农业生产系统氮磷环境影响分析——以安徽省为例

为探讨农业生产过程中氮、磷营养物质流动造成的环境影响,采用生命周期评价方法以农业生产系统中种植和养殖过程中的氮、磷物质流动为研究对象,比较和分析了安徽省2014年农业生产系统氮、磷在不同作物和畜禽生产中造成的能源消耗、全球变暖、酸化和富营养化等环境影响。结果表明:生产1 t水稻、小麦、玉米、大豆和油菜的综合环境影响指数分别为0.35、0.34、0.50、0.63和0.40,生产单位数量猪、牛、羊和家禽的综合环境影响指数分别为0.29、1.21、0.14和0.01。由此,水稻、小麦、羊和家禽的综合环境影响指数较小;从各类农产品总量造成的环境影响来看,水稻、小麦、猪和家禽对整个系统的能源消耗、全球变暖、酸化和富营养化的贡献比较突出,4种农产品之和占各种影响类型的78.45%、70.97%、81.21%和79.79%;再对比种植和养殖两个子系统,种植和养殖分别对能耗和富营养化影响突出,分别占78.53%和72.83%,而二者对全球变暖和酸化的影响大致相同。研究提出改善饮食结构、优化施肥和资源化畜禽粪便等是减轻农业生产氮、磷环境影响的有效途径。     

茶叶主产区订单农业有效性及契约稳定性研究——以西南地区茶叶生产为例

订单农业是促进产业融合、提高农业产业化水平的重要方式,但订单农业的效果却参差不齐。同时,违约率高、稳定性差是中国订单农业实践中的客观现实。利用西南地区茶叶主产县茶叶种植户调查数据,基于心理契约理论,分析订单农业模式的有效性、稳定性,探讨订单农业稳定性的影响因素。结果表明,尽管订单农业参与率低,只有33.79%茶农参加了订单农业,但无论是农民增收还是技术及服务普及方面,订单农业模式都有效,不过就其效果而言,生产合同模式效果优于销售合同模式。农户对高的相对收益、技术及服务可得性、交易公平合理性、满意度、风险共担关系的感知越强烈,越把交易伙伴视为朋友,农户履行协议可能性越高。在是否履约方面,农户是理性的。只有在不损害自己经济利益时,交易伙伴对农户的人情投资才对农户履行协议起促进作用。因此,应鼓励茶叶加工企业通过生产合同模式与农户展开互利合作;茶叶加工企业应通过推广普及现代茶叶生产技术及服务来提高茶业整体经济效益,并与农户分享,还应加强与农户的沟通、交流,争取得到农户的理解,让农户感受到交易的公平性,提高对交易的满意度,把茶叶加工企业当作帮助自己发家致富的朋友。     

农业生产性服务对我国粮食生产成本效率的影响分析——以水稻产业为例

农业生产性服务对于缓解粮食生产节本上涨压力,实现农业可持续发展具有重要意义。本文以我国农业生产性服务发展水平较高的水稻产业为例,在分析水稻生产性服务发展现状的基础上,利用国家水稻产业综合实验站固定观察点的农户调查数据,采用随机前沿方法,分析了农业生产性服务对粮食成本效率的影响。结果表明,当前我国水稻生产性服务在生产环节发展上差异明显,金融保险服务、技术服务、机械服务等产中环节服务发展水平要高于农资供应、加工销售等产前和产后环节;水稻种植农户平均成本效率为0.73,总体还处于较低水平,水稻生产的实际成本相对于前沿成本存在较大偏离,这种偏离主要是由成本无效率导致的;金融保险服务、技术服务、机械服务和加工销售服务等水稻生产性服务对于提高成本效率、节约生产成本具有显著作用,但农资供应服务作用并不显著;户主受教育水平和水稻种植经验对提高成本效率也具有显著作用。在此基础上,提出了拓宽农业生产性服务发展环节,提高农业生产性服务整体发展水平、充分发挥产中环节和产后环节对成本效率的提升作用,以及加强农民教育和职业培育等提高我国水稻生产成本效率的对策建议。     

Effects of different nitrogen fertilizer management practices on wheat yields and N2O emissions from wheat ifelds in North China

Nitrogen (N) is one of the macronutrients required for plant growth, and reasonable application of N fertilizers can increase crop yields and improve their quality. However, excessive application of N ...     

