Effects of Potassium Fertilizing Rates on Yield, Fiber Quality and Potassium Use Efficiency of Three Hybrid Cotton Cultivars

The effects of potassium （K） application rates on the yield, fiber quality and K fertilizer use efficiency of three hybrid cotton varieties （Jin102, Xiangzamian8, Siyang328） were studied in field experiment. Fertilizer rates of K2O 135 and 270 kg/hm2, representing 1x and 2x recommended K rates, were applied, no application of k fertilizer as the CK. The results show that the lint yield increased 39.13%-57.48%with potassium application, highly significantly. Al yield components of the three hy-brid cotton varieties increased with the increase of K application amounts. The bol number per plant, single bol weight and lint percentage were increased by 14.24%-40.29%, 3.59%-15.51% and 0.16%-4.89%, respectively, and the fiber length and specific strength also increased with the increasing K application amounts, showing no significant influence on Micronaire. When the K application amounts increased from 135 to 270 kg/hm2, the partial factor productivity （PFPk） reduced by 45.93%-48.01%, and the agronomic efficiency （AEk） reduced by 37.1%-42.9%. The PFPk and KE （K efficiency coefficients） of S328 were the highest among the three varieties, which also showed the strongest resistance to low potassium stress, and with no potassi-um fertilizer application （K0）, the lint yield of S328 was 5.54% and 11.19% higher than that of X8 and J102. The AEk of J102 was the highest, and its reward of K fertilizer was the greatest among the three varieties.

Nutrient Uptake and Use Efficiency of Irrigated Rice in Response to Potassium Application

Potassium is one of the most important nutrients for rice production in many areas of Asia, especially in southeast China where potassium deficiency in soil is a widespread problem. Field experiments were conducted for four consecutive years in Jinhua City, Zhejiang Province, to determine utilization of nutrients (N, P and K) by inbred and hybrid rice and rice grain yields as affected by application of potassium fertilizer under irrigated conditions. Grain yield and nutrient harvest index showed a significant response to the NPK treatment as compared to the NP treatment. This suggested that potassium improved transfer of nitrogen and phosphorus from stems and leaves to panicles in rice plants. N and P use efficiencies of rice were not strongly responsive to potassium, but K use efficiency decreased significantly despite the fact that the amount of total K uptake increased. A significant difference between varieties was also observed with respect to nutrient uptake and use efficiency. Hybrid rice exhibited physiological advantage in N and P uptake and use efficiency over inbred rice. Analysis of annual dynamic change of exchangeable K and non-exchangeable K in the test soil indicated that non-exchangeable K was an important K source for rice. Potassium application caused an annual decrease in the concentration of available K in the soil tested, whereas an increase was observed in non-exchangeable K. It could be concluded that K fertilizer application at the rate of 100 kg ha-1 per season was not high enough to match K output, and efficient K management for rice must be based on the K input/output balance.

Transgenic approaches for improving use efficiency of nitrogen, phosphorus and potassium in crops

The success of the Green Revolution largely relies on fertilizers, and a new Green Revolution is very much needed to use fertilizers more economically and efficiently, as well as with more environmental responsibility. The use efficiency of nitrogen, phosphorus, and potassium is controlled by complex gene networks that co-ordinate uptake, re-distribution, assimilation, and storage of these nutrients. Great progress has been made in breeding nutrient-efficient crops by molecularly engineering root traits desirable for efficient acquisition of nutrients from soil, transporters for uptake, redistribution and homeostasis of nutrients, and enzymes for efficient assimilation. Regulatory and transcription factors modulating these processes are also valuable in breeding crops with improved nutrient use efficiency and yield performance.

Effects of Nitrogen-phosphorus-potassium Combined Fertilization on Rice Yield and Fertilizer Use Efficiency in Jianghan Plain

[Objectives]This study was conducted to explore the rational formula for rice fertilization in Jianghan Plain.[Methods]An experiment on the combined application of nitrogen,phosphorus and potassium fertilizers was carried out in Jianghan Plain,an important rice producing area in Hubei,with a total of five treatments to study the effects of nitrogen,phosphorus and potassium fertilizers on the fertilizer use efficiency and yield of rice.[Results]Fertilization had a significant effect on improving rice yield,and nitrogen fertilizer had the greatest effect on rice yield,followed by potassium fertilizer and phosphorous fertilizer.[Conclusions]This study provides a scientific basis for the application of rice fertilizers and the reduction and efficiency improvement of chemical fertilizers in Jianghan Plain.

