氮肥减量配施土壤调理剂对水稻产量及Cd含量的影响

Effect of Nitrogen Reduction Combined with Soil Conditioners on Yields and Cd Contents of Rice

旨在探明氮肥减量配施土壤调理剂对水稻生长和Cd吸收的影响,为Cd污染稻田的安全利用与合理施肥提供科学依据。利用Cd污染稻田,采用田间小区试验,研究氮肥减量配施碱性缓释肥、生物有机肥、微生物肥对水稻产量和Cd含量的影响。结果表明,施用碱性缓释肥、生物有机肥、微生物菌肥的水稻产量分别比对照增产7.42%(P<0.05),8.59%(P<0.05)和4.59%,氮肥减量20%配施碱性缓释肥、生物有机肥的水稻产量分别比对照增产5.55%和7.61%(P<0.05),而氮肥减量20%配施微生物菌肥的水稻产量仅比对照降低2.48%,无显著差异,表明在氮肥一次性基施条件下实行氮肥减量20%可行。施用碱性缓释肥及其与氮肥减量20%配施皆可显著提高土壤p H值,降低土壤有效态Cd含量,并显著降低水稻秸秆及稻米Cd含量,其稻米Cd含量分别比对照降低31.29%(P<0.05)和26.58%(P<0.05);施用生物有机肥也可有效提高土壤p H值,降低土壤有效态Cd含量,并显著降低水稻秸秆和稻米Cd含量,但生物有机肥与氮肥减量20%配施时降低水稻秸秆和稻米Cd含量的效果不明显,施用生物有机肥及其与氮肥减量20%配施的稻米Cd含量分别比对照降低31.27%(P<0.05)和11.96%;施用微生物菌肥及其与氮肥减量20%配施的水稻稻米及秸秆降Cd效果皆不明显。配施碱性缓释肥、生物有机肥、微生物菌肥时,氮肥减量20%皆减弱了其对水稻秸秆和稻米的降Cd效果。

In order to research the influences of nitrogen reduction combined with soil conditioners on the growth and Cd uptake of rice to provide a scientific basis for Cd pollution paddy field used safely and fertilization reasonably. A field experiment was conducted to investigate the influences of nitrogen reduction combined with the alkaline slow-release fertilize,organic fertilizer and microbial fertilizer on the rice yields and Cd contents in the Cd contaminated paddy soil. The results showed that the rice yields increased by 7. 42%( P < 0. 05),8. 59%( P <0. 05) and 4. 59% than the contrast with the application of alkaline slow-release fertilize,organic fertilizer and microbial fertilizer respectively. And the rice yields increased by 5. 55% and 7. 61%( P < 0. 05),respectively,of the nitrogen reduction 20% combined with alkaline slow-release fertilizer and organic fertilizer,but the nitrogen reduc-tion 20% with microbial fertilizer decreased the production by 2. 48%. So the results suggested that it was feasible to reduce the N fertilizer under this experiment condition. Both the alkaline slow-release fertilizer applied alone or combined with nitrogen reduction 20% could increase the soil p H effectively and decrease the soil available Cd content,and reduced the Cd contents of rice stem and grain efficiently with 31. 29%( P < 0. 05) and 26. 58%( P < 0. 05) than the contrast. Applying of organic fertilizer also increased the soil p H value and reduced the soil available Cd content effectively,and reduced the Cd contents of stem and rice obviously,but there was no evident effect of decreasing of Cd contents in stem and rice when organic fertilizer combined with nitrogen reduction 20%,the Cd content of rice lowered by 31. 27%( P < 0. 05) and 11. 96% compared to the contrast when applied organic fertilizer alone and with nitrogen reduction 20%. And the Cd contents of stem and rice had no significant differences compared to the contrast both applied microbial fertilizer alone and with nitrogen reduction 20%. The effect on decreasing Cd content of stem and rice weakened when nitrogen reduction 20% combined with alkaline slow-release fertilizer and organic fertilizer and microbial fertilizer. Overall consideration of the rice yields and the Cd reduction effects of rice and stem,nitrogen reduction 20% combined with alkaline slow-release fertilizer could enhance rice yield as well as reduce Cd content in rice stem and rice,which was applicable for rice production in Cd contaminated paddy soil.