When designing a solar power plant, it is much more important to avoid the shadow on the PV Panels. As the shadow falls on the PV Panels;it significantly reduces the generation of required power as planned and designe...When designing a solar power plant, it is much more important to avoid the shadow on the PV Panels. As the shadow falls on the PV Panels;it significantly reduces the generation of required power as planned and designed. This research paper and case study will help a lot to avoid shadow, especially when selecting inter-row spacing between the strings of solar power plants.展开更多
Biological yield indicates the potential for increasing yield.Leaf carbon metabolism plays an important role in the biomass accumulation of rapeseed(Brassica napus L.).Field experiments with the hybrid HZ62(with a con...Biological yield indicates the potential for increasing yield.Leaf carbon metabolism plays an important role in the biomass accumulation of rapeseed(Brassica napus L.).Field experiments with the hybrid HZ62(with a conventional plant architecture)grown in 2016–2017,and HZ62 and accession 1301(with a compact plant architecture)grown in 2017–2018 were conducted to characterize the physiological and proteomic responses of leaf photosynthetic carbon metabolism to density and row spacing configurations.The densities were set at 15×10;ha^(-1)(D1),30×10^(4)ha^(-1)(D2),and 45×10^(4)ha^(-1)(D3)(main plot),with row spacings of 15 cm(R15),25 cm(R25),and 35 cm(R35)(subplot).Individual and plant population biomass accumulation was greatest at R25,R15,and R15 for D1,D2,and D3,respectively,for both genotypes.In comparison with D1 R25,the individual aboveground biomass of HZ62 decreased by60.2%,whereas the population biomass increased by 31.9%,and the individual biomass of genotype1301 decreased by 54.0%and the population biomass increased by 53.9%at D3 R15.Leaf carbon metabolic enzymes varied between genotypes at flowering stage.In contrast to D1 R25,at D3 R15 the activities of ribulose-1,5-bisphosphate carboxylase/oxygenase(Rubisco)and sucrose phosphate synthase(SPS)and the contents of starch,sucrose and soluble sugars in leaves were significantly decreased in HZ62 and increased in genotype 1301.The activities of fructose-1,6-bisphosphatase(FBPase)decreased,in consistency with the abundance of fructose-bisphosphate aldolase in HZ62.In contrast,sucrose synthase(Su Sy)activity appeared to decrease in both genotypes,but a significant increase in abundance of a protein with sucrose synthase was found in the 1301 genotype by proteomic analysis.With increased density and reduced row spacing,the expression of most key proteins involved in carbon metabolism was elevated,and enzyme activity and carbon assimilate content were increased in 1301,whereas HZ62 showed the opposite trend,indicating that the compact plant type can accumulate more population biomass with denser planting.展开更多
One of the main reasons behind reduced cane yield is pathetic method of planting. Planting method and row spacing are the most important yield contributing factors in sugarcane. A field experiment was carried out in o...One of the main reasons behind reduced cane yield is pathetic method of planting. Planting method and row spacing are the most important yield contributing factors in sugarcane. A field experiment was carried out in order to determine quality and yield of sugarcane in various spatial arrangements. Treatments are 180 cm spaced trenches with triple row strips;180 cm spaced trenches with alternate row strips;120 cm spaced trenches with double row strips and 60 cm spaced furrow with single row. Perusal of data revealed that 3.6%, 13.4%, 15%, 15.3% more cane diameter (cm), cane length (cm), stripped cane yield (t·haˉ1</sup>), sugar yield (t·haˉ1</sup>) were obtained from 180 cm spaced trenches with triple row strips as compared to conventional planting method i.e. 60 cm spaced furrows. While the number of millable canes mˉ2</sup>, polarity %, cane juice purity %, cane juice %, commercial cane sugar % and cane sugar recovery % remained non-significant by different planting techniques.展开更多
Green gram(Vigna radiata(L.)wilczek,)commonly known as moong or mung bean or golden gram was introduced to Eritrea as a pulse crop by Ministry of Agriculture at its National Agricultural Research Institute(NARI)in col...Green gram(Vigna radiata(L.)wilczek,)commonly known as moong or mung bean or golden gram was introduced to Eritrea as a pulse crop by Ministry of Agriculture at its National Agricultural Research Institute(NARI)in collaboration with Association for Strengthening Agricultural Research in Eastern and Central Africa(ASARECA)in 2012.But its agronomic practices for semi-arid conditions of Eritrea are not yet standardised.Therefore,to find the optimum inter row spacing and phosphorus dose for its higher productivity,a field experiment was conducted at the experimental farm of Hamelmalo Agricultural College,Keren,Eritrea during summer 2015 and 2016.The experiment was conducted in randomised complete block design(RCBD)with 12 treatment combinations of two factors consisting of four inter row spacing(Broadcast,18 cm,30 cm,and 45 cm)and three phosphorus levels(0,20 and 40 kg P2O5 ha^(-1))each replicated thrice.The results of the study revealed that sowing of K-26 bold seeded variety either by broadcast method or at 18 cm inter row spacing at10 cm plant to plant spacing fertilized with 40 kg P2O5 ha-1 through DAP fertilizer drilled at the time of sowing proved significantly superior to increase growth,yield attributes and seed yield of green gram.展开更多
Optimizing irrigation frequency and intra row spacing for specific environment is one the major agronomic practices to improve productivity of haricot bean. Hence, a field experiment was conducted to evaluate the effe...Optimizing irrigation frequency and intra row spacing for specific environment is one the major agronomic practices to improve productivity of haricot bean. Hence, a field experiment was conducted to evaluate the effect of irrigation frequency and intra row spacing on growth, nodulation and agronomic performance of haricot bean at Arba Minch during dry season of 2018/19. The treatments consisted of three levels of irrigation frequency based on IW/CPE ratio (0.5, 0.67 and 1.0) with irrigation depth of 60 mm and three intra row spacing (6, 10 and 14 cm) which were factorially arranged in split plot design with three replications. Data were collected on phenological, nodulation, growth, yield and yield related parameters of the crop. The measured parameters were subjected to analysis of variance using SAS software version 9.0. Among the measured parameters, plant height, pod number per plant, dry matter and seed yield were significantly influenced by interaction effect of the treatments. The maximum seed yield (2873.7 kg ha<sup>−1</sup>) was recorded with interaction effect of irrigation at IW/CPE of 1 and intra row spacing of 10 cm. As for economic analysis, the same treatment combination also resulted in the highest net benefit (11254.1 Ethiopian Birr ha<sup>−1</sup>) and marginal rate of return (422.1%). Therefore, it could be concluded that irrigating haricot bean at IW/CPE ratio of 1 and planting at 10 cm intra row spacing could maximize both seed yield and economic benefit of the crop in the study area.展开更多
