Nitrogen(N) and seeding rates are important factors affecting grain yield and N use efficiency(NUE) in directseeded rice. However, these factors have not been adequately investigated on direct-seeded and double-season...Nitrogen(N) and seeding rates are important factors affecting grain yield and N use efficiency(NUE) in directseeded rice. However, these factors have not been adequately investigated on direct-seeded and double-season rice(DDR) in Central China. The objective of this study was to evaluate the effects of various N and seeding rates on the grain yield and NUE of an ultrashort-duration variety grown under DDR. Field experiments were conducted in 2018 in Wuxue County and 2019 in Qichun County, Hubei Province, China with four N rates and three seeding rates.The results showed that the grain yield of the ultrashort-duration variety ranged from 6.32 to 8.23 t ha–1with a total growth duration of 85 to 97 days across all treatments with N application. Grain yield was increased significantly by N application in most cases, but seeding rate had an inconsistent effect on grain yield. Furthermore, the response of grain yield to the N rates was much higher than the response to seeding rates. The moderate N rates of 100–150 and 70–120 kg N ha–1in the early and late seasons, respectively, could fully express the yield potential of the ultrashort-duration variety grown under DDR. Remarkably higher N responses and agronomic NUE levels were achieved in the early-season rice compared with the late-season rice due to the difference in indigenous soil N supply capacity(INS) between the two seasons. Seasonal differences in INS and N response should be considered when crop management practices are optimized for achieving high grain yield and NUE in ultrashort-duration variety grown under DDR.展开更多
The paper was to study the effects of seeding rate, water and fertilizer ( N, P, K) coupling on grass yield of forage millet Jigu No. 18 (Setaria itlica). A quadratic regression otthogonal rotation combination wit...The paper was to study the effects of seeding rate, water and fertilizer ( N, P, K) coupling on grass yield of forage millet Jigu No. 18 (Setaria itlica). A quadratic regression otthogonal rotation combination with five factors was designed in pot experiment. The mathematical model between hay yield of forage millet (Y) and soil moisture content ( x1 ), N fertilizer (x2 ), P fertilizer (x3 ), K fertilizer (x4) and seeding rate (x5 ) was established to simulate optimization. The results showed that moisture content, seeding rate, P fertilizer and K fertilizer had important effects on hay yield. Soil moisture content had the biggest impact on yield, followed by seeding rate, P and K fertilizer. The coupling effects of various factors successively were moisture content / seeding rate 〉 K fertil- izer/seeding rate 〉 N / P fertilizer 〉 soil moisture/N fertilizer 〉 soil moisture/ P fertilizer. Moreover, the mathematical model, Y = 20 543. 756 - 565. 570xI -39. 942x2 -23. 102x3 -38. 470x4 - 151. 877x5 + 1. 052x^x2 + 1. 604xIx3 + 12. 953xt x5 - 0. 173x2x3 + 0. 737x4x5 - 2. 292x5^2, was established. The optimum soil moisture and seeding rate were determined as 10% andl5 kg/hm2, respectively. In this scheme, the hay yield was 14 037. 151 0 kg/hm^2 and the economic benefit was 13 887.15 yuan/hm^2 ; the income was increased by 23.68% ( 3 288.98 yuan/hm^2 ) compared to the optimal combination in the test. The results provided a theoretical basis and technical support for forage millet production in Hebei Province.展开更多
[Objectives]This study was conducted to investigate the effects of seeding rate and light on the seed yield and active ingredients of Vernonia anthelmintica.[Methods]With V.anthelmintica L.Willd as the research object...[Objectives]This study was conducted to investigate the effects of seeding rate and light on the seed yield and active ingredients of Vernonia anthelmintica.[Methods]With V.anthelmintica L.Willd as the research object,the seed yield was determined by staged harvesting combined with the actual cutting and measuring method;and the caffeoylquinic acids(CQA)were used as the characterization indexes,and high performance liquid chromatography was used to determine the contents of 3,4-CQA,3,5-CQA and 4,5-CQA of V.anthelmintica seeds under different seeding rate+light treatments,so as to compare the changes in seed yield and chemical composition of V.anthelmintica under different seeding rates and light factors.[Results]In Moyu County,Hetian and similar areas,the suitable planting rate of V.anthelmintica was in the range of 13.5-15.0 kg/hm^(2).For different harvesting purposes,the optimal seeding rate and light conditions of V.Anthelmintica were different.[Conclusions]The seeding rate and light conditions can be used to interfere with the seed yield and quality of V.anthelmintica.展开更多
<span style="font-family:Verdana;">A field trial was conducted at a private farm in AL-Hashimiya district Babylon Governorate—the republic of Iraq during the 2016</span><span style="font...<span style="font-family:Verdana;">A field trial was conducted at a private farm in AL-Hashimiya district Babylon Governorate—the republic of Iraq during the 2016</span><span style="font-family:Verdana;">-</span><span style="font-family:Verdana;">2017 and 2017</span><span style="font-family:Verdana;">-</span><span style="font-family:;" "=""><span style="font-family:Verdana;">2018 growing seasons.</span><span style="color:red;"> </span><span style="font-family:Verdana;">This study was conducted using two irrigation methods, sprinkler and surface irrigation, for each of them had three Tillage methods (zero-tillage</span></span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> medium-tillage</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> deep-tillage) and each tillage system had four seeding rate of wheat yield (120</span><span style="font-family:Verdana;">, </span><span style="font-family:Verdana;">180</span><span style="font-family:Verdana;">, </span><span style="font-family:Verdana;">240</span><span style="font-family:Verdana;">, </span><span style="font-family:Verdana;">300) kg<span style="white-space:nowrap;">∙</span>ha</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;">.</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">Results indicated that the consumptive water use was 557.5 and</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">535.9 mm for surface irrigation and 460.9 and 442.6 mm for sprinkler irrigation in </span><span style="font-family:Verdana;">the </span><span style="font-family:;" "=""><span style="font-family:Verdana;">2016-2017 and 2017-2018 growing seasons. Sprinkler irrigation significantly increased the flag leaf area with no significant effect on plant height. However, the minimum tillage and seeding rate (240 kg<span style="white-space:nowrap;">∙</span>ha</span><sup><span style="font-family:Verdana;">-1</span></sup></span><span style="font-family:;" "=""><span style="font-family:Verdana;">) significantly increased the plant height and flag leaf </span><span style="font-family:Verdana;">area in both growing seasons. For the grain yield, the sprinkler irrigation, m</span><span style="font-family:Verdana;">inimum tillage, and seeding rate (240 </span></span><span style="font-family:;" "=""><span style="font-family:Verdana;">kg<span style="white-space:nowrap;">∙</span>ha</span><sup><span style="font-family:Verdana;">-1</span></sup></span><span style="font-family:;" "=""><span style="font-family:Verdana;">) also increased the plant height and flag leaf area by 13%, 10, % 11%, 11%, 12%, and 14% in both growing seasons, respectively, through an increased number of spikes/m</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;">, the number of grain spike-1, and 1000-grain weight in both growing seasons, respe</span></span><span style="font-family:Verdana;">ctively. Interestingly the grain yield was increased by 33% and 32% in both growing seasons under the effects of these three factors altogether, respectively. It can be concluded that these factors act synergistically, resulting in a significant improvement in the wheat grain-yield of, less consumptive water use, and high water use efficiency.</span>展开更多
