Abstract:

On the basis of previous regular experiments, this simple contrast intermediate test was carried out to further verify the effect of agricultural lime on acid soil improvement, rice yield increase and rice cadmium reduction in acid and cadmium contaminated paddy fields. The results showed that under the condition of pH 5.64 in the tested paddy field, liming of an average of 750 kg/hm² raised the pH of the soil by 0.153 units. The average yield of rice increased by 1529.98 kg/hm² with lime application of 3000 kg/hm² compared with that without lime application, and the yield increase rate was 14.74%, the t-test reached an extremely significant level. The average income increased by 1738.15 yuan/hm²with lime application of 3000 kg/hm² than that without lime application. The main reason for the yield increase was that lime application promoted the growth and tillering of rice and increased the grain weight per plant. The lime application of 3000kg/hm² reduced the cadmium content of rice by 0.21 mg/kg, with a reduction rate of 37.8%, and the t-test reached an extremely significant level. The results indicated once again that agricultural lime application in acid and cadmium contaminated paddy fields could have good effects on improving acid soil, increasing both production and income, and reducing cadmium content in rice, which could be popularized according to local conditions.

Key words: farmland, soil acidification, cadmium pollution, soil improvement, agricultural lime, rice