Effects of different nitrogen fertilizer management practices on wheat yields and N_2O emissions from wheat fields in North China

Nitrogen(N) is one of the macronutrients required for plant growth, and reasonable application of N fertilizers can increase crop yields and improve their quality. However, excessive application of N fertilizers will decrease N use efficiency and also lead to increases in N2 O emissions from agricultural soils and many other environmental issues. Research on the effects of different N fertilizer management practices on wheat yields and N2 O emissions will assist the selection of effective N management measures which enable achieving high wheat yields while reducing N2 O emissions. To investigate the effects of different N management practices on wheat yields and soil N2 O emissions, we conducted field trials with 5 treatments of no N fertilizer(CK), farmers common N rate(AN), optimal N rate(ON), 20% reduction in optimal rate+dicyandiamide(ON80%+DCD), 20% reduction in optimal rate+nano-carbon(ON80%+NC). The static closed chamber gas chromatography method was used to monitor N2 O emissions during the wheat growing season. The results showed that there were obvious seasonal characteristics of N2 O emissions under each treatment and N2 O emissions were mainly concentrated in the sowing-greening stage, accounting for 54.6–68.2% of the overall emissions. Compared with AN, N2 O emissions were decreased by 23.1, 45.4 and 33.7%, respectively, under ON, ON80%+DCD and ON80%+NC, and emission factors were declined by 22.2, 66.7 and 33.3%, respectively. Wheat yield was increased significantly under ON80%+DCD and ON80%+NC by 12.3 and 11.9%, respectively, relative to AN while there was no significant change in yield in the ON treatment. Compared with ON, overall N2 O emissions were decreased by 29.1 and 13.9% while wheat yields improved by 18.3 and 17.9% under ON80%+DCD and ON80%+NC, respectively. We therefore recommend that ON80%+DCD and ON80%+NC be referred as effective N management practices increasing yields while mitigating emissions.     

轮作体系下麦/油减量施氮与水稻氮肥运筹对作物产量和氮素吸收的影响

为了研究麦/油-稻轮作体系麦/油减量施氮与水稻氮肥运筹对作物产量、氮素吸收和氮肥偏生产力的影响,于2017—2018年开展麦-稻轮作和油-稻轮作的田间试验,在麦/油季设置常规施氮(小麦,N 150 kg·hm^-2;油菜,N 180 kg·hm^-2)、减量施氮(小麦,N 120 kg·hm^-2;油菜,N 150 kg·hm^-2)2个处理,在水稻季N 150 kg·hm^-2用量基础上设置3个运筹M1~M3,基肥、分蘖肥、穗肥的用量比分别为2∶2∶6、3∶3∶4和4∶4∶2。结果表明:在麦-稻轮作体系下,小麦季减量施氮小麦产量、地上部生物量和地上部氮素吸收量分别显著(P<0.05)降低15.36%、14.21%和17.14%,小麦氮肥偏生产力显著(P<0.05)增加5.79%。小麦季常规施肥处理下,M3运筹的水稻产量最高,而减量施氮处理下,M2运筹的水稻产量、地上部氮素吸收量和氮肥偏生产力最高。在油-稻轮作体系下,油菜季减量施氮显著(P<0.05)降低了油菜的产量和地上部氮素吸收量,降幅分别为14.28%和16.76%。无论油菜季减氮与否,M3运筹的水稻产量、地上部生物量和氮肥偏生产力均最高。     