A field experiment was conducted to study the growth and productivity of wheat as affected by row spacing and direction of sowing at Rampur, Chitwan, Nepal during the 2007-2008 wheat growing season. The experiment was...A field experiment was conducted to study the growth and productivity of wheat as affected by row spacing and direction of sowing at Rampur, Chitwan, Nepal during the 2007-2008 wheat growing season. The experiment was carried out in 3-factors factorial randomized complete block design comprising two varieties (Gautam and BL-2800), three row spacings (15, 20 and25 cm) and two row directions of sowing (east-west and north-south). The effects of variety and row direction of sowing on grain yield were significant (p < 0.05), but the grain yield was not affected by the row spacing treatment. BL-2800 variety produced higher grain yield (3.53 t·ha-1) as compared to Gautam (3.11 t·ha-1). Both wheat varieties yielded about 11% higher (p < 0.05) grain in the north-south sowing as compared to the eastwest sowing.展开更多
Soybean isoflavones compounds such as genistein, daidzein, and glycitein have numerous human health benefits including the reduction of risks of cardiovascular diseases, breast and prostate cancers, and menaupose symp...Soybean isoflavones compounds such as genistein, daidzein, and glycitein have numerous human health benefits including the reduction of risks of cardiovascular diseases, breast and prostate cancers, and menaupose symptoms in women. Understanding the genetic and environmental control of isoflavones accumulation is of great importance for developing new cultivars with high amounts of seed isoflavones. This study was conducted to analyze the effect of row spacing (25 cm vs. 50 cm) on seed isoflavones accumulation using a recombinant inbred line (RIL) population derived from the cross of PI 438489B and “Hamilton” (PIxH, n = 50). The two row spaces generated plant densities of 250,000 plants/ha and 90,000 plants/ha, respectively. Significant differences in soybean seed isoflavones (daidzein, genistein and glycitein) contents have been observed between plants grown in the two different plant densities. The mean daidzein content was 0.03458 μg·g-1 in plants grown in 50 cm row spaces (low plant density), which was significantly higher than its content (0.03019 μg·g-1) in plants grown in 25 cm row spaces (high plant density). Similarly, the mean glycitein content in plants grown in 50 cm row spaces (0.01905 μg·g-1) was significantly higher than its content in plants grown in 25 cm row spaces (0.00498 μg·g-1. Also, the mean genistein content in plants grown in 50 cm row spaces (0.01466 μg·g-1) was higher than its content in plants grown in 25 cm row spaces (0.00831 μg·g-1). These preliminary results are important in guiding farmers and breeders on choosing the best row spaces to grow soybean plants in order to optimize isoflavones contents. Further studies are needed to understand the correlation between seed isoflavones contents and other agronomic traits such as seed yield, protein, and oil contents.展开更多
During 2013-2014 a field experiment was conducted at experimental area of Faculty of Agriculture under Lasbela University of Agriculture, Water and Marine Science, Uthal, Lasbela to evaluate the influence of various r...During 2013-2014 a field experiment was conducted at experimental area of Faculty of Agriculture under Lasbela University of Agriculture, Water and Marine Science, Uthal, Lasbela to evaluate the influence of various row spacing on the yield and yield components of Raya Anmol and Faisal Canola under coastal climatic conditions of Lasbela. Randomized complete block design (RCBD) with factorial arrangement having 3 replications was used. Experiment comprises two canola varieties, C1 = Raya Anmol, C2 = Faisal Canola at 3 row spacing distances RS1 = 30 cm, RS2 = 45 cm and RS3 = 60 cm respectively. Result showed that yield and yield contributing traits are significant. It was concluded that seed yield of C1 (Faisal Canola) was better as compared to that of Raya Anmol. Row spacing (RS3 = 60 cm) yielded more crop canopy and the highest number of pod per plant, pod length and seed yield under agro climatic condition of Lasbela as compared to other densely arranged row spacing.展开更多
[Objective]The aim was to provide a theoretical basis for the rational configuration of ratio of row spacing to intrarow spacing(RS/IS)of double-cropping rice.[Methods]With early rice‘Ganxin 203’and‘Zhongjiazao 17...[Objective]The aim was to provide a theoretical basis for the rational configuration of ratio of row spacing to intrarow spacing(RS/IS)of double-cropping rice.[Methods]With early rice‘Ganxin 203’and‘Zhongjiazao 17’and late rice‘Ganxin 688’and‘Wufengyou T025’as materials,the effects of RS/IS on yield,nitrogen accumulation and utilization were studied in the same planting density of31.20×104hills/hm2.[Results]The results showed that yield of early rice was higher in RS/IS2.8(30.0 cm×10.7 cm)and RS/IS2.0(25.0 cm×12.8 cm)treatment,and lower in RS/IS5.0(40.0 cm×8.0 cm)and RS/IS1.3(20.0 cm×16.0 cm)treatment,while late rice were higher in RS/IS5.0and RS/IS2.0treatment,and lower in RS/IS2.8and RS/IS1.3treatment.Total nitrogen accumulation and apparent utilization ratio of nitrogen of early rice were higher in RS/IS2.0treatment and lower in RS/IS5.0treatment,while,for late rice were higher in RS/IS2.8treatment and lower in RS/IS5.0treatment.Nitrogen requirement for 100 kg grain production of early rice was higher in RS/IS1.3treatment and lower in RS/IS2.0treatment,while,for late rice were higher in RS/IS2.8treatment,lower in RS/IS5.0treatment.[Conclusion]In sum,4 varieties of early and late rice obtained higher yield in 25.0 cm×12.8 cm and lower yield in 20.0 cm×16.0 cm,and total nitrogen accumulation,nitrogen requirement for 100 kg grain production and apparent utilization ratio of nitrogen were all lower in 40.0 cm×8.0 cm.展开更多
