基于水基反应成膜技术的聚合物包膜肥料的研制

以3种水基硅丙乳液(SD-528、SD-5281和GA-1710)为材料,利用水基反应成膜技术对这3种材料进行化学改性,制备了聚合物包膜肥料模型膜;研究了模型膜的养分扩散性能,在此基础上研制了水基聚合物包膜肥料;测定了包膜肥料养分释放曲线,并利用红外光声光谱对聚合物膜进行原位表征.结果表明,通过化学交联改性,硅丙基模型膜具有优良的成膜性和扩散性能,不同的乳液对包膜尿素的缓释效果影响显著;GA-1710和SD-528的缓释效果较好,在静态水中的释放时间可达到30 d,而SD-5281缓释性能较差,需要做进一步的化学改性;不同的乳液类型制备的包膜尿素的释放模式也不同,GA-1710累积释放曲线为"S"型,而SD-528为"L"型.因此,利用反应成膜技术,硅丙乳液在水基包膜肥料的研制中具有广阔的应用前景.     

急性心肌缺血大鼠左心室流出道自发性慢反应电位去极离子流变化分析

目的探讨急性心肌缺血大鼠左室流出道自发性慢反应电位去极离子流的变化。方法常规玻璃微电极细胞内方法观测急性心肌缺血大鼠的离体心脏最大舒张电位(MDP)、0相除极幅度(APA)、0相最大除极速度(Vmax)、4相自动除极速度(VDD)、复极50%(APD50)和90%(APD90)的时间以及自发放电频率(RPF)。结果与给药前相比①1.2mmol.L-1河豚毒(TTX)使APA和Vmax有所减小(P<0.05),VDD和RPF明显减慢(P<0.01);②1.0μmol.L-1维拉帕米(VER)可使该慢电位的APA、Vmax、VDD明显减小,RPF减慢(P<0.01);APD、APD90延长(P<0.05);③2mmol.L-1 4-氨基吡啶(4-AP)使该慢电位的MDP的绝对值、APA、Vmax减小,VDD和RPF加快(P<0.01);④1.5mmol.L-1 CsCl作用6min时,VDD和RPF明显降低(P<0.05),10min时恢复。结论①左心室流出道的自发慢电位0相主要去极离子流除Ca2+内流外,还有少量Na+内流。②4相去极离子流中,除Ca2+、Na+的内流和Ik衰减外,If电流可能也起部分作用。     

明胶/PVA类肥料包膜材料的制备与环保性能研究

具有较好环保性能的包膜材料用于缓控释肥生产,可防止膜材料对土壤造成的潜在危害。本文以明胶、聚乙烯醇为原料复合共混制备膜材料,利用红外光谱(FTIR),扫描电镜(SEM)表征材料结构,并研究了膜材料拉伸强度和断裂伸张率力学性能,受控堆肥条件下的生物降解行为,明胶/PVA复合材料包膜尿素的养分缓释性及对小鼠的急性经口毒性。结果表明:当复合膜材料配比为m_(PVA):m_(Gel)=4:1时,组分相容性最好,并表现出良好力学性能、养分缓释性能和生物降解性能,复合材料包膜的肥料对小鼠无毒性作用,具有较好安全性。因此明胶/PVA复合膜材料具有较好的环保性能,其作为缓控释肥料的包膜材料具有较好应用前景。     

Utilization of biochar impregnated with anaerobically digested slurry as slow‐release fertilizer

We examined the possibility of an environment‐friendly slow‐release fertilizer (SRF) made of biochar impregnated by anaerobically digested slurry. The biochar materials were produced from three types of feedstocks (orange peel, residual wood, water‐treatment sludge) at different temperatures of 300°C, 500°C, and 700°C via pyrolysis. The release behaviors of the water‐soluble K⁺, Ca²⁺, and Mg²⁺ were similar for all impregnated biochars and the commercial SRF used. The water‐retention capacity was greatly improved by mixing the biochar‐SRF with the soil. The yield of lettuce was lower for the biochar‐SRF applications of 3.7 to 34.2 t ha^–1 than for the commercial SRF application of 51.4 t ha^–1. This might be due to excessive increase of soil pH for the biochar‐SRF application. Based on these results, the authors concluded that the biochar impregnated with nutrients could become an effective slow‐release K⁺ fertilizer.     

