渭北旱塬不同耕作措施对土壤养分分布及作物产量的影响

Effects of different tillage practices on nutrient distribution in soil profile and crop yield in Weibei Highland

基于8年(2007—2015)定位试验,在小麦-玉米轮作下研究了免耕-深松(NS)、深松-翻耕(SC)、翻耕-免耕(CN)和连年免耕(NN)、深松(SS)、翻耕(CC)等轮耕措施对土壤养分分布及作物产量的影响。结果表明:深松处理(连年深松、免耕-深松)使表层(0~10 cm)土壤与底层(10~20、20~35、35~50 cm)土壤有机质、全氮、全磷、速效磷、速效钾等养分含量差异更大,翻耕或免耕的相对差异较小;在0~50 cm的土层中,硝态氮含量在20~35 cm土层相对较高,且以翻耕(CC)处理的含量最高;铵态氮含量在10~20 cm土层相对较高,以免耕-深松(NS)处理的含量最高;连年深松(SS)处理使土壤全钾表层含量较高。免耕-深松(NS)措施在6种耕作措施中小麦和玉米产量均为最高,显著高于翻耕(CC)、免耕(NN)措施。

The aim of the present study was to investigate the effect of different tillage measures on soil nutrient distribution and crop yield in Weibei Highland. An eight-year( 2007—2015) field experiment with six tillage measures under wheat-maize rotation system was conducted. The tillage measures were as follows: no-tillage,subsoiling( NS); subsoiling,conventional tillage( SC); conventional tillage,no-tillage( CN); continuous no-tillage( NN); continuous sbusoiling( SS); conventional tillage( CC). The results showed that SS and NS treatments could promote soil total organic carbon( TOC),total nitrogen( TN),total phosphorus( TP),available phosphorus( AP) and available potassium( AK) on the surface of soil,which led a significant difference in soil nutrient between the surface soil( 0 ~ 10 cm) and bottom soil( 10 ~ 20 cm,20 ~ 35 cm and 35 ~ 50 cm). However,CC and NN treatments had no significant effect on soil nutrient movement. For the top 50 cm soil layer,nitric nitrogen( NO_3^--N) content at the depth of 20 ~ 35 cm was higher than 10 ~ 20 cm and 35 ~ 50 cm soil layer,and compared with the SC,CN,NN,SS and NS treatments,CC treatment had the highest NO3--N content. However,soil ammonium nitrogen( NH_4^+-N) content was higher in the 10 ~ 20 cm soil layer and the maximum content of NH_4^+-N appeared in the NS treatment. In the SS treatment,had the highest total potassium on the surface of soil. The yield of maize and wheat in the NS treatment was the highest and significant higher than CC and NN treatments.