淀粉黏结剂对颗粒有机复混肥养分释放的影响

以自制的两种淀粉基黏结剂作为有机复混肥造粒黏结剂，以无机黏结剂硅酸钠为对照处理，以废物堆肥和市售无机化肥作为原料，经圆盘造粒获得3种不同颗粒有机复混肥。3种有机复混肥颗粒平均抗压碎力都达到了中国国家标准(≥6 N)的要求；无机黏结剂C颗粒经24 h的水浸泡后，其崩解率为6.1%；而A和B淀粉黏结剂颗粒保持完好，崩解率为0。通过168 h养分溶出试验发现，有机黏结剂A和B能明显降低颗粒肥中营养元素的释放速率；PVA(聚乙烯醇)改性淀粉黏结剂B作为有机复混肥造粒黏结剂，能明显延缓颗粒肥中NH⁺₄-N、全氮、全磷和全钾释放速率。虽然黏结剂A比黏结剂B延缓颗粒肥无机养分释放的效果差，但与无机黏结剂C相比，其延缓颗粒肥无机养分释放速率的效果要好的多。试验结果表明：用改性淀粉黏结剂作为有机复混肥造粒黏结剂，可以同步实现对速溶无机养分的控制释放，也为新型非包膜控施肥的研制和开发提供新的思路和参考。     

缓释复合肥对黄连营养效应的研究

田间试验研究了4种黄连缓释专用复合肥（SRF）对3～5年生黄连产量与药用品质的影响。结果表明,缓释复合肥料较普通复合肥料（CK）显著或极显著提高各年份黄连的生物量与根茎产量，以SRF4与SRF-的增加幅度最大（6．3％～18．7％）。各缓释复合肥处理对不同年份黄连植株地上部和地下部养分含量的影响表现为氮、磷养分含量变化特点相同。钾含量则相反。缓释复合肥的养分比例明显影响不同年份黄连的药用品质，SRF3对3年生和5年生黄连小檗碱、生物碱含量增加明显，4年生黄连则以SRF-的提高作用最大。无论地上部还是地下部，较高的N／P比、N／K比，较低的K／P比均有利于提高不同年份黄连的产量，提出的高产（量）优质处理对应的养分比例可作为高产优质黄连植株营养诊断的重要依据。     

福州茉莉花种植园土壤化学计量比及其对碳释放潜力的影响

选取有机茉莉花种植园、常规茉莉花种植园、茉莉花+龙眼间作种植园为研究对象,通过测定3种种植园土壤全碳(TC)、全氮(TN)、全磷(TP)、全钾(TK)质量分数及二氧化碳(CO2)释放潜力,研究不同种植方式下茉莉花种植园土壤化学计量比及其对碳释放潜力的影响。结果表明:1)3种茉莉花种植园土壤碳氮质量比值(C/N)分别为11.33、10.93、9.48,碳磷质量比值(C/P)为23.23、25.33、10.91,碳钾质量比值(C/K)为1.02、0.88、1.66,氮磷质量比值(N/P)为2.05、2.32、1.14,氮钾质量比值(N/K)为0.09、0.08、0.17,磷钾质量比值(P/K)为0.04、0.03、0.15;2)3种茉莉花种植园土壤C/N表现为有机茉莉花种植园>常规茉莉花种植园>茉莉花+龙眼间作种植园,有机茉莉花种植园土壤N/P显著低于常规茉莉花种植园,土壤P/K则相反,茉莉花+龙眼间作种植园土壤C/P、N/P显著低于常规茉莉花种植园,土壤C/K、N/K、P/K则相反;3)3种茉莉花种植园土壤CO2释放潜力分别为5.80、3.79、4.92μg/(g·d),但差异性均不显著,茉莉花+龙眼间作种植园土壤C/P、C/K、N/P、N/K对CO2释放潜力的剖面变化具有一定指示作用,间作-有机种植相结合是福州茉莉花种植系统较合理的种植模式。     

旱地豆科绿肥腐解及养分释放动态研究

采用田间埋袋法对长武怀豆、大豆和绿豆在土壤中长达287 d的养分释放状况进行了监测,旨在查明三种豆科绿肥分解及其养分释放规律。结果表明,三种绿肥均表现为前期腐解快、后期腐解慢,高峰均出现在最初的1个月内。在残留率平稳的阶段,长武怀豆残留率显著高于大豆和绿豆。不同养分的释放有差异:氮、磷、钾在最初的21d内快速释放,其中钾的释放最彻底,287d 后钾的残留率仅为3.2%～5.9%。钙的残留率最高,而且始终没有显著的变化,287d后残留率仍为74.8%～89.8%。镁在前28d 矿化速率较快,残留率已降至30%左右。铜的释放有较明显的波浪起伏。铁在最初的21d内有明显释放,随后变幅不大。锌的残留率在最初的49d内呈下降趋势,49～175d内变化不大,175d后,三种绿肥锌残留率均显著降低。锰残留率的变化在起伏中呈下降趋势,至 287d 时,残留率降到了67.3%～74.1%,仅低于钙。三种绿肥养分释放状况的差异因养分种类而不同:氮、钙、铁、铜和锌的残留率在三种绿肥之间差异较大,钾和镁的残留率差异不显著。除了碳、氮、铜和锌外,其他养分残留率均表现为绿豆最低;除了碳、氮、铜和铁外,其他养分残留率均表现为大豆最高。     