不同缓释肥用量对莴笋品质的效应

通过盆栽试验研究了不同缓释肥（SR）用量对莴笋产量和品质的效应。结果表明：不同施肥处理间莴笋产量有极显著差异。不同缓释肥用量处理提高莴笋产量32．3％～59．9％,以SR（M）〉SR（L）〉SR（H）,莴笋产量与缓释肥用量间存在二次回归关系（Y＝-10．7　x^2＋60．62x＋11．2R^2—0．9872）,缓释肥的增产效率以SR（L）〉SR（M）〉SR（H）．不同缓释肥用量处理提高莴笋叶绿素a、叶绿素a＋b含量和叶绿素a／b达38．9％～88．9％和20．5％～58．9％和6．3％～40．7％,增加莴笋叶绿素b含量28．7％～33．3％（SR（M）处理除外）。除SR（L）处理使莴笋可溶性糖含量降低32．7％外,不同缓释肥用量处理提高莴笋硝酸盐、Vc、可溶性糖和氨基酸含量达10．3％～27．0％,40．9％～151．7％,11．5％～19．2％和0．4％～61．1％。结合产量和品质来看,缓释肥用量处理中SR（M）是莴笋获得高产优质的最佳处理。     

Release Characteristics of Different N Forms in an Uncoated Slow/Controlled Release Compound Fertilizer

This study examined the release characteristics of different N forms in an uncoated slow/controlled-release compound fertilizer （UCRF） and the N uptake and N-use efficiency by rice plants. Water dissolution, soil leaching, and pot experiments were employed. The dynamics of N release from the UCRF could be quantitatively described by three equations： the first-order kinetics equation [N1=N0 （1-e^-kt）], Elovich equation （N1=a ＋ blnt）, and parabola equation （N1=a ＋ bt^0.5）, with the best fitting by the first-order kinetics equation for different N （r= 0.9569^＊＊-0.9999^＊＊）. The release potentials （No values estimated by the first-order kinetics equation） of different N in the UCRF decreased in the order of total N 〉 DON 〉 urea-N 〉 NH4^＋-N 〉 NO3^-N in water, and total N 〉 NH4^＋-N 〉 DON 〉 urea-N 〉 NO3^--N in soil, respectively, being in accordance with cumulative amounts of N release. The constants of N release rate （k values and b values） for different N forms were in decreasing order of total N 〉 DON 〉 NH4^＋-N 〉 NO3^--N in water, whereas the k values were urea- N 〉DON 〉 NH4^＋-N 〉 total N 〉 NO3^--N, and the b values were total N 〉 NH4^＋-N 〉 DON 〉 NO3^--N 〉 urea-N in soil. Compared with a common compound fertilizer, the N-use efficiency, N-agronomy efficiency, and N-physiological efficiency of the UCRF were increased by 11.4%, 8.32 kg kg^-1, and 5.17 kg kg^-1, respectively. The ratios of different N to total N in the UCRF showed significant correlation with N uptake by rice plants. The findings showed that the first-order kinetics equation [Nt=N0 （l-e^kt）] could be used to describe the release characteristics of different N forms in the fertilizer. The UCRF containing different N forms was more effective in facilitating N uptake by rice compared with the common compound fertilizer containing single urea-N form.     

Metabolite profiling of Komatsuna (Brassica rapa L.) field-grown under different soil organic amendment and fertilization regimes

Among agricultural soil fertility management options, the environmental benefits of organic amendments have recently drawn particular attention. However, little information exists about their effects on crop metabolites or quality. Field plots of Komatsuna (Brassica rapa L. var. perviridis) were planted in a fractional factorial design with the following treatments: soil amendments of cattle manure (0, 2 or 4?kg?m^?2), wheat straw (0, 0.05 or 0.1?kg?m^?2), fast release nitrogen (N) (0, 6 or 12?g?N?m^?2 of ammonium sulfate), slow release N (0, 3 or 6?g?N?m^?2 of coated ammonium nitrate), phosphorus (P) [0, 5 or 10?g phosphorus pentoxide (P₂O₅)?m^?2 of lime superphosphate] and potassium (K) [0, 6 and 12?g potassium oxide (K₂O)?m^?2 as potassium sulfate]. Metabolite profiling was carried out using a gas chromatograph/mass spectrometer (GC/MS), which yielded 62 and 67 metabolites in the leaves and the petioles, respectively. Metabolite peak areas were subjected to principal component analysis (PCA). The first component accounted for 44.1% of the total variance and bore a close relationship to N. The third component accounted for 8.8% of the total variance and was used to distinguish between different levels of manure application. An analysis of variance (ANOVA) of treatment factor effects on individual metabolites showed that the three most significant factors, from highest to lowest, were N absorption, manure amendments and slow release N. The effects of the manure amendments were not fully explained by its attendant N, P or K inputs. This result raises the question as to what mechanisms may bring about the metabolic changes caused by the manure amendment. The current findings will serve to direct further studies on the relationship between crop quality and cultivation procedures and will lead to more efficient quality control methods.     