农户兼业化、土地细碎化与农机社会化服务——以江西省为例

随着农户兼业化发展,务农劳动力流失效应日趋严重,农机社会化服务急需加强。但我国户均承包的小规模经营方式以及土地肥瘦搭配的细碎化问题又阻滞农机社会化服务的发展,其间矛盾亟待解决。基于理性小农理论,利用江西省水稻种植户的微观调查数据,采用二元Probit模型,分析农户兼业化与土地细碎化对农机社会化服务的影响,探讨其作用机制,并通过工具变量法解决农户兼业化与农机社会化服务采用之间的内生性问题。结果表明:农机社会化服务已成为大多数农户的选择,82.41%的农户在其农业生产任一环节使用了农机社会化服务,农户在收割和整地两大生产环节的农机社会化服务采用比例分别为84.01%和59.53%。矫正内生性后,农户兼业化对农机社会化服务的采用具有显著的正向影响,土地细碎化负向调节农户兼业化对农机社会化服务采用的积极影响。同时,农机社会化服务满意度、户主年龄、受教育情况、健康状况、家里到县城距离对农户采用农机社会化服务有显著的影响。据此,提出应抓住高标准农田建设机遇,降低土地细碎化程度;加强农机社会化服务供给侧结构性改革,保障农机社会化服务供需协调;加快培育新型农业经营主体,促进小农户与现代农业有机衔接。     

Effects of different agricultural treatments on narrowing winter wheat yield gap and nitrogen use efficiency in China

Under the limited cultivated land area and the pursuit of sustainable agricultural development,it is essential for the safety of grain production to study agricultural management approaches on narrowing the winter wheat yield gap and improving nitrogen use efficiency (NUE) in China.In this study,DSSAT-CERES-Wheat Model is used to simulate winter wheat yield under different agricultural treatments,and we analyze yield gaps and NUE with different management scenarios at regional scales and evaluate the suitable approaches for reducing yield gap and increasing NUE.The results show that,the potential of narrowing yield gap ranges 300–900 kg ha~(–1) with soil nutrients increase,400–1 200 kg ha~(–1) with sowing date adjustment and 0–400 kg ha~(–1) with planting density increase as well as 700–2 200 kg ha~(–1) with adding nitrogen fertilizer.Contribution rates of management measures of soil nutrients,sowing date adjusting,planting density,and nitrogen fertilizers are 5–15%,5–15%,0–4%,and 10–20%,respectively.Difference in nitrogen partial productivity ranges 3–10 kg kg~(–1) for soil nutrients,1–10 kg kg~(–1) for sowing date adjusting,1–5 kg kg~(–1) for planting density increase,and–12–0 kg kg~(–1) for adding nitrogen fertilizers,respectively.It indicates that four treatments can narrow yield gap and improve the NUE in varying degrees,but increasing nitrogen fertilizer leads to the decrease of NUE.     

微喷水肥一体化氮肥管理对冬小麦产量、品质、氮素积累和利用的影响

为探究冬小麦微喷水肥一体化适宜的氮肥施用方式,于2018—2019年在微喷水肥一体化条件下,以‘济麦22’为材料,设置120(N₁)、210(N₂)和300 kg/hm²(N₃)3个施氮量处理,每个施氮量下设置拔节期一次性追氮(JS)和拔节期、孕穗期、开花期和灌浆期等量分次追氮(4T)2种追氮方式,测定冬小麦产量、蛋白质组分含量、面团品质、氮素积累和土壤硝态氮含量。结果表明：微喷灌条件下,氮肥分施(4T)显著促进冬小麦花后干物质积累,显著提高千粒重,进而显著提高籽粒产量,N₃-4T处理的产量最高,为9 951.2 kg/hm²。在相同追氮方式下,随着施氮量的增加,JS处理显著提高了球蛋白、醇溶蛋白和谷蛋白含量,显著延长了面团稳定时间;4T处理随着施氮量增加,籽粒总蛋白含量无显著变化,清蛋白、醇溶蛋白和谷蛋白含量均呈下降趋势,高氮处理下(N₃)湿面筋含量和面团形成时间均显著下降。在相同施氮量下,相较于JS处理,4T处理可显著提高花后干物...     

农户行为视角下农业生产性服务对土地规模经营的影响

以我国农业生产性服务发展水平较高的水稻产业为例,在分析农业生产性服务发展现状的基础上,采用国家水稻产业综合实验站固定观察点的农户调查数据,从农户土地规模经营行为视角实证研究农业生产性服务对土地规模经营的影响。结果表明:1)当前我国农业生产性服务产中环节发展水平较高,产前和产后环节发展相对薄弱;2)农业生产性服务促进了土地的规模经营,产中和产后环节生产性服务对农户土地规模经营行为的影响更为显著;3)对不同经营规模农户而言,农业生产性服务对大规模农户土地规模经营行为影响更为显著;4)个体特征、生产经营特征对农户土地规模经营行为也存在显著影响。     

