不同施氮水平对甜菜地和休闲地土壤微生物数量的影响

本文比较了不同施氮水平对甜菜种植地和休闲地土壤中好气性细菌、放线菌和真菌数量的影响，并对土壤中的硝化细菌进行了测定。试验表明，氮肥能增加土壤中好气性细菌和硝化细菌的数量，并显著增加３０～６０ｃｍ土层中亚硝酸细菌数量，对５～１０ｃｍ、１０～３０ｃｍ和３０～６０ｃｍ土层中的硝酸细菌表现出促进作用。各施氮水平的土壤微生物总数达１×１０￣８个／ｇ干土以上。其中细菌为主要类群，约占９０％以上，其次为放线菌和真菌。在甜菜定苗前和收获期，５～３０ｃｍ土层中微生物总数顺序为施用Ｎ＿（１２０）＞Ｎ＿（１８０）＞Ｎ＿０，与甜菜的产量呈极显著正相关（ｒ＝０．９２８）．     

晾晒烟大田缓苗死苗原因及防治对策

针对晾晒烟生产中遇到的烟苗移栽后缓苗死苗问题，采用对土壤增施有机质肥料和熟石灰的办法进行试验研究与示范，结果表明，晾晒烟生产区，对土壤增施有机质肥料和熟石灰1125-1875kg/hm^2使土壤pH值达到5.5-7.0，能有效地解决烟苗移栽后的缓苗死苗问题，并能提高烟叶的产量、产值。     

氮磷钾化肥对甜菜产量和品质的影响

氮磷钾化肥对甜菜产量和品质的影响苏永中，秦来寿，张树清（甘肃省土壤肥料工作站）甜菜是甘肃河西走廊灌区主要的经济作物之一，种植面积４０余万亩。近几年在甜菜生产中施肥强调氮、磷配施，改变了传统的偏施氮肥、少施和不施磷肥的现象，使产量大幅度增加．为进一步提...     

新疆焉耆盆地甜菜高产与土壤深耕

甜菜属直根系作物,吸收养分多而广,块根下扎能力强。因此,通过土壤深耕来改善其物理性状,调节土壤中温度、水分、空气及养分的关系,减少甜菜根系生长阻力,是提高甜菜产量的又一有效措施。二十四团位于焉耆盆地北缘冲积扇溢出带,地下水位１～１．２ｍ,土壤板结,通...     

浅析九三地区甜菜含糖率下降原因及对策

九三地区位于黑龙江省西北部，海拔２８８．１ｍ，土壤属黑土类，地势以平坡地居多，肥力中等。这里种植甜菜已有近３０年的历史，一般年份含糖率在１６．５度以上，个别年份在１７～１８．５度。近几年由于甜菜栽培水平的提高，产量逐渐上升，而含糖率有下降趋势。特别是...     

甜菜工艺有害物质的影响因素及控制途径

本文据国内外资料初步探讨了原料甜菜中工艺有害物质的存在、影响因素及控制途径。甘肃甜菜中的Ｋ，Ｎａ含量高于黑龙江和欧美各地，与内蒙古河套地区相近。影响甜菜工艺有害物的最重要的栽培因素是氦肥，应根据０～９０ｃｍ上层含氮量科学施氮并配施磷肥。改善甜菜工艺品质的栽培措施同提高单位面积糖产量措施基本上是一致的。采用和选育工艺品质好的甜菜品种以及小平头切削法均有利于降低工艺有害物质的含量。     

土壤钙素水平对花生施钙效果的影响

２７个点次的田间试验表明，土壤钙素水平与花生施钙增产效果关系密切。土壤钙素水平越低，增产效果越显著。在土壤水溶性钙３９～１６２ｍｇ／ｋｇ范围内，每公斤ＣａＯ可增收花生果－０．７５～２８．２ｋｇ，其增产幅度为－３．５％～８２．７％。同时，施钙对改善花生品质有一定作用，可明显增加饱果、减少秕果，提高出米率。     

