沼液沼渣暗灌施肥机设计与试验

沼液沼渣既是速效与迟效兼备、速效多于迟效的有机肥,又是防治病虫害的无污染、无残毒、无抗药性的"生物农药"。但由于没有沼液沼渣这种液态沼肥的机械化施肥技术和装备,无法施用于田间。同时,由于大中型沼气工程缺乏沼液沼渣的消纳途径,制约了沼气产业的发展。为此本文设计出一种液态沼肥暗灌施肥机械,该机械采用分配器对沼肥进行分配和防堵,一次进地能完成开沟、松土、施肥、起垄及镇压多道工序,减少了拖拉机及罐车进出耕地的次数。同时分析了分配器中沼液沼渣在管道中的流动性,发现其能集中沼液沼渣从总管到分管的瞬时流体能量。最后对施肥机进行了田间试验,结果表明所设计机具通过拖拉机配套牵引能进行沼肥运输、抽排工作。     

HMW-GS与北方手工馒头加工品质关系的研究

以我国黄淮麦区的114个小麦品种（系）为材料,探讨了高分子量麦谷蛋白亚基与手工馒头加工品质的关系,分析了供试材料中占比例较大的8种亚基和9种亚基组合对馒头品质的影响。结果表明,N、2+12亚基对各品质指标的作用均好或较好,没有明显缺点,是适合制作优质手工馒头的亚基;1、7+8和5+10亚基对馒头黏性的作用较差,7+9亚     

Nitrogen-15 balance in transplanted and direct-seeded flooded rice as affected by different methods of urea application

Summary Alternative N-fertilizer management practices are needed to increase productivity and the N-use efficiency of flooded rice (Oryza sativa L.). In the 1987 dry season, a field study using ¹⁵N-labeled urea evaluated the effect of the time and method of fertilizer-N application on grain yield and N-use efficiency in transplanted and direct-seeded flooded rice. Conventional fertilizer application (broadcasting and incorporation) was compared with band placement of liquid urea and point placement of urea supergranules. With band or point placement, the grain yields were significantly greater, and the partial pressure of NH₃ (pNH₃) in the floodwater was significantly reduced. In the transplanted rice, conventional fertilizer-N application gave a 64% total ¹⁵N recovery and 38% crop (grain and straw) recovery. Band placement of liquid urea N resulted in 92% total and 73% crop recovery. In the direct-seeded flooded rice, a conventional N application gave 72% total and 42% crop recovery; band placement, 98% total and 73% crop recovery; and urea supergranule point placement, 97% total and 75% crop recovery.Dedicated to Prof. Dr. K. Mengel, Giessen, FRG, in honor of his 60th birthday.     

Availability of soil and fertilizer nitrogen to wetland rice following wheat straw amendment

Summary A pot experiment was conducted to study the availability of soil and fertilizer N to wetland rice as influenced by wheat straw amendment (organic amendment) and to establish the relative significance of the two sources in affecting crop yield. Straw was incorporated in soil at 0.1, 0.2, and 0.3% before transplanting rice. Inorganic N as ¹⁵N-ammonium sulphate was applied at 30, 60, and 90 g g^-1 soil either alone or together with wheat straw in different combinations. After harvesting the rice, the plant and soil samples were analyzed for total N and ¹⁵N. Straw incorporation significantly decreased the dry matter and N yield of rice, the decrease being greater with higher rates of straw. The reduction in crop yield following the straw incorporation was attributed mainly to a decrease in the uptake of soil N rather than fertilizer N. The harmful effects of organic matter amendment were mitigated by higher levels of mineral N addition. The uptake of applied N increased and its losses decreased due to the straw incorporation. Mineral N applied alone or together with organic amendment substantially increased the uptake of unlabelled soil N. The increase was attributed to a real added N interaction.     

我国污泥土地利用的展望

城市污水污泥含有大量有机物质及植物养分，具有改土和肥田的正效应；但它有臭味，含病原菌、寄生虫卵、重金属和某些有毒有机物等而具有负效应。污泥的处置过去所采用的填埋法受到填埋场地的限制，投海已被禁止，焚烧则投资大，有二次污染及浪费能源而应用较少。目前，大量采用并得到广泛重视的是土地利用，即把污泥直接施用或经过堆肥化形成的生物固体应用于林地、草地、市政绿化、容器育苗基质、农田、果树及蔬菜地，使严重扰动的土地迅速恢复植被和促进土壤熟化，这是一种利用生物能源且符合我国国情的方法，今后必将迅速发展。     