山东省冬小麦-夏玉米轮作体系土壤氮素盈余指标体系的构建与评价——以德州市为例

山东省德州市是我国重要的粮食生产基地,大量施用氮肥以及氮素流失是该地氮素污染的重要原因,设定合理的氮素盈余指标体系迫在眉睫。本研究以田间试验研究和文献荟萃为基础,探究德州市冬小麦-夏玉米轮作氮素盈余情况,建立该地氮盈余指标体系,并运用欧氏距离法对德州市当前氮素管理指标进行评价。结果表明:德州市整个冬小麦-夏玉米轮作体系轮作周期氮素盈余量为196.84 kg N·hm~(-2)·a~(-1),小麦季氮素盈余量为111.07 kg N·hm~(-2),玉米季氮素盈余量为85.77 kg N·hm~(-2)。氮素盈余量在30～70 kg N·hm~(-2)·a~(-1)时为德州市整个轮作周期氮素盈余量推荐值;德州市小麦季氮素盈余量推荐值为10～50 kg N·hm~(-2);德州市玉米季氮素盈余量推荐值为20～60 kg N·hm~(-2)。在氮素的损失方面,氨挥发以及淋洗是氮素损失的主要去向。小麦季的氮素污染程度高,玉米季氮素污染程度相对较低。运用欧氏距离法计算德州市氮素管理水平(A值)为0.63,属于中级管理水平。综上,德州市冬小麦-夏玉米轮作体系农田氮素含量较高,从而导致氮素大量损失。加强氮素管理水平,提高氮素利用率是德州市氮素资源管理的长期任务。     

Effects of irrigation and nitrogen management on hybrid maize seed production in north-west China

Scientific irrigation and nitrogen management is important for agricultural production in arid areas. To quantify the effect of water and nitrogen management on yield components, biomass partitioning and harvest index (HI) of maize for seed production with plastic film-mulching, field experiments including different irrigation and N treatments were conducted in arid north-west China in 2013 and 2014. The results indicated that kernel number per plant (KN) was significantly affected by irrigation and N treatments. However, 100-kernel weight was relatively stable. Reducing irrigation quantity significantly increased stem partitioning index (PI_stem) and leaf partitioning index (PI_leaf), and decreased ear partitioning index (PI_ear) at harvest, but lowering N rate (from 500 to 100 kg N·hm^-2) did not significantly reduce PI_stem, PI_leaf, and PI_ear at harvest. HI was significantly reduced by reducing irrigation quantity, but not by reducing N rate. Linear relationships were found between KN, PI_stem, PI_leaf, PI_ear at harvest and HI and evapotranspiration (ET).     

封闭型内陆湖泊夏季氮素赋存特征——以达里诺尔湖为例

氮素是影响湖泊初级生产力的主要因素之一。近年来,受气候干旱及上游用水量增加等因素的影响,大多数封闭性内陆湖都面临着湖面萎缩、湖水因营养盐浓度增加而逐渐恶化的问题。本文以内蒙古高原境内封闭型内陆湖泊——达里诺尔湖为例,于2017年夏季采集湖水、间隙水、沉积物、入湖河流等样品。对湖泊氮素赋存特征、迁移趋势做出分析,并且对入湖河流携带的氮素对湖泊水质的影响展开讨论。结果表明:氨氮(NH_4~+-N)是上覆水中占比例最高的形态氮。总氮(TN)、硝酸盐氮(NO_3~--N)、亚硝酸盐氮(NO_2~--N)含量随水深从浅到深基本保持不变。只有B6、E2、E5样点的NH_4~+-N在水深1.5 m向下处含量有所波动。表层沉积物TN均值2 809.97 mg·kg~(-1),可交换态氮占TN含量6.74%;河水中占比例最高的形态氮是NO_3~--N,四条入湖河流中,TN、NH_4~+-N含量最高的是沙里河,NO_3~--N含量最高的是亮子河;每年由入湖河流携带入湖的TN量为120 t。总体来看,达里诺尔湖氮素赋存特征为:NH_4~+-N是上覆水的主导形态氮,TN及各形态氮含量在不同深度水层掺混均匀,无明显的分层现象。沉积物TN含量较高且氮素迁移能力较强。TN、NO_3~--N、NO_2~--N表现为由沉积物到上覆水的释放状态,而NH_4~+-N则以上覆水到沉积物的吸附状态为主。河流的输入对湖水TN含量有稀释作用,但会增加湖水NO_3~--N的负荷。     