To adapt to the diversity of hybrid rice and meet its requirements of precision seeding,a rice pneumatic seeder with adjustable seeding rates was designed in this study.The seeder employed an independent vortex pump t...To adapt to the diversity of hybrid rice and meet its requirements of precision seeding,a rice pneumatic seeder with adjustable seeding rates was designed in this study.The seeder employed an independent vortex pump to provide the air source for the seed metering device.According to the requirements of air flow in the seed metering device,a sub-pipeline and a general pipeline were designed.The performances of the two types of pipelines were verified by the air pressure uniformity tests.The results showed that the sub-pipeline can distribute the air pressure more evenly than the general pipeline.The coefficient of variation of the sub-pipeline pressure was less than 5%.Wuyou 1179 hybrid rice was selected as the experimental object.The field seeding tests were carried out with different negative pressures and different numbers of groups of sucking holes as experimental factors.The results showed that the average qualified rate of seeding was 93.35%when only 2 groups of sucking holes were working under the seed sucking negative pressure of 2.0 kPa.The average qualified rate of seeding was 87.21%when 3 groups of sucking holes were working under the seed sucking negative pressure of 1.6 kPa.The average qualified rate of seeding was 83.73%when 4 groups of sucking holes were working under the seed sucking negative pressure of 1.6 kPa.The average qualified rate of seeding was 79.86%when 5 groups of sucking holes were working under the seed sucking negative pressure of 1.6 kPa.The main factors affecting the seeding effect were analyzed and the feasibility of a rice pneumatic seeder with adjustable seeding rates was verified by field tests.The research results can provide a basis for its practical production and application.展开更多
Rice(Oryza sativa)plants acquired excess photosynthates in the form of nonstructural carbohydrates(NSCs)in their stems and grain.Despite keen interest in rice NSC,the dynamics of NSC accumulation,translocation and re-...Rice(Oryza sativa)plants acquired excess photosynthates in the form of nonstructural carbohydrates(NSCs)in their stems and grain.Despite keen interest in rice NSC,the dynamics of NSC accumulation,translocation and re-accumulation have not yet been well investigated.AG1 and AG2 QTLs associated with flooding tolerance through catalyzing starch into soluble sugar in germinating seeds.Here we conducted three experiments,greenhouse and field to lay the groundwork for large-scale diversity studies on grain NSC and some agronomic traits under direct-seeded rice(DSR)system,using elite lines incorporating AG1,AG2 and AG1-AG2 QTLs into the popular varieties PSB Rc82 and Ciherang-Sub1 along with the donors Kho Hlan On(AG1)and Ma-Zhan Red(AG2).In germinating seedlings,soluble sugars increased,while starch concentration decreased gradually especially in the tolerant checks and AG1-AG2 introgression lines under flooded soil.Soluble sugar accumulation in stem started to increase from the vegetative stage and peaked at the panicle initiation stage then gradually decreased towards the maturity stage.But Sub1-AG lines had higher sugar and starch concentrations at different growth stages than other genotypes in wet season 2016 and dry season 2017.Plant survival rate was positively correlated with the stem NSC at the early vegetative stage(21 days after sowing),and stem NSC was positively associated with plant height at different growth stages.Among the tested seeding rate,the most suitable seeding rate,4 g/m2 with shallow burial depth(0.5 cm),resulted in better seedling establishment,relatively higher seedling vigor index and higher leaf area index under flooding in DSR system.Introgression of AG1-AG2 QTLs had no any negative impact on nonstructural carbohydrate,germination rate,and growth and biomass production.展开更多
To explore the relation of maize grain texture and phenotypic traits with grain thin-layer drying rate,we observed the ultra-structure of maize grain,and tested three traits about the maize grain texture and four phen...To explore the relation of maize grain texture and phenotypic traits with grain thin-layer drying rate,we observed the ultra-structure of maize grain,and tested three traits about the maize grain texture and four phenotypic traits.The vitreous part percentage was different(P〈0.05) among different maize inbred lines.There was a significant relationship between the drying rate with grain texture and phenotypic traits.Main factors that influenced the drying rate were different during different drying stages.New results observed that empirical constants(k and N) in drying equation were different for seed of the 30 inbred lines of maize.The k of simplified diffusion equation and N of page equation were significantly influenced by both grain texture and phenotypic traits.These results could be used as guideline parameters for drying maize seeds having different grain characteristics during different drying stages.展开更多
The influences of N application rate, timing, sowing date and seeding rate on β-glucan and protein content in barley grains were studied through the field experiments in Hangzhou, China during 1997 -2001. Protein con...The influences of N application rate, timing, sowing date and seeding rate on β-glucan and protein content in barley grains were studied through the field experiments in Hangzhou, China during 1997 -2001. Protein content increased with N application rate and with N proportion applied at late stage. β-glucan content also responded significantly to N application rate and timing, but with different pattern with protein content. Of three N rate treatments, the medium N rate (135 kg ha-1) had the highest β-glucan content, being significantly higher than low N rate (90 kg ha-1) and no difference with high N rate (180 kg ha-1). A-mong three N timing treatments, two times of N top-dressing at both tillering and booting stage had significantly higher β-glucan content than once N top-dressing at tillering or booting stage. Sowing date has the dramatic effect on both β-glucan and protein content. Protein content decreased with the delayed sowing, and kernel weight showed opposite tendency. Either earlier or later sowing caused increased β-glucan content relative to sowing in early November, which is the normal date for barley sowing locally. Seeding rate had no significant influence on both β-glucan and protein content.展开更多
When being planted in wide areas in southern China (23°23' - 33°23' N, 98°35' - 120°19' E, sea level above 2.7 - 1285 m), Liangyoupeijiu (LYPJ), a two-line hybrid rice combination, ...When being planted in wide areas in southern China (23°23' - 33°23' N, 98°35' - 120°19' E, sea level above 2.7 - 1285 m), Liangyoupeijiu (LYPJ), a two-line hybrid rice combination, showed a seed setting rate of 75.2 - 77.2%, which was lower by 4.3 - 7.5 percent point than that of an indica hybrid rice Shanyou 63 (CK), with similar values of grain yield and coefficients of variation to CK. Sowing during 5-25th of May in Nanjing (32°3' N, 118°48' E), China, LYPJ headed before 4th September, and gave a seed setting rate of 75 - 90%, and grain yield over 1 kg/m2. If the sowing date was delayed to 14 - 15th, June, its heading date would be as late as 17th - 21st September, and seed setting rate would be declined by 10 - 15% in comparison with that on a suitable sowing date. When flowering took place at an average daily temperature range of 13.7 - 28.5℃ for five days, the spikelet fertility (SF) would be increased by 1.9- 10.7%, for each increment of 1℃. The suitable (SF≥90%) and safe (SF≥75%) temperatures for flowering stage were indicated to be 26.5℃ and 22.9℃, respectively. To get a high and stable seed set in cultivating LYPJ, it was recommended that LYPJ would be planted in the areas south of 34癗, and the favorable average daily temperature during flowering stage should be at 26 - 28℃.展开更多