Gene expression pattern of K transporter GhHAK5 gene of potassium efficient and in-efficient cotton cultivars based on morphological physiognomies as affected by potassium nutrition and reduced irrigation

Background Under K deficiency the uptake and distribution pattern in plant cells is mediated through different transport proteins and channels which were controlled by specific gene family.Therefore,a hydroponic experiment was conducted under control condition for testing the gene expression pattern of the K transporter under adequate and low K supply levels.After that,a 2-year field experiment was conducted to evaluate five selected cotton cultivars(four K-efficient cultivars,viz.,CIM-554,CYTO-124,FH-142,IUB-2013,and one K non-efficient,BH-212) screened from the initial hydroponics culture experiment and two levels of potassium(0 K_(2)O kg·ha^(-1) and 50 K_(2)O kg·ha^(-1)) were tested under reduced irrigation(50% available water content;50 AWC) and normal irrigation conditions(100% available water content;100 AWC).Result Results revealed that the transcript levels of GhHAK5aD in roots were significantly higher in K^(+) efficient cultivars than that in K^(+) non-efficient cultivars.The GhHAK5aD expression upon K^(+) deficiency was higher in roots but lower in shoots,indicating that GhHAK5aD could have a role in K^(+) uptake in roots,instead of transport of K^(+) from root to shoot.Similarly,under field conditions the cultivar FH-142 showed an increase of 22.3%,4.9%,2.4%,and 1.4% as compared with BH-212,IUB-2013,CYTO-124,and CIM-554,respectively,in seed cotton yield(SCY) with K application under reduced irrigation conditions.With applied K,the FH-142 showed an increase in net photosynthetic rate by 57.3% as compared with the rest of the cultivars under reduced irrigation over K control.However,the overall performance indicators of K-efficient cultivars like FH-142,CYTO-124,CIM-554,and IUB-2013 were better than BH-212(K in-efficient) under reduced irrigation conditions with applied K at 50 kg·ha^(-1).Fiber quality trait improved significantly with K application under water deficit.The increase in micronaire was 3.6%,4.7%,7.8%,3.4%,and 6.7% in BH-212,IUB-2013,CIM-554,CYTO-124,and FH-142,respectively,with K application at 50 kg·ha^(-1) over without K application under reduced irrigation conditions during the cotton growing season.Similarly,the cultivars FH-142 increased by 12% with K application under reduced irrigation as compared with other cultivars.The performance of K-efficient cultivars under reduced irrigation conditions was 30% better in SCY and quality traits with the application of K at 50 kg·ha^(-1) as compared with K-non-efficient cultivars.Similarly,water use efficiency(WUE)(40.1%) and potassium use efficiency(KUE)(20.2%) were also noted higher in case of FH-142 as compared with other cultivar with K application under reduced conditions.Conclusion Higher expression of GhHAK5aD gene was observed in K-efficient cultivars as compared with K-nonefficient cultivars in roots indicates that GhHAK5aD may be contributing to genotypic differences for K^(+) efficiency in cotton.K-efficient cotton cultivars can be used for the low-K environments and can also be recommended for general cultivars.

