公顷产10000kg小麦氮素和干物质积累与分配特性

以泰山23和济麦22为试验品种,通过连续2年的田间试验,对单产高达10 000 kg hm^-2的小麦进行了施氮量和氮素吸收转运和分配特性的研究。在2006-2007年生长季,随着施氮量的增加,小麦籽粒产量先增加后降低,施纯氮240 kg hm^-2 (N240)和270 kg hm^-2(N270)处理的产量分别达9 954.73 kg hm^-2和10 647.02 kg hm^-2,比不施氮肥处理(N0)分别增加11.20%和18.93%。与N0处理相比,施氮处理显著增加了小麦植株氮素积累量、籽粒氮素积累量和开花后营养器官氮素向籽粒的转运量;随着施氮量的增加,成熟期小麦植株氮素积累量呈先增后降趋势,以N270处理最高;开花后营养器官氮素向小麦籽粒转运量和转运率先升后降,转运量以N270处理最大,为213.78 kg hm^-2;而转运率以N240处理最高,为67.98%。随施氮量的增加,小麦成熟期各器官干物质积累量、花后营养器官干物质再分配量和再分配率先增后降,均以N270处理最高;开花后干物质积累对籽粒的贡献率亦呈先增后降的趋势,以N240处理最高。2005-2006年的试验结果呈相同变化趋势。在本试验条件下,小麦产量水平达10 000 kg hm^-2时的适宜施氮量为240~270 kg hm^-2,可供生产中参考。     

气吹供种滚筒式播种机取种性能的试验研究

针对现有番茄穴盘育苗播种机空穴率多、单粒率少,难以满足尺寸小、外形不规整、流动性差的加工番茄种子"一穴一粒"精量播种技术要求的规状,创新设计了一种基于气吹供种方式的滚筒式番茄育苗播种机。以此为基础搭建了基于气吹供种方式的滚筒式育苗播种试验装置,并以单粒率、空穴率、多粒率为试验评价指标,试验探究了主要因素(种箱气室正压力、孔径、滚筒转速)对主要评价指标的影响规律。试验结果表明:影响取种性能质量指标的主次关系依次为种箱气室正压力、孔径、滚筒转速;影响取种性能质量指标最优组合:当种箱气室正压力为2k Pa、孔径为1.2mm、转速为14r/min时取种综合效果效果较理想。     

杭州市农业机械化发展水平总体评价的研究

根据2000-2010年杭州市农业机械化统计数据,利用国内现有的农业机械化发展水平评价方法,测算了杭州市在此期间各年度的农业机械化发展水平。计算结果表明,目前杭州市处于农业机械化发展中级阶段,且“十一五”农机化发展速度较“十五”有了较大提高。在此基础上。提出了加快杭州市农业机械化发展的相关措施与建议。     

Vermicomposting of coffee pulp using the earthworm Eisenia fetida: Effects on C and N contents and the availability of nutrients

In Colombia, more than 1 million tons of coffee pulp are produced every year. Its transformation into compost by means of turned piles has led to a final product with poor physical and chemical characteristics and vermicomposting has been suggested as an alternative method of transforming these wastes into a useful organic fertilizer. The ability of the earthworm Eisenia fetida to transform coffee pulp into a valuable compost was evaluated. The influence of bed depth and time on different C fractions, N content and availability of nutrients was studied. The results showed that the C and N contents were not affected by the depth of the bed, whereas time affected both. An increase in the fractionation ratio, determined by calculating the C in the fraction smaller than 100 m as a percentage of C in the samples as a whole, and low values of humic-like substances were recorded during vermicomposting. After ingestion of the pulp by the earthworms, an increase in available P, Ca, and Mg but a decrease in K were detected.     

地热吸收式热泵在农村供热中的应用

本文针对中低温地热水,力求实现梯级利用,提高热利用率,探讨了以中低温地热水作热源的(驱动热源)第Ⅱ类吸收式热泵供热装置,提出了几种可能的方案。文中讨论了第Ⅱ类热泵的工作原理,介绍了本研究装置的系统,提出评价这类热泵的性能指标(当量供热系数)。并以氨·水工质为例,进行了计算。结果表明,这种装置具有较好的供热性能和高的热能利用率。     

The influence of nitrogen fertilisation on bacterial activity in the rhizosphere of barley