Growing soybeans in different row-spacings introduces competition. Competition begins when the immediate supply of a single necessary factor falls below the combined demands of all plants. This paper reviews the main ...Growing soybeans in different row-spacings introduces competition. Competition begins when the immediate supply of a single necessary factor falls below the combined demands of all plants. This paper reviews the main competition factors of genotypes, light, water, nutrients and weed in responses to row spacings for the past four decades. It demonstrated that responses of soybean genotypes to row width differ among cultivars, which depend on seasonal rainfall and irrigation. Determinate types produce more yield in narrow-rows, and cultivars with lodging resistance should be adopted in narrow-spacings, but indeterminate soybean should also be used to optimize yields in certain system. Narrow-compared with wide-row soybean (Glycine max) cultivation increases light interception (LI) and dominant components for the increase come from LAI, light extinction coefficients and branch types. Water use efficiency (WUE) and evapotranspiration are not influenced by row spacing, but seed yield could be increased if irrigation is applied. Nutrient uptake is significantly affected by row spacing, seed yields and uptake of N, P, K in plants increases with decreasing row spacing, and the effects depend on the fertilizer levels. Other factors rather than row spacing affect nitrogen fixation. Weed density, peak time and periodicity of weed emergence are not affected by row spacing, but better complementary weed control by the herbicides at the used doses can be obtained in narrow spacing due to the reduced weed number and dry weight. More researches are required to investigate the physiological responses, nutrient and water uptake and translocation, light utilization at different layers of canopy and soil environment changes in different row-spacings.展开更多
[Objective]This study was conducted to investigate the relationship between each of planting density and row spacing and plant productivity of forage sweet sorghum planted in autumn idle land. [Methods]Using split-plo...[Objective]This study was conducted to investigate the relationship between each of planting density and row spacing and plant productivity of forage sweet sorghum planted in autumn idle land. [Methods]Using split-plot experiment design experiment method and LSD method of IBM. SPSS. Statistics. v22 statistics software,the effects of planting density and row spacing on plant productivity of forage sweet sorghum planted in autumn idle land were compared. [Result]The results showed that the planting density and row spacing had important influences on plant productivity of forage sweet sorghum planted in autumn idle land. Moreover,the optimal combination of plant productivity for A_1B_4,i. e.,under the combination of the planting density of 7. 5 × 104 plants/hm^2 and the row spacing of40 cm,the fresh weight and dry weight per plant were 654. 37 and 147. 11 g/plant,respectively.[Conclusion]The results provided a theoretical basis for the production of forage sweet sorghum in autumn idle land.展开更多
A field experiment was carried out to determine the effect of variety and plant spacing on yield and growth of groundnuts. The field experiment was laid in a 3 × 3 factorial experiment in a Randomized Complete Bl...A field experiment was carried out to determine the effect of variety and plant spacing on yield and growth of groundnuts. The field experiment was laid in a 3 × 3 factorial experiment in a Randomized Complete Block Design (RCBD) with three (3) replications. The factor A included three (3) groundnut varieties (Nkatie Sari, Sum Nutt 22 and Yenyawoso) and Factor B was the three (3) spacing of 30 cm × 15 cm, 30 cm × 30 cm and 30 cm × 40 cm. All recommended agronomic practices were followed. Data was collected from eight (8) tagged plants. Growth data were recorded on plant height, number of branches, number of leaves, and the number of flowers while yield data were collected on the number of flowers, number of pods per plant, 100 seeds weight and the pod yield (kg/ha). The plant spacing significantly influenced (P < 0.05) the growth and yield parameters. Groundnut grown at a spacing of 30 cm × 15 cm produced the maximum plant height, whereas the maximum number of leaves, number of branches and number of flowers were produced from 30 cm × 40 cm. Yenyawoso variety with a wider plant spacing performed better vegetatively among all the varieties. The Yenyawoso variety produced the highest number of pods, 100 seeds weight and pod yield as compared to the other varieties. Also, Yenyawoso at 30 cm × 40 cm spacing and Nkatie Sari at 30 cm × 15 cm spacing produced the maximum pod yield.展开更多
Platooning represents one of the key features that connected automated vehicles may possess as it allows multiple automated vehicles to be maneuvered cooperatively with small headways on roads. However, a critical cha...Platooning represents one of the key features that connected automated vehicles may possess as it allows multiple automated vehicles to be maneuvered cooperatively with small headways on roads. However, a critical challenge in accomplishing automated vehicle platoons is to deal with the effects of intermittent and sporadic vehicle-to-vehicle data transmissions caused by limited wireless communication resources. This paper addresses the co-design problem of dynamic event-triggered communication scheduling and cooperative adaptive cruise control for a convoy of automated vehicles with diverse spacing policies. The central aim is to achieve automated vehicle platooning under various gap references with desired platoon stability and spacing performance requirements, while simultaneously improving communication efficiency. Toward this aim, a dynamic event-triggered scheduling mechanism is developed such that the intervehicle data transmissions are scheduled dynamically and efficiently over time. Then, a tractable co-design criterion on the existence of both the admissible event-driven cooperative adaptive cruise control law and the desired scheduling mechanism is derived. Finally, comparative simulation results are presented to substantiate the effectiveness and merits of the obtained results.展开更多
This paper addresses a multicircular circumnavigation control for UAVs with desired angular spacing around a nonstationary target.By defining a coordinated error relative to neighboring angular spacing,under the premi...This paper addresses a multicircular circumnavigation control for UAVs with desired angular spacing around a nonstationary target.By defining a coordinated error relative to neighboring angular spacing,under the premise that target information is perfectly accessible by all nodes,a centralized circular enclosing control strategy is derived for multiple UAVs connected by an undirected graph to allow for formation behaviors concerning the moving target.Besides,to avoid the requirement of target’s states being accessible for each UAV,fixed-time distributed observers are introduced to acquire the state estimates in a fixed-time sense,and the upper boundary of settling time can be determined offline irrespective of initial properties,greatly releasing the burdensome communication traffic.Then,with the aid of fixed-time distributed observers,a distributed circular circumnavigation controller is derived to force all UAVs to collaboratively evolve along the preset circles while keeping a desired angular spacing.It is inferred from Lyapunov stability that all errors are demonstrated to be convergent.Simulations are offered to verify the utility of proposed protocol.展开更多