河北省猪粪尿氮产生量及氨挥发量的研究

根据统计资料和文献数据,在确定不同养殖方式的(农户散养、集约化养殖)各猪种(育肥猪、母猪、幼猪)氮排泄量和NH3排放因子参数基础上,对2004年河北省农户散养和集约化养殖下各猪种粪尿N产生量及NH3挥发量进行了估算分析。结果表明:(1)2004年河北省猪粪尿N产生量约为81.6×104t,空间变异性较大,主要集中在石家庄、唐山、保定等地区;农户散养下猪粪尿N产生总量约为集约化养殖下总量的2倍;(2)2004年河北省猪粪尿NH3挥发量约为28.5×104t,石家庄、保定、唐山等地区挥发量最大;农户散养下猪粪尿NH3挥发量约为集约化养殖下总量的3倍多;(3)农户散养、集约化养殖下猪粪尿NH3-N损失率分别为34%、19%,集约化养殖要比农户散养更有利于N素保持与利用,有利于减少NH3挥发所带来的环境污染。     

秸秆还田与水分管理对双季水稻氮素吸收及氮肥?利用率的影响

秸秆还田是促进农田养分循环的重要方式,也对提升农田地力有较好效果。以南方典型双季稻田为研究对象,设置三个秸秆还田水平和两种水分管理方式的两因子田间定位试验,于定位试验开展后的第5年通过测定早稻和晚稻季稻田土壤无机氮、微生物生物量氮动态、植株吸氮量动态以及收获期主要土壤肥力因子、水稻产量和植株各部分氮素累积量,分析秸秆还田与水分管理制度下水稻氮素吸收和氮肥利用率的特征及其影响因素。结果表明:秸秆还田提高了土壤有机碳和全氮含量以及土壤p H,长期淹水较之间歇灌溉降低了土壤有机碳、全氮和全磷含量。在氮肥用量一致条件下,早稻季秸秆还田降低了分蘖期土壤氮素有效性,导致水稻生育期内氮素吸收量显著下降,且显著降低水稻籽粒产量及氮肥利用率;氮肥利用率较对照下降2.0~7.6个百分点,且随秸秆还田量的增加而降低。晚稻季秸秆还田提高了生育期内土壤氮素有效性,显著提高了水稻生育期内氮素吸收量,增加水稻产量且显著提高氮肥利用率;氮肥利用率较对照提高8.6~13个百分点,且随秸秆还田量的增加而增加。研究表明,间歇灌溉和长期淹水灌溉两种水分管理方式对水稻氮素吸收、籽粒产量及氮肥利用率的影响差异不显著。早稻季秸秆还田配合长期淹水灌溉将加剧水稻产量和氮肥利用率下降。双季稻稻田实行间歇灌溉下的早稻季秸秆不还田、晚稻季秸秆全量还田(6 t/hm2)有利于获得较高水稻产量和氮肥利用率。     

我国农业资源管理研究现状及展望

农业资源管理是人们为了保持资源处于良好状态和提高资源整体利用效率,实现资源的永续利用,而对农业资源及其运用采取一系列的行动。本文介绍了农业资源管理研究从利用传统人工的方式到利用现代信息技术的发展过程,并展望了农业资源管理研究的发展前景。     

Growth and nitrogen productivity of drip-irrigated winter wheat under different nitrogen fertigation strategies in the North China Plain

