论文部分内容阅读
在陇中黄土高原半干旱区进行保护性耕作定位试验,研究了不同保护性耕作措施对表层土壤结构和有机碳含量的影响。结果表明:与传统耕作(T)、传统耕作结合秸秆还田(TS)相比,免耕秸秆覆盖(NTS)土壤容重在作物生长期保持稳定;虽然两种序列NTS处理土壤总孔度较低,但其>30μm的非毛管孔度显著高于其它三种处理,W→P→W序列(2002年小麦→2003年豌豆→2004年小麦)NTS处理分别比T处理、TS处理和NT处理提高3.605%、4.749%、3.338%;P→W→P序列(2002年豌豆→2003年小麦→2004年豌豆)NTS处理分别比T处理、TS处理和NT处理提高2.834%、4.023%、2.728%;就大团聚体(>0.25 mm)含量而言,W→P→W序列下T处理、TS处理、NT处理和NTS处理分别为7.412%、9.493%、9.098%、10.577%,P→W→P序列下分别为7.600%、10.027%、8.085%、9.933%,且统计分析表明两种序列下NTS处理均与T和TS两处理差异显著。同时发现,NTS处理可显著增加土壤有机碳含量,两种序列下分别比T处理增加0.958 g/kg和1.045 g/kg,而单一的免耕(NT)或覆盖(TS)效果并不显著。
In the semi-arid area of Longzhong Loess Plateau, the experiment of conservation tillage was carried out to study the effects of different tillage practices on soil structure and organic carbon. The results showed that the soil bulk density of no-tillage straw mulching (NTS) remained stable during crop growth compared with conventional tillage (T) and conventional tillage (TS). Although total N2O , But the non-capillary porosity of> 30μm was significantly higher than that of the other three treatments. Compared with T treatment, TS treatment and NT treatment, N → W → P → W sequences (2002 wheat → 2003 pea → 2004 wheat) 3.605%, 4.749% and 3.338% respectively. Compared with T treatment, TS treatment and NT treatment increased by 2.834%, 4.023% and 2.728%, respectively, for P → W → P sequence (2002 pea → 2003 wheat → 2004 pea) For large aggregates (> 0.25 mm), T, TS, NT and NTS treatments were 7.412%, 9.493%, 9.098%, 10.577%, P → W → P The results showed that there was significant difference between NTS and T and TS under the two sequences. It was also found that NTS treatment could significantly increase soil organic carbon content, which increased by 0.958 g / kg and 1.045 g / kg, respectively, compared with T treatment under both sequences, while no NT or TS effect was significant.