The nanoscale confinement is of great important for the industrial applications of molecular sieve,desalination,and also essential in bio-logical transport systems.Massive efforts have been devoted to the influence of...The nanoscale confinement is of great important for the industrial applications of molecular sieve,desalination,and also essential in bio-logical transport systems.Massive efforts have been devoted to the influence of restricted spaces on the properties of confined fluids.However,the situation of channel-wall is crucial but attracts less attention and remains unknown.To fundamentally understand the mechanism of channel-walls in nanoconfinement,we investigated the interaction between the counter-force of the liquid and interlamellar spacing of nanochannel walls by considering the effect of both spatial confinement and surface wettability.The results reveal that the nanochannel stables at only a few discrete spacing states when its confinement is within 1.4 nm.The quantized interlayer spacing is attributed to water molecules becoming laminated structures,and the stable states are corresponding to the monolayer,bilayer and trilayer water configurations,respectively.The results can potentially help to understand the characterized interlayers spacing of graphene oxide membrane in water.Our findings are hold great promise in design of ion filtration membrane and artificial water/ion channels.展开更多
In the Philippines, rice monoculture systems are common. Compared to these systems, the rice-soybean cropping system may prove more water-efficient and there is a trend of increasing soybean area in the response to wa...In the Philippines, rice monoculture systems are common. Compared to these systems, the rice-soybean cropping system may prove more water-efficient and there is a trend of increasing soybean area in the response to water scarcity and need for crop diversification in the Philippines. A field study was conducted to evaluate the effect of row and plant to plant spacing (20 × 10, 20 × 5, 40 × 10, and 40 × 5 cm) on growth and yield of soybean. Plant height was not influenced by the plant geometry. Spacing, however, influenced leaf area and shoot biomass of soybean. Plants grown at the widest spacing (i.e., 40 × 10 cm) produced lowest leaf area and shoot biomass at 6 and 12 weeks after planting. Leaf area and shoot biomass at other three spacing were similar. There was a negative and linear relationship between weed biomass and crop shoot biomass at 6 and 12 weeks after planting. Grain yield of soybean was not affected by plant geometry and it ranged from 1.3 to 1.9 t·ha-1 at different spacing.展开更多
Soil respiration(SR) in crop field is affected by environmental factors, agronomic practices and crop types. To clarify how planting density affects the SR dynamics in switchgrass(Panicum virgatum L.) field on the sem...Soil respiration(SR) in crop field is affected by environmental factors, agronomic practices and crop types. To clarify how planting density affects the SR dynamics in switchgrass(Panicum virgatum L.) field on the semi-arid Loess Plateau, this research investigated diurnal and seasonal changes of soil respiration rate(RS) under three different row-spacing treatments(20, 40 and 60 cm) in the fourth growing year of switchgrass. Results showed that RS presented a pronounced seasonality under all row-spacing treatments. The highest daily average RS values appeared in August, while the lowest(P<0.05) were in September for each row-spacing. Diurnal variations of RS exhibited single-peak curves in each month. Daily average RS increased significantly as row-spacing enlarged during May and August but there was no significant difference among row-spacing treatments in September. Soil water storage in the depth of 0–100 cm had no significant difference(P>0.05) among the row-spacing treatments, and similar results were found for soil temperature in 0–15 cm soil depth. Soil respiration temperature sensitivity(Q_(10)) values were 1.0–3.7 during the growing months, which were strongly correlated with air temperature in May and June and the soil temperature at 15 cm depth in August. Higher aboveground biomass production and lower RS in most growth months indicated that 20 cm row-spacing treatment was beneficial for increasing the carbon fixation in switchgrass field. Results also implied that it is necessary to take into account the influence of phenology and root growth of switchgrass on soil respiration for accurately evaluating the carbon cycle in the region.展开更多
Two loblolly pine (Pinus taeda L.) culture/density studies were established in 1995-1998 across the Lower Coastal Plain and Upper Coastal Plain/Piedmont regions of the southern USA. Each installation contains 12 plots...Two loblolly pine (Pinus taeda L.) culture/density studies were established in 1995-1998 across the Lower Coastal Plain and Upper Coastal Plain/Piedmont regions of the southern USA. Each installation contains 12 plots of loblolly pine planted at six levels of density from 741 to 4448 trees/ha in combination with two levels of cultural intensity, operational and intensive. The data from 37 viable installations were used to evaluate the crown ratio and relative spacing relationship of loblolly pine plantations. The effects of planting density, site quality, and cultural intensity on the relationship were investigated with a nonlinear mixed-effects modeling approach. The crown ratio and relative spacing relationship is exceedingly predictable. When loblolly pine plantation stands reached the average live crown ratio of 0.40, a critical point representing a generally acceptable level of tree vigor, the corresponding relative spacing index ranged from 0.11 to 0.20, mainly depending on initial planting density. The information about the crown ratio and relative spacing relationship would be useful for selecting the best intensity and timing of thinning.展开更多
An electromagnetic shielding metacomposite based on the absorbing mechanism was prepared by weaving ferromagnetic microwires into the three-dimensional(3D)fabric.The influence of the ferromagnetic microwire spacing on...An electromagnetic shielding metacomposite based on the absorbing mechanism was prepared by weaving ferromagnetic microwires into the three-dimensional(3D)fabric.The influence of the ferromagnetic microwire spacing on electromagnetic shielding performance and the electromagnetic shielding mechanism of 3D metacomposites were studied.The total electromagnetic shielding performance increases with the increase of electromagnetic wave frequency.3D metacomposites based on the absorbing mechanism can avoid the secondary pollution of electromagnetic waves,and have great potential in military,civil,aerospace and other fields.展开更多
文摘When designing a solar power plant, it is much more important to avoid the shadow on the PV Panels. As the shadow falls on the PV Panels;it significantly reduces the generation of required power as planned and designed. This research paper and case study will help a lot to avoid shadow, especially when selecting inter-row spacing between the strings of solar power plants.
