Uniform seed spacing is considered a fundamental factor in quality and yield for many crops and drill manufacturers continuously try to improve the accuracy in seed placement, according to the cultivation standard req...Uniform seed spacing is considered a fundamental factor in quality and yield for many crops and drill manufacturers continuously try to improve the accuracy in seed placement, according to the cultivation standard requirements. This paper reports the results of tests on the performances of a six row pneumatic precision drill in which the depression into each sowing unit is created by means of flexible pipes that do not start directly from the fan, as in most pneumatic drills, but from an air duct having the function of uniformly distributing the air flow along the working width. Field tests have been conducted, using three graded seeds, to evaluate the accuracy of the single seed metering system, according to ISO 7256/1 standard, and the uniformity of negative pressure, through the measurement of the distance between seeds in the furrow, under two speed conditions （5 and 8 km bl）.展开更多
Both seeding performance of seed metering unit and travel speed of seed planter have significant effects on seeding quality,thereby affecting crop growth and yields.In order to determine the effects of different trave...Both seeding performance of seed metering unit and travel speed of seed planter have significant effects on seeding quality,thereby affecting crop growth and yields.In order to determine the effects of different travel speeds on seed spacing uniformity,four different types of seed meters were evaluated at five different travel speeds on seed meter test bench and in field.The tested seed meters included a finger pickup seed meter,a scoop-wheel seed meter,an air-pressure type seed meter and an air-blowing type seed meter.The seeding performance of the horizontal distribution of seeds within a row was described by using the coefficient of variation,the quality of feed index,the multiple index and the miss-seeding index.Experiments were performed in laboratory and field,respectively.Results indicated that different travel speeds have statistically significant effects on seed spacing uniformity.The four types of seed meters performed better on the seed meter test bench than in the field.Coefficient of variation increases and quality of feed index decreases as the travel speed of seed planter increases.The best seed spacing uniformity was obtained with the air-pressure type seed meter,followed with the air-blowing type seed meter,the finger pickup seed meter and the scoop-wheel seed meter.There were considerable differences between the performances of the scoop-wheel seed meter in the bench test and field test;the seeding qualities were much better in the bench test than in the field test.The scoop-wheel seed meter is more sensitive to vibration than the other types of seed meters.展开更多
Aiming at improving the seed spacing uniformity of maize planter at high forward speed,a seed precise delivery mechanism driven by electric motor has been developed and evaluated in laboratory.The mechanism was design...Aiming at improving the seed spacing uniformity of maize planter at high forward speed,a seed precise delivery mechanism driven by electric motor has been developed and evaluated in laboratory.The mechanism was designed to deliver single seed from seed meter to furrow.Seed’s movement from the seed release point in a seed meter to the seed delivery cavity in the belt was analyzed,the mathematical model of seed movement in the seed precise delivery mechanism was established based on seed delivery time analysis.A mechanical prototype was designed and associated control system was developed.The performance contrast experiment was conducted between a traditional seed tube and newly developed seed precise delivery mechanism,and test results indicated that the qualities of feed index of the seed precise delivery mechanism were higher than those of the traditional seed tube delivery mechanism,and the coefficients of variation of the seed precise delivery mechanism were lower than those of the traditional seed tube delivery mechanism when the forward speed of planter was set at 10 km/h,12 km/h and 14 km/h,respectively.It indicated the seed precise delivery mechanism significantly improved seed spacing uniformity of maize planter compared with the traditional seed tube delivery mechanism.展开更多
The two cultivation patterns,no-tillage and ridge cultivation,are widely used in maize planting in Northeast China.However,the seed bounce in the falling process and drought seriously at the seedling stage often occur...The two cultivation patterns,no-tillage and ridge cultivation,are widely used in maize planting in Northeast China.However,the seed bounce in the falling process and drought seriously at the seedling stage often occur to affect the sowing quality,mean emergence time,percentage of emergence,root biomass,aboveground biomass and root shoot ratio of maize,and eventually reduces the grain yield.To solve the problems,a seed furrow liquid spraying device was designed and thereby the effects of spraying water volumes[0 L/m(V0),0.6 L/m(V1),1.2 L/m(V2)and 1.8 L/m(V3)]and nozzle types[conical nozzle(N1)and sectorial nozzle(N2)]on the sowing quality and seedling growth of maize were studied.The water volume and nozzle type had significant effects on the sowing quality(QR,CV,LD),not seedling growth(MET,PE,RB,AB,RSR)(p<0.05).Spraying water into seed furrow further humidified the soils around the maize seeds,effectively suppressing the bounce and rolling of seed and significantly promoting the growth and development of seeds.The sowing quality in the N2 treatment was significantly better than that in the N1 treatment.The qualified rate of seed spacing was increased with the increase of the water volume(V3>V2>V1>V0).However,the variability coefficient of seed spacing and lateral deviation of seed position were the opposite.The larger spraying water volume led to shorter mean emergence time(V0>V1>V2>V3)and higher percentage of emergence(V3>V2>V1>V0).The root biomass and aboveground biomass increased significantly with the enlargement of spraying water volume.Under different water volumes,the root shoot ratio differed significantly.The plants in the V1,V2 and V3 treatments had lower root shoot ratios compared with the V0 treatment.The increase of spraying water volume significantly reduced the root shoot ratio.The seed furrow liquid spraying device provides a reference for improving sowing quality and promoting seedling growth.展开更多
