汾渭平原农户冬小麦氮磷养分投入调查与分析

为明确汾渭平原农户冬小麦施肥现状,并指导农户合理施肥,在汾渭平原冬小麦种植区选取22个区/县,连续2年进行农户冬小麦产量及氮、磷养分投入调查。结果表明,汾河平原和渭河平原农户冬小麦平均产量分别为6 949和6 442 kg·hm^-2,其中中等产量水平（5 500 kg·hm^-2）以上的农户超过80%。汾河平原农户冬小麦N和P₂O₅的平均投入量分别为272.6和139.1 kg·hm^-2,施氮不足、适中和过量的农户分别占11.84%、23.68%和64.47%,施磷不足、适中和过量的农户分别占14.03%、7.89%和78.07%。渭河平原农户N和P₂O₅的平均投入量分别为196.3和147.2 kg·hm^-2,施氮不足、适中和过量的农户分别占 28.63%、31.97%和39.40%,施磷不足、适中和过量的农户分别占5.95%、14.50%和79.56%。汾河平原农户冬小麦氮肥基肥和追肥比例分别为60.3%和39.7%,而渭河平原农户冬小麦氮肥基肥和追肥比例分别为 97.3%和2.7%。此外,汾河平原农户冬小麦N、P₂O₅的平均偏生产力分别为30.4和59.6 kg·kg^-1,渭河平原农户冬小麦N、P₂O₅的平均偏生产力分别为38.4和56.1 kg·kg^-1。总之,在汾渭平原农户冬小麦种植过程中,氮、磷肥过量施用依然严重,导致肥料利用率低,因此,未来需进一步加强对农民的宣传培训,使其科学合理施肥,促进农业绿色发展。     

Relay-intercropping soybean with maize maintains soil fertility and increases nitrogen recovery efficiency by reducing nitrogen input

Optimized nitrogen(N)management can increase N-use efficiency in intercropping systems.Legume-nonlegume intercropping systems can reduce N input by exploiting biological N fixation by legumes.Measurement of N utilization can help in dissecting the mechanisms underlying N uptake and utilization in legume-nonlegume intercropping systems.An experiment was performed with three planting patterns:monoculture maize(MM),monoculture soybean(SS),and maize-soybean relay intercropping(IMS),and three N application levels:zero N(NN),reduced N(RN),and conventional N(CN)to investigate crop N uptake and utilization characteristics.N recovery efficiency and 15N recovery rate of crops were higher under RN than under CN,and those under RN were higher under intercropping than under the corresponding monocultures.Compared with MM,IMS showed a lower soil N-dependent rate(SNDR)in 2012.However,the SNDR of MM rapidly declined from 86.8%in 2012 to 49.4%in 2014,whereas that of IMS declined slowly from 75.4%in 2012 to 69.4%in 2014.The interspecific N competition rate(NCRms)was higher under RN than under CN,and increased yearly.Soybean nodule dry weight and nitrogenase activities were respectively 34.2%and 12.5%higher under intercropping than in monoculture at the beginning seed stage.The amount(Ndfa)and ratio(%Ndfa)of soybean N2 fixation were significantly greater under IS than under SS.In conclusion,N fertilizer was more efficiently used under RN than under CN;in particular,the relay intercropping system promoted N fertilizer utilization in comparison with the corresponding monocultures.An intercropping system helps to maintain soil fertility because interspecific N competition promotes biological N fixation by soybean by reducing N input.Thus,a maize-soybean relay intercropping system with reduced N application is sustainable and environmentally friendly.     

Identification and evaluation of high nitrogen nutrition efficiency in rapeseed (Brassica napus L.) germplasm

