Effect of Tillage and Residue Management on Crop Yield and Soil Properties

A split-plot study on conservation tillage was conducted on a loamy soil in the low plain of Hebei province.The main treatment consisted of deep-shallow tillage,shallow tillage,minimum tillage and zero tillage.The sub-treatments were no residue return,chopped residue return and whole residue mulching.Result showed that the minimum tillage and zero tillage did not affect the crop yield in first 3 years.After then,the wheat yield was significantly reduced up to 31.83%.This reduction probably was the response to higher soil bulk density,low soil temperature,lack of available nutrients and weed problem.But continuous zero tillage did not affect the corn yield remarkably.Deep tillage did not increase the crop yield.Residue mulch sometimes limited the wheat growth.Zero tillage increased the soil organic matter and total nitrogen content but decreased the available nitrogen.