水稻耐低钾基因型的筛选及吸钾特性的研究

筛选水稻耐低钾基因型最直接、客观方法是在低钾土壤上进行田间实验直接筛选,其结果可作为其他方法的比较标准.但该方法需时较长、工作量大,不能满足大批量快速、高速筛选的要求.因此,近年来国内外许多学者在探索用液培的方法进行筛选[1,2].     

人参的营养需要与施肥效应

人参(Panax ginseng)主产于吉林省长白山区的林下暗棕壤及白浆土上。已有三百余年的栽培历史,人工栽培,多模拟野生条件,不施肥。近二、三十年来,随着种植面积扩大,注意改进栽培技术的同时,仿效农田施肥,基、种、追、喷肥并施,复合肥、专用肥皆用，缺乏针对性(人参、土壤)。为发展人参生产，合理施用肥料，从了解人参营养需要和土壤供肥水平人手，田间试验与室内分析相结合，进行了研究。     

INTERACTION EFFECT OF POTASSIUM AND SULFUR FERTILIZATION ON PRODUCTIVITY AND MINERAL NUTRITION OF SUNNHEMP

The interactive effect of potassium (K) and sulfur (S) fertilization on productivity and mineral nutrition of sunnhemp (Crotalaria juncea L.) was evaluated in a field experiment during 2008 and 2009 cropping seasons at Uttar Pradesh, India. Potassium and sulfur fertilizers increased fiber yield and nutrient uptake of sunnhemp. It was observed that an application of K and S at 40 kg ha^?1 each significantly increased the total dry matter, fiber yield, and nutrient uptake of sunnhemp. The crop yield response to the added S was greater than for K and the nutrient use efficiency was also higher at lower levels of fertilizer addition. The increased levels of K and S improved the number of nodules and crude protein content of sunnhemp leaves.     

生物钾肥的增产作用及对土壤钾平衡的影响

生物钾肥是指具有高钾低氮磷养分组成的植物的绿色体或秸杆。生物钾肥作用的实质是:植物不断吸收并活化土壤钾,富集土壤和水体中钾,通过以绿色体或秸秆形式归还,促进土壤钾的良性循环和再利用。生物钾肥中钾的溶解度和利用率都较高,其供钾性能类似矿质钾肥。在等钾量下,各种生物钾肥的增产效果和矿质钾肥接近。     

ALLEVIATION OF CADMIUM TOXICITY IN SOYBEAN BY POTASSIUM SUPPLEMENTATION

This study was undertaken to determine the effect of potassium (K) on alleviating cadmium (Cd) toxicity in soybean. Two genotypes of soybean, namely ‘Liao 1’ and ‘Zhechun 3’ were used in hydroponics experiment with the following treatments: control without Cd addition; 1μM Cd addition; K supplementation at a rate of 380 mg L^?1; and both Cd addition and K supplementation. Plant growth, chlorophyll content, and fluorescence, rate of photosynthesis and stomatal conductance reduced significantly in Cd-stressed plants. Meanwhile, Cd treatment increased malondialdehyde content, and activities of superoxide dismutase and peroxidase enzymes. Concentration of K, calcium (Ca), magnesium (Mg), and zinc (Zn) in shoot and root tissues also reduced in Cd treatment. ‘Liao 1’ had higher, antioxidant enzyme activity than ‘Zhechun 3’. Potassium supplementation alleviated the reduction of growth, photosynthesis and nutrients uptake in Cd-treated plants. It was concluded that Cd toxicity could be alleviated through enhanced K nutrition in soybean.     

