Closing the nitrogen use efficiency gap and reducing the environmental impact of wheat-maize cropping on smallholder farms in the Guanzhong Plain,Northwest China     

Feng-lian LÜ  Miao-miao HOU  Hong-tao ZHANG  Asif Khan  Muhammad Ayaz  Ciren QIANGJIU  Chang-lu HU  Xue-yun YANG  Ben-hua SUN  Shu-lan ZHANG 《农业科学学报》2019,18(1):169-178

A high crop yield with the minimum possible cost to the environment is generally desirable. However, the complicated relationships among crop production, nitrogen (N) use efficiency and environmental impacts must be clearly assessed. We conducted a series of on-farm N application rate experiments to establish the linkage between crop yield and N₂O emissions in the Guanzhong Plain in Northwest China. We also examined crop yield, partial factor productivity of applied N (PFPN) and reactive N (Nr) losses through a survey of 1 529 and 1 497 smallholder farms that grow wheat and maize, respectively, in the region. The optimum N rates were 175 and 214 kg ha^–1 for winter wheat and summer maize, respectively, thereby achieving the yields of 6 799 and 7 518 kg ha^–1, correspondingly, with low N₂O emissions based on on-farm N rate experiments. Among the smallholder farms, the average N application rates were 215 and 294 kg ha^–1 season^–1, thus producing 6 490 and 6 220 kg ha^–1 of wheat and maize, respectively. The corresponding PFPN values for the two crops were 36.8 and 21.2 kg N kg^–1, and the total N₂O emissions were 1.50 and 3.88 kg ha^–1, respectively. High N balance, large Nr losses and elevated N₂O emissions could be explained by the overdoses of N application and low grain yields under the current farming practice. The crop yields, N application rates, PFPN and total N₂O for wheat and maize were 18 and 24% higher, 42 and 37% less, 75 and 116% higher, and 42 and 47% less, correspondingly, in the high-yield and high-PFPN group than in the average smallholder farms. In conclusion, closing the PFPN gap between the current average and the value for the high-yield and high-PFPN group would increase crop production and reduce Nr losses or the total N₂O emissions for the investigated cropping system in Northwest China.  相似文献   

Molecular mapping of stripe rust resistance gene YrH9017 in wheat-Psathyrostachys huashanica introgression line H9017-14-16-5-3     

Dong-fang MA  Lu HOU  Cai SUN  Xing ZHANG  Jun-liang YIN  Qing-yun GUO  Yong-xing ZHU 《农业科学学报》2019,18(1):108-114

Several new stripe rust pathogen races emerged in the wheat growing regions of China in recent years. These races were virulent to most of the designated wheat seedling resistance genes. Thus, it is necessary and worthwhile to identify new valuable resistant materials for the sake of diversifying resistant sources, pyramiding different resistance genes and achieving durable resistance. Here, we identified the resistance gene, temporarily designated as YrH9017, in wheat-Psathyrostachys huashanica introgression line H9017-14-16-5-3. A total of 146 F₂ plants and their derived F_2:3 families in a cross of Mingxian 169 and H9017-14-16-5-3 were used to evaluate seedling stripe rust response and as a mapping population. Finally, we constructed a genetic map including eight simple sequence repeat (SSR) markers and expressed sequence tag (EST) markers. YrH9017 was located on the long arm of chromosome 2A and closely linked with two EST-sequence tagged site (EST-STS) markers BG604577 and BE471201 at 1.3 and 1.8 cM distance, respectively. The two closest markers could be used for marker-assisted selection of YrH9017 in breeding.  相似文献   

Cryopreservation of farm animal gametes and embryos: recent updates and progress     

Zhengyuan HUANG  Lei GAO  Yunpeng HOU  Shien ZHU  Xiangwei FU 《农业科学与工程前沿(英文版)》2019,6(1):42

Cryopreservation has undergone tremendous advances and is widely used in animal production based on decades of study of cellular permeability, freezability and empirical generalization. Several improvement are particularly important: the cryopreservation protocol has been continuously refined over the years to achieve greater reproductive performance; cryoprotective agents are more effective and less toxic than previously; there has been significant innovation in advanced cryopreservation systems and carriers. Despite this, there are still problems that urgently require practical solutions, such as remedies for cryodamage and encouraging the use of frozen–thawed porcine sperm in pig production.  相似文献   

Innovations of phosphorus sustainability: implications for the whole chain     

Jianbo SHEN  Liyang WANG  Xiaoqiang JIAO  Fanlei MENG  Lin ZHANG  Gu FENG  Junling ZHANG  Lixing YUAN  Lin MA  Yong HOU  Tao ZHANG  Weifeng ZHANG  Guohua LI  Kai ZHANG  Fusuo ZHANG 《农业科学与工程前沿(英文版)》2019,6(4):321

