen fertilization and planting density are two of the most important crop management practices that affect the formation of yield components and final yield of oat. A 2 year 3 × 5 factorial field experiment was conducted to investigate the effects of nitrogen (N) fertilizer and planting density on the flag leaf photosynthetic characteristics, grain yield, and yield components under rainfed conditions. The experiment consisted of three sowing densities (60, 180, and 300 kg·ha−1) and five nitrogen fertilizer rates (0, 45, 90, 135, and 180 kg·ha−1). Results showed that the grain yield was significantly (p < 0.05) correlated with the leaf net photosynthesis rate (Pn), stomatal conductance (Gs), intercellular CO2 concentration (Ci), transpiration rate (Tr), water-use efficiency (WUE), stomatal limitation value (Ls), chlorophyll content (SPAD value), leaf area index (LAI), panicle length, number of spikelets per panicle (NSP), number of grains per panicle (NGP), weight of grains per panicle (WGP), and 1000-kernel weight. Among the yield components, grain yield was driven by number of spikelets per panicle (NSP) and number of grains per panicle (NGP) at low (or high) planting density with low N supply, whereas, at high N supply, 1000-kernel weight was also an important factor for yield. Nitrogen fertilizer and sowing density had significant (p < 0.05) effects on the flag leaf photosynthetic characteristics, grain yield, and yield components of oat. The yield components increased and then decreased with the increase in nitrogen fertilizer, while they decreased with the increase in planting density. The maximum values (p < 0.05) of grain yield were observed in the nitrogen fertilization of 90 kg·ha−1 and sowing density of 180 kg·ha−1 treatment in both growing seasons, mainly contributing to the improved leaf photosynthesis traits (Pn, Gs, Tr, Ls, SPAD, and LAI). The combination of nitrogen fertilization of 90 kg·ha−1 and sowing density of 180 kg·ha−1 is suitable for oat production on a cool semiarid plateau or other agroecozones with similar environmental conditions.

This paper is focused on dependence of corn yield on plant density at harvest time and the influence of weather conditions during crop growth period on the parameters of yield--factor response models. It is established that the main parameters of the models are significantly influenced by both moisture supply (precipitation and water productivity in the soil) and hydrothermal conditions (hydrothermal coefficient and moisture coefficient). The 2016-2018 years are characterized by quite close mathematical relationship (R² =0.9672-0.99940) between the corn grain yield and sowing density. It was found the existing dependence of the model parameters on weather conditions and sufficiently high resistance of hybrid DS0493B to external conditions, since the deviation of the values of these conditions has turned out to be much greater than the deviation of the model parameters. [ABSTRACT FROM AUTHOR]

Mechanized transplanting of rapeseed (Brassica napus L.) blanket seedling is an effective strategy to cope with the seasonal conflict and large labor cost in rapeseed production. The sowing density is a key factor to cultivate high-quality seedlings suitable for mechanized transplanting. An experiment was conducted to investigate the effects of different sowing density levels of 638, 696, 754, 812, 870 and 928 seeds per tray (referred as D1, D2, D3, D4, D5 and D6, respectively) on agronomic traits and survival rate after mechanized transplanting of two rapeseed cultivars (Zheyouza108 and Heza17) in 2020 and 2021. The results showed that high sowing density increased plant height but decreased leaf area, collar diameter, biomass accumulation, the ratio of root to shoot and seedling fullness. These negative effects jointly decreased the seedling rate and survival rate after mechanized transplanting. However, the seedlings under D1 and D2 posed a great plant survival rate of more than 95% after mechanized transplanting, suggesting that the seedlings under the two densities were perfect for mechanized transplanting. In addition, hierarchical analysis grouped D1 and D2 into the same class, indicating that their seedling qualities were not significantly different, though the blanket seedlings under D1 outperformed those under D2 in some traits. A sowing density of 696 seeds per tray (D2) is then recommended in this study, altogether considering its high-quality seedlings suitable for mechanized transplanting, and economically, fewer seedling trays required.

White sweet clover (Melilotus albus) cultivation, despite its many positive features such as the high yield of green mass, as well as protein content, is currently not widespread. This study aimed to determine the effect of the different sowing densities (500, 1000, and 1500 seeds per m2) and harvesting at different growth stages (before budding, budding, and full flowering) on the quality of fodder from the white sweet clover (Adela variety). The field experiment was carried out in the years 2018–2020 in a split-plot design. Plant biometric measurements, green and dry yield, the content of total protein, crude fat, crude fiber, ash, macro and microelements, and coumarin content were determined. The results show that an increase in the sowing density significantly increased the plant population after emergence and green and dry matter. However, it does not affect the total protein, crude fat, crude fiber, ash, macro and microelements, and coumarin content. Harvesting plants at the flowering stage increased plant height and green fodder yield. Plants harvested at the prebudding phase were characterized by the highest share of leaves (40.3%) and were the most abundant in protein (21.7%) and minerals (ash content 12.71%). Unfortunately, sweet clover at this growth stage contained the highest level of coumarin, which limits its use in animal feed.

The sowing density of the parental inbred lines of maize hybrids shoud be chosen in such a way as to obtain the maximum seed yield without affecting the quality of the seed. Based on the data published in other articles on the production of hybrid maize seed, it is considered that for parental inbred lines, optimum density is in the range of 50-80000 plants/ha, while for parental single hybrids between 40-60000 plants/ha. Sowing density is conditioned both by environmental factors as well as suitability of parental forms to different densities. The present study was carried out in 2015 to 2017, at the ARDS Turda, to investigate the impact of three plant densities on behavior of five parental inbred lines of maize hybrids. The obtained results indicated that increasing the plant density (≥70000 plants/ha) determined the increase of the seed yield (kg/ha) for all genotypes. Although several production characters were reduced by increasing density, this decrease did not influence the level of yield, because it was compensated by higher number of plants per unit area. Parental forms TA 452 and TA 447 were identified as the most stable at changing the sowing density, while the lines TC 344 and TA 426 were sensitive to the increase of the plant density, with negative effects on the quality of the seeds. [ABSTRACT FROM AUTHOR]