耕作覆盖对宁南旱区土壤团粒结构及马铃薯水分利用效率的影响

【目的】探讨耕作覆盖对旱作土壤团粒结构、马铃薯产量和水分利用效率的影响。【方法】于2013—2016年进行连续3个作物生长季定位试验,通过设置3种耕作方式（深松、免耕、翻耕）和3种覆盖措施（秸秆覆盖、地膜覆盖和不覆盖）,研究耕作结合覆盖对土壤团聚体数量、土壤蓄水量及马铃薯产量和水分利用效率的影响。【结果】耕作方式、覆盖措施及二者交互作用可显著增加0—40 cm土层>0.25 mm土壤团聚体含量,深松覆盖秸秆处理0—20 cm土层>0.25 mm土壤团聚体含量在欠水年（2016）和相对欠水年（2014）分别较翻耕不覆盖显著提高14.2%、16.9%,而免耕覆盖秸秆处理在平水年（2015）较翻耕不覆盖显著提高8.5%;20—40 cm土层>0.25 mm土壤团聚体含量在欠水年以深松覆盖秸秆、相对欠水年深松覆盖地膜和平水年免耕覆盖秸秆处理最高,分别较翻耕不覆盖显著提高18.2%、21.5%、18.7%。耕作方式、覆盖措施及二者交互作用对0—200 cm土层蓄水量影响显著,深松覆盖秸秆处理休闲期土壤蓄水量分别在相对欠水年、欠水年和平水年较翻耕不覆盖处理显著提高29.6%、9.3%、11.4%;其关键生育时期平均土壤蓄水量分别在欠水年和相对欠水年较翻耕不覆盖显著增加21.9%、28.9%,而免耕覆盖秸秆处理在平水年较翻耕不覆盖处理显著增加17.1%。在相对欠水年,耕作方式对马铃薯产量和水分利用效率无显著影响,而覆盖措施及耕作与覆盖交互作用对其有显著影响,以免耕覆盖秸秆处理最佳,分别较翻耕不覆盖处理显著提高51.8%和50.5%;在平水年和欠水年,耕作方式、覆盖措施及其二者交互对马铃薯产量和水分利用效率有极显著影响,产量、水分利用效率均以深松覆盖秸秆处理效果最佳,平均较翻耕不覆盖处理显著提高56.9%和44.8%。【结论】耕作结合覆盖措施可改善耕层土壤团粒结构,显著增强休闲期和生育期土壤蓄水保墒能力,从而显著提高马铃薯产量和水分利用效率,在平水年和欠水年采用深松结合秸秆覆盖、相对欠水年采用免耕结合秸秆覆盖模式可实现宁南旱作马铃薯增产。     

养分专家系统推荐施肥对夏玉米生理特性及产量的影响

为探究养分专家系统推荐施肥对夏玉米生理特性的影响,于2019年6月—10月在河南省鹤壁市、新乡市两地同步开展肥效田间试验,设置农户施肥(FP)、经验施肥(ST)、养分专家推荐施肥(NE)、在NE基础上施用缓控释肥(RNE,50％包膜氮肥,施肥量同NE)、在NE基础上不施氮肥(NE-N)、在NE基础上不施磷肥(NE-P)、在NE基础上不施钾肥(NE-K)共7个处理.以夏玉米浚单22为试验品种,于关键生育时期测试叶片叶绿素、冠层光合有效辐射、光合速率和叶片解剖结构,并于成熟期测定产量,分析计算肥料利用特征,研究不同施肥措施对夏玉米产量和光合生理特性的影响.结果 表明:基于养分专家系统的推荐施肥(NE、RNE)处理较肥料减施状态下(NE-N、NE-P、NE-K)处理分别增产28.69％、23.23％、22.89％,较FP平均增产16.62％、11.40％.氮、磷、钾合理施用有效降低叶片胞间CO2浓度、提高净光合速率,并且对叶片解剖结构和叶绿素含量具有积极影响,光合有效辐射分量在夏玉米整个生育期内对产量的影响较大.进一步研究表明,NE处理氮、磷、钾肥料利用率平均为29.63％、15.23％、40.55％,肥料农学效率分别是11.95、22.59、24.49 kg?kg-1.综上可知,氮磷钾合理施肥显著改善夏玉米生育期叶片的光合性能,提升肥料利用率,促进干物质的合成,提高了夏玉米产量.     