Effects of Potassium Humate Fertilizers and Irrigation Rate on Potato Yield and Consumptive Use under Drip Irrigation Method

The current study was carried out at Agricultural College, University of Baghdad in the vegetable farm, Department of Horticulture during 2013 spring growing season. Yield response to irrigation of different crops is of major importance in production planning where water resources are limited. This study aims to determine the effect of different irrigation treatment （deficit irrigation） and potassium humate fertilizer on yield, content of nitrogen, potassium, and phosphor in tuber of potato and water use efficiency in the Abu-Graib Region, Iraq. Potato was grown under drip irrigation with three treatments： irrigation applied when evaporation 75%, 100% and 125% from pan A, and three potassium humate fertilizers： 0, 1.2 and 2.4 kg/ha with three times additions. The seasonal potato evapotranspiration ranged from 267 mm to 372 mm. The drip irrigation treatment had significant effecting tuber yield of potato recorder 29,530, 27,630 and 24,880 kg/ha for 125%, 100% and 75% from pan A evapotranspiration, respectively. Humus fertilizers addition has the lowest value of ETa 309 mm and maximum value of yield 2,930 kg/ha. Water use efficiency （WUE） and irrigation water use efficiency （IWUE） values increased with increasing humus fertilizers, recording 9.92, 14.52, 8.59, 12.42 and 7.51, 10.70 kg/m3 for potassium humate K3 （2.4 kg/ha）, K2 （1.2 kg/ha） and KI （0.0 kg/ha）, respectively. Plants irrigated with 125% from class pans A evaporation, produced a significant increase in N, P and K content in tubers recorder 0.96%, 0.58% and 1.52%, respectively. Potassium humus-fertilizer significant differences among K1, K2 and K3 on high of plants reached 41.52, 50.08 and 56.39 cm, respectively, number of stems/plant 2.69, 3.22 and 3.78, respectively, leaves area index recorder 2.80, 3.35 and 3.73.

Potassium accumulation and translocation a mongrice genotypes in relation to internal potassium use efficiency(IKUE)

Abiotie stresses including potassium deficiency are limitingfactors for increasing rice yield.Nine rice genotypes(Oryza Sativa L.,indica)differing in sensitivity to low Kstress selected from 200 volume-solution screening wereused in this study to examine accumulation and transloca-tion ofK.The powdery-muddy paddy soil tested contained 30.6mg·kgavailable K(1 N NHAcO extracted),1.92%

Study on the Nutrition Characteristics of Different K Use Efficiency Cotton Genotypes to K Deficiency Stress

To study the mechanism of plant K use efficiency, both K high and low use efficiency cotton genotypes, 103 and 122, respectively, were selected from 86 cotton cultivars （Gossypium hirsutum L.）. The research was conducted using pot experiment for planting cotton on without K （0.0 g kg-1 soil） and with K （0.4 g kg-1 soil） treatments in 2005. Experimental result showed that, with K deficiency stress, genotype 103 grew much better than genotype 122 except that its lower leaves showed the symptoms of K deficiency, whereas all the leaves of genotype 122 showed the symptoms of K deficiency. Root dry matter weights of treatments for genotype 103 with and without K application were 1.07 and 1.25 times of genotype 122. It indicated that the root system of genotype 103 was well developed and has better nutrition uptake capability than that of genotype 122. The result also showed that the cotton shoots of genotype 103 were 1.07 and 1.13 times over genotype 122 on treatments of with and without K application. It indicated that genotype 103 has stronger transport organs. In genotype 103, plants, dry matter, and potassium were mainly transported to cotton bolls. The boll dry weight of genotype 103 was 2.58 times in without K treatment and 1.90 times in with K treatment over genotype 122. The potassium accumulation in bolls of genotype 122 was only 49.3% of that in genotype 103. Potassium accumulation in the other organs of genotype 103 was relatively low compared with in bolls. This indicated that the distribution of K and organic matter in genotype 103 was more efficient than genotype 122. The main differences between high K efficiency cotton genotype 103 and low K efficiency genotype 122 lie in their potassium nutrition and organic matter using efficiency on uptake, transportation, accumulation, distribution, and utilization.

