超大颗粒肥水田气力深施加速器设计及参数优化

为解决水稻撒施追肥存在的肥料流失、利用率低及机械深施肥工作部件易堵塞、伤根等问题,该研究设计了一种用于水田深施追肥机的超大颗粒肥气力式加速器。该加速器利用双螺旋高压气流,在其与肥料上端构成的近封闭空间内加速超大颗粒肥,实现其高速射入泥壤,并可避免肥料颗粒与管壁碰撞;出口设置渐扩管扩散气流,可减轻对泥壤的冲击,提高施肥位置的稳定性。根据超大颗粒肥参数与加速器功能要求,确定了加速器的结构参数,并根据肥料入泥深度所需的射出速度,分析确定了加速器的工作参数。在此基础上,基于Fluent软件的六自由度重叠动网格建立了加速器仿真模型,以进口气流速度、螺旋角和加速管直径为试验因素,进行单因素仿真试验与三因素三水平Box Behnken组合仿真试验,研究各因素对肥料射出速度与气流扩散率的影响。多因素试验分析及响应面分析结果表明,加速器的最佳工作参数为进口气流速度47 m/s、加速管直径21 mm、螺旋进气口螺旋角43°。在此条件下进行台架验证试验,得到肥料射出速度均值为12.61 m/s,出口气流扩散率均值为85.5%,肥料入泥平均深度为4.68 cm,达到了水稻追肥要求。该研究可为超大颗粒肥水田气力深施追肥机设计提供参考。     

有机肥配施荧光假单胞菌肥对玉米产量与复垦土壤磷素有效性的影响

复垦土壤贫瘠,磷素含量极低,严重影响作物的生长发育。研究化肥、有机肥配施荧光假单胞菌对玉米产量和复垦土壤磷素形态以及酶活性的影响,为加速培肥矿区复垦土壤提供技术支持和理论依据。该研究在山西省晋中市采煤塌陷区进行了2a的定位培肥试验,共设置7个处理：不施肥（CK）、单施化肥（CF）、化肥配施荧光假单胞菌（CFB）、单施有机肥（M）、有机肥配施荧光假单胞菌（MB）、化肥配施有机肥（MCF）、化肥有机肥配施荧光假单胞菌（MCFB）。采集各处理土壤样品测定相关指标,并通过相关性分析和结构方程模型来探究各形态磷与有效磷以及土壤磷酸酶之间的关系。结果表明：1）在整个试验周期（2021—2022年）,与CK相比,不同施肥处理均能显著提高玉米产量以及各形态磷素。其中,以MB处理下的玉米产量、有效磷、磷活化系数、不稳定态磷以及部分不稳定态磷含量最高,与CK处理相比,玉米产量显著提高2.4倍,有效磷含量、磷活化系数值、不稳定态磷含量、部分不稳定态磷含量分别显著提高4.5倍、4.67倍、0.98倍、1.16倍。2）与CK处理相比,化肥、有机肥配施荧光假单胞菌能够显著提高土壤微生物量磷以及酸性和碱性磷酸酶活性,配施荧光假单胞菌后,微生物量磷水平和碱性磷酸酶活性均以MB较M处理提升效果最佳,分别显著提高27.08%和9.56%。3）结合相关性分析以及结构方程模型,随着荧光假单胞菌和化肥有机肥的施入,在提高不稳定态磷素含量的同时也提高有效磷的供应能力,促进磷素在农田生态系统中的循环转化,产生积极的正向影响。化肥、有机肥配施荧光假单胞菌能够一定程度上影响复垦土壤玉米产量及产量性状、各形态磷素及有效性和微生物活性,对复垦土壤脆弱的农田生态系统产生积极影响。     

6-硫-6-烷硫基-12H-氯代双苯并[d,g][1,3,2]-二氧磷杂八环的合成

通过双- (2 -羟基 -氯代苯基 )甲烷 2与 P4S10 在三乙胺存在下的关环反应 ,得到了6 -硫 - 6巯基 - 12 H-氯代双苯并 [d,g][1,3,2 ]-二氧磷杂八环三乙胺盐 3,后者与卤代烷酯化得到了一系列 6 -硫 - 6 -烷硫基 - 12 H-氯代双苯并 [d,g][1,3,2 ]-二氧磷杂八环 4 ,测试并讨论了它们的1H和31P NMR数据。初步生物试验结果表明化合物 4对黄瓜霜霉病菌具有较好的抑制活性。     

不同施肥配比对大头菜产量的影响

采取随机区组设计,研究了大头菜合理施肥量,结果表明三穗县适合大头菜种植的最佳施肥量为：667m2施复混肥50kg,生态肥150kg,最高产量达1888kg/667m2.     