基金the National Natural Science Foundation of China(31671616)the China Agriculture Research System(CARS-12)the Fundamental Research Funds for the Central Universities(2662019PY076)。
文摘Biological yield indicates the potential for increasing yield.Leaf carbon metabolism plays an important role in the biomass accumulation of rapeseed(Brassica napus L.).Field experiments with the hybrid HZ62(with a conventional plant architecture)grown in 2016–2017,and HZ62 and accession 1301(with a compact plant architecture)grown in 2017–2018 were conducted to characterize the physiological and proteomic responses of leaf photosynthetic carbon metabolism to density and row spacing configurations.The densities were set at 15×10;ha^(-1)(D1),30×10^(4)ha^(-1)(D2),and 45×10^(4)ha^(-1)(D3)(main plot),with row spacings of 15 cm(R15),25 cm(R25),and 35 cm(R35)(subplot).Individual and plant population biomass accumulation was greatest at R25,R15,and R15 for D1,D2,and D3,respectively,for both genotypes.In comparison with D1 R25,the individual aboveground biomass of HZ62 decreased by60.2%,whereas the population biomass increased by 31.9%,and the individual biomass of genotype1301 decreased by 54.0%and the population biomass increased by 53.9%at D3 R15.Leaf carbon metabolic enzymes varied between genotypes at flowering stage.In contrast to D1 R25,at D3 R15 the activities of ribulose-1,5-bisphosphate carboxylase/oxygenase(Rubisco)and sucrose phosphate synthase(SPS)and the contents of starch,sucrose and soluble sugars in leaves were significantly decreased in HZ62 and increased in genotype 1301.The activities of fructose-1,6-bisphosphatase(FBPase)decreased,in consistency with the abundance of fructose-bisphosphate aldolase in HZ62.In contrast,sucrose synthase(Su Sy)activity appeared to decrease in both genotypes,but a significant increase in abundance of a protein with sucrose synthase was found in the 1301 genotype by proteomic analysis.With increased density and reduced row spacing,the expression of most key proteins involved in carbon metabolism was elevated,and enzyme activity and carbon assimilate content were increased in 1301,whereas HZ62 showed the opposite trend,indicating that the compact plant type can accumulate more population biomass with denser planting.
文摘One of the main reasons behind reduced cane yield is pathetic method of planting. Planting method and row spacing are the most important yield contributing factors in sugarcane. A field experiment was carried out in order to determine quality and yield of sugarcane in various spatial arrangements. Treatments are 180 cm spaced trenches with triple row strips;180 cm spaced trenches with alternate row strips;120 cm spaced trenches with double row strips and 60 cm spaced furrow with single row. Perusal of data revealed that 3.6%, 13.4%, 15%, 15.3% more cane diameter (cm), cane length (cm), stripped cane yield (t·haˉ1</sup>), sugar yield (t·haˉ1</sup>) were obtained from 180 cm spaced trenches with triple row strips as compared to conventional planting method i.e. 60 cm spaced furrows. While the number of millable canes mˉ2</sup>, polarity %, cane juice purity %, cane juice %, commercial cane sugar % and cane sugar recovery % remained non-significant by different planting techniques.
文摘Green gram(Vigna radiata(L.)wilczek,)commonly known as moong or mung bean or golden gram was introduced to Eritrea as a pulse crop by Ministry of Agriculture at its National Agricultural Research Institute(NARI)in collaboration with Association for Strengthening Agricultural Research in Eastern and Central Africa(ASARECA)in 2012.But its agronomic practices for semi-arid conditions of Eritrea are not yet standardised.Therefore,to find the optimum inter row spacing and phosphorus dose for its higher productivity,a field experiment was conducted at the experimental farm of Hamelmalo Agricultural College,Keren,Eritrea during summer 2015 and 2016.The experiment was conducted in randomised complete block design(RCBD)with 12 treatment combinations of two factors consisting of four inter row spacing(Broadcast,18 cm,30 cm,and 45 cm)and three phosphorus levels(0,20 and 40 kg P2O5 ha^(-1))each replicated thrice.The results of the study revealed that sowing of K-26 bold seeded variety either by broadcast method or at 18 cm inter row spacing at10 cm plant to plant spacing fertilized with 40 kg P2O5 ha-1 through DAP fertilizer drilled at the time of sowing proved significantly superior to increase growth,yield attributes and seed yield of green gram.