Phosphorus (P) is a non-renewable resource, therefore ensuring global food and environmental security depends upon sustainable P management. To achieve this goal, sustainable P management in the upstream and downstream sectors of agriculture from mineral extraction to food consumption must be addressed systematically. The innovation and feasibility of P sustainability are highlighted from the perspective of the whole P-based chain, including the mining and processing of P rock, production of P fertilizers, soil and rhizosphere processes involving P, absorption and utilization of P by plants, P in livestock production, as well as flow and management of P at the catchment scale. The paper also emphasizes the importance of recycling P and the current challenges of P recovery. Finally, sustainable solutions of holistic P management are proposed from the perspective of technology improvement with policy support.  相似文献   

玉米秸秆生物质炭基肥的结构与性质表征   总被引：2，自引：0，他引：2  

刘长涛  侯建伟  索全义  史李萍 《土壤》2019,51(3):465-469

为了解玉米秸秆生物质炭基肥的结构与性质,通过实验室自制玉米秸秆生物质炭基化肥,研究生物质炭添加量对炭基肥的形貌特征、pH、表面官能团种类和元素组分的影响。结果表明:玉米秸秆生物质炭具有丰富的孔隙结构,化学肥料添加量越大,结构表面无序化程度越高;总孔容和平均孔径的变异范围分别为2.1～3.3 cm3/kg和2.7～3.2 nm,平均为2.8 cm3/kg和2.9 nm。生物质炭化后,C-O-C、-COOH、-CH3、-CH2消失,化学肥料并不影响生物质炭缓释载体原有的分子结构,只是影响其元素含量。与未加化肥的生物质炭对照相比,炭基肥中C、H元素含量降低,而N、O元素含量升高,变幅分别为47.7%～68.4%、20.2%～28.2%、59.5%～82.6%和164.0%～228.8%,平均为59.4%、24.1%、71.9%和196.5%;而元素组分的H/C、O/C和(N+O)/C都有所增大。总之,化学肥料存在于生物质炭表面和孔隙之中,其添加并未改变生物质炭的骨架结构和官能团种类,而元素组分含量和原子比(H/C、O/C和(N+O)/C)的改变将可能更有利于增强生物质炭基肥的保水与吸附性能。  相似文献   

农用水泵轴承材料的研究与应用     

侯仰海 《农机化研究》2006,(12):178-179

水泵作为一种通用机械,应用广泛,除用于抽水外,还可用来抽送酸碱盐溶液或固体粒块的浆状物。由于工作环境差,大大缩短了水泵的使用寿命。通过对农用泵使用情况的跟踪调查,发现泵中轴承损坏是导致水泵寿命缩短的关键。另外,由于泵的轴承所使用材料单一,不可能完全承受泵的上述工作条件,是造成轴承破(磨)损的主要原因。为此,以一种塑铜合金塑料(聚四氟乙烯加青铜粉)为材料,利用冷压烧结成型法,研制出了塑铜合金水泵轴承。经大量试验研究证明:该材料提高了水泵轴承抗拉、抗压和抗弯强度,增加了硬度,摩擦系数小,承载能力强,导热系数大,润滑性能好,使用寿命长达1500h,完全可以推广应用。  相似文献   

秦岭火地塘林区不同海拔不同林型土壤CO_2、CH_4、N_2O通量研究     

刘岳坤  庞军柱  扆凡  彭长辉  张硕新  侯琳  王效科  张红星 《西北林学院学报》2019,(1):1-10

二氧化碳(CO_2)、甲烷(CH_4)、氧化亚氮(N_2O)是3种主要的温室气体,温带森林土壤是CO_2、N_2O重要的源,是CH_4重要的汇,以前的研究大部分都关注这3种温室气体在时间上的变化,而很少开展在空间变化上的研究。2014年10月至2015年10月,采用静态箱-气相色谱法对秦岭南坡火地塘林区不同海拔(海拔1 560、1 585、1 963、2 040、2 160m,分别为落叶阔叶林、温性针叶林、温性针叶林、寒温性针叶林、落叶阔叶林)森林土壤CO_2、CH_4和N_2O通量进行了为期1a的监测。结果表明,CO_2全年都为排放,季节波动较大,总体上随海拔增加排放量减少,海拔由低到高(包括3种林型)年排放量依次为:19.12、12.53、11.78、16.95、14.87t·hm^-2;CH_4全年主要为吸收,在非生长季出现排放,季节波动幅度较大,总体上随海拔增加吸收量增加,海拔由低到高年通量依次为:-2.57、-3.60、-5.94、-5.59、-3.92kg·hm^-2;N_2O全年以排放过程为主,存在吸收现象,季节波动幅度不大,海拔对其通量影响不明显,海拔由低到高年排放量依次为:0.23、0.62、0.63、0.60、0.95kg·hm^-2。土壤温度是影响CO_2、N_2O通量的关键因子。5个样地森林土壤CO_2通量与土壤铵态氮含量(20～40cm)显著相关(P<0.05)。高的土壤NH_4^+含量对CH_4的吸收有抑制作用。在冻融交替期,降雨对N_2O的通量有明显影响。海拔由低到高5个样地的GWP(全球增温潜势)分别为:119.13、12.65、11.85、17.02t·hm^-2和15.07t·hm^-2。  相似文献   