Crop yield and grain quality of emmer populations grown in central Italy, as affected by nitrogen fertilization

The increasing demand for traditional and natural foods has renewed the interest in hulled wheat species. Among these, Triticum dicoccum Schübler has survived in Italy only in a few hilly and mountainous areas of central and southern Italy. As a rule, emmer is cultivated in marginal areas with organic farming procedures that use very low N inputs, since this wild species is characterised by low yield, long and weak culms that easily lodge under windy conditions. Unfortunately, there is a lack of information on crop productivity and N effect for this crop. Research was carried out to study the effect of cultivation year (2004 and 2005), plant origin (Garfagnana, Leonessa and Molise) and N dressing (N₀, N₃₀, N₆₀ and N₉₀ kg ha⁻¹) on crop yield and grain quality of emmer grown in south-central Italy. Fertilizer was split at seeding, tillering and stem elongation. Tested parameters were highly influenced either by crop origin or N application (biomass, hulled and threshed grain yield, spikes m⁻², spikelets per spike, kernel weight, plant height, lodging, kernel ash and proteins). Several parameters augmented as fertilization rate increased (hulled and unhulled grain yield, biomass accumulation, spikes m⁻², kernels m⁻², protein content); 1000-kernel weight showed an opposite trend and in some cases no differences were noticed among fertilized treatments (plant height and spikelets per spike). Molise was the most productive population, closely followed by Garfagnana. The present research rejected some common belief that emmer has to be grown without N dressing, and crop undergoes lodging in marginal mountainous areas. Besides, grain yield of N₉₀ and N₆₀ treated emmer was only 6 and 18% lower compared to the five most important durum wheat varieties cultivated in the same area, suggesting emmer as a possible alternative crop to durum wheat in marginal areas of Mediterranean-type agro-ecosystems.     

桉树速丰林鸡粪施用效应分析

采用随机区组设计开展桉树施用鸡粪的试验研究,对不同施肥处理的林分生长量、林相特征以及经济效益进行分析,结果表明,穴施0.5kg以上近似绝干的鸡粪作基肥,其施用优势明显,能显著提高林分生产力,叶片浓绿、宽大、肥厚,叶绿素含量较高,树势强壮,而且经济效益较好,2年生林分平均树高、胸径、材积和蓄积分别达8.0～8.5m、7.0～7.4cm、0.015 6～0.018 6m3和21.5～26.3m3·hm-2,比穴施钙镁磷肥0.5kg为基肥的分别提高9.5% ～15.8%、9.6% ～15.7%、31.1% ～56.3%和32.8% ～62.7%,其中尤以穴施0.75kg鸡粪的经济效益最好,投入产出比高达14.91.     

不同氮磷锌施肥水平对盐碱地牧草生物产量的影响

［目的］优化氮磷锌肥配比施用量。［方法］选择苜蓿、草木樨、星星草、沙打旺、羊草等耐盐牧草,采用311-A最优回归设计,比较氮磷锌施肥水平。 ［结果］最高产草量16 534.10 kg/hm^2,相应的氮肥、磷肥、锌肥用量分别为116.55 、121.35 、31.20 kg/hm^2;最佳经济效益牧草产量16 233.90 kg/hm^2,相应的氮肥、磷肥、锌肥用量分别为116.40、121.20、30.90 kg/hm^2,纯收益为2 472.40元/hm^2。［结论］对牧草产量影响的顺序依次是磷肥、氮肥和锌肥。     

Dry matter and primary nutrient accumulation in soybeans as affected by combined Nitrogen levels

Nodulating and non‐nodulating soybeans were grown on a Alfic Udipsamment and a Typic Hapludoll amended with 10 or 100 kg N/ha. Tissue and grain samples were analyzed to determine N₂‐fixation, dry matter, and N, P, and K accumulation. Highest grain yields were associated with the highest levels of N₂‐fixation and N and K accumulation in grain. The largest dry matter production was by nodulating plants grown on a high soil N regime. Nodulating plants accumulated more grain and tissue N, P, and K than non‐nodulating plants. Nitrogen stress increased P concentrations in both grain and tissue and decreased harvest indices.     

福寿螺细胞色素P450 基因CYP3192A1 的克隆与表达分析

细胞色素P450酶 (Cytochrome P450, CYPs) 由P450基因编码,其中Cyp1a基因参与不同类型外源物质的生物转化和代谢。克隆了紫红笛鲷 (Lutjanus argentimaculatus) Cyp1a基因,对其组织表达模式进行分析,探讨了不同质量浓度 (10、50和250 μg·L⁻¹) 一溴联苯醚 (4-bromodiphenyl ether, BDE-3) 和十溴联苯醚 (decabromodiphenyl ether, BDE-209) 胁迫对紫红笛鲷肝脏Cyp1a表达及7-乙氧基香豆素-O-脱乙基酶 (7-ethoxyresorufin O-deethylase, EROD) 活性的影响。结果表明,紫红笛鲷Cyp1a cDNA全长2540 bp,开放阅读框长1 566 bp,编码521个氨基酸。同源分析结果表明紫红笛鲷CYP1A与花鲈 (Lateolabrax maculatus) CYP1A蛋白相似性最高 (92.69%),进化树分析与白梭吻鲈 (Sander lucioperca) 聚为一支,进化地位最近。Cyp1a基因在紫红笛鲷肝脏表达量最高,其次是脑和鳃,肌肉最低。10 μg·L⁻¹ BDE-3和BDE-209未对Cyp1a基因表达和EROD活性产生影响,而50和250 μg·L⁻¹BDE-3胁迫7~15 d则对两者产生显著抑制,且呈现剂量效应。与BDE-3相反,50和250 μg·L⁻¹ BDE-209 处理组Cyp1a基因表达和EROD活性显著增加,且Cyp1a基因表达与EROD活性呈显著正相关。高浓度BDE-3和BDE-209可对紫红笛鲷肝脏Cyp1a基因的表达产生影响,但两者的影响模式不同。