侧深施氮对我国水稻产量和氮利用效率影响的整合分析          下载免费PDF全文

胡洋  肖大康  李炫  李锦涛  胡仁  任科宇  侯俊  曹玉贤 《中国土壤与肥料》2024,(2):138-145

探讨在不同条件下侧深施氮(SDN)对水稻产量及氮肥利用效率的影响,为水稻精准施氮提供理论依据。通过搜集已发表的文献,建立了214组SDN和农民常规撒施(BN)下水稻产量和氮肥利用效率的数据库。采用整合分析的方法,研究在水稻种植区、土壤氮素含量、不同施氮量等条件下SDN对水稻产量及氮肥利用效率的提升幅度,采用随机森林方法明确了影响SDN效果的主控因素。相对于BN,SDN能够显著提高产量、氮肥偏生产力、氮肥农学利用率和氮肥吸收利用率,提高幅度分别为4.57%、4.57%、23.94%和21.11%。不同种植区域下SDN对产量的提升幅度东北稻区最大。不同水稻类型下SDN的产量和氮肥利用效率提升幅度不同,产量提升方面,粳稻(6.85%)>籼稻(5.11%),杂交稻无显著提升;SDN对氮肥农学利用率和吸收利用效率的提升幅度方面,籼稻>粳稻>杂交稻。不同种植模式下SDN对产量和氮肥利用效率的提升幅度均为单季稻>双季稻。土壤全氮<2 g/kg、速效氮<150 mg/kg时SDN对产量的提升幅度较大。当SDN的氮肥施用量≤150 kg/hm²和...  相似文献   

Predicting the potential geographic distribution of Bactrocera bryoniae and Bactrocera neohumeralis(Diptera: Tephritidae) in China using MaxEnt ecological niche modeling          下载免费PDF全文

Jing Wan  QI Guo-jun  MA Jun  Yonglin Ren  WANG Rui  Simon MCKIRDY 《农业科学学报》2020,19(8):2072-2082

Bactrocera bryoniae and Bactrocera neohumeralis are highly destructive and major biosecurity/quarantine pests of fruit and vegetable in the tropical and subtropical regions in the South Pacific and Australia. Although these pests have not established in China, precautions must be taken due to their highly destructive nature. Thus, we predicted the potential geographic distribution of B. bryoniae and B. neohumeralis across the world and in particular China by ecological niche modeling of the Maximum Entropy(Max Ent) model with the occurrence records of these two species. Bactrocera bryoniae and B. neohumeralis exhibit similar potential geographic distribution ranges across the world and in China, and each species was predicted to be able to distribute to over 20% of the globe. Globally, the potential geographic distribution ranges for these two fruit fly species included southern Asia, the central and the southeast coast of Africa, southern North America, northern and central South America, and Australia. While within China, most of the southern Yangtze River area was found suitable for these species. Notably, southern China was considered to have the highest risk of B. bryoniae and B. neohumeralis invasions. Our study identifies the regions at high risk for potential establishment of B. bryoniae and B. neohumeralis in the world and in particular China, and informs the development of inspection and biosecurity/quarantine measures to prevent and control their invasions.  相似文献   

Deep neural network algorithm for estimating maize biomass based on simulated Sentinel 2A vegetation indices and leaf area index     

Xiuliang Jin  Zhenhai Li  Haikuan Feng  Zhibin Ren  Shaokun Li 《作物学报(英文版)》2020,(1):87-97

Accurate estimation of biomass is necessary for evaluating crop growth and predicting crop yield.Biomass is also a key trait in increasing grain yield by crop breeding.The aims of this study were(i)to identify the best vegetation indices for estimating maize biomass,(ii)to investigate the relationship between biomass and leaf area index(LAI)at several growth stages,and(iii)to evaluate a biomass model using measured vegetation indices or simulated vegetation indices of Sentinel 2A and LAI using a deep neural network(DNN)algorithm.The results showed that biomass was associated with all vegetation indices.The three-band water index(TBWI)was the best vegetation index for estimating biomass and the corresponding R2,RMSE,and RRMSE were 0.76,2.84 t ha−1,and 38.22%respectively.LAI was highly correlated with biomass(R2=0.89,RMSE=2.27 t ha−1,and RRMSE=30.55%).Estimated biomass based on 15 hyperspectral vegetation indices was in a high agreement with measured biomass using the DNN algorithm(R2=0.83,RMSE=1.96 t ha−1,and RRMSE=26.43%).Biomass estimation accuracy was further increased when LAI was combined with the 15 vegetation indices(R2=0.91,RMSE=1.49 t ha−1,and RRMSE=20.05%).Relationships between the hyperspectral vegetation indices and biomass differed from relationships between simulated Sentinel 2A vegetation indices and biomass.Biomass estimation from the hyperspectral vegetation indices was more accurate than that from the simulated Sentinel 2A vegetation indices(R2=0.87,RMSE=1.84 t ha−1,and RRMSE=24.76%).The DNN algorithm was effective in improving the estimation accuracy of biomass.It provides a guideline for estimating biomass of maize using remote sensing technology and the DNN algorithm in this region.  相似文献   

Construction of oxime ester derivatives of osthole from Cnidium monnieri,and evaluation of their agricultural activities and control efficiency     

Zili Ren  Min Lv  Tianze Li  Meng Hao  Shaochen Li  Hui Xu 《Pest management science》2020,76(11):3560-3567