基于三温模型和热红外遥感的不同大豆品种蒸腾特征研究     

鲁赛红  蒋适莲  王眺  张彤  侯梦杰  田菲 《中国生态农业学报》2019,27(10):1553-1563

蒸腾耗水是水循环中重要的水分存在形式之一,是准确量化水分利用效率的关键参数,对研究碳水循环关系及节水农业有重要意义。本研究以大豆品种‘晋21’(J21)和‘Union’(C08)为研究对象,设置两种水分处理[当地经验灌水定额的75%(A0)和37.5%(A1)],基于三温模型(3TModel)和热红外遥感,定量研究不同品种和不同水分胁迫下的大豆蒸腾速率,揭示其时空特征差异,从而为抗旱节水大豆品种筛选提供参考。研究结果表明:1)不同处理下大豆的蒸腾速率日变化趋势与气温、太阳净辐射和冠层温度的基本一致,呈先增加后减小的单峰曲线,且于午间达到峰值,峰值为1.2～2.5mm·h~(-1);各处理的大豆冠层温度和蒸腾速率均呈现出明显的空间异质性。2)J21与C08大豆的冠层温度A0处理分别低于A1处理6.55K和5.91K,蒸腾速率A0处理高于A1处理0.28 mm·h~(-1)和0.29 mm·h~(-1);大豆蒸腾速率与灌水量呈正相关、与冠层温度呈负相关。3)在相同水分胁迫下,大豆冠层温度J21低于C08 1.83～2.47 K,蒸腾速率J21高于C08 0.13～0.14 mm·h~(-1)。本研究与传统方法相比,所需要的参数较少,避开了空气动力学阻抗等难获取的参数,对农田尺度更具有适宜性,更能揭示不同农田环境下作物的蒸腾时空异质性,在农业水分高效利用和节水品种筛选上有十分重要的科学意义。  相似文献   

不同比例化肥与猪粪肥配施对稻穗不同部位磷含量分布的影响          下载免费PDF全文

唐先干  秦文婧  谢金水  王萍  侯红乾  李祖章  刘光荣  刘增兵 《中国土壤与肥料》2019,(1):30-34

为了综合评价中国南方施用猪粪肥对稻穗不同部位籽粒磷素积累的影响,本研究在水稻施肥量N 180kg/hm~2,N∶P_2O_5∶K_2O=3∶1∶2.5情况下,比较施用化肥(NPK)、70%化肥配施30%猪粪(F7M3)、50%化肥配施50%猪粪(F5M5)、30%化肥配施70%猪粪(F3M7)的稻穗不同部位籽粒含磷量。结果发现,化肥配施猪粪肥能有效促进水稻产量的增加与稻穗含磷量的下降,但猪粪肥配施与NPK处理的水稻籽粒吸磷量无明显差异;与NPK处理相比,猪粪肥配施可以显著降低一次枝梗与穗上部二次枝梗含磷量,并能有效降低不同穗位的籽粒含磷量。故猪粪肥能有效影响稻穗不同部位的磷含量,猪粪肥资源的合理利用有利于水稻的高产稳产。  相似文献   

UAN氮溶液对潮土上玉米生长和氮素吸收的作用效果   总被引：1，自引：1，他引：0       下载免费PDF全文

徐丽萍  刘红芳  侯晓娜  保万魁  孙蓟锋  荣向农  王旭 《中国土壤与肥料》2019,(6):142-148

为探究UAN氮溶液在潮土上对玉米生长和氮素吸收的作用效果,采用盆栽试验,研究UAN氮溶液对玉米收获期干物质积累、氮磷钾吸收量和土壤氮磷钾养分状况及pH值的影响。结果表明,等氮量的UAN氮溶液和尿素均促进了玉米的生长和对氮磷钾的吸收,两者的氮肥利用率无显著差异,分别为65.35%和64.76%。与全量UAN氮溶液相比,减施UAN氮溶液20%使玉米的生物量减少14.71%,植株中氮、磷、钾的养分吸收量分别降低24.27%、18.65%、10.47%。在低肥力潮土上,等氮量的UAN氮溶液和尿素对玉米的生长和氮素吸收的效果相当;减施UAN氮溶液20%影响玉米的生长和氮素的吸收,而氮肥利用率无明显变化。  相似文献