Early studies showed that the irregular operations of the center pivot sprinkling system would decrease its uniformity while the reason was lack of discussion.Taking Herman-Hein uniformity coefficient(CUH)and Distribu...Early studies showed that the irregular operations of the center pivot sprinkling system would decrease its uniformity while the reason was lack of discussion.Taking Herman-Hein uniformity coefficient(CUH)and Distribution uniformity coefficient(DU)as evaluation indicators,the reason that irregular operation management and configurations can decrease the uniformity of center pivot sprinkling irrigation was discussed and the impact on maize yield was tested.The reasons for such decrease in uniformity include:(1)With the increase of moving speed,the effect of sprinkling overlaying became worse,which resulted in the lower uniformity of sprinkling irrigation;(2)With the increase of head pressure,the inlet pressure could be adjusted to the same pressure by pressure regulator,which kept the uniformity of sprinkling irrigation constant;(3)When end gun worked abnormally,total head pressure decreased,which led to the decrease of sprinkling irrigation’s uniformity;(4)When pressure regulator worked abnormally,the water flow was subject to great pressure loss,which could decrease the uniformity of sprinkling irrigation;(5)When pressure regulator was uninstalled,significant abnormality of sprinkling irrigation depth occurred,resulting in the decreasing of sprinkling irrigation’s uniformity;(6)Different types of nozzles could produce different uniformity of sprinkling irrigation,which was due to different structures of micro-nozzles;(7)Due to lower uniformity,at the seedling stage of maize,both height and seedling emergence rate decreased.Final yield decreased by 18.35%.This study is important to the proper use and the improvement of configuration selection and field management of center pivot sprinkling system.展开更多
In order to fully understand the relationships of power consumption of no-till planter among tractor,soil properties and working parameters which affect the field operation,the power consumption model for no-till plan...In order to fully understand the relationships of power consumption of no-till planter among tractor,soil properties and working parameters which affect the field operation,the power consumption model for no-till planter applied to overcome the coupling difficulties was developed in the study.Based on operation depth of no-till planter and soil properties as constraints in accordance with a certain distribution,the relationship data among traction force,forward speed and power output shaft by field test were collected and analyzed.The results showed that the relationship between traction power and power-take-off(PTO)power was negatively correlated.Under the same power consumption condition,the relationship between traction force and the PTO torque was linearly correlated,and the slope was basically consistent.Different power consumptions corresponded to different intercepts.When the forward speed was 6-7 km/h and PTO shaft rotational speed was 370-450 r/min,lower power consumption with higher working efficiency can be achieved.There was a direct correlation between total power consumption and the square of rotational speed multiplied by forward speed.The maximum correlation coefficient was found around 0.82.The findings set up a foundation for designing control system of no-till planter.展开更多
基金the 59th Chinese Postdoctoral Science Foundation(2016M59068)Breeding programs of Heilongjiang Bayi Agricultural University(Grant No.XZR2014-04).
文摘Early studies showed that the irregular operations of the center pivot sprinkling system would decrease its uniformity while the reason was lack of discussion.Taking Herman-Hein uniformity coefficient(CUH)and Distribution uniformity coefficient(DU)as evaluation indicators,the reason that irregular operation management and configurations can decrease the uniformity of center pivot sprinkling irrigation was discussed and the impact on maize yield was tested.The reasons for such decrease in uniformity include:(1)With the increase of moving speed,the effect of sprinkling overlaying became worse,which resulted in the lower uniformity of sprinkling irrigation;(2)With the increase of head pressure,the inlet pressure could be adjusted to the same pressure by pressure regulator,which kept the uniformity of sprinkling irrigation constant;(3)When end gun worked abnormally,total head pressure decreased,which led to the decrease of sprinkling irrigation’s uniformity;(4)When pressure regulator worked abnormally,the water flow was subject to great pressure loss,which could decrease the uniformity of sprinkling irrigation;(5)When pressure regulator was uninstalled,significant abnormality of sprinkling irrigation depth occurred,resulting in the decreasing of sprinkling irrigation’s uniformity;(6)Different types of nozzles could produce different uniformity of sprinkling irrigation,which was due to different structures of micro-nozzles;(7)Due to lower uniformity,at the seedling stage of maize,both height and seedling emergence rate decreased.Final yield decreased by 18.35%.This study is important to the proper use and the improvement of configuration selection and field management of center pivot sprinkling system.
基金the 59th Chinese Postdoctoral Science Foundation(2016M59068)the National Science Foundation(51605008).
文摘In order to fully understand the relationships of power consumption of no-till planter among tractor,soil properties and working parameters which affect the field operation,the power consumption model for no-till planter applied to overcome the coupling difficulties was developed in the study.Based on operation depth of no-till planter and soil properties as constraints in accordance with a certain distribution,the relationship data among traction force,forward speed and power output shaft by field test were collected and analyzed.The results showed that the relationship between traction power and power-take-off(PTO)power was negatively correlated.Under the same power consumption condition,the relationship between traction force and the PTO torque was linearly correlated,and the slope was basically consistent.Different power consumptions corresponded to different intercepts.When the forward speed was 6-7 km/h and PTO shaft rotational speed was 370-450 r/min,lower power consumption with higher working efficiency can be achieved.There was a direct correlation between total power consumption and the square of rotational speed multiplied by forward speed.The maximum correlation coefficient was found around 0.82.The findings set up a foundation for designing control system of no-till planter.
