Effects of combined application of different organic fertilizers on cadmium accumulation , distribution , and transport in wheat and oat

[ Objective ] Cadmium pollution in farmland soil poses a serious threat to the quality and safety of agricultural products. To explore the characteristics of cadmium accumulation , distribution , and transport in various organs of wheat and oat under different conditions of reduced chemical fertilizer and organic fer- tilizer application is of great importance in guiding appropriate fertilizer application on crops and ensuring the safety of agricultural products. [ Methods ] Based on a 20% reduction in fertilizer application , four fer- tilization treatments were set up : Stable fertilizer 30 000 kg / hm 2 ( AM ), bioorganic fertilizer 600 kg / hm 2 ( BF ), stable fertilizer 30 000 kg / hm 2 +bioorganic fertilizer 600 kg / hm 2 ( AM+BF ), and normal fertilizer application ( CK ) . The effects of the above four different organic fertilizer treatments on cadmium accumu- lation , distribution , and transport in wheat and oat were studied. [ Results ] ( 1 ) Compared with CK , dif- ferent organic fertilizer combinations increased the biomass of wheat and oat by 6.78%-11.00%. At the same time , it reduced the overall cadmium content in various organs , with a decrease of 11.76%-47.06% in grain cadmium content. ( 2 ) The combined application of various organic fertilizers resulted in an overall decrease in the cadmium enrichment coefficient of various organs , with a decrease of 0-38.46% in the grain enrichment coefficient. The transport coefficients of cadmium from roots , stems , leaves , and pani- cles to grains were decreased by 16.67%-42.86% , 15.79%-42.03% , 0-56.10% , and 6.82% - 22.06% , respectively in BF and AM+BF treatments. ( 3 ) The decrease in stem cadmium content after oat filling period was accompanied by an increase in grain cadmium content. The transfer amount , transfer rate , and contribution rate of cadmium from various organs to grains in oats after heading stage were the highest in the stem. [ Conclusion ] Reducing the amount of chemical fertilizers combined with organic fertil- izers could reduce cadmium content , enrichment coefficient , and transport coefficient in crop grains , and the cadmium reduction effect on oat grains was better than that on wheat. The cadmium transported from the stem after the heading stage of oats was the main source of grain cadmium accumulation.