The double-disc opener of maize precision seeder is an important component which affects sowing quality.After the double-disc opening operation,there will be many unfavorable phenomena such as a W-shaped bottom with p...The double-disc opener of maize precision seeder is an important component which affects sowing quality.After the double-disc opening operation,there will be many unfavorable phenomena such as a W-shaped bottom with pointed ridge,returning soil to furrow,loose and rough furrow sidewall,and large soil blocks in the furrow bottom.These phenomena often cause the problems of poor sowing depth consistency and seed spacing uniformity.In order to solve the above problems,the furrow compaction device with opener was designed to compact and reshape the original seed furrow,eventually forming a smooth and flat V-shaped seed furrow.Through theoretical calculations and kinematic analysis,the main structural parameters of the device were limited to a small range:the spring stiffness coefficient k=0.96-4.19 N/mm and the angle of the furrow compaction wheelφ=30°-60°.In the soil-bin experiment,the rotary combination design was adopted to study the effects of the parameters of the furrow compaction device with opener on the seeds location variation.The regression model of two factors with respect to each indicator was established in the Design-Expert software,revealing the effects of two factors on the indicators.Finally,the optimal structural parameters obtained were:the spring stiffness coefficient k=4.0 N/mm,and the angle of furrow compaction wheelφ=42.4°.The field test was carried out to verify the effect of the furrow compaction device with opener on the performance of precision seeder.The results showed that the average values of the sowing depth variable coefficient,the lateral deviation and the seed spacing variable coefficient respectively were 5.77%,5.1 mm and 9.54%in the treatment of the furrow compaction device with opener.All indicators were superior to the traditional double-disc opener.This research can provide references for the design of furrow opening device and maize precision seeder.展开更多
Space plant-breeding technology is the future of agriculture chinese yews are on the verge of extinction. A chemical extracted from their barks is used to produce drugs for cancer treatment,
文摘Uniform seed spacing is considered a fundamental factor in quality and yield for many crops and drill manufacturers continuously try to improve the accuracy in seed placement, according to the cultivation standard requirements. This paper reports the results of tests on the performances of a six row pneumatic precision drill in which the depression into each sowing unit is created by means of flexible pipes that do not start directly from the fan, as in most pneumatic drills, but from an air duct having the function of uniformly distributing the air flow along the working width. Field tests have been conducted, using three graded seeds, to evaluate the accuracy of the single seed metering system, according to ISO 7256/1 standard, and the uniformity of negative pressure, through the measurement of the distance between seeds in the furrow, under two speed conditions （5 and 8 km bl）.
基金supported by the National Natural Science Foundation of China(Grant No.51575515)the National Science and Technology Research Program(2013BAD08B01-3)the National Industry System of Corn Technology of P.R.China(CARS-02).
文摘Both seeding performance of seed metering unit and travel speed of seed planter have significant effects on seeding quality,thereby affecting crop growth and yields.In order to determine the effects of different travel speeds on seed spacing uniformity,four different types of seed meters were evaluated at five different travel speeds on seed meter test bench and in field.The tested seed meters included a finger pickup seed meter,a scoop-wheel seed meter,an air-pressure type seed meter and an air-blowing type seed meter.The seeding performance of the horizontal distribution of seeds within a row was described by using the coefficient of variation,the quality of feed index,the multiple index and the miss-seeding index.Experiments were performed in laboratory and field,respectively.Results indicated that different travel speeds have statistically significant effects on seed spacing uniformity.The four types of seed meters performed better on the seed meter test bench than in the field.Coefficient of variation increases and quality of feed index decreases as the travel speed of seed planter increases.The best seed spacing uniformity was obtained with the air-pressure type seed meter,followed with the air-blowing type seed meter,the finger pickup seed meter and the scoop-wheel seed meter.There were considerable differences between the performances of the scoop-wheel seed meter in the bench test and field test;the seeding qualities were much better in the bench test than in the field test.The scoop-wheel seed meter is more sensitive to vibration than the other types of seed meters.
基金The authors disclosed receipt of the following financial support for the research,authorship,and/or publication of this article:This work was funded by the National Natural Science Foundation of China(Grant No.51575515)the National key research and development program in 13th Five-Year(Grant No.2017YFD0700703)the Soil-Machine-Plant Key Laboratory of the Ministry of Agriculture of PR China and Project of the Modern National Industry System of Maize Industrial Technology(CARS-02).