文摘Optimizing irrigation frequency and intra row spacing for specific environment is one the major agronomic practices to improve productivity of haricot bean. Hence, a field experiment was conducted to evaluate the effect of irrigation frequency and intra row spacing on growth, nodulation and agronomic performance of haricot bean at Arba Minch during dry season of 2018/19. The treatments consisted of three levels of irrigation frequency based on IW/CPE ratio (0.5, 0.67 and 1.0) with irrigation depth of 60 mm and three intra row spacing (6, 10 and 14 cm) which were factorially arranged in split plot design with three replications. Data were collected on phenological, nodulation, growth, yield and yield related parameters of the crop. The measured parameters were subjected to analysis of variance using SAS software version 9.0. Among the measured parameters, plant height, pod number per plant, dry matter and seed yield were significantly influenced by interaction effect of the treatments. The maximum seed yield (2873.7 kg ha<sup>−1</sup>) was recorded with interaction effect of irrigation at IW/CPE of 1 and intra row spacing of 10 cm. As for economic analysis, the same treatment combination also resulted in the highest net benefit (11254.1 Ethiopian Birr ha<sup>−1</sup>) and marginal rate of return (422.1%). Therefore, it could be concluded that irrigating haricot bean at IW/CPE ratio of 1 and planting at 10 cm intra row spacing could maximize both seed yield and economic benefit of the crop in the study area.
文摘A field experiment was conducted to study the growth and productivity of wheat as affected by row spacing and direction of sowing at Rampur, Chitwan, Nepal during the 2007-2008 wheat growing season. The experiment was carried out in 3-factors factorial randomized complete block design comprising two varieties (Gautam and BL-2800), three row spacings (15, 20 and25 cm) and two row directions of sowing (east-west and north-south). The effects of variety and row direction of sowing on grain yield were significant (p < 0.05), but the grain yield was not affected by the row spacing treatment. BL-2800 variety produced higher grain yield (3.53 t·ha-1) as compared to Gautam (3.11 t·ha-1). Both wheat varieties yielded about 11% higher (p < 0.05) grain in the north-south sowing as compared to the eastwest sowing.
文摘Soybean isoflavones compounds such as genistein, daidzein, and glycitein have numerous human health benefits including the reduction of risks of cardiovascular diseases, breast and prostate cancers, and menaupose symptoms in women. Understanding the genetic and environmental control of isoflavones accumulation is of great importance for developing new cultivars with high amounts of seed isoflavones. This study was conducted to analyze the effect of row spacing (25 cm vs. 50 cm) on seed isoflavones accumulation using a recombinant inbred line (RIL) population derived from the cross of PI 438489B and “Hamilton” (PIxH, n = 50). The two row spaces generated plant densities of 250,000 plants/ha and 90,000 plants/ha, respectively. Significant differences in soybean seed isoflavones (daidzein, genistein and glycitein) contents have been observed between plants grown in the two different plant densities. The mean daidzein content was 0.03458 μg·g-1 in plants grown in 50 cm row spaces (low plant density), which was significantly higher than its content (0.03019 μg·g-1) in plants grown in 25 cm row spaces (high plant density). Similarly, the mean glycitein content in plants grown in 50 cm row spaces (0.01905 μg·g-1) was significantly higher than its content in plants grown in 25 cm row spaces (0.00498 μg·g-1. Also, the mean genistein content in plants grown in 50 cm row spaces (0.01466 μg·g-1) was higher than its content in plants grown in 25 cm row spaces (0.00831 μg·g-1). These preliminary results are important in guiding farmers and breeders on choosing the best row spaces to grow soybean plants in order to optimize isoflavones contents. Further studies are needed to understand the correlation between seed isoflavones contents and other agronomic traits such as seed yield, protein, and oil contents.
文摘During 2013-2014 a field experiment was conducted at experimental area of Faculty of Agriculture under Lasbela University of Agriculture, Water and Marine Science, Uthal, Lasbela to evaluate the influence of various row spacing on the yield and yield components of Raya Anmol and Faisal Canola under coastal climatic conditions of Lasbela. Randomized complete block design (RCBD) with factorial arrangement having 3 replications was used. Experiment comprises two canola varieties, C1 = Raya Anmol, C2 = Faisal Canola at 3 row spacing distances RS1 = 30 cm, RS2 = 45 cm and RS3 = 60 cm respectively. Result showed that yield and yield contributing traits are significant. It was concluded that seed yield of C1 (Faisal Canola) was better as compared to that of Raya Anmol. Row spacing (RS3 = 60 cm) yielded more crop canopy and the highest number of pod per plant, pod length and seed yield under agro climatic condition of Lasbela as compared to other densely arranged row spacing.
基金Supported by the Project of "Demonstration and Integration of Agricultural Non-point Source Pollution Prevention and Control Technology in Rice Production Areas of Southern Plain of China"Belonging to National Science and Technology Program for"Twelfth Five-Year"Plan(2012BAD15B03)Youth Innovation Funds of Jiangxi Academy of Agricultural Sciences "Effects of Row-Spacing on Yield of Different Double Cropping Rice Varieties and Its Mechanism"(2010-CQN004)
文摘[Objective]The aim was to provide a theoretical basis for the rational configuration of ratio of row spacing to intrarow spacing(RS/IS)of double-cropping rice.[Methods]With early rice‘Ganxin 203’and‘Zhongjiazao 17’and late rice‘Ganxin 688’and‘Wufengyou T025’as materials,the effects of RS/IS on yield,nitrogen accumulation and utilization were studied in the same planting density of31.20×104hills/hm2.[Results]The results showed that yield of early rice was higher in RS/IS2.8(30.0 cm×10.7 cm)and RS/IS2.0(25.0 cm×12.8 cm)treatment,and lower in RS/IS5.0(40.0 cm×8.0 cm)and RS/IS1.3(20.0 cm×16.0 cm)treatment,while late rice were higher in RS/IS5.0and RS/IS2.0treatment,and lower in RS/IS2.8and RS/IS1.3treatment.Total nitrogen accumulation and apparent utilization ratio of nitrogen of early rice were higher in RS/IS2.0treatment and lower in RS/IS5.0treatment,while,for late rice were higher in RS/IS2.8treatment and lower in RS/IS5.0treatment.Nitrogen requirement for 100 kg grain production of early rice was higher in RS/IS1.3treatment and lower in RS/IS2.0treatment,while,for late rice were higher in RS/IS2.8treatment,lower in RS/IS5.0treatment.[Conclusion]In sum,4 varieties of early and late rice obtained higher yield in 25.0 cm×12.8 cm and lower yield in 20.0 cm×16.0 cm,and total nitrogen accumulation,nitrogen requirement for 100 kg grain production and apparent utilization ratio of nitrogen were all lower in 40.0 cm×8.0 cm.