  相似文献   

晋中盆地典型耕地厚度、土壤养分空间变异   总被引：3，自引：1，他引：2  

乔磊  黄明镜  张吴平  王国芳  任健 《中国农学通报》2020,36(1):89-97

旨在探究旱作区耕地土壤耕层厚度及土壤养分空间格局与变异规律。以晋中盆地典型耕地土壤为研究对象,运用地统计学方法对耕地耕层厚度及土壤养分的空间变异进行分析,土壤养分选取有机质、pH、有效磷、缓效钾4个指标。结果表明：（1）各个指标的空间自相关性都是随着距离的增加而减小;（2）有效磷的半变异函数最优模型为高斯模型,其他指标的最优模型均为指数模型。各指标的块金系数由大到小依次为：有机质>有效磷>pH>耕层厚度>缓效钾;（3）耕层厚度、有效磷均为西北高东南低的空间格局,缓效钾为东北高西南低,有机质为西南高东北低,pH除北洸乡偏低外均偏高。地统计方法能良好地描述土壤性质的空间分布和变异特征,各土壤性质的空间变异过程中随机性与结构性并存,并且随机性均小于50%。  相似文献   

接骨木无性系苗期干旱胁迫响应及抗旱性综合评价     

姚俊修  刘学良  李善文  任飞  李庆华  吴海涛  翟红莲  吴德军 《中国农学通报》2020,36(9):75-81

为揭示不同种接骨木无性系的抗旱性,探讨其对干旱环境的适应能力,为干旱瘠薄山地造林提供材料。采用盆栽法进行自然干旱胁迫试验,运用主成分分析对不同处理下各无性系生理指标进行综合评价。结果表明：干旱胁迫下,无性系PT-1的生物量增量最大,PT-2的根冠比最大。在干旱胁迫逐增情况下,细胞膜透性逐增,当干旱达到中、重度时,无性系PT-1和PT-2的细胞膜透性最小。叶绿素含量及超氧化物岐化酶活性均随干旱程度增加呈先增后降趋势。随干旱胁迫增加可溶性糖和脯氨酸均随之增大。在重度干旱胁迫下,无性系PT-1的可溶性糖含量最大。主成分分析得出,各无性系抗旱能力由强到弱为：XY-2、JY-1、XY-1、XY-3、PT-1、PT-3、PT-2。其中,XY-2、JY-1具有较强抗旱性,可初步作为抗旱材料进行后续研究。  相似文献   

基于用户参与的科研院所机构知识库建设模式研究     

任妮  荀广连  戴秀  郭婷  程金花  陆学文 《农业科技管理》2020,39(2):1-6

文章以用户参与为理论基础,以融入科研管理为实践目标,创新性地提出一种适合科研院所的机构知识库建设模式,并以江苏省农业科学院为例进行了实证研究,该模式兼具传统机构知识库功能,又能体现科研机构特色、解决科研机构成果管理问题.在此基础上,还分析明确了适用于科研院所成果管理和共享的数据审核流程、元数据标准规范、功能模块、系统架构、管理运行机制等.  相似文献   

棉铃虫棉田自然种群变化动态及对天敌观察研究初报     

史磊  任莉  宁跃翠  韩晓辉  姚刘亮  颜金龙 《现代农业科技》2020,(17)

棉铃虫在上世纪80~90年代,在我国多个老棉区严重发生或大暴发,致使棉花生产造成了严重损失。而后棉区迁移至新疆,加上抗虫棉的推广、综合治理措施的落实,有效遏制了棉铃虫的猖獗发生。近几年,在冀南多种作物上又有抬头,并有逐年加重的趋势,为对棉铃虫发生规律研究提出了新课题。  相似文献   

新乡贤队伍建设与乡村振兴:来自绍兴的调查与研究     

游海华  任钰佩 《古今农业》2020,(1):1-14

作为"乡贤研究会"首创之地和"新乡贤"概念诞生之地,绍兴市自然也是新乡贤队伍建设的先行之地,已经成为全国乡贤文化之乡和新乡贤队伍建设的标杆。绍兴市的新乡贤队伍建设,肇始于2001年上虞乡贤研究会的成立,在2015年的乡贤政策年臻于高峰。经过多年培育和发展,定位为"村民自治的有益补充"、起"补位和辅助作用"的近2万新乡贤队伍,在乡村经济、文化、公益、自治等方面发挥着积极作用,但与此同时也显现了新乡贤队伍建设流于形式、结构相对失衡,以及党政介入过度、党政机构与新乡贤组织职责和权力边界不清晰等问题。解剖这一领先全国的典型个案,对于其他地区的新乡贤队伍建设和现代乡村振兴,无疑具有较好的理论意义和现实价值。  相似文献   

苦荞粒形相关性状的遗传分析     

李春花  黄金亮  尹桂芳  王艳青  卢文洁  孙道旺  王春龙  郭来春  洪波  任长忠  王莉花 《作物杂志》2020,36(3):42-123

利用籽粒大小差异较大的2个苦荞品种的杂交后代开展了与产量具有密切关系的粒形相关性状的遗传规律及其性状间的相关性分析。结果表明,F₂和F₃群体的粒长、粒宽、长宽比和千粒重表现值范围都超过亲本的表现值,并且粒长、粒宽和长宽比的变异系数均小于10%,千粒重的变异系数大于10%。另外,粒长、粒宽、长宽比和千粒重的加性方差均大于显性方差,广义遗传率在F₂和F₃代中分别为0.77~0.82和0.82~0.85,固定遗传率都达到0.80以上。粒形性状间的相关性分析结果表明,粒长、粒宽和千粒重相互间都存在极显著的正相关,粒宽和千粒重,粒长和长宽比的遗传相关系数较大。以上结果表明,具有较高遗传率的粒形相关性状可以在后代早期进行选择,但由于这些性状是数量性状而且受多个基因的控制,因此建议继续繁殖后代到基因型稳定,同时考虑性状间的相关性选拔最为有效。  相似文献