甜菜覆膜栽培技术增产效应分析

甜菜覆膜栽培可改善甜菜生长的环境条件，提高土壤含水率１．６４％￣５．４１％，降低土壤容重５．４８％，增加土壤孔隙度２．３４％，增加土壤空气含量０．８１％，并能提高土壤养份利用率，覆膜栽培甜菜可比裸地直播甜菜增产５６．６％，提高含糖０．２度。     

熟石灰在西洋参生产上的应用试验

目前由于化肥的大量施用等原因，使我国大部分土壤pH值降低，酸化严重。熟石灰的化学成分是氢氧化钙。呈碱性。施用熟石灰不但可以调节土壤的pH值，而且熟石灰还有一定的杀虫杀菌作用。我国现在已有部分参场、果园开始应用熟石灰，国外也有施用熟石灰于西洋参栽培中的做法。为探索出土壤施用熟石灰这一措施对西洋参生产的效果，并找出合理的施用量，设计了本试验。     

地膜甜菜创高产

地膜甜菜创高产孙彦彬（新疆石河子甜菜研究所）地膜栽培甜菜正在我区农村中应用。１９９２年乌兰乌苏乡张卫东种植的１２．５亩地膜甜菜，创亩产５９３０ｋｇ的高产纪录，具体措施如下：１、施足底肥，蓄足底墒。地膜甜菜前茬冬麦，麦收后每亩施农家肥２．５ｔ，均匀撒于...     

Sorghum and millet phenols and antioxidants

Sorghum is a good source of phenolic compounds with a variety of genetically dependent types and levels including phenolic acids, flavonoids, and condensed tannins. Most sorghums do not contain condensed tannins, but all contain phenolic acids. Pigmented sorghums contain unique anthocyanins that could be potential food colorants. Some sorghums have a prominent pigmented testa that contains condensed tannins composed of flavan-3-ols with variable length. Flavan-3-ols of up to 8–10 units have been separated and quantitatively analyzed. These tannin sorghums are excellent antioxidants, which slow hydrolysis in foods, produce naturally dark-colored products and increase the dietary fiber levels of food products. Sorghums have high concentration of 3-deoxyanthocyanins (i.e. luteolinidin and apigenidin) that give stable pigments at high pH. Pigmented and tannin sorghum varieties have high antioxidant levels that are comparable to fruits and vegetables. Finger millet has tannins in some varieties that contain a red testa. There are limited data on the phenolic compounds in millets; only phenolic acids and flavones have been identified.     

种子加工、检验理论与技术现状及思考

种子加工及检验是种子向市场流通的关键，是商业化育种中赋予种子商品属性不可或缺的环节。种子加工、检验理论与技术的研究是完善种业产业链、实现规模化商业育种、夯实“育繁推一体化”种业科学的重要一环。中国的种业科学技术体系正在形成与完善之中，受制于行业发展水平，种子加工及检验理论与技术相对薄弱。本文回顾了种子加工及检验理论与技术研究发展历程，提出了完善中国种业科学发展的策略与建议。围绕种业发展的需要，在做好品种优质化繁育的基础上，分析种子加工及检验理论与技术的新方向和新需求，加强种业应用性研究，建立先进的种子质量检验体系，研制适合现代种业发展需求的种子加工设备，打造种子加工产业标准化生产体系，完善种业科学技术学科建设，促进种业产业持续健康发展。     

Tuber and starch quality of wild and cultivated potato species and cultivars

Summary Between 1993 and 1998 205 different potato cultivars and 1220 accessions/genotypes of wild and cultivated potato species from the IPK Genebank Gatersleben were evaluated. Parameters interesting for starch isolation and especially for the use of starch were determined. Altogether, there was a higher variability in wild potato species than in cultivated potatoes for all characteristics investigated: dry matter content, starch content, protein content, amylose content and mean particle diameter of starch granules.     