The structures of mature embryo sacs in 13 genetic stock lines of autotetraploid rice (Oryza sativa L.), including indica, japonica and javanica, were studied by using the whole-mount stain-clearing laser scanning c...The structures of mature embryo sacs in 13 genetic stock lines of autotetraploid rice (Oryza sativa L.), including indica, japonica and javanica, were studied by using the whole-mount stain-clearing laser scanning confocal microscopy (WCLSM). Among the 13 autotetraploid rice, the majority of ovaries possess normal polygonum-type embryo sacs, while a few ovaries were characterized by abnormal embryo sacs. The abnormalities of embryo sacs could be classified into six categories, i. e. no female germ unit, abnormal polar nuclei, embryo sac degeneration, no egg apparatus, small embryo sac and 'double set' of embryo sacs. The frequency of abnormal embryo sac in japonica (26.6%) was higher than that in indica (19.34%). In addition, the major abnormalities in each autotetraploid line varied, suggesting that the abnormalities may be related to the genotypes of the varieties.展开更多
The germination of pollen grain in vitro and the growth of pollen tube in the pistil of rice were observed with a microscope. The stigma was removed at different time points after pollination to study its effect on se...The germination of pollen grain in vitro and the growth of pollen tube in the pistil of rice were observed with a microscope. The stigma was removed at different time points after pollination to study its effect on seed setting rate. The rice pollen grain started to germinate at 2 min after pollination and the pollen tube penetrated stigma into style in 5-10 min, 30 min later the end of pollen tube reached the bottom of ovary, and only some pollen tubes arrived at embryo sac at 40 min after pollination. Meanwhile, a small amount of callose began to deposit in the pollen tubes, a great deal of callose was observed at 50 min after pollination, whereas the pollen grain began to shrink. The growing rates of pollen tube in the rice stigma, style and ovary were 1500, 5000, and 5400 μm/h, respectively. The seed setting rate was quite low when the stigma was removed at about 10-15 min after pollination, gradually increased when it removed at 20 min to 50 min after pollination, and over 60% when it removed at 50 min after pollination and finally tended to be stable.展开更多
Na4EDTA and EDTA were adopted as new additives to intensify the seeded precipitation process of sodium aluminate solution. The effects of the two additives at certain concentrations on the seeded precipitation rate of...Na4EDTA and EDTA were adopted as new additives to intensify the seeded precipitation process of sodium aluminate solution. The effects of the two additives at certain concentrations on the seeded precipitation rate of sodium aluminate solution, particle size distribution (PSD) and morphology of precipitated gibbsite were investigated using titration method, particle size analyzer and scanning electron microscope (SEM), respectively. The results show that the two additives can accelerate the seeded precipitation rate of sodium aluminate solution. At relatively high concentration, the facilitative effect of EDTA on sodium aluminate solution is more obvious than that of Na4EDTA. EDTA makes gibbsite particles thinner than Na4EDTA. The Na+ and H+ result in the different effects on the seeded precipitation rate of sodium aluminate solution in spite of the same EDTA anion in the two additives.展开更多
Comparison of seed setting rate, plant height and Cheng's morphological traits were made between the F_2 progeny of indica-japonica hybrids, 02428/Pei'ai 64 and Taichung 65/Teqing. There existed resemblance no...Comparison of seed setting rate, plant height and Cheng's morphological traits were made between the F_2 progeny of indica-japonica hybrids, 02428/Pei'ai 64 and Taichung 65/Teqing. There existed resemblance normal distribution in plant height, and the distribution had no relationship with the seed setting rate and plant height in F_1 progeny, suggesting that there were no gametic selection for the plant height in the F_2 progeny of indica-japoniea hybrids. An average seed setting rate of the F_2 was equal to the F_1 populations in the recombination of 02428/Pei'ai 64 in which there was an excellent cross compatibility, but the remarkable increase in the seed setting rate from the F_1 to F_2 in Taichung 65/Teqing, indicating that gametic selection only took place in the indica-japonica crosses with low cross compatibility while null or little in the hybrids with high compatibility. There were many intermediate types among the leaf pubescence, color of hull at heading, and length of the first and second panicle internode, and these Cheng's morphological traits was distributed normally; there were also a little intermediate types in hull hairness and phenol reaction with bi-peak distribution; while length to width ratio of grain was inclined to the japonica types obviously showing a skewed distribution in the F2 population. Although Cheng's morphological traits in F_2 populations had inconsistent distribution types, Cheng's morphological traits index showed normal distribution, which suggested that intermediate types, i.e. indicalinous or japonicalinous, were primary in F_2 population.展开更多
Based on a series of polyploid indica-japonica hybrid plant lines obtained from a new breeding strategy of using double predominance of wide cross and polyploidization to breed super flee, two polyploid indica-japonic...Based on a series of polyploid indica-japonica hybrid plant lines obtained from a new breeding strategy of using double predominance of wide cross and polyploidization to breed super flee, two polyploid indica-japonica hybrids, PSR073 and PSR120 were studied in their growth periods to show the powerful heterosis in a larger scale and to study the characteristics of polyploid indica-japonica hybrids more elaborately. The leaf age, tiller growth, flowering habits, and agronomic traits of them were observed to analyze their growth habits and characteristics. The results showed that the.agronomic traits of PSR073 and PSR120, such as the plant height, panicle length, grain length, grain width, and 1000-grain weight, all acquired obvious predominance of polyploidy, and that the seed setting rate was more than 83%. No significant difference was observed between the two tetraploids and common diploids in the leaf age, tiller growth, and flowering habits. It was concluded that the characteristics of the two powerful heterosis polyploid hybrids were different from those of the polyploid rice reported earlier. Wide cross and polyploidization had no negative effects on their growth habits and characteristics; on the contrary these had powerful heterosis. This had provided theoretic and practical evidences for their application to agricultural production.展开更多
Using photo-thermo sensitive genie male rice (PTGMS) Pei' ai 64S, W7415S, W6154S, N26S, Annong S, Nongken 58S, 7001S and 5088S as female parents and conventional indica lines 8258 and U89 as male parents, the fact...Using photo-thermo sensitive genie male rice (PTGMS) Pei' ai 64S, W7415S, W6154S, N26S, Annong S, Nongken 58S, 7001S and 5088S as female parents and conventional indica lines 8258 and U89 as male parents, the factors affecting outcrossed seed-setting were analyzed. The PTGMS had obstacles in outcrossed seed setting influenced by inheritance and environment at varying degrees. Environmental temperature was regarded as the main factor that resulted in the outcrossed seed-setting obstacles. The sensitive stage was at the early stage of grain filling for outcrossed seed setting. There existed remarkable differences at the sensitivity stage, the duration of sensitive period, the sensitive level and the effective level of outcrossed seed-setting obstacles caused by environmental temperature among different PTGMS lines. Therefore, attention should be paid to outcrossed seed-setting obstacles in selection and utilization of PTGMS lines.展开更多