Nitrogen fertilizers promote denitrification

A laboratory study was conducted to compare the effects of different N fertilizers on emission of N₂ and N₂O during denitrification of NO₃ ^– in waterlogged soil. Field-moist samples of Drummer silty clay loam soil (fine-silty, mixed, mesic Typic Haplaquoll) were incubated under aerobic conditions for 0, 2, 4, 7, 14, 21, or 42 days with or without addition of unlabelled (NH₄)₂SO₄, urea, NH₄H₂PO₄, (NH₄)₂HPO₄, NH₄NO₃ (200 or 1000 mg N kg^–1 soil), or liquid anhydrous NH₃ (1000 mg N kg^–1 soil). The incubated soil samples were then treated with ¹⁵N-labelled KNO₃ (250 mg N kg^–1 soil, 73.7 atom% ¹⁵N), and incubation was carried out under waterlogged conditions for 5 days, followed by collection of atmospheric samples for ¹⁵N analyses to determine labelled N₂ and N₂O. Compared to samples incubated without addition of unlabelled N, all of the fertilizers promoted denitrification of ¹⁵NO₃ ^–. Emission of labelled N₂ and N₂O decreased in the order: Anhydrous NH₃>urea<$>\gg<$> (NH₄)₂HPO₄>(NH₄)₂SO₄≃NH₄NO₃≃NH₄H₂PO₄. The highest emissions observed with anhydrous NH₃ or urea coincided with the presence of NO₂ ^–, and ¹⁵N analyses indicated that these emissions originated from NO₂ ^– rather than NO₃ ^–. Emissions of labelled N₂ and N₂O were significantly correlated with fertilizer effects on soil pH and water-soluble organic C. Received: 17 January 1996     

旱地长期施肥对土地生产力和肥力的影响

本文总结了半干旱黑垆土区 1 990～ 1 999年长期定位施肥的试验结果 .有机肥在提高旱地生产力和土壤肥力方面起着主导作用 .在施入等量氮磷养分下 ,平均有机肥增产 4 6 6% ,有机肥 +化肥增产4 4 8% ,化肥增产 2 2 4 % .施肥后效和土壤肥力均随施肥量的增加而提高 .后效的增产率在 3年内的约占原施肥处理的 1 / 4～ 1 / 3.     

浙中红壤油菜田供钾特性和钾肥用量研究

通过多点田间试验研究红壤性水田油菜供肥特性和钾肥施用量 .1 8个田间试验施钾油菜籽增产幅度为 7.5～ 90 .8kg/亩 ,无钾区相对产量变幅为 48.2～ 93.1 % .1mol/LNH4OAc提取的土壤速效钾含量与无钾区相对产量之间达极显著相关 ,相关系数为 0 .6 44 9 (n =1 8) .土壤速效钾的“临界水平”为80mg/kgK ,能满足 95 %相对产量的“足够水平值”为 1 5 0mg/kgK ,系统研究平衡施肥法中各参数的确定 ,并用平衡施肥法和施肥曲线确定油菜钾肥合理用量 ,两种方法具有可比性     

Effects of Azospirillum brasilense on root morphology of common bean (Phaseolus vulgaris L.) under different water regimes

 The effects of inoculation with Azospirillum brasilense Cd on root morphology and growth of common bean (Phaseolus vulgaris L.) were studied under different growth systems and water regimes. The root systems were evaluated by image analysis. In a PVC-tube growth system, inoculation with A. brasilense at 10⁷ colony forming units (CFU) ml^–1 increased root length, root projection area, specific root length (m g^–1) and specific root area (cm² g^–1), as compared with non-inoculated controls, resulting in root systems with longer and thinner roots. Water stress induced similar root responses to those observed after inoculation with A. brasilense. No increase in plant biomass was observed in inoculated plants, suggesting that under the tested growth conditions, a relatively larger amount of resources is required for the maintenance of the thinner roots. In water-stressed potted plants, the effect of A. brasilense on tap root length was inoculum-concentration dependent. At 10⁷ CFU ml^–1 this effect was significant as compared to non-inoculated controls. In a pouch system without water stress, inoculation with A. brasilense at a concentration of 10⁵–10⁷ CFU ml^–1 2 days after germination resulted initially (2 days after inoculation) in an increase in root length (95%) and root fresh weight (66%), but reduced root diameter (20%), compared to controls. At this early stage of growth the distribution of root length among the different root diameter classes changed: the thinner-root classes had the largest proportion of longer roots. Received: 3 January 2000     

化学调控技术在旱地水肥利用中的应用进展

围绕旱地农业生产中的水肥资源高效利用展开讨论,主要介绍了以3种典型化学调控制剂(土壤改良剂PAM、土壤保水剂SAP和蒸腾抑制剂FA)为代表的化学调控技术在旱地农业水肥资源利用方面的调控机制和应用方法,重点对化学调控技术在旱地农业生产中的增强水肥保蓄、提高坡地水土保持、改善作物水肥利用性能及提升作物品质和产量4个重要环节上的应用研究进行了综述,最后提出未来化学调控技术在旱地农业中应用的重点研究方向.