To establish identification and evaluation methods of N (nitrogen) absorption and utilization of rapeseed (Brassica napus L.), difference of N nutrition efficiency (NNE) among rapeseed germplasms and relationship between NNE and plant traits under various N application rates were analyzed in this research. Pot cultivating experiments were conducted to investigate NNE with 3 ​N application rates in soil (0.05, 0.2 and 0.3 ​g/kg). A total of 12 rapeseed germplasms were planted, nitrogen absorption efficiency (NAE) and nitrogen utilization efficiency (NUE) in seedling stage, bolting stage, initial flowering stage, final flowering stage, and maturity stage were obtained. Results showed that bolting stage was the best period for NAE identification and evaluation. Low N application rate in soil (0.05 ​g/kg) was the best for NAE, and the indirect indexes were basal stem diameter, plant root dry weight and above ground plant dry weight. Maturity stage was the best period for NUE identification and evaluation. High N application rate in soil (0.3 ​g/kg) was the best for NUE, and indirect indexes were above ground plant dry weight and basal stem diameter. N application rates of 0.05 ​g/kg in soil was the best for nitrogen harvest index at maturity stage, and indirect indexes was number of pods per plant. Plant traits of rapeseed germplasms affected NNE. Higher basal stem diameter, plant root dry weight and above ground plant dry weight at bolting stage under low N application rate were important characteristics of N absorption in rapeseed. Higher above ground plant dry weight and basal stem diameter at maturity stage under high N application rate were important characteristics of N utilization. Higher number of pods per plant at maturity stage under lowe N application rate was an important characteristic of N harvest index. These results provided a reliable index for N management and provided theoretical basis for guiding rapeseed breeding.     

施氮量对粮饲兼用玉米子粒产量和饲用品质的影响

2017~2018年以主推粮饲兼用玉米陕科9号品种为材料,设0、90、180、270和360 kg/hm² 5个氮肥水平进行大田试验,测定不同氮肥处理下叶面积指数、产量和饲用品质和氮肥利用率等性状指标,分析施氮量对玉米子粒产量、饲用品质和氮肥利用率的影响。结果表明,随施氮量的增加,叶面积指数、SPAD值和生物量增加;子粒产量随施氮量的增加先增加后稳定,此时最佳施氮量为268 kg/hm²,产量增加64.4%。随着氮肥增加,氮肥农学效率呈先增加后降低,氮肥偏生产力降低。饲用品质分析显示,子粒蛋白质、淀粉和脂肪含量随着施氮量增加而增加,在氮肥270 kg/hm²处理下分别较不施氮处理增加2.4%、13.7%和22.5%;秸秆中性洗涤纤维和酸性洗涤纤维含量分别减少20.4%和18.1%,秸秆粗蛋白和体外干物质消化率分别增加22.5%和17.6%。适当增施氮肥改善玉米群体质量,增加产量和氮肥利用率,提高饲用价值。陕北灌区粮饲兼用玉米生产实践中,推荐适宜施氮量为268 kg/hm²。     

驳枝和施氮对早花烤烟成熟期水溶性总糖和淀粉含量的影响

在大田条件下,研究驳枝和追施氮肥对早花烤烟成熟期叶片中水溶性总糖和淀粉含量的影响。结果表明：高施氮量抑制烟草叶片的水溶性总糖和淀粉积累,然而低氮促进了中部叶水溶性总糖和淀粉积累。     

不同施氮量对冬小麦产量、效益及土壤理化性状的影响

为探明豫北地区高肥力地块不同施氮量对冬小麦产量、经济效益及土壤理化性状的影响,在安阳市北关区壤质潮土上开展了冬小麦不同施氮量试验,设常规施磷钾肥（W1,CK）、常规施肥减施氮肥30%（W2）、常规施肥减施氮肥15%（W3）、常规施肥减施氮肥5%（W4）、常规施肥（W5）和常规施肥增施氮肥5%（W6）6个处理。结果表明,随着氮肥施用量的减少冬小麦主茎叶龄、次生根数、茎蘖数、株高及穗长等农艺性状呈下降趋势,以W6处理最佳。冬小麦产量随着施氮量的增加呈上升趋势,W4、W5、W6处理与W1处理相比增幅分别达48.7%、48.9%、49.1%,W4、W5、W6处理间差异不显著;但与W2、W3处理间差异达到显著水平。不同施氮量处理经济效益较W1处理均有不同程度增加,W4较W1处理净增效益5 869.80元/hm ²,较W5处理净增效益24.45元/hm ²。不同施氮量处理对土壤有机质、全氮、有效磷、速效钾、缓效钾含量和土壤容重有显著影响,但对pH影响不显著。土壤全氮含量随施氮量的增加呈上升趋势;W4处理土壤容重最低。综合分析,以常规施肥减施氮肥5%处理效果最佳。     