The quality of seedbed after sowing such as soil surface roughness is one of the key factors affecting the seedling emergence of rapeseed,which ultimately affected crop yield.However,the effect of soil surface roughne...The quality of seedbed after sowing such as soil surface roughness is one of the key factors affecting the seedling emergence of rapeseed,which ultimately affected crop yield.However,the effect of soil surface roughness on seedling emergence and yield of rapeseed is still unclear.In this study,field experiments at the experimental site of Jianli and Shayang were carried out.Three treatments were designed:relative slow(M1),medium(M2),and fast(M3)forward speed of the unit.Soil surface roughness measured by a 3D laser scanner,seed quantity of the seeder,emergence rate and yield of rapeseed were determined to investigate the soil surface roughness effect on emergence rate and yield of rapeseed.The results showed that as the forward speed of the unit increased,the compartment surface became rougher.Compared with the M1 and M2 treatments,soil surface roughness under the M3 treatment increased by 36.5%and 9.8%,respectively.The actual seed quantity of the seeder under different treatments ranged from 3806.56 to 4158.18 g/hm2.The average error rate of the actual and theoretical seed quantity was less than 5%,which met the operational quality requirements for seeding rapeseed crops.As the forward speed of the unit increased,the actual seed quantity of the seeder gradually increased while the emergence rate and yield of rapeseed decreased.The seed quantity under the M3 treatment increased by 6.9%and 4.7%,while the emergence rate of rapeseed decreased by 3.3%and 2.0%,and the yield decreased by 23.2%and 13.1%,compared with the M1 and M2 treatments,respectively.Correlation analysis indicated that emergence rate and yield of rapeseed were negatively influenced by soil surface roughness.Considering rapeseed emergence rate,seed yield,and economic benefits,the M1 treatment was recommended.But considering the factor that the M1 treatment may reduce the unit operation efficiency,and thus resulting in lower cost of production,M2 could be recommended in actual farming.The results of this study laid a theoretical foundation for analyzing the relationship between the seedbed surface quality and seedling emergence and yield.展开更多
The purpose of this study was to promote the development of large-scale agricultural machines in China and meet the demand of air seeder localization.This study investigated the relationship between the working parame...The purpose of this study was to promote the development of large-scale agricultural machines in China and meet the demand of air seeder localization.This study investigated the relationship between the working parameters and the performance of pneumatic seeding system,Cangmai 6004 wheat seed was used.A test platform for pneumatic seeding systems was developed,and then a series of experiments were performed based on the quadratic general rotary unitized design and response surface methodology(RSM).The seeding rate and the air flow rate were selected as affecting factors,coefficient of variation(CV)of evenness of feeding rate between rows and CV of seeding stability of total rows were assigned as the test indexes.Regression models between factors and indexes were established,and finally,an optimal equation based on this pneumatic seeding system were established as well,which can determine the proper air flow rate once the seeding rate was set based on the practical agronomic requirements.For example,when the seeding rate is set as 250 kg/hm^(2),the proper air flow rate of 7.53 m3/min can be obtained.The verification experiment results showed that the predicted working parameters obtained by RSM were feasible,which might provide a theoretical basis for further research of pneumatic seed metering systems.展开更多
To increase the accuracy and real-time performance of on-line assessment of maize planting,a CAN bus based maize monitoring system for precision planting was designed and tested both in laboratory and field.The system...To increase the accuracy and real-time performance of on-line assessment of maize planting,a CAN bus based maize monitoring system for precision planting was designed and tested both in laboratory and field.The system was mainly comprised of:(a)seeding rate sensors based on opposite-type infrared photoelectric cell for counting the dropping seeds;(b)a decimeter GPS receiver for acquiring planter position and operation speed;(c)a vehicle monitoring terminal based on ARM Cotex-m4 core chip to acquire and process the whole-system data;(d)a touchscreen monitor to display the planter performance for the operator;and(e)a buzzer alarm to sound a warning when skip and double seeding happened.Taking the applicability,dependability and feasibility of the monitoring system into consideration,the opposite-type infrared photoelectric sensors were selected and their deployment strategies in the 6-port seed tube were analyzed.To decrease the average response time,a distributed information communication structure was adopted.In this information communication mode,collectors were designed for each individual sensor and communicated with sensors through two-wire CAN bus.A sensor together with the designed collector is called a sensor node,and each of them worked individually and took the responsibility for acquiring,processing,and transiting the on-going information.Laboratory test results showed that the random error distribution was approximately normal,and by liner analysis,the system observed value and the true value had as a liner relationship with coefficient of determination R^(2)=0.9991.Series of field tests showed that the seeding rate maximum relative error of the 6-port seed tube was 2.92%,and the maximum root mean square error(RMSE)was about 1.64%.The monitoring system,including sensor nodes,vehicle monitoring terminal and a touch-screen monitor,was proved to be dependable and stable with more than 14 d of continuous experiments in field.展开更多
基金supported by the National Natural Science Foundation of China(31971845 and 32101819)the earmarked fund for China Agriculture Research System(CARS-01-20)the China Postdoctoral Science Foundation(2021M691179)。
文摘Nitrogen(N) and seeding rates are important factors affecting grain yield and N use efficiency(NUE) in directseeded rice. However, these factors have not been adequately investigated on direct-seeded and double-season rice(DDR) in Central China. The objective of this study was to evaluate the effects of various N and seeding rates on the grain yield and NUE of an ultrashort-duration variety grown under DDR. Field experiments were conducted in 2018 in Wuxue County and 2019 in Qichun County, Hubei Province, China with four N rates and three seeding rates.The results showed that the grain yield of the ultrashort-duration variety ranged from 6.32 to 8.23 t ha–1with a total growth duration of 85 to 97 days across all treatments with N application. Grain yield was increased significantly by N application in most cases, but seeding rate had an inconsistent effect on grain yield. Furthermore, the response of grain yield to the N rates was much higher than the response to seeding rates. The moderate N rates of 100–150 and 70–120 kg N ha–1in the early and late seasons, respectively, could fully express the yield potential of the ultrashort-duration variety grown under DDR. Remarkably higher N responses and agronomic NUE levels were achieved in the early-season rice compared with the late-season rice due to the difference in indigenous soil N supply capacity(INS) between the two seasons. Seasonal differences in INS and N response should be considered when crop management practices are optimized for achieving high grain yield and NUE in ultrashort-duration variety grown under DDR.
