Application effect of wheat straw biochar in vegetable continuous cropping soil in Guangdong Province

Soil quality improvement，vegetable growth，vegetable quality and their sustainable effect influenced by disposable wheat straw biochar input containing four treatments（ wheat straw biochar dosages were 0，2.5，5，10 t/hm2 respectively） were researched through 16 months’ vegetable rotation field experiment. Results showed that the application of different dosages of wheat straw biochar could increase soil pH value，soil organic carbon content and vegetable yield of every crop，but had little influence on soil available nitrogen，available phosphorus and available potassium content. The enhanced unit of soil pH value，increased rate of soil organic carbon and vegetable yield affected by different dosages of wheat straw biochar were 0.1-0.8，1.0%-27.9% and 1.2%-124.3%，respectively. The optimal dosage was 5 t/hm2，which could significantly increase soil pH value，soil organic carbon content and yield of every stubble vegetable. Compared with the control treatment，5 t/hm2 of wheat straw biochar could increase soil pH value by 0.2-0.8 units，soil organic carbon content by 0.10%-0.30% and vegetable yield by 9.6-56.1 t/hm2. The increase rates of soil organic carbon content and vegetable yield were up to 6.4%-19.3% and 15.6%-124.3%， respectively. After successive stubbles of vegetables，the soil pH value，soil organic carbon content and vegetable yield treated by 5 t/hm2 wheat straw biochar were still 8.1%，8.2% and 33.2% higher than those of control treatment. The application of wheat straw biochar could effectively alleviate the acidity of soil，significantly enhance soil organic carbon content and vegetable yield at the more than one year rotation field experiment of continuous stubbles of vegetable. There is a persistent effect on the improvement of soil acidity，organic carbon content and vegetable production of wheat straw biochar during the experiment time.