Quantitative determination of red-soil erosion by an Eu tracer method

Soil erosion is a serious problem and it is affected by land use and tillage (positive or negative). Even though there are a lot of studies to quantify soil erosion through erosion plots, the models used so far for determination the soil erosion are not well accepted. The purposes of this study were to set up a new erosion quantitative method in determination short-term erosion and sedimentation and to develop spatial erosion distribution models. We chose Eu (europium) as tracer atom. Based on the field experiment, positioning soil core Eu (europium) tracer (PSCET) was established. There were 80 cores set to 8 different slope sections. The samples were taken with soil sampler in 1.5 months interval. We further analyzed the data using multiple linear regressions and multiple linear stepwise regressions to model relationships between soil erosion and its factors. PSCET was applied to bamboo field (Deqing county, southeastern of China). The field was 54 m in length and 15 m in width. The experimental results indicated that erosion modulus increased with gradient increasing and ranged from 83.6 to −53.4 t ha yr⁻¹ in different slope sections. Temporal erosion distribution pattern was consistent with rainfall within a year. The 57.0% of annual rainfall (1068 mm) were accumulated in 3 months (June–August) and 80.1% of the annual soil losses were recorded on bamboo field in 1996–1997 (June–August). The statistical data showed that correlations between erosion modulus with rainfall agent of erosion, slope length, and slope degree index were positive; and with plant cover, organic matter contents, and clay particle contents were negative. Our field experiment results strongly suggest that PSCET makes it possible to study spatial erosion and deposition distributions.     

早熟抗虫棉新品种冀石929的选育及栽培技术要点

主要介绍早熟转基因抗虫棉冀石929的选育过程、特征特性及栽培技术措施。     

油菜不同生长期稻田土壤无机氮形态及氮肥利用率对控释氮肥施用的响应

通过盆栽土培试验研究了尿素、控释氮肥对南方稻田冬油菜生长、产量、土壤肥效和氮肥利用效率的影响,为控释氮肥在油菜生产上的推广应用提供参考。试验选用油菜品种"湘油15",参考油菜大田种植施氮量,共设4个处理,以不施氮肥(CK)为对照,在施氮量均为200kg/hm^2的水平下,设置了3种氮肥处理:尿素(Urea)、控释氮肥1(CRNF1)和控释氮肥2(CRNF2)。对油菜生物量和产量、不同生育期下土壤无机氮、油菜氮素吸收、油菜生理特性、土壤微生物氮以及土壤酶活性等相关指标进行测定及分析。结果表明:较常规Urea处理相比,控释氮肥处理显著提高了油菜花期、收获期生物量,增产11.2%～20.1%;CRNF1处理显著提高了油菜花期、收获期土壤NO3--N含量,相比尿素处理分别提高43.2%和61.8%,CRNF2处理显著提高了油菜花期、收获期土壤NH4+-N含量,相比尿素处理分别提高18.7%和64.1%,保证了油菜生育后期土壤氮素供应;与Urea处理相比,控释氮肥显著提高了油菜薹期及生殖生长期油菜总氮吸收,最终氮肥利用率(NUE)提高23.1%～60.2%,氮肥农学利用率(NAE)提高19.1%～30.5%;CRNF1处理显著提高了油菜生长后期SPDA值和总叶绿素含量,相比尿素处理分别提高6.5%,10.1%;CRNF1处理极显著提高了油菜生长后期土壤微生物氮,较尿素处理提高142.5%;此外,控释氮肥显著提高了油菜生长后期土壤脲酶、FDA水解酶活性,相比尿素处理分别提高8.4%～12.9%,24.5%～32.4%。在总氮施用量不变的前提下,施用控释氮肥可提高油菜生殖生长期土壤有效氮含量,改善光合作用,增强土壤微生物量和微生物活性,促进氮素的吸收,提高氮肥的利用效率,进而增加油菜干物质累积,最终提高产量。     

丘陵山地针阔混交林光合作用-光响应特性研究

为探讨丘陵山地针阔混交林中杉木、马尾松、红榉、闽楠、南酸枣5个混交树种对光环境的适应及生理响应,对5个混交树种树冠上、下层叶绿素含量、净光合速率、光响应曲线等光合特性进行了研究。结果表明:混交林中各树种净光合速率与树冠部位、叶绿素含量均达到显著相关性。闽楠叶绿素a/b最低,并具有较高的表观量子效率,为耐阴树种;南酸枣与红榉的叶绿素a/b较高,表观量子效率较低,为喜光树种;杉木、马尾松叶绿素a/b和表观量子效率居中,为喜光树种,略耐阴。闽楠、红榉、杉木光适应幅度较大,且兼具不同需光特性,是适宜的针阔混交造林配置树种。     