基金Special Fund for Agro-scientific Research in the Public Interest Research and Demonstration of Development and Utilization Technology of Forage Feed Resources in Pastoral Areas(20120304201)
文摘The paper was to study the effects of seeding rate, water and fertilizer ( N, P, K) coupling on grass yield of forage millet Jigu No. 18 (Setaria itlica). A quadratic regression otthogonal rotation combination with five factors was designed in pot experiment. The mathematical model between hay yield of forage millet (Y) and soil moisture content ( x1 ), N fertilizer (x2 ), P fertilizer (x3 ), K fertilizer (x4) and seeding rate (x5 ) was established to simulate optimization. The results showed that moisture content, seeding rate, P fertilizer and K fertilizer had important effects on hay yield. Soil moisture content had the biggest impact on yield, followed by seeding rate, P and K fertilizer. The coupling effects of various factors successively were moisture content / seeding rate 〉 K fertil- izer/seeding rate 〉 N / P fertilizer 〉 soil moisture/N fertilizer 〉 soil moisture/ P fertilizer. Moreover, the mathematical model, Y = 20 543. 756 - 565. 570xI -39. 942x2 -23. 102x3 -38. 470x4 - 151. 877x5 + 1. 052x^x2 + 1. 604xIx3 + 12. 953xt x5 - 0. 173x2x3 + 0. 737x4x5 - 2. 292x5^2, was established. The optimum soil moisture and seeding rate were determined as 10% andl5 kg/hm2, respectively. In this scheme, the hay yield was 14 037. 151 0 kg/hm^2 and the economic benefit was 13 887.15 yuan/hm^2 ; the income was increased by 23.68% ( 3 288.98 yuan/hm^2 ) compared to the optimal combination in the test. The results provided a theoretical basis and technical support for forage millet production in Hebei Province.
基金Autonomous Region Science and Technology Supporting Xinjiang Project Plant Project(2016E02007)the West Light Foundation of The Chinese Academy of Sciences(2019-FPGGRC-004).
文摘[Objectives]This study was conducted to investigate the effects of seeding rate and light on the seed yield and active ingredients of Vernonia anthelmintica.[Methods]With V.anthelmintica L.Willd as the research object,the seed yield was determined by staged harvesting combined with the actual cutting and measuring method;and the caffeoylquinic acids(CQA)were used as the characterization indexes,and high performance liquid chromatography was used to determine the contents of 3,4-CQA,3,5-CQA and 4,5-CQA of V.anthelmintica seeds under different seeding rate+light treatments,so as to compare the changes in seed yield and chemical composition of V.anthelmintica under different seeding rates and light factors.[Results]In Moyu County,Hetian and similar areas,the suitable planting rate of V.anthelmintica was in the range of 13.5-15.0 kg/hm^(2).For different harvesting purposes,the optimal seeding rate and light conditions of V.Anthelmintica were different.[Conclusions]The seeding rate and light conditions can be used to interfere with the seed yield and quality of V.anthelmintica.
文摘<span style="font-family:Verdana;">A field trial was conducted at a private farm in AL-Hashimiya district Babylon Governorate—the republic of Iraq during the 2016</span><span style="font-family:Verdana;">-</span><span style="font-family:Verdana;">2017 and 2017</span><span style="font-family:Verdana;">-</span><span style="font-family:;" "=""><span style="font-family:Verdana;">2018 growing seasons.</span><span style="color:red;"> </span><span style="font-family:Verdana;">This study was conducted using two irrigation methods, sprinkler and surface irrigation, for each of them had three Tillage methods (zero-tillage</span></span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> medium-tillage</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> deep-tillage) and each tillage system had four seeding rate of wheat yield (120</span><span style="font-family:Verdana;">, </span><span style="font-family:Verdana;">180</span><span style="font-family:Verdana;">, </span><span style="font-family:Verdana;">240</span><span style="font-family:Verdana;">, </span><span style="font-family:Verdana;">300) kg<span style="white-space:nowrap;">∙</span>ha</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;">.</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">Results indicated that the consumptive water use was 557.5 and</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">535.9 mm for surface irrigation and 460.9 and 442.6 mm for sprinkler irrigation in </span><span style="font-family:Verdana;">the </span><span style="font-family:;" "=""><span style="font-family:Verdana;">2016-2017 and 2017-2018 growing seasons. Sprinkler irrigation significantly increased the flag leaf area with no significant effect on plant height. However, the minimum tillage and seeding rate (240 kg<span style="white-space:nowrap;">∙</span>ha</span><sup><span style="font-family:Verdana;">-1</span></sup></span><span style="font-family:;" "=""><span style="font-family:Verdana;">) significantly increased the plant height and flag leaf </span><span style="font-family:Verdana;">area in both growing seasons. For the grain yield, the sprinkler irrigation, m</span><span style="font-family:Verdana;">inimum tillage, and seeding rate (240 </span></span><span style="font-family:;" "=""><span style="font-family:Verdana;">kg<span style="white-space:nowrap;">∙</span>ha</span><sup><span style="font-family:Verdana;">-1</span></sup></span><span style="font-family:;" "=""><span style="font-family:Verdana;">) also increased the plant height and flag leaf area by 13%, 10, % 11%, 11%, 12%, and 14% in both growing seasons, respectively, through an increased number of spikes/m</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;">, the number of grain spike-1, and 1000-grain weight in both growing seasons, respe</span></span><span style="font-family:Verdana;">ctively. Interestingly the grain yield was increased by 33% and 32% in both growing seasons under the effects of these three factors altogether, respectively. It can be concluded that these factors act synergistically, resulting in a significant improvement in the wheat grain-yield of, less consumptive water use, and high water use efficiency.</span>
基金The authors are thankful for funding from the National Natural Science Foundation of China under Grant No.31871529,the earmarked fund for the National key research program of China under Grant No.2017YFD07000700,2017YFD07000704,and China Agriculture Research System under Grant CARS-01-41.The authos also acknowledge the anonymous reviewers for their critical comments and suggestions for improving the manuscript.
