不同管理模式对春玉米土壤硝态氮累积与氮素利用率的影响

在高肥力(文水)、中肥力(祁县)、低肥力(东阳)条件下,研究了不同管理模式(无氮肥对照、农户习惯、优化处理、高产高效处理)对春玉米土壤剖面硝态氮分布、累积与氮素平衡以及氮肥利用率的影响。通过3年定位试验,结果表明,春玉米收获后0~200 cm土壤剖面硝态氮累积量,在2011,2012年3个试验点都表现为:农户习惯高产高效优化处理无氮对照。文水试验点硝态氮累积量最高,三季平均为287.7 kg/hm2,比东阳和祁县土壤硝态氮累积量分别高18.4%和11.6%。氮素表观损失在3个肥力水平都均表现为农户习惯高产高效优化处理无氮对照。作物携出量在3个肥力水平均表现为:高产高效优化处理农户习惯无氮对照。在2011,2012年氮素农学利用率均表现为:高产高效处理优化处理农户习惯,2013年氮素回收率最高为祁县。高产高效处理达67.6%。通过合理的管理模式,可以在提高产量的同时显著提高氮素的利用率,并降低土壤中硝态氮的残留量。

Effects of Different Management Patterns on Soil Nitrate Nitrogen Accumulations and Nitrogen Use Efficiency in Spring Maize

The effects of different management patterns(Control treatment /CK,Farmer practice treatment /FP, Optimized application treatment /OPT,High yield and high efficiency treatment /HY),nitrate nitrogen accumulation, nitrogen balance and use efficiency in 3 sites(WS,QX,DY)with different soil fertilities (high,mid,low).The re-sults of three-year field experiments showed that the nitrate nitrogen accumulations decreased in the order:FP >HY >OPT >CK in 0 -200 cm soil profiles,at the harvest stage(201 1 ,2012)of spring maize in 3 sites.The highest nitrate nitrogen residue average was 287.7 kg /ha at the site of WS,respectively 18.4% and 1 1 .6% higher com-pared with the site of DY and QX.The nitrogen apparent losses were the highest from FP,which were FP >HY >OPT >CK in 3 sites,except the CK treatment.The crop uptake decreased as HY >OPT >FP >CK at all the sites. Nitrogen agronomic use efficiency decreased as HY >OPT >FP(201 1 ,2012),the highest nitrogen recovery efficien-cy was HY(67.6%)at the site of QX(2013).The residue mineral N and nitrogen apparent losses were influenced by soil fertilities,whereas nitrogen utilization were no significantly with soil fertilities.It was suggested that the pat-tern like HY with controlled N application rate and increasing organic fertilizer should be generalized,to reduce ni-trate nitrogen residue and improve N use efficiency.