文摘Aiming at improving the seed spacing uniformity of maize planter at high forward speed,a seed precise delivery mechanism driven by electric motor has been developed and evaluated in laboratory.The mechanism was designed to deliver single seed from seed meter to furrow.Seed’s movement from the seed release point in a seed meter to the seed delivery cavity in the belt was analyzed,the mathematical model of seed movement in the seed precise delivery mechanism was established based on seed delivery time analysis.A mechanical prototype was designed and associated control system was developed.The performance contrast experiment was conducted between a traditional seed tube and newly developed seed precise delivery mechanism,and test results indicated that the qualities of feed index of the seed precise delivery mechanism were higher than those of the traditional seed tube delivery mechanism,and the coefficients of variation of the seed precise delivery mechanism were lower than those of the traditional seed tube delivery mechanism when the forward speed of planter was set at 10 km/h,12 km/h and 14 km/h,respectively.It indicated the seed precise delivery mechanism significantly improved seed spacing uniformity of maize planter compared with the traditional seed tube delivery mechanism.
基金We acknowledge that this work was financially supported by the 13th Five Year National Key R&D Plan Project(Grant No.:2017YFD0700701)the Development Programme of Science and Technology of Jilin Province of China(Grant No.20170312005ZX,20160441004SC).
文摘The two cultivation patterns,no-tillage and ridge cultivation,are widely used in maize planting in Northeast China.However,the seed bounce in the falling process and drought seriously at the seedling stage often occur to affect the sowing quality,mean emergence time,percentage of emergence,root biomass,aboveground biomass and root shoot ratio of maize,and eventually reduces the grain yield.To solve the problems,a seed furrow liquid spraying device was designed and thereby the effects of spraying water volumes[0 L/m(V0),0.6 L/m(V1),1.2 L/m(V2)and 1.8 L/m(V3)]and nozzle types[conical nozzle(N1)and sectorial nozzle(N2)]on the sowing quality and seedling growth of maize were studied.The water volume and nozzle type had significant effects on the sowing quality(QR,CV,LD),not seedling growth(MET,PE,RB,AB,RSR)(p<0.05).Spraying water into seed furrow further humidified the soils around the maize seeds,effectively suppressing the bounce and rolling of seed and significantly promoting the growth and development of seeds.The sowing quality in the N2 treatment was significantly better than that in the N1 treatment.The qualified rate of seed spacing was increased with the increase of the water volume(V3>V2>V1>V0).However,the variability coefficient of seed spacing and lateral deviation of seed position were the opposite.The larger spraying water volume led to shorter mean emergence time(V0>V1>V2>V3)and higher percentage of emergence(V3>V2>V1>V0).The root biomass and aboveground biomass increased significantly with the enlargement of spraying water volume.Under different water volumes,the root shoot ratio differed significantly.The plants in the V1,V2 and V3 treatments had lower root shoot ratios compared with the V0 treatment.The increase of spraying water volume significantly reduced the root shoot ratio.The seed furrow liquid spraying device provides a reference for improving sowing quality and promoting seedling growth.
基金The financial support for this study came from three projects:the National Key Research and Development Program of China(Grant No.2017YFD0700703)the Development Program of Science and Technology of Jilin Province of China(Grant No.20170312005ZX)the National Natural Science Foundation of China(Grant No.51905318).
文摘The double-disc opener of maize precision seeder is an important component which affects sowing quality.After the double-disc opening operation,there will be many unfavorable phenomena such as a W-shaped bottom with pointed ridge,returning soil to furrow,loose and rough furrow sidewall,and large soil blocks in the furrow bottom.These phenomena often cause the problems of poor sowing depth consistency and seed spacing uniformity.In order to solve the above problems,the furrow compaction device with opener was designed to compact and reshape the original seed furrow,eventually forming a smooth and flat V-shaped seed furrow.Through theoretical calculations and kinematic analysis,the main structural parameters of the device were limited to a small range:the spring stiffness coefficient k=0.96-4.19 N/mm and the angle of the furrow compaction wheelφ=30°-60°.In the soil-bin experiment,the rotary combination design was adopted to study the effects of the parameters of the furrow compaction device with opener on the seeds location variation.The regression model of two factors with respect to each indicator was established in the Design-Expert software,revealing the effects of two factors on the indicators.Finally,the optimal structural parameters obtained were:the spring stiffness coefficient k=4.0 N/mm,and the angle of furrow compaction wheelφ=42.4°.The field test was carried out to verify the effect of the furrow compaction device with opener on the performance of precision seeder.The results showed that the average values of the sowing depth variable coefficient,the lateral deviation and the seed spacing variable coefficient respectively were 5.77%,5.1 mm and 9.54%in the treatment of the furrow compaction device with opener.All indicators were superior to the traditional double-disc opener.This research can provide references for the design of furrow opening device and maize precision seeder.
文摘Space plant-breeding technology is the future of agriculture chinese yews are on the verge of extinction. A chemical extracted from their barks is used to produce drugs for cancer treatment,