文摘To adapt to the diversity of hybrid rice and meet its requirements of precision seeding,a rice pneumatic seeder with adjustable seeding rates was designed in this study.The seeder employed an independent vortex pump to provide the air source for the seed metering device.According to the requirements of air flow in the seed metering device,a sub-pipeline and a general pipeline were designed.The performances of the two types of pipelines were verified by the air pressure uniformity tests.The results showed that the sub-pipeline can distribute the air pressure more evenly than the general pipeline.The coefficient of variation of the sub-pipeline pressure was less than 5%.Wuyou 1179 hybrid rice was selected as the experimental object.The field seeding tests were carried out with different negative pressures and different numbers of groups of sucking holes as experimental factors.The results showed that the average qualified rate of seeding was 93.35%when only 2 groups of sucking holes were working under the seed sucking negative pressure of 2.0 kPa.The average qualified rate of seeding was 87.21%when 3 groups of sucking holes were working under the seed sucking negative pressure of 1.6 kPa.The average qualified rate of seeding was 83.73%when 4 groups of sucking holes were working under the seed sucking negative pressure of 1.6 kPa.The average qualified rate of seeding was 79.86%when 5 groups of sucking holes were working under the seed sucking negative pressure of 1.6 kPa.The main factors affecting the seeding effect were analyzed and the feasibility of a rice pneumatic seeder with adjustable seeding rates was verified by field tests.The research results can provide a basis for its practical production and application.
基金This study was supported by the Lee Foundation Scholarship(PhD)through International Rice Research Institute,the PhilippinesThe authors are thankful to Melencio J.APOSTOL for his technical assistance,and to Frederickson ENTILA and Evangelina S.ELLA for helpful suggestions and comments during this study.
文摘Rice(Oryza sativa)plants acquired excess photosynthates in the form of nonstructural carbohydrates(NSCs)in their stems and grain.Despite keen interest in rice NSC,the dynamics of NSC accumulation,translocation and re-accumulation have not yet been well investigated.AG1 and AG2 QTLs associated with flooding tolerance through catalyzing starch into soluble sugar in germinating seeds.Here we conducted three experiments,greenhouse and field to lay the groundwork for large-scale diversity studies on grain NSC and some agronomic traits under direct-seeded rice(DSR)system,using elite lines incorporating AG1,AG2 and AG1-AG2 QTLs into the popular varieties PSB Rc82 and Ciherang-Sub1 along with the donors Kho Hlan On(AG1)and Ma-Zhan Red(AG2).In germinating seedlings,soluble sugars increased,while starch concentration decreased gradually especially in the tolerant checks and AG1-AG2 introgression lines under flooded soil.Soluble sugar accumulation in stem started to increase from the vegetative stage and peaked at the panicle initiation stage then gradually decreased towards the maturity stage.But Sub1-AG lines had higher sugar and starch concentrations at different growth stages than other genotypes in wet season 2016 and dry season 2017.Plant survival rate was positively correlated with the stem NSC at the early vegetative stage(21 days after sowing),and stem NSC was positively associated with plant height at different growth stages.Among the tested seeding rate,the most suitable seeding rate,4 g/m2 with shallow burial depth(0.5 cm),resulted in better seedling establishment,relatively higher seedling vigor index and higher leaf area index under flooding in DSR system.Introgression of AG1-AG2 QTLs had no any negative impact on nonstructural carbohydrate,germination rate,and growth and biomass production.
基金funded by the Shandong Modern Agricultural Technology & Industry System,Chinathe Seed Production Technology and Development of Key Equipment and Demonstration(201203052) from Special Funds for Agro-scientific Research in the Public Interest,China+1 种基金the Maize Germplasm Innovation of Shandong Seed Industry Project,Chinathe Shandong Province Modern Agriculture Industrial Production Technology System,China (SDAIT-01-022-02)
文摘To explore the relation of maize grain texture and phenotypic traits with grain thin-layer drying rate,we observed the ultra-structure of maize grain,and tested three traits about the maize grain texture and four phenotypic traits.The vitreous part percentage was different(P〈0.05) among different maize inbred lines.There was a significant relationship between the drying rate with grain texture and phenotypic traits.Main factors that influenced the drying rate were different during different drying stages.New results observed that empirical constants(k and N) in drying equation were different for seed of the 30 inbred lines of maize.The k of simplified diffusion equation and N of page equation were significantly influenced by both grain texture and phenotypic traits.These results could be used as guideline parameters for drying maize seeds having different grain characteristics during different drying stages.
基金the National Natural Science Foundation of China(39870506) Zhejiang Natural Science Foundation(397259).
文摘The influences of N application rate, timing, sowing date and seeding rate on β-glucan and protein content in barley grains were studied through the field experiments in Hangzhou, China during 1997 -2001. Protein content increased with N application rate and with N proportion applied at late stage. β-glucan content also responded significantly to N application rate and timing, but with different pattern with protein content. Of three N rate treatments, the medium N rate (135 kg ha-1) had the highest β-glucan content, being significantly higher than low N rate (90 kg ha-1) and no difference with high N rate (180 kg ha-1). A-mong three N timing treatments, two times of N top-dressing at both tillering and booting stage had significantly higher β-glucan content than once N top-dressing at tillering or booting stage. Sowing date has the dramatic effect on both β-glucan and protein content. Protein content decreased with the delayed sowing, and kernel weight showed opposite tendency. Either earlier or later sowing caused increased β-glucan content relative to sowing in early November, which is the normal date for barley sowing locally. Seeding rate had no significant influence on both β-glucan and protein content.
