保护性耕作对土壤养分及有机碳库的影响

Effects of conservation tillage on soil nutrient and organic carbon pool

以稻草覆盖免耕方式稻田冬种马铃薯（Solanum tuberosum L.）为例,研究了保护性耕作对土壤养分以及有机碳库的影响。结果表明：保护性耕作能显著增加表层土层的养分含量,土壤氮素含量比传统耕作增加0.81%7.24%,磷素含量增加14.95%19.21%,钾素含量增加0.57%15.40%,且全氮、全磷、全钾含量与传统耕作之间均达到了极显著差异水平,除碱解氮含量与传统耕作之间差异不显著外,速效磷与速效钾含量与传统耕作之间达到了显著差异水平与极显著差异水平;保护性耕作能增加土壤总有机碳与活性有机碳含量,提高土壤碳库管理指数,0-10cm土层土壤的碳库管理指数分别比传统耕作高出9.10%、13.95%,10-20cm土层则比传统耕作略低。因此保护性耕作能使土壤朝着有利于土壤质量提高的方向发展。两个保护性耕作处理：免耕稻草覆盖（8cm）、免耕覆盖稻草（8cm）后盖黑色地膜之间差异不大。

The experiment was conducted with two treatments of conservation tillage of winter potato（Solanum tuberosum L.）, no-tillage with mulch of 8 cm-thick rice straw and no-tillage with mulch of 8 cm-thick rice straw covered with black plastic, to study the effect of the conservation tillage on the soil nutrient and the organic carbon pool. The results indicated that： the conservation tillage could increase the content of the soil nutrient, the content of nitrogen in the soil increased 0.81%～7.24%, the content of phosphorus increased 14.95%～19.21%, and the potassium increased 0.57%～15.40% compared with the traditional cultivation, and also the contents of total nitrogen, total phosphorus, total potassium had the significant difference with the conventional cultivation. The content of available phosphorus and available potassium was significant higher than that of the traditional cultivation; and the conservation tillage could increase the content of the total soil organic carbon and the soil active organic carbon, enhance the soil carbon pool management index in the soil of the depth of 0～10 cm, the soil carbon pool management index in the soil of 0～10 cm depth was 9.10% and 13.95% higher than the traditional cultivation’s; and the soil carbon pool management index in the soil of 10～20 cm depth was lower than the traditional cultivation’s. Thus conservation tillage had effects to improve soil’s quality. There was no significant different effect between the two conservation tillage.