施肥深度对大豆氮磷钾吸收及产量的影响

采用分层施肥和15N示踪方法,研究施肥深度对大豆氮磷钾吸收及产量的影响,为大豆合理施肥深度的确定提供理论依据。研究表明,施肥深度对大豆前、中期植株干物质、氮磷钾的积累影响较大,而对植株成熟期影响较小;大豆苗期(V3)与种子同层施肥处理植株干物质和氮磷钾的积累量最大;盛花期(R2)以种下6cm处理效果最明显。施肥深度对大豆产量的影响也表现为种下6cm处理最高,但与种子同层施肥、种下12、18和24cm施肥处理差异不显著;施于种子同层至种下6cm最有利于大豆苗期氮肥吸收,表层施肥、种下24cm施肥处理氮肥吸收效果不好。     

江苏省土壤钾素的供应能力与钾肥施用问题

随着我国农业生产的不断发展,复种指数和单位面积产量的不断提高,南方不少地区施用钾肥已成为夺取高产稳产的重要条件之一,有关土壤钾素状况和钾肥施用问题愈来愈受到人们的重视.江苏省地处我国南北的过渡带,其土壤是否缺钾,钾肥的需要程度如何,是生产实践上有待明确的一个问题.     

EFFECT OF DIFFERENT FERTILIZATION MODES ON PHYSIOLOGICAL CHARACTERISTICS,YIELD AND QUALITY OF CHINESE CABBAGE

In field conditions, seven fertilization treatments were applied by randomized design with three replications. At a late growth stage of Chinese cabbage, the plant leaf chlorophyll content, photosynthetic rate (P_n), transpiration rate (T_r), and stomatal conductance (G_s) significantly increased upon the three fertilization modes, which were synthetic and organic fertilizers combined (SOF), synthetic fertilizer and dicyandiamide combined (SFD), and organic fertilizer inoculated live earthworms (OFE) than the other treatments. Organic fertilizer application significantly improved superoxide dismutase (SOD), Peroxidase (POD) and Catalase (CAT) activities and decreased malondialdehyde (MDA) accumulation, especially in the organic fertilizer inoculated live earthworms treatment. The SOF, SFD and OFE treatments improved the plant yield by 40.5%, 38.0% and 36.1% than the synthetic fertilizer applied alone treatment (SFB) and by 23.4%, 21.1% and 19.6% than the synthetic fertilizer in a split application treatment (SFT). Compared to single applied synthetic fertilizer, the OFE treatment significantly reduced nitrate content, and also improved sugar-acid ratio and soluble sugar and Vc content in the heads of the plant at the harvest stage. All this suggests the OFE treatment is a healthy, sustainable and environmentally friendly fertilization way for the Chinese cabbage production in north of China.     

不同施肥条件与年限对土壤胡敏酸能态及热分解特性的影响

氧弹量热计测定结果表明，不同施肥条件土壤胡敏酸热值呈现堆肥＞秸杆＞化肥＞无肥＞休闲的顺序，各施肥处理定位试验１０年的胡敏酸能态比４年者为低。     

黄土区土壤长期施肥对胡敏酸结构特征的影响

从黄土区长期肥料定位试验地中采集土壤样品,分离纯化胡敏酸,室内分析其化学性质、热分解特性和红外光谱特征。结果表明:长期施用化肥和有机肥均能不同程度地提高土壤胡敏酸分子的氮素含量,降低碳素含量,使其脂肪族侧链增多,芳香核结构减少,芳构化程度降低,向着简单化、年轻化方向发展。有机肥作用效果大于化肥。     

耗竭条件下冬小麦的吸钾特点及其对土壤不同形态钾的利用

在耗竭条件下研究了冬小麦在我国11种主要土壤上的吸钾特点及其对不同形态钾利用。结果表明,冬小麦对钾的吸收具有明显的阶段性。拔节至齐穗期为吸钾高峰,成熟后出现排钾现象。耗竭条件下冬小麦各生育期土壤交换性钾含量变化不大,而缓效性钾从开穗后开始回升。冬小麦吸收的钾中,交换性钾占的比例较小,11种土壤平均为21.5％;1mol／LHNO3不能提取的钾占绝大部分,平均为78.5％。表明土壤经耗竭后,1mol／LHNO3不能提取的钟对作物钾营养的作用较大。耗竭后土壤交换性钾最低值出现的时期及数量大小是土壤重要的供钾特性之一。