文摘When being planted in wide areas in southern China (23°23' - 33°23' N, 98°35' - 120°19' E, sea level above 2.7 - 1285 m), Liangyoupeijiu (LYPJ), a two-line hybrid rice combination, showed a seed setting rate of 75.2 - 77.2%, which was lower by 4.3 - 7.5 percent point than that of an indica hybrid rice Shanyou 63 (CK), with similar values of grain yield and coefficients of variation to CK. Sowing during 5-25th of May in Nanjing (32°3' N, 118°48' E), China, LYPJ headed before 4th September, and gave a seed setting rate of 75 - 90%, and grain yield over 1 kg/m2. If the sowing date was delayed to 14 - 15th, June, its heading date would be as late as 17th - 21st September, and seed setting rate would be declined by 10 - 15% in comparison with that on a suitable sowing date. When flowering took place at an average daily temperature range of 13.7 - 28.5℃ for five days, the spikelet fertility (SF) would be increased by 1.9- 10.7%, for each increment of 1℃. The suitable (SF≥90%) and safe (SF≥75%) temperatures for flowering stage were indicated to be 26.5℃ and 22.9℃, respectively. To get a high and stable seed set in cultivating LYPJ, it was recommended that LYPJ would be planted in the areas south of 34癗, and the favorable average daily temperature during flowering stage should be at 26 - 28℃.
基金supported by the National Natural Science Foundations of China(Grant No.30270814)the Teaching and Research Award Program for 0utstanding Young Teachers in Higher Education Institutions of M0E,P.R.China.
文摘The structures of mature embryo sacs in 13 genetic stock lines of autotetraploid rice (Oryza sativa L.), including indica, japonica and javanica, were studied by using the whole-mount stain-clearing laser scanning confocal microscopy (WCLSM). Among the 13 autotetraploid rice, the majority of ovaries possess normal polygonum-type embryo sacs, while a few ovaries were characterized by abnormal embryo sacs. The abnormalities of embryo sacs could be classified into six categories, i. e. no female germ unit, abnormal polar nuclei, embryo sac degeneration, no egg apparatus, small embryo sac and 'double set' of embryo sacs. The frequency of abnormal embryo sac in japonica (26.6%) was higher than that in indica (19.34%). In addition, the major abnormalities in each autotetraploid line varied, suggesting that the abnormalities may be related to the genotypes of the varieties.
基金the National Natural Science Foundation of China (Grants Nos. 30070454 and 30471045)
文摘The germination of pollen grain in vitro and the growth of pollen tube in the pistil of rice were observed with a microscope. The stigma was removed at different time points after pollination to study its effect on seed setting rate. The rice pollen grain started to germinate at 2 min after pollination and the pollen tube penetrated stigma into style in 5-10 min, 30 min later the end of pollen tube reached the bottom of ovary, and only some pollen tubes arrived at embryo sac at 40 min after pollination. Meanwhile, a small amount of callose began to deposit in the pollen tubes, a great deal of callose was observed at 50 min after pollination, whereas the pollen grain began to shrink. The growing rates of pollen tube in the rice stigma, style and ovary were 1500, 5000, and 5400 μm/h, respectively. The seed setting rate was quite low when the stigma was removed at about 10-15 min after pollination, gradually increased when it removed at 20 min to 50 min after pollination, and over 60% when it removed at 50 min after pollination and finally tended to be stable.
基金Project(20476107) supported by the National Natural Science Foundation of ChinaProject(2005CB623702) supported by the National Basic Research Program of China
文摘Na4EDTA and EDTA were adopted as new additives to intensify the seeded precipitation process of sodium aluminate solution. The effects of the two additives at certain concentrations on the seeded precipitation rate of sodium aluminate solution, particle size distribution (PSD) and morphology of precipitated gibbsite were investigated using titration method, particle size analyzer and scanning electron microscope (SEM), respectively. The results show that the two additives can accelerate the seeded precipitation rate of sodium aluminate solution. At relatively high concentration, the facilitative effect of EDTA on sodium aluminate solution is more obvious than that of Na4EDTA. EDTA makes gibbsite particles thinner than Na4EDTA. The Na+ and H+ result in the different effects on the seeded precipitation rate of sodium aluminate solution in spite of the same EDTA anion in the two additives.
文摘Comparison of seed setting rate, plant height and Cheng's morphological traits were made between the F_2 progeny of indica-japonica hybrids, 02428/Pei'ai 64 and Taichung 65/Teqing. There existed resemblance normal distribution in plant height, and the distribution had no relationship with the seed setting rate and plant height in F_1 progeny, suggesting that there were no gametic selection for the plant height in the F_2 progeny of indica-japoniea hybrids. An average seed setting rate of the F_2 was equal to the F_1 populations in the recombination of 02428/Pei'ai 64 in which there was an excellent cross compatibility, but the remarkable increase in the seed setting rate from the F_1 to F_2 in Taichung 65/Teqing, indicating that gametic selection only took place in the indica-japonica crosses with low cross compatibility while null or little in the hybrids with high compatibility. There were many intermediate types among the leaf pubescence, color of hull at heading, and length of the first and second panicle internode, and these Cheng's morphological traits was distributed normally; there were also a little intermediate types in hull hairness and phenol reaction with bi-peak distribution; while length to width ratio of grain was inclined to the japonica types obviously showing a skewed distribution in the F2 population. Although Cheng's morphological traits in F_2 populations had inconsistent distribution types, Cheng's morphological traits index showed normal distribution, which suggested that intermediate types, i.e. indicalinous or japonicalinous, were primary in F_2 population.
文摘Based on a series of polyploid indica-japonica hybrid plant lines obtained from a new breeding strategy of using double predominance of wide cross and polyploidization to breed super flee, two polyploid indica-japonica hybrids, PSR073 and PSR120 were studied in their growth periods to show the powerful heterosis in a larger scale and to study the characteristics of polyploid indica-japonica hybrids more elaborately. The leaf age, tiller growth, flowering habits, and agronomic traits of them were observed to analyze their growth habits and characteristics. The results showed that the.agronomic traits of PSR073 and PSR120, such as the plant height, panicle length, grain length, grain width, and 1000-grain weight, all acquired obvious predominance of polyploidy, and that the seed setting rate was more than 83%. No significant difference was observed between the two tetraploids and common diploids in the leaf age, tiller growth, and flowering habits. It was concluded that the characteristics of the two powerful heterosis polyploid hybrids were different from those of the polyploid rice reported earlier. Wide cross and polyploidization had no negative effects on their growth habits and characteristics; on the contrary these had powerful heterosis. This had provided theoretic and practical evidences for their application to agricultural production.
