木薯渣复合基质在辣椒穴盘育苗上的应用效果

为了综合利用木薯渣废弃资源,本研究以木薯渣作为基本原料,辅以不同比例的蔗渣、菌糠等,配制成9个配方的木薯渣复合基质,并进行理化性状分析和辣椒穴盘育苗试验。试验结果表明,绝大部分复合基质的容重、pH、C/N、电导率和大小孔隙比均在优良无土栽培基质要求的范围内;其中,复合基质配方2（67%木薯渣＋5%蔗渣）、配方7（62%木薯渣＋10%菌糠）和配方9（42%木薯渣＋30%菌糠）对辣椒穴盘育苗的效果最好,所对应的辣椒苗的株高、地上部鲜重和根鲜重均比其它基质配方高,辣椒苗根部结团效果亦较好。因此,利用木薯渣可以合成复合基质用于辣椒的无土栽培穴盘育苗,该研究结果将为木薯渣废弃资源的再利用提供了一条新的途径。     

立秆式搂膜机搂膜齿的设计与有限元分析

为了解决新疆棉花秋收作业后的残膜回收难题,设计了适用于新疆棉花种植模式的立秆式搂膜机。介绍了整机的基本结构和工作原理,运用相关理论对关键部件搂膜齿进行受力分析,并利用ANSYS对3种不同形式的搂膜齿在作业过程中的总变形和等效应力进行有限元分析。结果表明:单个搂膜齿在搂膜作业时承受水平方向的土壤阻力约为28.8~43.2N,竖直方向的土壤支持力约为47.4N;弯齿形式的搂膜齿作业过程中的最大总变形和等效应力最小,分别为34.61mm和340.29MPa;直齿与斜齿形式的搂膜齿作业过程中的最大总变形和等效应力值相接近,分别为65.67、68.28mm和462.06、472.28MPa。研究结果可为搂膜式残膜回收机的设计与改进提供参考。     

蔬菜中乙烯利使用现状调查、残留量测定及安全性评价

对济宁市12个县市区随机抽样,调查乙烯利在蔬菜生产中的使用对象、使用方法、使用时期、使用浓度、使用目的及效果。采集蔬菜样品6次、6种、共68份,利用气相色谱法测定乙烯利的残留量。结果表明:乙烯利检出(含量≥0.01 mg/kg)59份,检出率86.76%,残留量较大的样品(≥2.00mg/kg)有3份,均是番茄。参照我国及其它多数国家和组织的残留限量标准(2 mg/kg),29份番茄样品合格率89.66%,其它5种蔬菜、39份样品参照美国的黄瓜残留限量标准(0.1mg/kg),合格率92.31%。     

保水材料对河套灌区土壤硝态氮和铵态氮动态变化的影响

为了研究内蒙古河套灌区农业化肥面源污染检测和治理措施,采用大田土壤淋溶试验,分析了河套灌区农田在保水材料处理下,玉米生育期内土壤硝态氮、铵态氮累积量及动态变化特征。结果表明,与CK相比,保水材料处理玉米苗期土壤NO_3~--N累积量平均提高20.49%,收获期平均降低13.98%;苗期土壤NH_4~+-N累积量平均提高35.21%,收获期平均降低28.93%。保水材料有效地抑制了氮素的淋溶损失,提高了氮素利用率,同时保证了玉米生育后期有效氮的供应,避免短时间内氮素的大量累积,在一定程度上减少了化肥面源污染,为农业面源污染治理提供有力措施。     

Laboratory vs. in situ resin‐core methods to estimate net nitrogen mineralization for comparison of rotation and tillage practices

Properly estimating soil nitrogen (N) mineralization as a consequence of different agronomic practices would result in better soil N fertility management. In this study, we tested the differences between laboratory and in situ resin‐core incubation methods for estimating soil net N mineralization for long‐term burley tobacco (Nicotiana tobacum L .) tillage and rotation systems. The laboratory incubation method used crushed, homogenized, litter‐free soil samples, and the in situ resin‐core incubation method used an intact soil core with the inclusion of any plant residue below or above ground. Comparisons showed that no‐tillage had significantly increased soil net N mineralization compared to conventional tillage with the laboratory incubation method, while there was no significant difference between tillage methods with the in situ resin‐core method. This indicates that soil pretreatment in the laboratory incubation method can create an “artificial tillage effect” for soil previously managed with no‐tillage, resulting in overestimated soil net N mineralization. The rotation comparison showed that different crop sequences had no impact on measured net N mineralization with the laboratory incubation method. However, a preceding soybean crop did significantly increase net soil N mineralization compared to preceding corn when measured with the in situ resin‐core method. This suggests that discarding plant residue in the laboratory incubation method can neglect the potential effect of plant residue on soil N mineralization. Therefore, it is important to be aware that soil pretreatment may influence soil N mineralization estimates, potentially resulting in flawed decisions for soil N fertility management.     

