Effect of Soil Physical Properties on Mechanical Pulling Process of Carrot

Carrot is an important vegetable in our country.The rule on carrot pulling was analyzed to support evelopment of carrot pulling combine harvester.Pulling test on typical carrot of harvest was carried out by the self-developed numerical control test bench of vegetable pulling force.Test data were analyzed using regression to study predicts relationship between soil physical parameters（soil moisture content, hardness, bulk density）and carrot pulling process/force.Results showed that soil hardness and bulk density will decrease with increase of soil moisture when soil moisture was between 20% and 30%.Also mechanical pulling force of carrot decreases,and resistance time of soil on carrot pulling prolongs with increase of soil moisture.