| 【Objective】The study was carried out to investigate the effects of two agronomic measures of cornstalk returning directly and after carbonization on soil physical and chemical properties, corn growth and quality improvement.【Method】Plot experiments of two crops of sweet corn including three treatments, the control（CK）, cornstalk returning directly（T1）and cornstalk returning after carbonization（T2）were carried out in Hengli Town, Nansha District, Guangzhou City.【Results】As compared with CK treatment, T1 and T2 treatments could increase soil pH value, soil available N, P, K and organic carbon content, significantly increase the contents of vitamin C and soluble sugar in corn kernels, but had no significant effect on corn yield. In the first-crop corn experiment, the effect of T1 and T2 treatments on the content of vitamin C in corn kernels was increased by 16.5% and 25.9%, the content of soluble sugar was increased by 20.7% and 22.3%, and the content of soil organic carbon was increased by 10.3% and 10.0%, respectively. There were no significant effects on soil available N, P and K contents, soil pH value and corn plant height between T1（T2）and CK treatment. In the second-crop corn experiment, T1 and T2 treatments significantly increased the content of vitamin C in corn kernels by 10.3% and 1.7%, soluble sugar content by 24.7% and 10.6%, soil pH value by 0.33 and 0.23 units, and soil available potassium content by 16.8% and 36.0%, respectively. The soil organic carbon content was decreased by 1.7% under T1 and significantly increased by 3.6% under T2. The plant heights of corn were increased by 0.3% and 4.59% under T1 and T2, respectively.【Conclusion】The improved effect of cornstalk returning after carbonization on soil physical and chemical properties and corn growth was stronger than that of cornstalk returning directly. The speed of improvement of corn quality by cornstalk returning after carbonization was faster than that of cornstalk returning directly, but the continuity of the improved effect of cornstalk returning directly was better than that of cornstalk returning after carbonization. The effects of
the two kinds of cornstalk returning measures on the corn yield are difficult to be reflected in a short time. |