文摘Growing soybeans in different row-spacings introduces competition. Competition begins when the immediate supply of a single necessary factor falls below the combined demands of all plants. This paper reviews the main competition factors of genotypes, light, water, nutrients and weed in responses to row spacings for the past four decades. It demonstrated that responses of soybean genotypes to row width differ among cultivars, which depend on seasonal rainfall and irrigation. Determinate types produce more yield in narrow-rows, and cultivars with lodging resistance should be adopted in narrow-spacings, but indeterminate soybean should also be used to optimize yields in certain system. Narrow-compared with wide-row soybean (Glycine max) cultivation increases light interception (LI) and dominant components for the increase come from LAI, light extinction coefficients and branch types. Water use efficiency (WUE) and evapotranspiration are not influenced by row spacing, but seed yield could be increased if irrigation is applied. Nutrient uptake is significantly affected by row spacing, seed yields and uptake of N, P, K in plants increases with decreasing row spacing, and the effects depend on the fertilizer levels. Other factors rather than row spacing affect nitrogen fixation. Weed density, peak time and periodicity of weed emergence are not affected by row spacing, but better complementary weed control by the herbicides at the used doses can be obtained in narrow spacing due to the reduced weed number and dry weight. More researches are required to investigate the physiological responses, nutrient and water uptake and translocation, light utilization at different layers of canopy and soil environment changes in different row-spacings.
基金Supported by Special Fund for Agro-scientific Researchin the Public Interest(20120304201)
文摘[Objective]This study was conducted to investigate the relationship between each of planting density and row spacing and plant productivity of forage sweet sorghum planted in autumn idle land. [Methods]Using split-plot experiment design experiment method and LSD method of IBM. SPSS. Statistics. v22 statistics software,the effects of planting density and row spacing on plant productivity of forage sweet sorghum planted in autumn idle land were compared. [Result]The results showed that the planting density and row spacing had important influences on plant productivity of forage sweet sorghum planted in autumn idle land. Moreover,the optimal combination of plant productivity for A_1B_4,i. e.,under the combination of the planting density of 7. 5 × 104 plants/hm^2 and the row spacing of40 cm,the fresh weight and dry weight per plant were 654. 37 and 147. 11 g/plant,respectively.[Conclusion]The results provided a theoretical basis for the production of forage sweet sorghum in autumn idle land.
文摘A field experiment was carried out to determine the effect of variety and plant spacing on yield and growth of groundnuts. The field experiment was laid in a 3 × 3 factorial experiment in a Randomized Complete Block Design (RCBD) with three (3) replications. The factor A included three (3) groundnut varieties (Nkatie Sari, Sum Nutt 22 and Yenyawoso) and Factor B was the three (3) spacing of 30 cm × 15 cm, 30 cm × 30 cm and 30 cm × 40 cm. All recommended agronomic practices were followed. Data was collected from eight (8) tagged plants. Growth data were recorded on plant height, number of branches, number of leaves, and the number of flowers while yield data were collected on the number of flowers, number of pods per plant, 100 seeds weight and the pod yield (kg/ha). The plant spacing significantly influenced (P < 0.05) the growth and yield parameters. Groundnut grown at a spacing of 30 cm × 15 cm produced the maximum plant height, whereas the maximum number of leaves, number of branches and number of flowers were produced from 30 cm × 40 cm. Yenyawoso variety with a wider plant spacing performed better vegetatively among all the varieties. The Yenyawoso variety produced the highest number of pods, 100 seeds weight and pod yield as compared to the other varieties. Also, Yenyawoso at 30 cm × 40 cm spacing and Nkatie Sari at 30 cm × 15 cm spacing produced the maximum pod yield.
基金supported in part by the Australian Research Council Discovery Early Career Researcher Award(DE200101128)。
文摘Platooning represents one of the key features that connected automated vehicles may possess as it allows multiple automated vehicles to be maneuvered cooperatively with small headways on roads. However, a critical challenge in accomplishing automated vehicle platoons is to deal with the effects of intermittent and sporadic vehicle-to-vehicle data transmissions caused by limited wireless communication resources. This paper addresses the co-design problem of dynamic event-triggered communication scheduling and cooperative adaptive cruise control for a convoy of automated vehicles with diverse spacing policies. The central aim is to achieve automated vehicle platooning under various gap references with desired platoon stability and spacing performance requirements, while simultaneously improving communication efficiency. Toward this aim, a dynamic event-triggered scheduling mechanism is developed such that the intervehicle data transmissions are scheduled dynamically and efficiently over time. Then, a tractable co-design criterion on the existence of both the admissible event-driven cooperative adaptive cruise control law and the desired scheduling mechanism is derived. Finally, comparative simulation results are presented to substantiate the effectiveness and merits of the obtained results.
基金supported in part by the National Natural Science Foundation of China under Grant Nos.62173312,61922037,61873115,and 61803348in part by the National Major Scientific Instruments Development Project under Grant 61927807+6 种基金in part by the State Key Laboratory of Deep Buried Target Damage under Grant No.DXMBJJ2019-02in part by the Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi under Grant 2020L0266in part by the Shanxi Province Science Foundation for Youths under Grant No.201701D221123in part by the Youth Academic North University of China under Grant No.QX201803in part by the Program for the Innovative Talents of Higher Education Institutions of Shanxiin part by the Shanxi“1331Project”Key Subjects Construction under Grant 1331KSCin part by the Supported by Shanxi Province Science Foundation for Excellent Youths。
文摘This paper addresses a multicircular circumnavigation control for UAVs with desired angular spacing around a nonstationary target.By defining a coordinated error relative to neighboring angular spacing,under the premise that target information is perfectly accessible by all nodes,a centralized circular enclosing control strategy is derived for multiple UAVs connected by an undirected graph to allow for formation behaviors concerning the moving target.Besides,to avoid the requirement of target’s states being accessible for each UAV,fixed-time distributed observers are introduced to acquire the state estimates in a fixed-time sense,and the upper boundary of settling time can be determined offline irrespective of initial properties,greatly releasing the burdensome communication traffic.Then,with the aid of fixed-time distributed observers,a distributed circular circumnavigation controller is derived to force all UAVs to collaboratively evolve along the preset circles while keeping a desired angular spacing.It is inferred from Lyapunov stability that all errors are demonstrated to be convergent.Simulations are offered to verify the utility of proposed protocol.