Present Situation and Consideration of Seed Processing and Testing Theory and Technology

Seed processing and testing hold the key to the market circulation of seeds, and are an indispensable link in commercial breeding to endow seeds with commodity attributes. The research of seed processing and testing theory and technology is an important link in improving the seed industry chain, realizing large-scale commercial breeding and consolidating the seed industry science of ‘integration of breeding, propagation and promotion’. The scientific and technological system of seed industry in China is being formed and perfected, which is subject to the development level of the industry. The theory and technology of seed processing and testing are relatively weak. We reviewed the development of seed processing and testing theory and technology, and put forward strategies and suggestions to improve the sound development of China’s seed industry. In order to meet the needs of seed industry development and on the basis of high quality breeding of varieties, the new directions and demands of seed processing and testing theory and technology were analyzed. We will work to strengthen the applied research of seed industry, establish advanced seed quality inspection system, improve seed processing equipment suitable for the development needs of modern seed industry, establish standardized production system of seed processing industry, develop the scientific and technological disciplines of seed industry, and promote the sustainable and healthy development of seed industry.     

种子加工、检验理论与技术现状及思考

种子加工及检验是种子向市场流通的关键,是商业化育种中赋予种子商品属性不可或缺的环节。种子加工、检验理论与技术的研究是完善种业产业链、实现规模化商业育种、夯实"育繁推一体化"种业科学的重要一环。中国的种业科学技术体系正在形成与完善之中,受制于行业发展水平,种子加工及检验理论与技术相对薄弱。本文回顾了种子加工及检验理论与技术研究发展历程,提出了完善中国种业科学发展的策略与建议。围绕种业发展的需要,在做好品种优质化繁育的基础上,分析种子加工及检验理论与技术的新方向和新需求,加强种业应用性研究,建立先进的种子质量检验体系,研制适合现代种业发展需求的种子加工设备,打造种子加工产业标准化生产体系,完善种业科学技术学科建设,促进种业产业持续健康发展。     

芸薹属多倍体与二倍体作物 花柱及角果的发育差异

通过比较分析芸薹属多倍体复合种与其祖先二倍体基本种在花柱、柱头大小、角果长度、宽度、种子直径 及种子干重变化上的异同,发现多倍体复合种在这些发育性状上表现出处于两个祖先二倍体亲本之间,或只偏向 于其中一个祖先亲本。同一个多倍体品种在不同发育性状上具有不同的表现,即在某一发育性状上偏向于其祖先 亲本之一,而在另一发育性状上偏向其另一祖先亲本。     

Effects of Organic and Chemical Fertilizers and Arbuscular Mycorrhizal Inoculation on Growth and Quality of Cucumber and Lettuce

Summary

Arbuscular mycorrhizae were inoculated into phosphorus-deficient soil fertilized with either organic or chemical fertilizer with cucumber (Cucumis sativus L.) as the first crop and lettuce (Lactu-ca sativa L.) as the second crop but without additional fertilization and AM inoculation. AM increased dry matter and fruit yield of cucumber significantly in the unfertilized, organic-fertilized and P-deficient plants compared with the fully chemical-fertilized plants. AM inoculation increased the available phosphorus in plant and soil by around 30% for all treatments except for those chemically-fertilized. The rate of AM infection did not differ significantly among the fertilization treatments, but the infection intensity was higher in unfertilized, organic-fertilized and phosphorus-deficient treatments than chemical-fertilized treatment. The residual effects of AM-inoculated to cucumber were evident for lettuce in all pre-treatments that were unfertilized and un-inoculated for the second cropping. Without P-fertilization, neither crop could grow optimally even when the soil was inoculated with AM, suggesting that AM could not serve as a substitute for phosphorus fertilizer. However, the other beneficial effects of AM on crop growth and yield could not be fulfilled with phosphorus fertilizer.     