Seed Iron in Diverse Soybean Genotypes

ABSTRACT

Iron (Fe) in the embryo fraction of soybean (Glycine max L.) seed is important for seedling growth. Seed Fe accumulation in 27 soybean genotypes differing in seed size was studied at two field locations. Mean seed weight was 148 mg seed^?1 with mean individual genotypic values ranging from 68 to 217 mg seed^?1. Percentage of total seed dry matter in the seed-coat fraction, which was inversely correlated with individual seed weight, was 8.2%, with mean individual genotypic values ranging from 7.0% to 12.4%. Mean seed-Fe concentration [Fe] was 65 μg Fe g^?1, with individual genotypic values ranging from 48 to 81 μg Fe g^?1. Seed Fe relative to dry-matter distribution was much more concentrated in seed coats than in embryos of all genotypes. Mean percentage of total seed Fe located in the seed-coat fraction was 29%, with mean genotypic values ranging from 23% to 38%. Neither seed-Fe characteristic was correlated with individual seed weight. Seed [Fe] was not correlated with seed-manganese (Mn) concentration [Mn]. Mean seed [Fe] for the 27 genotypes was different at the two locations, presumably due to differences in available soil Fe. Both genotype and environment affected seed [Fe] of soybean. Soybean seed coats, a major by-product after oil extraction, are a possible rich source of Fe for human nutrition.     

几种农作物对绿黄隆敏感性的生物测定及在残留检测中的应用

采用土壤添加培养的方法测定了绿黄隆对玉米、水稻、大豆等作物的生物活性。结果表明 :绿黄隆在土壤中对玉米的致害阈限 ( IC1 0 )为 0 .1 7μg/ kg,对水稻的致害阈限则为 0 .4 3 4 9～ 0 .94 1 0μg/ kg,同时 ,绿黄隆的代谢产物之一的邻氯苯磺酰胺对玉米的生物活性要比绿黄隆的低得多 ,它对以玉米根系鲜重为指示指标的生物测定方法不会产生干扰 ,确定了以玉米根系鲜重为指示指标的生物测定方法 ,并以此得到了标准方程 ( P=4 .6653 1 .0 2 3 5lg C,r=0 .9859* * ) ,用该方法检测了田间连续 2年使用绿黄隆后土壤中的残留量。检测结果表明 :第 1年使用 ,6个月后土壤中绿黄隆的残留量约为施药当日的 1 0 %左右 ;连续 2年使用 ,土壤中的残留量较上一年略有增加     

人造板企业减少锅炉SO2排放的途径

介绍了减少锅炉SO2排放的基本途径与主要方法,重点分析了这些方法在人造板企业的适用性.     

银杏叶类胡萝卜素的研究

银杏叶和提取黄酮(GBE)生产过程中的废弃物含有的类胡萝卜素主要为叶黄素、紫堇新质、隐黄质、新黄质和其他胡萝卜素,是天然的着色剂,如能加以利用,是银杏产业资源综合利用和循环经济发展的途径之一。     

喹胺醇在鸡组织的消除及残留研究

以鸡为靶动物,多次口服(50 mg/kg,每12 h 1次,连续6次)喹胺醇,测定其在肝脏、肾脏及肌肉中的残留.用乙腈-乙酸乙酯(3/2,V/V)提取组织中的药物,反相高效色谱法测定组织中喹胺醇的浓度.色谱条件:C18-ODS柱(25 ㎝×4 .6),流动相为乙腈:水(2/3,V/V);流速1.0 ml/min,紫外检测波长为334 nm.鸡多次口服喹胺醇,于第6次给药后在肝脏、肾脏、肌肉药物的消除半衰期为5.91、6.489、5.727 h.若规定组织中喹胺醇浓度最高残留限量为1ng/g可食用,则休药期应为2天.