Abstract:

By the experiment in a cadmium-contaminated paddy field in Shanghai to study the effects of different agronomic measures on the cadmium content in soil and plants. In the field test, different treatments were sets: variety replacement + optimal fertilization (treatment 1), variety replacement + water regulation+ optimal fertilization (treatment 2), variety replacement + water regulation (treatment 3). Different agronomic combinations measures were compared with conventional rice planting (CK) to explore the effects of different comprehensive technologies on the migration and transformation of different forms of Cd in soil, brown rice and straw. The results showed that compared with CK, the contents of Cd and available Cd in soil and cadmium in brown rice in all treatments decreased. Compared with before the test, the contents of total Cd and available Cd in soil in treatment 2 decreased most significantly, by 12.86% and 18.33%, respectively. The Cd enrichment coefficient of brown rice in treatment 1, 2 and 3 decreased by 43.18%, 51.90% and 25.74%, respectively. Compared with CK, rice yield in treatment 1 increased by 4.9%. In conclusion, the selection of rice varieties with low Cd accumulation, combined application of biochar organic fertilizer and foliar blocking agent can reduce the Cd content in rice and regulate the enrichment and transport of Cd in crops on the basis of maintaining rice yield.

Key words: cadmium, safety utilization integrated technology, agronomic measures, soil, rice