Excessive application of nitrogen (N) fertilizer is the main cause of N loss and poor use efficiency in winter wheat (Triticum aestivum L.) production in the North China Plain (NCP).  Drip fertigation is considered to be an effective method for improving N use efficiency and reducing losses, while the performance of drip fertigation in winter wheat is limited by poor N scheduling.  A two-year field experiment was conducted to evaluate the growth, development and yield of drip-fertigated winter wheat under different split urea (46% N, 240 kg ha^–1) applications.  The six treatments consisted of five fertigation N application scheduling programs and one slow-release fertilizer (SRF) application.  The five N scheduling treatments were N0–100 (0% at sowing and 100% at jointing/booting), N25–75 (25% at sowing and 75% at jointing and booting), N50–50 (50% at sowing and 50% at jointing/booting), N75–25 (75% at sowing and 25 at jointing/booting), and N100–0 (100% at sowing and 0% at jointing/booting).  The SRF (43% N, 240 kg ha^–1) was only used as fertilizer at sowing.  Split N application significantly (P<0.05) affected wheat grain yield, yield components, aboveground biomass (ABM), water use efficiency (WUE) and nitrogen partial factor productivity (NPFP).  The N50–50 and SRF treatments respectively had the highest yield (8.84 and 8.85 t ha^–1), ABM (20.67 and 20.83 t ha^–1), WUE (2.28 and 2.17 kg m^–3) and NPFP (36.82 and 36.88 kg kg^–1).  This work provided substantial evidence that urea-N applied in equal splits between basal and topdressing doses compete economically with the highly expensive SRF for fertilization of winter wheat crops.  Although the single-dose SRF could reduce labor costs involved with the traditional method of manual spreading, the drip fertigation system used in this study with the N50–50 treatment provides an option for farmers to maintain wheat production in the NCP.     

城镇化与农业现代化协调发展研究——以昆山市为例

城镇化与农业现代化相互依托、相互促进。推动城镇化和农业现代化相互协调,是坚持走中国特色新型工业化、信息化、城镇化、农业现代化道路的重要内容。昆山市作为全国百强县之首和苏南现代化建设示范区之一,常住人口城镇化率达到92.39%,并进入基本实现农业现代化阶段,但也存在城镇化与农业现代化质量不高、主体"错位"、"争地"矛盾突出、社会资本"下乡"目标"不纯"等问题和挑战。要结合昆山市实际,探索具有昆山特色新型城镇化与农业现代化协调发展道路,加快机制创新,提高基本公共服务均等化水平,推进城乡一体化进程,以现代产业体系支撑新型城镇化与农业现代化,构建科学合理的城镇化格局与农业发展格局。要进一步完善和创新用地保障机制、多元化投入机制,尽快建立新型城镇化与农业现代化协调发展实施机制。     

寒地稻田施氮状况与氮素调控对水稻投入和产出的影响

文章通过对黑龙江省1～3积温带240个农户的施肥情况调查,以及对试验区水稻氮素收支状况分析,研究了黑龙江省稻田土壤氮循环规律。结果表明,寒地稻田化肥投入氮量平均为150 kg.hm-2,占投入总量的72.4%,而且90%以上作基蘖肥施用,近60%的稻田氮素用量过高,稻田氮有17.2%的盈余,氮肥利用率较低。针对寒地水稻施氮问题,提出进行实地氮肥管理的策略,经过3年9个点次田间对比试验,证明该技术能降低氮肥用量30%以上,水稻产量增加10%以上,每公顷增收1 450元。     

新型农业经营体系与现代农业发展的关联效应研究——以湖北省为例

构建集约化、专业化、组织化、社会化相结合的新型农业经营体系,是加快现代农业发展的重要举措。探讨新型农业经营体系与现代农业发展的关联效应,对于推动新型农业经营体系与现代农业协同发展意义重大。基于2013—2017年湖北省新型农业经营体系与现代农业发展水平的主要评价指标数据,采用灰色关联模型测算分析了新型农业经营体系与现代农业发展的关联效应。结果显示:1)新型农业经营体系与现代农业发展之间存在显著的关联效应;2)新型农业经营体系各评价指标与现代农业发展水平的关联度存在一定差异性,其中,注册登记家庭农场数、农林牧渔服务业产值占比、家庭承包耕地流转面积占比、农业机械化程度与现代农业发展水平的关联度最大,农业劳动生产率、农户入社率、省级农业龙头企业数、规模经营面积、通过农产品质量安全认证的农业企业数与现代农业发展水平的关联度次之,土地生产率与现代农业发展水平的关联度最小。为促进湖北省现代农业持续稳定协调发展,提出着力培育多元规范的新型农业经营主体;加快构建多元高效的现代农业社会化服务体系;深化农村土地产权制度改革与流转机制创新;创建新型农业经营体系运营高效的体制机制等政策建议。