茶树施用控释氮肥的产量和品质效应

采用盆栽和大田试验,研究了控释氮肥对茶树生长发育、茶叶产量和品质的影响。结果表明,控释氮肥能明显促进茶树的生长发育,茶树新梢数、百芽重、成熟叶片数量及叶绿素含量、树高和主杆直径等均有明显提高,从而使盆栽茶树根、茎和叶各部位的生物产量比施普通尿素分别提高了58.3%、36.9%和17.2%。10个大田试验的茶叶产量增加了4.2%￣24.1%,平均9.6%。茶叶品质成分氨基酸、咖啡碱和水浸出物含量有不同程度提高,其中氨基酸增幅明显,但对茶多酚含量的影响不大,茶叶酚氨比明显降低。可见,控释氮肥具有明显的增产提质效果。     

Short‐term potassium release and fixation in some calcareous soils

Potassium (K⁺) directly released from primary K‐bearing minerals can contribute to plant nutrition. The objective of this research was to assess short‐term K⁺ release and fixation on a range of intensively cropped calcareous soils. Potassium sorption and desorption properties and the contributions of exchangeable‐K⁺ (EK) and nonexchangeable‐K⁺ (NEK) pools to K⁺ dynamics of the soil‐solution system was measured using a modified quantity‐to‐intensity (Q : I) experiment. Release and fixation of K⁺ were varied among soils. The relation between the change in the amount of NEK during the experiment and the initial constrain was linear, and soil ability for K⁺ release and fixation (β) for all soils varied from 0.041 to 0.183, indicating that 4% to 18% of added K⁺ converted to NEK when fixation occurred. The equilibrium potential buffering capacity (PBC) for K⁺ derived from Q : I experiments had significant correlation (r = 0.75, p < 0.01) with β, indicating that PBC depends not only on exchange properties but also on release and fixation properties. The depleted soils showed higher β value than the other soils, indicating much of the added K⁺ was converted to NEK in case of positive constraint. The range of the amount of EK which was not in exchange equilibrium with Ca (E_min) in the experimental conditions was large and varied from 0.68 to 9.00 mmol kg^–1. On average, E_min amounted to 64% of EK. This fraction of EK may not be available to the plant. The parameters obtained from these short‐term K⁺ release and fixation experiments can be used in plant nutrition.     

控释肥对水稻产量和氮肥利用效率的影响

氮肥施用量大,氮素利用效率低一直是困扰我国水稻生产的突出问题,如何提高氮肥利用效率,减少因施用氮肥而引起的环境污染问题,是目前肥料研究中共同关心的课题。通过田间试验研究了美国Scotts控释肥、自制控释肥(AgroBB)、未包膜复合肥(Com)和混合肥(NPK)在等氮、磷、钾养分下对水稻产量和氮肥利用效率的影响。结果表明,(1)美国控释肥、自制控释肥与未包膜的复合肥比较,早稻增产8.57%～12.45%,晚稻增产9.64%～11.49%,差异达极显著或显著水平,而AgroBB与Scotts间的差异不显著。NPK与Com比较,晚稻增产7.20%,早稻仅增产2.47%。(2)早稻各处理的氮肥农学效率明显高于晚稻。Scotts、AgroBB和NPK的氮肥农学效率分别比Com明显地提高了26.93%～29.82%、18.52%～25.06%和5.35%～18.69%,其中两种控释肥之间、AgroBB与NPK间差异未达显著水平。(3)Scotts、AgroBB一次施用,NPK分次施用的氮肥回收效率分别比Com一次施用明显地提高了25.72%～28.82%、3.75%～23.70%和8.46%～27.73%。本试验条件下,控释肥处理的氮肥回收效率虽然与分次施用混合肥处理无显著性差异,但是其农学效率和生理效率明显大于混合肥处理。     

Soil microbial biomass and activities in a Japanese Andisol as affected by controlled release and application depth of urea

This experiment was conducted in maize field plots to study the effects of controlled release and application depth of urea on soil microbial biomass and activities at two depths of surface soil of a Japanese Andisol from June to September, 2001. Three N amendment treatments and a Control were included in this experiment: deep application (8 cm) of controlled release urea; deep application (8 cm) of conventional urea; surface application of conventional urea; Control, without N application. Prior to this experiment, the field plots received the same N fertilizer treatments for two consecutive years under maize/barley rotation. Soil microbial biomass, dehydrogenase and nitrification activities exhibited great vertical and temporal variations during the maize growth season, and the microbial biomass was significantly correlated to soil water-filled pore space (p<0.01). N fertilization did not significantly affect the microbial biomass, but greatly increased the dehydrogenase and nitrification activities. The increase in the microbial activities following N fertilization was not attributed to the increase in microbial biomass but to the increase in intrinsic microbial activities. Controlled release urea was found to continuously affect the dehydrogenase activity over a shorter distance, while conventional urea could greatly increase the enzyme activity for a shorter period of time. Both controlled release and deep application of urea had potentials to reduce the nitrification activity and suggested that the nitrate production might be decreased in 0–10 cm surface soil. Deep application of urea increased aboveground N uptake by maize and then the recovery rate of N fertilizer, whereas controlled release of urea greatly increased grain yield and N uptake by grain.     

含硫尿素养分缓释释放测定方法的研究

包膜尿素肥料是提高肥料利用率，解决环境污染问题的一种新型肥料。针对目前对缓释肥料释放特性的研究集中在化工制作领域这一现状，采用不同的测定方法，阐明含硫尿素中的养分氮在水及土壤中的转化特点，确定养分的释放速率，以求找出适合农业生产应用的方法。研究表明，可以用电导率法快速准确地定性评价缓释肥料的供肥特性和供肥速度，用土壤培养法和水培法定量测定其供肥性能。     

辐射不育技术防治柑桔大实蝇的效果

在贵州省惠水县中联桔园(500亩)中,1987年和1989年分别释放56272头和95320头辐射不育柑桔大实蝇,释放比分别为12.5:1和45:1,使柑桔大实蝇虫果率由常年的5—8％下降到0.005％,防治效果十分显著。测得柑桔大实蝇可飞翔扩散1500米远。