有机无机肥配施对精量穴直播水稻产量及氮素利用的影响

为探究有机无机肥配施对精量穴直播水稻产量及氮素利用的影响,2018—2020年,选用鸡粪型有机肥进行不同比例有机肥替代化肥田间小区试验。试验采用两因素裂区设计,主区为3个杂交水稻品种,分别是宜香优1108、F优498、德优4727;副区为不同比例有机肥替代化肥,在总施氮量150 kg·hm^-2水平下,设置100%化学N肥（M1）、75%化学N肥+25%有机肥（M2）、50%化学N肥+50%有机肥（M3）、25%化学N肥+75%有机肥（M4）和100%有机肥（M5）共5个处理,以不施N肥为对照（CK）。结果表明,随着有机肥比例的增加,3个品种的每穗粒数和产量均先增加后降低。对于宜香优1108,M2处理的每穗粒数最多、产量最高,2018、2019和2020年分别较M1处理增产2.92%、5.53%和8.07%。对于F优498和德优4727,M3处理的每穗粒数最多、产量最高,3年分别较M1处理平均增产9.13%、7.33%、7.21%和2.7%、6.03%、8.69%。施肥处理中均以M5处理的产量最低。对于氮素转运率,M2和M3处理水稻的氮素转运率增加,其中,宜香优1108在M2和M3处理下氮素转运率3年平均较M1处理提高9.40%和11.41%,F优498提高9.63%和19.18%,德优4727提高9.40%和18.03%。随着有机肥比例的增加,氮素表观利用率降低,氮素收获指数、氮素农学利用率和氮肥偏生产力均先增加后减少。宜香优1108在M2和M3处理下氮素收获指数3年平均较M1处理提高5.05%和5.54%,F优498提高4.53%和8.80%,德优4727提高4.88%和8.98%。由此表明,在精量穴直播下,有机肥与无机肥的合理配施能更好地调控水稻对养分的吸收利用,从而提高产量;宜香优1108采用25%有机肥替代化学氮肥时产量最佳,而F优498和德优4727采用50%有机肥替代化学氮肥增产效果更好。     

PROGRESS ON IMPROVING AGRICULTURAL NITROGEN USE EFFICIENCY: UK-CHINA VIRTUAL JOINT CENTERS ON NITROGEN AGRONOM

● Virtual joint centers on N agronomy were established between UK and China. ● Key themes were improving NUE for fertilizers, utilizing livestock manures, and soil health. ● Improved management practices and technologies were identified and assessed. ● Fertilizer emissions and improved manure management are key targets for mitigation. Two virtual joint centers for nitrogen agronomy were established between the UK and China to facilitate collaborative research aimed at improving nitrogen use efficiency (NUE) in agricultural production systems and reducing losses of reactive N to the environment. Major focus areas were improving fertilizer NUE, use of livestock manures, soil health, and policy development and knowledge exchange. Improvements to fertilizer NUE included attention to application rate in the context of yield potential and economic considerations and the potential of improved practices including enhanced efficiency fertilizers, plastic film mulching and cropping design. Improved utilization of livestock manures requires knowledge of the available nutrient content, appropriate manure processing technologies and integrated nutrient management practices. Soil carbon, acidification and biodiversity were considered as important aspects of soil health. Both centers identified a range of potential actions that could be taken to improve N management, and the research conducted has highlighted the importance of developing a systems-level approach to assessing improvement in the overall efficiency of N management and avoiding unintended secondary effects from individual interventions. Within this context, the management of fertilizer emissions and livestock manure at the farm and regional scales appear to be particularly important targets for mitigation.     