Differences of yield and nitrogen use efficiency under different applications of slow release fertilizer in spring maize

Excessive or insufficient application of fertilizer has raised broader concerns regarding soil and environmental degradation. One-time application of slow release fertilizer (SF) has been widely used to reduce yield gap with potential maize yield and improve nitrogen use efficiency (NUE). A 2-year field experiment (2018–2019) was conducted to evaluate the effects of SF rates from 0 to 405 kg N ha^–1 (named F0, SF225, SF270, SF315, SF360, and SF405) and 405 kg N ha^–1 of common fertilizer (CF405) on the grain yield, biomass and N accumulation, enzymatic activities related with carbon–nitrogen metabolism, NUE and economic analysis. Results indicated that the highest grain yields, NUEs and economic returns were achieved at SF360 in both varieties. The enzymatic activities related with carbon–nitrogen metabolism, pre- and post-silking accumulation of biomass and N increased with increasing SF rate, and they were the highest at SF360 and SF405. The grain yield at SF360 had no significant difference with that at SF405. However, the N partial factor productivity, N agronomic efficiency and N recovery efficiency at SF360 were 9.8, 6.6 and 8.9% higher than that at SF405. The results also indicated that the average grain yields, NUE and economic benefit at SF405 were 5.2, 12.3 and 18.1% higher than that at CF405. In conclusion, decreasing N rate from 405 kg ha^–1 (CF) to 360 kg ha^–1 (SF) could effectively reduce the yield gap between realized and potential maize yields. The N decreased by 11.1%, but the yield, NUE and economic benefit increased by 3.2, 22.2 and 17.5%, which created a simple, efficient and business-friendly system for spring maize production in Jiangsu Province, China.     

茭白冷藏期间蛋白质表达谱的变化

为探讨茭白冷藏期间衰老的分子机理,应用蛋白质组学技术,研究了茭白冷藏期间蛋白质表达谱的变化。结果显示,双向电泳胶上共检测到大约650个蛋白点,其中35个蛋白表达量存在2.0倍以上显著(p0.05)差异,经过串联飞行时间质谱分析,成功鉴定出29个蛋白,根据其功能可分为6类,即代谢(20.7%)、细胞结构(27.6%)、抗胁迫(20.7%)、衰老(6.9%)、蛋白质合成(13.8%)和功能未知蛋白(10.3%);其中:代谢相关蛋白3个上调表达、3个下调表达,细胞结构相关蛋白6个上调表达、2个下调表达,抗胁迫相关蛋白4个上调表达、2个下调表达,衰老相关蛋白2个上调表达,蛋白质合成相关蛋白4个及功能未知蛋白3个均下调表达。这些差异表达蛋白的功能分析表明,茭白采后衰老机理可能涉及物质代谢过程的调整、能量代谢途径的改变、活性氧清除能力的减弱以及细胞结构的解体。     

快慢羽品系贵妃鸡体尺性状及屠宰性能的比较分析

对20周龄的6只快羽贵妃鸡与6只慢羽贵妃鸡的体尺性状与屠宰性能进行比较分析.结果表明,两品系间的体尺性状与屠宰性能均为慢羽鸡大于快羽鸡,且髋宽、半净膛率两品系间差异显著(P<0.05).两品系间的内脏器官的体积大小和骨架结构大小存在一定的规律性,骨架指数与睾丸重慢羽鸡均大于快羽鸡,器官指数则是慢羽鸡小于快羽鸡.