The effect of nitrogen addition on the activity of rhizosphere bacteria was studied using barley seedlings. Three different nitrogen sources were added to the soil (nitrate, ammonium and ammonium+nitrate) at four different concentrations (0, 100, 300 and 500 mg N kg⁻¹ soil) and the plants were allowed to grow for 6 weeks. The bacterial activity was estimated by measuring thymidine and leucine incorporation into bacteria extracted using homogenisation-centrifugation. Bulk soil bacterial activity was low compared with that of rhizosphere bacteria. Nitrogen addition did not affect the activity of the bulk soil bacteria, indicating that the activity was not nitrogen limited. The thymidine and leucine incorporation rates of rhizosphere bacteria decreased when ammonium or ammonium+nitrate was applied compared with the non-amended controls. No effect on bacterial activity was found following nitrate addition. There was a significant positive correlation between rhizosphere bacterial activity and rhizosphere pH. Shoot length following ammonium treatment was significant lower than in the non-amended control, while nitrate and ammonium+nitrate addition had no effect. This indicates that the varying effects due to nitrogen sources on rhizosphere bacterial activity were not due to effects on plant growth.     

耕作及轮作对土壤氮素径流流失的影响

5年轮作和1年水平沟耕作试验表明:在不同的坡度上,与传统耕作法相比,水平沟减少产流7%,径流液铵态氮浓度提高19%,流失量达到13.01kg/(km²·a),比传统耕作多流失1.11kg/(km²·a);径流硝态氮浓度减少27%,比传统耕作减少7.68kg/(km²·a);径流硝态氮流失减少量和铵态氮增加量相差6倍,水平沟可减少6.57kg/(km²·a)矿质氮流失;水平沟拦截泥沙25%左右,泥沙中全氮富集率提高13%,土壤全氮流失457kg/(km²·a),平均减少18%;一季黑豆和一季黄豆及两季黑豆和一季黄豆参与的5年轮作周期,土壤侵蚀量仅为896t/(km²·a)和984t/(km²·a),不及糜子和土豆参与轮作周期的1/2.     

农业元宇宙：关键技术、应用情景、挑战与展望

元宇宙这一新兴概念受到了产、学、研各界的广泛关注。农业与元宇宙的结合将极大地推动农业信息化和智能化发展,为农业智能化转型升级提供新动能。为深入分析元宇宙在农业领域的应用研究可行性,本文首先分析了农业元宇宙的概念,以及区块链、非同质化代币、5G/6G、人工智能、物联网、三维重建、云计算、边缘计算和扩展现实等元宇宙农业应用的关键技术。接着讨论了元宇宙在虚拟农场、农业教学系统和农产品追溯系统三个农业应用领域的主要情景,最后总结了农业元宇宙面临的系统建立、通信基础、硬件设备和运营等方面的主要挑战,并展望了未来的发展方向。本文可为元宇宙在农业的应用研究提供指导。     

NH_4~+-N与NO_3~--N不同配比对菠菜生长及食用品质的影响

为探究氮素形态对菠菜生长和品质的影响,试验采用盆钵培养的方法,在总氮浓度为15 mmol/L的条件下,设置了5种NO_3~--N与NH_4~+-N配比(分别为100:0、75:25、50:50、25:75和0:100),测定了5种铵硝配比条件下菠菜生长与品质相关指标。结果表明:与NH_4~+-N相比,NO_3~--N更有利于菠菜生长与Vc积累。适当增加NH_4~+-N比例后,Vc含量虽显著降低,但对菠菜的生长却无显著影响,并可显著降低可食用部分硝酸盐含量。因此,为了提供高产、低硝酸盐的优质菠菜,笔者认为适宜的NO_3~--N?NH_4~+-N为50:50。     

氮肥减量条件下间作绿豆压青对甘蔗生长及氮代谢的影响

以甘蔗单作常规施氮量为对照（CK）,设氮化肥减量20%+间作绿豆压青（A）、氮化肥减量40%+间作绿豆压青（B）和氮化肥减量60%+间作绿豆压青（C）3个处理,通过测定甘蔗农艺性状、蔗茎产量和甘蔗叶片氮代谢相关生理生化指标,研究氮肥减量条件下间作绿豆压青对甘蔗生长及氮代谢的影响。结果表明,间作绿豆影响新植蔗分蘖,分蘖率显著低于CK,但对甘蔗有效茎数影响不显著。新植蔗产量表现为A>B>CK>C。氮化肥减量条件下间作绿豆压青对宿根蔗发株率、株高、有效茎数、甘蔗茎径有促进作用。宿根蔗蔗茎产量表现为A>B>C>CK。2年的甘蔗蔗糖分含量表现为C>B>A>CK。氮化肥减少20%条件下间作绿豆压青对提高甘蔗叶片谷氨酰胺合成酶、硝酸还原酶活性和游离氨基酸、可溶性糖含量有促进作用。综合甘蔗农艺性状、蔗茎产量、氮代谢相关指标测定结果和经济效益的表现,试验以氮化肥减量20%+间作绿豆压青的A处理最优。