柏木、马褂木和杉木等针阔混交林结构化森林经营研究

以29a生柏木、马褂木和杉木针阔混交林为研究材料,利用结构化森林经营技术评价林分的稳定性。结果表明:柏木、马褂木和杉木等针阔混交林中树种优势程度最高的为柏木,其次为马褂木;整个林分中的树种为随机分布,林分中林木大多数处于强度混交和极强度混交的状态,其中刺槐、翅荚木、构树和马尾松平均混交度为1,为极强度混交。女贞、黄檀、蓝果树、香椿、和油桐为强度混交。优势树种柏木、马褂木和杉木中,马褂木的平均混交度0.615,处于中度混交状态,杉木的平均混交度0.519,处于中度混交状态,柏木的平均混交度为0.484,处于弱度混交与中度混交之间。林分中翅荚木和构树的平均大小比数为1,在它们所处的结构单元中处于绝对劣势状态;黄檀、蓝果树和油桐的平均大小比数在0.750~0.856之间,处于劣势状态;刺槐和杉木的平均大小比数在0.5~0.618之间,处于从劣势向中庸过渡状态;柏木、女贞、马褂木、马尾松、黄樟和香椿平均大小比数在0.25~0.5之间,处于从中庸向亚优势过渡状态;林分中,天然更新情况均达到了更新良好的等级,林分处于健康稳定的状态,目前不需要经营。结果为柏木、马褂木和杉木针阔混交林经营提供了理论依据和技术支持。     

高丽青瓷茶具初探

高丽青瓷是朝鲜半岛高丽王朝时代最具代表性的手工业制品之一。这一时期,受到中国的影响,茶文化在朝鲜半岛迅速发展,高丽青瓷茶具应运而生。本文以馆藏高丽青瓷和特展图录资料为基础,初步理清了高丽青瓷茶具的基本面貌,通过与中国瓷器的比较,考察高丽青瓷茶具中的中国文化因素和独特的本土风格。     

农村太阳能自动控温采暖装置

为减少北方农村地区采暖散煤带来的环境污染及天然气供应不足问题,调研和分析了不同的清洁采暖模式。设计出了以太阳能热水器为热源的自动控温采暖系统。该系统由太阳能热水器、管道、阀门、疏水器、管道泵、管道电磁加热器、温度传感器感应开关、温度传感器等组,用于农村居民采暖。使用结果表明:农村150余户应用后能达到既满足采暖需要,又节约采暖费用的目的。     

保水剂在农业生产上的应用研究

针对当前生态环建设及节水农业发展所产生的技术需求,简述保水剂在农业生产上的应用研究,并探讨了保水剂农用研究存在的问题。     

Genetic variation of wheat glutenin subunits between landraces and varieties and their contributions to wheat quality improvement in China

Glutenin, one of major factors effecting bread-making quality, is comprised of a mixture of polymers, viz. high-molecular-weight glutenin subunits (HMW-GSs) and low-molecular-weight glutenin subunits (LMW-GSs). Understanding variation among these glutenin subunits can help breeders determine allelic effects on specific quality traits and to use them as genetic markers. The HMW-GS and LMW-GS compositions of 390 landraces and 225 released varieties were analyzed by SDS–PAGE, and some quality traits, including Zeleny sedimentation volume, dough development time, stability time and strengths, were evaluated. The results indicated that 17 and 13 HMW-GSs were present in landraces and released varieties, respectively. For LMW-GS (Glu-A3 and Glu-B3 loci), 12 alleles were found in both landraces and released varieties. Total allelic richness at glutenin loci in landraces was higher, but the genetic dispersion index was lower than in released varieties. Two new subunit combinations 6 + 16 and 7 + 22, and some rare subunits 6 + 9*, 23 + 22, 6* + 8, 7 and 8, were identified in landraces and released varieties. The Glu-D1 and Glu-B3 loci had significantly positive effects. Based on the comparison of the effect of each subunit on quality, it was concluded that subunits 1 at Glu-A1, 13 + 16, 17 + 18 and 6 + 16 at Glu-B1, 5 + 10 at Glu-D1, Glu-A3b at Glu-A3 and Glu-B3d at Glu-B3 contributed larger positive effects on bread-making quality than alternative alleles. From this study, genetic materials with strong gluten and good quality were identified in landraces that did not carry the 1BL.1RS translocation.     

一株氨氮降解菌的筛选及其降解特性的初步研究

从上海崇明警备区富民养猪场污水处理池的污泥中分离得到1株去除氨氮效果较好的菌株（代号CM3）,对其氨氮降解特性进行了研究。初步研究表明,CM3菌株降解氨氮的最适温度和pH值分别为30℃和8．0,在氨氮初始浓度为300mg／L时,4d内其氨氮降解率可达40％以上,并可利用多种含碳化合物作为碳源生长。因此,CM3菌株具有一定的降解氨氮能力和潜在的应用价值。