生物可降解地膜对棉花产量及水分利用效率的影响

为了探求华北平原棉花可降解地膜覆盖替代普通膜覆盖的可行性,解决白色污染问题,试验设置4种处理:6 μm PE普通地膜(PE)、8 μm生物可降解地膜(M1)、6 μm生物可降解地膜(M2)及不覆盖地膜(CK),分析比较各处理对棉花出苗率、叶面积指数(LAI)、农田耗水速率、产量及水分利用效率(WUE)的影响.结果表明,与处理CK相比,覆盖地膜显著提高了棉花出苗率,但3种覆膜处理间差异不具有统计学意义;在棉花生育前期,2种生物可降解地膜处理的LAI显著低于PE处理的.3种覆膜处理之间的籽棉产量和霜前花率的差异均不具有统计学意义.3种覆膜处理间WUE的差异不具有统计学意义,但均显著高于CK的.2种生物可降解地膜处理相较于PE,对棉花的出苗率、霜前花率、籽棉产量及WUE的差异均不具有统计学意义.相较于PE,使用6 μm生物可降解膜不会造成棉花耗水量升高,而8 μm可降解膜则显著增加了棉花的耗水量.因此6 μm生物降解膜取代PE膜较好.     

The use of antibiotics on small dairy farms in rural Peru

Very little is known about the use of antibiotics on small dairy farms in lower/middle-income countries. The use of these drugs can have profound impacts on animal health, farmer income and public health. A survey of 156 farmers was conducted in Cajamarca, a major dairy-producing center in the highlands of Peru characterized by small farms (<15 cows) to assess patterns and determinants of antibiotic use and farmers’ knowledge of antibiotics. The reported incidence of disease on these farms was relatively low (0.571 episodes of disease per cow-year), but more than 83% of the reported episodes were treated with antibiotics. The most commonly used antibiotics were oxytetracycline, penicillin and trimethoprim-sulfamethoxazole drugs; antiparasitic drugs were also used to treat what were likely bacterial infections. An increased incidence of treated disease was significantly associated with smaller farm size, lower farmer income, the previous use of the Californian Mastitis test on the farm and antibiotic knowledge. Farmers’ knowledge of antibiotics was assessed with a series of questions on antibiotics, resulting in a “knowledge score”. Increased knowledge was significantly associated with the use of antibiotics for preventative reasons, the purchase of antibiotics from feed-stores, the experience of complications in animals after having administered antibiotics, the number of workers on the farm and the educational level of the farmer. Overall, antibiotics appeared to be used infrequently, most likely because therapeutic interventions were sought only when the animal had reached an advanced stage of clinical disease. Few farmers were able to define an antibiotic, but many farmers understood that the use of antibiotics carried inherent risks to their animals and potentially to the consumers of dairy products from treated animals. The results of this study are useful for understanding the patterns of antibiotic use and associated management, demographic and knowledge factors of farmers on small dairy farms in rural Peru.     

山西省浮山县土地利用问题研究

对浮山县土地利用的现状和存在的问题进行了系统的分析和研究,为了统筹安排浮山县的用地情况,保障土地资源的可持续利用,依据浮山县的经济社会发展水平,以及该县的土地资源利用和开发状况,并以耕地保护为中心,坚持节约集约利用土地资源的原则,提高土地资源的利用效率和管理水平,加强土地资源的结构调整和依法管理,在分析该县土地利用现状和问题的基础上,进一步研究了导致该县在土地利用方面的现状和问题的原因,提出了相应的对策与建议。     

浅谈牛栏江河道绿化的途径及措施

指出了当前牛栏江水污染严重,牛栏江生态廊道绿化的任务是提高河流“自净”能力,净化水质。探讨了绿化技术途径,包括对河岸带进行区划,确定各带（区）的功能,根据各带（区）特点,布置植物,强调在有限的空间内,千方百计地增加湿生与水生植物种植面积,利用水生植物净化水体,从而实现规划目标。     

小麦田除草剂应用技术

通过对麦田杂草生长状况以及影响麦田除草剂使用因素的剖析,针对性地提出了解决对策和途径,包括除草剂类型的选择,最佳防治期的选择,根据常见麦田的杂草选择何种化学除草药剂,除草药剂量的使用,提高除草剂喷施质量的要求等,并结合近几年我国小麦田的优势杂草种类,主要应用的除草剂分析了目前国内麦田杂草的抗药性现状及防治对策。     

不同玉米品种水分利用效率的研究

选用5个玉米杂交种为试材,探讨了苗期生长发育和水分利用效率的关系。结果表明,GWUE、产量和耗水量在品种间的差异显著,在3种供水条件下,郑单958是高GWUE品种,具有高产中耗水的特性,鲁单981是低GWUE的品种,是低产高耗水品种,而四单19的GWUE是在干旱胁迫下最具增长潜力的品种,具有稳产节水的特性。