文摘Using photo-thermo sensitive genie male rice (PTGMS) Pei' ai 64S, W7415S, W6154S, N26S, Annong S, Nongken 58S, 7001S and 5088S as female parents and conventional indica lines 8258 and U89 as male parents, the factors affecting outcrossed seed-setting were analyzed. The PTGMS had obstacles in outcrossed seed setting influenced by inheritance and environment at varying degrees. Environmental temperature was regarded as the main factor that resulted in the outcrossed seed-setting obstacles. The sensitive stage was at the early stage of grain filling for outcrossed seed setting. There existed remarkable differences at the sensitivity stage, the duration of sensitive period, the sensitive level and the effective level of outcrossed seed-setting obstacles caused by environmental temperature among different PTGMS lines. Therefore, attention should be paid to outcrossed seed-setting obstacles in selection and utilization of PTGMS lines.
基金This work was financially supported by the China Postdoctoral Science Foundation(Grant No.2020M672371)the National Key Research and Development Program of China(Grant No.2018YFD0200901)+1 种基金the Postdoctoral Science and Technology Activities project of Hubei Provincethe Talent Introduction Project of Xihua University(Grant No.Z221029).
文摘The quality of seedbed after sowing such as soil surface roughness is one of the key factors affecting the seedling emergence of rapeseed,which ultimately affected crop yield.However,the effect of soil surface roughness on seedling emergence and yield of rapeseed is still unclear.In this study,field experiments at the experimental site of Jianli and Shayang were carried out.Three treatments were designed:relative slow(M1),medium(M2),and fast(M3)forward speed of the unit.Soil surface roughness measured by a 3D laser scanner,seed quantity of the seeder,emergence rate and yield of rapeseed were determined to investigate the soil surface roughness effect on emergence rate and yield of rapeseed.The results showed that as the forward speed of the unit increased,the compartment surface became rougher.Compared with the M1 and M2 treatments,soil surface roughness under the M3 treatment increased by 36.5%and 9.8%,respectively.The actual seed quantity of the seeder under different treatments ranged from 3806.56 to 4158.18 g/hm2.The average error rate of the actual and theoretical seed quantity was less than 5%,which met the operational quality requirements for seeding rapeseed crops.As the forward speed of the unit increased,the actual seed quantity of the seeder gradually increased while the emergence rate and yield of rapeseed decreased.The seed quantity under the M3 treatment increased by 6.9%and 4.7%,while the emergence rate of rapeseed decreased by 3.3%and 2.0%,and the yield decreased by 23.2%and 13.1%,compared with the M1 and M2 treatments,respectively.Correlation analysis indicated that emergence rate and yield of rapeseed were negatively influenced by soil surface roughness.Considering rapeseed emergence rate,seed yield,and economic benefits,the M1 treatment was recommended.But considering the factor that the M1 treatment may reduce the unit operation efficiency,and thus resulting in lower cost of production,M2 could be recommended in actual farming.The results of this study laid a theoretical foundation for analyzing the relationship between the seedbed surface quality and seedling emergence and yield.
基金the Chinese Academy of Agricultural Mechanization Sciences,State Key Laboratory of Soil Plant Machinery System Technology,and the supports of the Rural Areas National Key Technology R&D Program during the Twelfth Five-year Plan Period-Development of Farm Work Equipment Matched on Large Horsepower Tractors(2011BAD20B03).
文摘The purpose of this study was to promote the development of large-scale agricultural machines in China and meet the demand of air seeder localization.This study investigated the relationship between the working parameters and the performance of pneumatic seeding system,Cangmai 6004 wheat seed was used.A test platform for pneumatic seeding systems was developed,and then a series of experiments were performed based on the quadratic general rotary unitized design and response surface methodology(RSM).The seeding rate and the air flow rate were selected as affecting factors,coefficient of variation(CV)of evenness of feeding rate between rows and CV of seeding stability of total rows were assigned as the test indexes.Regression models between factors and indexes were established,and finally,an optimal equation based on this pneumatic seeding system were established as well,which can determine the proper air flow rate once the seeding rate was set based on the practical agronomic requirements.For example,when the seeding rate is set as 250 kg/hm^(2),the proper air flow rate of 7.53 m3/min can be obtained.The verification experiment results showed that the predicted working parameters obtained by RSM were feasible,which might provide a theoretical basis for further research of pneumatic seed metering systems.
基金We acknowledge that this work was financially supported by the National Key Research and Development Program of China(2017YFD0700604,2017YFD0700701)the Beijing Science&Technology Plan Project(D161100003216001)the academy of science and technology innovation team program supported by Beijing Academy of Agriculture and Forestry(JNKYT201607).
文摘To increase the accuracy and real-time performance of on-line assessment of maize planting,a CAN bus based maize monitoring system for precision planting was designed and tested both in laboratory and field.The system was mainly comprised of:(a)seeding rate sensors based on opposite-type infrared photoelectric cell for counting the dropping seeds;(b)a decimeter GPS receiver for acquiring planter position and operation speed;(c)a vehicle monitoring terminal based on ARM Cotex-m4 core chip to acquire and process the whole-system data;(d)a touchscreen monitor to display the planter performance for the operator;and(e)a buzzer alarm to sound a warning when skip and double seeding happened.Taking the applicability,dependability and feasibility of the monitoring system into consideration,the opposite-type infrared photoelectric sensors were selected and their deployment strategies in the 6-port seed tube were analyzed.To decrease the average response time,a distributed information communication structure was adopted.In this information communication mode,collectors were designed for each individual sensor and communicated with sensors through two-wire CAN bus.A sensor together with the designed collector is called a sensor node,and each of them worked individually and took the responsibility for acquiring,processing,and transiting the on-going information.Laboratory test results showed that the random error distribution was approximately normal,and by liner analysis,the system observed value and the true value had as a liner relationship with coefficient of determination R^(2)=0.9991.Series of field tests showed that the seeding rate maximum relative error of the 6-port seed tube was 2.92%,and the maximum root mean square error(RMSE)was about 1.64%.The monitoring system,including sensor nodes,vehicle monitoring terminal and a touch-screen monitor,was proved to be dependable and stable with more than 14 d of continuous experiments in field.