免耕和秸秆覆盖对旱作区土壤氮素、水分和春小麦产量的影响

采用随机区组设计进行大田试验,设置传统耕作(CT)、免耕(NT)、传统耕作+秸秆覆盖(TS)、免耕+秸秆覆盖(NTS)4种处理,研究不同处理下旱作区春小麦田的土壤容重、含水量、全氮含量、铵态氮含量、硝态氮含量和小麦产量。结果表明:不同处理实施2 a后,NT和NTS处理的0~10 cm土层土壤容重显著(P<0.05)高于CT和TS处理;TS和NTS处理较CT处理增加了土壤含水量和土壤表层(0~40 cm)全氮含量,就2 a试验平均值而言,TS、NT和NTS处理的土壤含水量较CT处理分别增加8.33%、3.17%和3.82%,TS和NTS处理的土壤全氮含量分别较CT处理显著(P<0.05)增加1.78%和3.48%;但TS、NT和NTS处理的土壤铵态氮和硝态氮含量较CT处理显著(P<0.05)降低。从2 a试验平均值看,与CT处理相比,TS和NTS处理的春小麦产量明显增加,而NT处理的春小麦产量下降。

Effects of no tillage and straw mulching on soil nitrogen,water content and yield of spring wheat in dryland farming area

In the present study, a field experiment was conducted with randomized block design, including conventional tillage (CT), no tillage (NT), conventional tillage+straw mulching (TS), no tillage+straw mulching (NTS), to explore the water and fertilizer effect and yield characteristics of spring wheat under different treatments in dryland farming area. The soil bulk density, contents of total nitrogen, ammonium nitrogen, nitrate nitrogen, soil water content, and wheat yield were determined. It was shown that after two years' experiment, the soil bulk density of NT and NTS in 0-10 cm soil layer was significantly (P<0.05) higher than that of CT and TS. Compared with CT, TS and NTS increased soil water content and total nitrogen content in soil surface layer (0-40 cm). According to the average of two-year results, the soil water content of TS, NT and NTS was increased by 8.33%, 3.17% and 3.82% than that of CT, respectively. The soil total nitrogen content of TS and NTS was significantly (P<0.05) increased by 1.78% and 3.48% than that of CT, respectively. However, TS, NT and NTS significantly (P<0.05) decreased the content of ammonium nitrogen and nitrate nitrogen compared with CT. Based on the average of two-year result, compared with CT, TS and NTS increased the yield of spring wheat, while NT decreased the yield of spring wheat.