北方冬小麦-夏玉米复种区生物炭与明矾配施对土壤碳氮状况影响研究

旨在为大田施用土壤调理剂改善土壤碳氮状况提供理论依据。在北方冬小麦-夏玉米种植区,选用生物炭和明矾作为土壤调理剂材料,设计T1（对照）、T2（生物炭）、T3（明矾）、T4（生物炭+明矾）4个处理的两茬定位试验。结果表明,T2（生物炭）与T4（生物炭+明矾）处理改善土壤碳氮状况、提高作物产量和氮素养分吸收的效果较好。经过两茬作物种植后,T4（生物炭+明矾）处理土壤有机碳含量有所提高,为15.82 g/kg,表层土壤C/N增加为10.88。土壤硝态氮经两茬作物种植后,T4（生物炭+明矾）处理改善效果最好,0~30、30~60、60~90²最高,其次为T4（生物炭+明矾）处理,而小麦以T4（生物炭+明矾）处理产量最高,为10.28 t/hm²。T4（生物炭+明矾）处理夏玉米和冬小麦的吸氮量均最高,分别为168.32 kg/hm²和35.49 kg/hm²。总体来看T4（生物炭+明矾）处理对改善农田土壤碳氮状况效果较好。

Combined Application of Biochar and Alum in Winter Wheat-Summer Maize Multiple Cropping Area in North China: Effects on Soil Carbon and Nitrogen Status

The study aims to provide a basis for the application of soil conditioners in field to improve soil carbon and nitrogen condition. In the winter wheat-summer maize multiple cropping area of north China, biochar and alum were used as soil conditioners, a two-planting season experiment was conducted with four treatments, T1 (the control), T2 (biochar), T3 (alum) and T4 (biochar+alum). The results showed that T2 (biochar) and T4 (biochar+alum) had better effects on improving soil carbon and nitrogen, increasing crop yield and nitrogen nutrient uptake compared with the control. After two planting seasons, the content of organic carbon in soil treated with T4 (biochar+alum) increased by 15.82 g/kg, and the C/N of surface soil increased to 10.88. Furthermore, T4 (biochar+alum) treatment was efficient to reduce soil nitrate in 0-90 cm soil horizon. It was found that soil nitrate in the soil layers of 0-30, 30-60 and 60-90 cm were reduced by 86.96%, 86.82% and 60.41%, respectively, compared to the control. For the crop yield, the highest crop grain (11.34 t/hm²) was found in T2 (biochar). However, the highest yield of wheat (10.28 t/hm²) was found in T4 (biochar+alum). The nitrogen uptake of summer maize and winter wheat treated by T4 (biochar+alum) were the highest, which reached 168.32 kg/hm² and 35.49 kg/hm². Overall, T4 (biochar+alum) has better effect on improving soil carbon and nitrogen status in farmland.