不同堆沤方式下秸秆还田对滇中烤烟农田生态系统氮素平衡的影响
裴益乐1, 李太兴2, 王克勤1, 宋娅丽1, 代 立1, 温昌焘3, 杨锦泽1

(1.西南林业大学 生态与环境学院, 昆明 650224; 2.云南省玉溪市水土保持工作站, 云南 玉溪 653100; 3.云南省玉溪市红塔区水土保持工作站, 云南 玉溪653100)

秸秆还田; 堆沤方式; 氮素平衡; 农田生态系统; 烤烟

Effects of Returned Straw Composted Under Different Stockpile Methods on Nitrogen Balance of Flue-Cured Tobacco Farmland Ecosystem in Central Yunnan Province
PEI Yile1, LI Taixing2, WANG Keqin1, SONG Yali, DAI Li1, WEN Changtao3, YANG Jinze1

(1.College of Ecology and Environment, Southwest Forestry University, Kunming 650224, China; 2.Soil and Water Conservation Workstation, Yuxi, Yunnan 653100, China; 3.Soil and Water Conservation Workstation, Hongta District, Yuxi, Yunnan 653100, China)

straw returning; stockpile methods; nitrogen balance; farmland ecosystem; flue-cured tobacco

备注

以滇中二龙潭小流域烤烟农田生态系统为研究对象,设置对照(CK)及8种不同玉米秸秆堆沤方式进行秸秆还田,各处理包括2种秸秆还田重量(0.75或1.5 kg/m2),2种秸秆粒度(1或5 cm),2种秸秆堆沤方式(水或水与尿素堆沤),研究烤烟农田生态系统中不同堆沤方式下秸秆还田对径流泥沙氮素流失、土壤氮素残留量、烤烟氮素吸收量以及农田烤烟生态系统氮素平衡的影响。结果表明:(1)径流和泥沙全氮流失量分别随着降雨量和降雨强度的增加而增加;(2)施用5 cm粗秸秆较1 cm细秸秆、1.5 kg/m2还田量较0.75 kg/m2还田量可分别减少径流氮素流失量0.32%～35.05%和54.52%～77.23%;(3)秸秆还田显著增加了土壤全氮、硝态氮含量,各处理分别较CK高出2.60%～20.33%和0.35%～90.57%;(4)烤烟各器官全氮含量分布特征为叶>茎>根,各处理下叶、茎、根全氮含量较CK分别增加了67.69%,25.33%和42.27%,水与尿素堆沤较水堆沤可显著提高烤烟氮素含量6.60%～38.03%;(5)在氮素平衡中径流和泥沙氮素流失量分别占氮素输入量的8.27%～23.85%和4.37%～12.72%,氮素流失主要以径流为主,泥沙为辅; 土壤残留量占氮素输入量的4.97%～36.79%; 烤烟吸收量占41.10%～71.64%,烤烟吸收的氮素占输入的主体部分。采用水与尿素堆沤,还田量1.5 kg/m2,秸秆粒度5 cm的合理配置,可有效维系烤烟农田生态系统氮素平衡,增加烤烟产量,降低氮素流失量,并提高该流域农田生态系统经济和生态效益。
In this study, the farmland ecosystem of flue-cured tobacco in the Erlongtan small watershed in central Yunnan Province was used as the research object. The control(CK)and eight treatments(straw returning of corn)under different stockpile methods were set up. Different treatments included two kinds of straw returning amount(0.75 or 1.5 kg/m2), two kinds of straw particle size(1 or 5 cm)and two kinds of stockpile methods(water or mix water with urea). The effects of returned straw composted under different stockpile methods on nitrogen loss from runoff and sediment, soil nitrogen residues, nitrogen absorption in flue-cured tobacco, and nitrogen balance in flue-cured tobacco farmland were studied. The results show that:(1)TN loss from runoff and sediment increased with amount of rainfall and rainfall intensity, respectively;(2)application of 5 cm thick straw(compared with 1 cm thin straw), and 1.5 kg/m2 returning amount(compared with 0.75 kg/m2)could effectively reduce the nitrogen loss from runoff by 0.32%～35.05% and 54.52%～77.23%, respectively;(3)straw returning significantly increased the contents of soil total nitrogen and nitrate nitrogen, and the contents of total nitrogen and nitrate nitrogen were 2.60%～20.33% and 0.35%～90.57% higher than CK, respectively;(4)the distribution characteristics of total nitrogen content in each organ of flue-cured tobacco were showed as the sequence: leaves>stems> roots, the total nitrogen content in the leaves, stems and roots increased by 67.69%, 25.33% and 42.27%, respectively, compared with CK; compared with water stockpile, mix water and urea significantly increased the nitrogen content of flue-cured tobacco by 6.60%～38.03%;(5)in the nitrogen balance, the nitrogen loss from runoff and sediment accounted for 14.36%～24.33% and 2.32%～14.32% of nitrogen input, respectively; the nitrogen loss was mainly caused by runoff nitrogen loss, followed by sediment loss; soil residues of nitrogen accounted for 4.97%～36.79% of nitrogen input; the absorption nitrogen amount of flue-cured tobacco accounted for 41.10%～71.64%, and the nitrogen absorbed by flue-cured tobacco accounted for the main part of nitrogen input. By using the reasonable configuration of mix water and urea, straw returning amount 1.5 kg/m and straw particle size of 5 cm can effectively maintain nitrogen balance in flue-cured tobacco farmland ecosystem, increase flue-cured tobacco yield, reduce nitrogen loss, and improve the economic and ecological benefits of the farmland ecosystem in this basin.