不同土壤条件下氮肥处理对小麦产量及品质的影响

为探讨不同土壤条件下氮肥处理对小麦产量及品质的影响,采用盆栽试验,以Egypt1和津强7号为供试材料,研究不同土壤条件下氮肥处理对小麦产量及品质的影响。试验设黑土、潮土2种土壤类型和不追肥、拔节期追氮肥、挑旗期追氮肥3种肥料处理,3次重复。结果表明: 在2种土壤条件下,小麦籽粒产量和各蛋白质组分产量表现为黑土>潮土,除球蛋白产量外,土壤处理间均差异显著。不同时期追施氮肥均显著提高了籽粒产量和蛋白质产量。黑土和潮土配合追施氮肥都可以有效提高小麦籽粒产量,改善品质。     

稻麦两熟制下秸秆还田模式的产量和经济效益分析

明确不同秸秆还田模式对小麦、水稻产量和经济效益的影响,对推广秸秆还田具有重要意义。利用稻麦复种长期田间定位试验2012-2018年的数据,分析了秸秆不还田（S0）、麦秸还田（WS）、稻秸还田（RS）和稻麦秸均还田（WRS）4种秸秆还田模式对作物产量、氮肥利用率、秸秆增产率、秸秆边际产量和秸秆农学利用率的影响。结果表明：秸秆还田均增加水稻产量,其中RS和WRS模式增产效果均显著大于WS模式;小麦产量随秸秆还田年限呈“减产-稳产-增产”的变化趋势。秸秆的周年增产率和农学利用率分别为5.65%~13.60%和0.11~0.17kg/kg。与RS模式相比,WRS模式属于秸秆过量还田,其秸秆增产效率降低。秸秆还田提高稻麦氮肥周年利用率1.67~4.01kg/kg,其中RS和WRS模式较WS模式更利于作物的氮吸收。WS、RS和WRS模式的稻田周年净收益较不还田模式分别增加1 690、4 875和4 177元/（hm²·年）,其中RS和WRS模式均显著高于WS模式。综合以上结果,麦季稻秸还田模式（RS）既可提高还田秸秆利用率,又可增加稻田净收益,推荐在稻麦两熟农田采用。     

播期对直播水稻产量、花后各器官干物质和氮素积累及转运的影响

为探究播期对直播水稻产量、花后干物质和氮素积累与转运的影响,以水稻品种白粳1号、长白9号和龙粳31号为供试材料,设置3个播期（SD1、SD2和SD3）,比较不同播期条件下3个品种的产量、抽穗期和成熟期各器官干物质及氮素积累与转运特点。3个品种抽穗期和成熟期各器官干物质及氮素积累量、抽穗至成熟期各器官干物质及氮素转运量和产量均表现为SD2>SD3>SD1。相关分析表明,产量与成熟期穗干物质及氮素积累量呈显著正相关,与叶片干物质和氮素转运量呈显著正相关。在本试验条件下,播期的推迟提高了3个品种有效穗数及结实率,进而提高了产量,同时促进了各器官物质转运量与转运率的提高。各品种SD2处理的产量及花后干物质、氮素积累量最高,SD2为适宜播期。     

施氮处理对不同筋型小麦产量和品质的影响

为探究施氮处理对不同筋型小麦的植株性状、籽粒产量和品质的影响,采用盆栽试验,选用强筋小麦品种中麦578（A1）和中麦5051（A2）、弱筋小麦品种扬麦15（A3）和扬麦24（A4）为供试品种,在施氮量相同的条件下进行底施（B1）和追施（B2）处理。结果表明：在其他栽培措施相同条件下,强筋小麦穗长、总小穗数、千粒重和籽粒产量均优于弱筋小麦,其中A1籽粒产量分别比A2、A3和A4高0.44%、49.81%和15.27%;施氮处理中B2的株高、穗长、穗粒数、总小穗数和籽粒产量均高于B1;不同处理组合中,强筋小麦品种A1B2的植株和产量性状优于其他处理;强筋小麦品种的籽粒蛋白质含量和蛋白质产量均高于弱筋小麦品种,且具有极显著差异（P<0.01)。本试验中强筋小麦品种中麦5051在氮肥追施处理中可以兼顾籽粒产量、蛋白质含量和蛋白质产量。