【摘要】 以典型半干旱区干湿砂质新成土(Ust-Sandic Entisols)为供试土壤进行田间试验,研究地膜覆盖、施氮及补充灌水量对春玉米(Zea maysL.)产量、土壤矿质氮(NO3--N和NH4+-N)及氮素平衡的影响。结果表明,0—100 cm土体范围内,随着土层加深,播前和收获后土壤NO3--N含量呈降低趋势,NH4+-N有所增加,但变幅不大;总矿质氮量(NO3--N和NH4+-N)表现为下降。说明地膜覆盖和施氮并没有使NO3--N深层累积量增加,这可能与土壤本身供氮能力严重不足有关。与不施氮相比,施氮各处理氮肥表观损失量增加;与不覆膜相比,作物氮素累积量比不覆膜显著增加(P<0.05)。在低灌(80 mm)覆膜和高灌(160 mm)覆膜条件下,玉米的氮肥利用率均比不覆膜提高了18.8%,说明覆膜低灌在相同施氮条件下,可节约80 mm灌水。但低灌(80 mm)与高灌(160 mm)不覆膜间氮肥利用率差异不显著,表明在相同施氮条件下,覆膜可有效提高氮肥利用率,减少氮素损失。综合考虑子粒产量和氮肥利用率,"覆膜+补灌80 mm+施氮90 kg/hm2"可能为本试验条件下较优的栽培模式。更多还原

【Abstract】 A field experiment was carried out on typical Ust-Sandiic Entisols soil in semi-arid area to study the effect of film mulching,nitrogen(N) application and supplementary irrigation on spring maize(Zea mays L.) yield,soil mineral N(NO-3-N and NH+4-N) and N balance.The result showed that in the 0-100 cm soil profile,with the depth of soil layers increasing,NO-3-N content before sowing and after harvest decreased,NH+4-N increased slowly,and the total mineral N content declined(NO-3-N and NH+4-N).It indicated that film mulching and N application did not increase NO-3-N accumulation in deep layer.This might be related to the soil’s insufficient N supplying ability.The N apparent losses increased in all the treatments under N application compared to the zero N application treatment.The crop N accumulation significantly increased(P<0.05) compared to the no film mulching treatment.In the 80 mm and 160 mm irrigation with film mulching treatments,the N fertilizer use efficiency of maize increased 18.8% compared with no film mulching.This indicated that under the same N levels,low irrigation(80 mm) with film mulching could save 80 mm water.However,the difference of N fertilizer use efficiency between 80 mm and 160 mm without film mulching was not significant.This indicated that film mulching increased N fertilizer use efficiency and decreased N losses under the same N application condition.In terms of grain yields and N fertilizer use efficiency,the recommended management practice would be "film mulching + supplementary irrigation at 80mm + N application at 90 kg/ha " based on results of this experiment.更多还原