基金support from the National Natural Science Foundation of China(Grant Nos.12372327,12372109,11972171)National Key R&D Program of China(Grant No.2023YFB4605101).
文摘The nanoscale confinement is of great important for the industrial applications of molecular sieve,desalination,and also essential in bio-logical transport systems.Massive efforts have been devoted to the influence of restricted spaces on the properties of confined fluids.However,the situation of channel-wall is crucial but attracts less attention and remains unknown.To fundamentally understand the mechanism of channel-walls in nanoconfinement,we investigated the interaction between the counter-force of the liquid and interlamellar spacing of nanochannel walls by considering the effect of both spatial confinement and surface wettability.The results reveal that the nanochannel stables at only a few discrete spacing states when its confinement is within 1.4 nm.The quantized interlayer spacing is attributed to water molecules becoming laminated structures,and the stable states are corresponding to the monolayer,bilayer and trilayer water configurations,respectively.The results can potentially help to understand the characterized interlayers spacing of graphene oxide membrane in water.Our findings are hold great promise in design of ion filtration membrane and artificial water/ion channels.
文摘In the Philippines, rice monoculture systems are common. Compared to these systems, the rice-soybean cropping system may prove more water-efficient and there is a trend of increasing soybean area in the response to water scarcity and need for crop diversification in the Philippines. A field study was conducted to evaluate the effect of row and plant to plant spacing (20 × 10, 20 × 5, 40 × 10, and 40 × 5 cm) on growth and yield of soybean. Plant height was not influenced by the plant geometry. Spacing, however, influenced leaf area and shoot biomass of soybean. Plants grown at the widest spacing (i.e., 40 × 10 cm) produced lowest leaf area and shoot biomass at 6 and 12 weeks after planting. Leaf area and shoot biomass at other three spacing were similar. There was a negative and linear relationship between weed biomass and crop shoot biomass at 6 and 12 weeks after planting. Grain yield of soybean was not affected by plant geometry and it ranged from 1.3 to 1.9 t·ha-1 at different spacing.
基金financially supported by the Program for New Century Excellent Talents in University (NCET-110444)the Fundamental Research Funds for the Central Universities (ZD2013020)
文摘Soil respiration(SR) in crop field is affected by environmental factors, agronomic practices and crop types. To clarify how planting density affects the SR dynamics in switchgrass(Panicum virgatum L.) field on the semi-arid Loess Plateau, this research investigated diurnal and seasonal changes of soil respiration rate(RS) under three different row-spacing treatments(20, 40 and 60 cm) in the fourth growing year of switchgrass. Results showed that RS presented a pronounced seasonality under all row-spacing treatments. The highest daily average RS values appeared in August, while the lowest(P<0.05) were in September for each row-spacing. Diurnal variations of RS exhibited single-peak curves in each month. Daily average RS increased significantly as row-spacing enlarged during May and August but there was no significant difference among row-spacing treatments in September. Soil water storage in the depth of 0–100 cm had no significant difference(P>0.05) among the row-spacing treatments, and similar results were found for soil temperature in 0–15 cm soil depth. Soil respiration temperature sensitivity(Q_(10)) values were 1.0–3.7 during the growing months, which were strongly correlated with air temperature in May and June and the soil temperature at 15 cm depth in August. Higher aboveground biomass production and lower RS in most growth months indicated that 20 cm row-spacing treatment was beneficial for increasing the carbon fixation in switchgrass field. Results also implied that it is necessary to take into account the influence of phenology and root growth of switchgrass on soil respiration for accurately evaluating the carbon cycle in the region.
文摘Two loblolly pine (Pinus taeda L.) culture/density studies were established in 1995-1998 across the Lower Coastal Plain and Upper Coastal Plain/Piedmont regions of the southern USA. Each installation contains 12 plots of loblolly pine planted at six levels of density from 741 to 4448 trees/ha in combination with two levels of cultural intensity, operational and intensive. The data from 37 viable installations were used to evaluate the crown ratio and relative spacing relationship of loblolly pine plantations. The effects of planting density, site quality, and cultural intensity on the relationship were investigated with a nonlinear mixed-effects modeling approach. The crown ratio and relative spacing relationship is exceedingly predictable. When loblolly pine plantation stands reached the average live crown ratio of 0.40, a critical point representing a generally acceptable level of tree vigor, the corresponding relative spacing index ranged from 0.11 to 0.20, mainly depending on initial planting density. The information about the crown ratio and relative spacing relationship would be useful for selecting the best intensity and timing of thinning.
基金Open Project Program of Key Laboratory of Yarn Materials Forming and Composite Processing Technology of Zhejiang Province,China(No.MTC2021-02)。
文摘An electromagnetic shielding metacomposite based on the absorbing mechanism was prepared by weaving ferromagnetic microwires into the three-dimensional(3D)fabric.The influence of the ferromagnetic microwire spacing on electromagnetic shielding performance and the electromagnetic shielding mechanism of 3D metacomposites were studied.The total electromagnetic shielding performance increases with the increase of electromagnetic wave frequency.3D metacomposites based on the absorbing mechanism can avoid the secondary pollution of electromagnetic waves,and have great potential in military,civil,aerospace and other fields.