云南咖啡主要病虫害及防治调查研究

对云南保山、德宏、普洱等地咖啡病虫害开展调查研究,结果表明：咖啡锈病(Hemileia vastatrix Berk et Br.)、炭疽病(Colletotrichum coffeanum Noack)、褐斑病(Cercospora coffeicola Berk. et Cooke)、幼苗立枯病(Rhizoctonia solani Kuhn.)、旋皮天牛(Acalolepta cervina Hope)、灭字虎天牛(Xylo     

Effects of crop density and tillage system on grain yield and N uptake from soil and atmosphere of sole and intercropped pea and oat

Pea (Pisum sativum L.) and oat (Avena sativa L.) were grown as sole and mixed crops in various densities under two different tillage systems on a loess soil near Göttingen/Germany in a 2-year field experiment (2002/2003). In the conventional tillage system a mouldboard plough (CT) was used and in the minimum tillage system a rotary harrow (MT) was employed. The effect of crop density and tillage system on the grain dry matter and grain N yields, N₂ fixation and soil N uptake were determined to address the following questions: (i) which mixture compositions exhibit the highest grain yields compared to the sole crops, (ii) which mixture compositions also fix a high level of N₂ and leave low levels of residual inorganic soil N after harvest, and (iii) whether the intercrop advantage is influenced by the tillage system. For (i) the result in 2002 showed that the highest grain yields of both sole cropped pea and oat and intercropped pea and oat were achieved at the highest densities. In 2003, when the inorganic soil N content was higher and weather conditions were warmer and drier, grain yields were significantly higher than in 2002, but sole as well as intercropped pea and oat gave their highest grain yields at lower densities. For both years and tillage systems, the highest intercrop advantages were achieved in mixtures with densities above the optimal sole crop densities. The result for (ii) was that a distinctly higher proportion of nitrogen was derived from the atmosphere (Ndfa) by intercropped pea than by sole cropped pea. However, the uptake of soil N by intercropped pea and oat was not reduced in comparison with that of sole cropped oat as the decrease in the uptake of N from the soil by oat at lower oat densities in the mixture was compensated for by the soil N uptake of pea. Additionally, the N_min-N content of the soil following the mixtures and sole cropped oat did not differ, especially in the deeper soil layers because oat in mixture was forced to take up more soil N from deeper layers. Therefore, the risk of soil N losses through leaching after mixtures was lower compared to sole cropped pea. The tillage system (iii) had no significant influence on grain yield and soil N uptake, but N₂ fixation and the competitive ability of intercropped pea were higher under CT than with MT. An additional result was that intercropping led to a significantly increased grain N content of both pea and oat compared to the sole crops. The increase in grain N content from sole to intercrop was from 3.30 to 3.42% for pea and from 1.73 to 1.96% for oat as a mean for both years and tillage systems. The present study confirms that growing pea and oat as intercrops highlights potential economic and environmental benefits which still need to be understood in more detail in order to exploit intercropping to a greater extent.     

Herbicide application and direct drilling improves establishment and yield of chicory and plantain

The herbs chicory ( C ichorium intybus L.) and plantain ( P lantago lanceolata L.) are increasingly popular summer forage cropping options for dairy producers. However, the impact of different establishment methods on their productivity is largely unknown. Four establishment methods for chicory and plantain crops sown into non‐cultivated ryegrass pastures in spring were compared. Establishment methods included direct‐drilling or broadcasting seed into existing pastures, with or without herbicide application before sowing in a 2 × 2 factorial design. It was hypothesized that plant establishment and growth would be enhanced by spraying to kill existing ryegrass pasture and direct‐drilling herbs (Spray and Drill, SD) compared with broadcasting seed with no herbicide application (Unsprayed and Broadcast, UB). This hypothesis was supported with an additional 2·1–2·3 t DM ha^?1 grown over 201 d from swards established by SD, compared with swards established by UB. The SD method also increased the plant density of the herbs and reduced the proportion of weed species. Spraying and direct drilling is more expensive than broadcasting seed with no herbicide application, but the increase in yield means that extra feed can be supplied at less than half the cost of purchasing the equivalent amount of feed. Therefore, for optimal economic outcomes, chicory and plantain swards should be established by applying herbicide to existing pasture and direct‐drilling seed.