Sunflower response to potassium fertilization and nutrient requirement estimation

Field experiments were conducted in oil and edible sunflower to study the effects of potassium(K) fertilization on achene yield and quality, and to estimate the nutrient internal efficiency(IE) and nutrient requirement in sunflower production. All trials in edible sunflower and 75% trials in oil sunflower showed positive yield responses to K fertilization. Compared with control without K fertilization, the application of K increased achene yield by an average of 406 kg ha–1for oil sunflower and 294 kg ha–1for edible sunflower. K application also increased 1 000-achene weight and kernel rate of both oil and edible sunflower. K fertilization improved the contents of oil, oleic acid, linoleic acid and linolenic acid in achenes of oil sunflower, and increased contents of oil, total unsaturated fatty acid and protein in achenes of edible sunflower. The average agronomic efficiency of K fertilizer was 4.0 for oil sunflower and 3.0 kg achene kg–1K2O for edible sunflower. The average IE of N, P and K under balanced NPK fertilization was 22.9, 82.8, and 9.9 kg kg–1for oil sunflower, and 27.3, 138.9, and 14.3 kg kg–1for edible sunflower. These values were equivalent to 45.5, 14.1, and 108.1 kg, and 39.0, 8.0, and 71.7 kg of N, P and K, respectively, in above-ground dry matter required for production per ton of achenes. The average harvest index of N, P and K was 0.47, 0.56 and 0.05 kg kg–1in oil sunflower, and 0.58, 0.58 and 0.14 kg kg–1in edible sunflower.

Relation of Root Growth of Rice Seedling with Nutrition and Water Use Efficiency Under Different Water Supply Conditions

Water deficiency is one of the primary yield-limiting factors in rice. In plants, the nutrition and water use efficiency depend on root growth efficiency under different water supply conditions （WSC）. Three rice genotypes, Azucena （an upland japonica）, IR1552 （a lowland indica） and Jia 9522 （a lowland japonica）, were grown under different WSC with 0 cm （submerged）, 40 cm and 80 cm groundwater levels below the soil surface to investigate the root parameters, water use efficiency, nitrogen, phosphorous and potassium contents, net photosynthetic rate and transpiration rate of the rice plant. The relative parameters were defined as the ratio of the parameters under submerged conditions （0 cm groundwater level below soil surface） to these under upland conditions （40 cm and 80 cm groundwater levels below soil surface）. The results indicated that different genotypes showed different relative root parameters and relative nutrition content and water use efficiency under different WSC. The length and number of adventitious root are more important than seminal root length in water and nutrition uptake, and maintaining the grain yield and increasing dry matter, but the adventitious root number could not be served as an index for screening drought-resistant genotypes. Furthermore, different drought-resistant genotypes have been also found, and Azucena was resistant to drought, IR1552 sensitive to drought and Jia 9522 neither sensitive nor resistant to drought.

Optimizing Nutrient Use Efficiency and Returns from Soybean Production under Smallholders in Three Agro-Ecologies of Malawi

Field trials were conducted to determine the economically optimum fertilizer rates for soybean production and for optimizing net profits in Dedza, Lilongwe and Salima Districts of Malawi. The effects of PK fertilizer rates on rain use efficiency (RUE), harvest index, agronomic use efficiency of phosphorous (AEP) and potassium (AEK), and value cost ratio (VCR) were evaluated. The applied diagnostic PK fertilizer rates significantly improved soybean grain yields, harvest index, rainwater use efficiency, AEP, AEK and returns to fertilizer use expressed as value cost ratio (VCR). However, the results differed significantly

含铋剂四联一线治疗方案根除幽门螺杆菌疗效观察

目的:评价含铋剂四联方案(耐信+克拉霉素+阿莫西林+丽珠得乐)治疗消化性溃疡或慢性胃炎Hp感染患者的疗效,寻找高效、经济的一线Hp根除方案。方法:①136例消化性溃疡或慢性胃炎Hp感染初治患者,随机分为四联组(67例)和三联组(69例);四联组采用埃索美拉唑20 mg+克拉霉素缓释0.5 g+阿莫西林1.0 g+枸橼酸铋钾胶囊220 mg/d,三联组采用埃索美拉唑20 mg+克拉霉素缓释片0.5 g+阿莫西林1.0 g/d,7 d为1疗程。②采用14C-UBT检测Hp根除率。③按ITT和PP分析,计算成本-效果比(C/E)及增量成本-效果比(△C/△E)。结果:四联组Hp根除率为88.71%,三联组Hp根除率为73.02%,两组比较差异有统计学意义(P<0.05)。四联组和三联组成本-效果比分别为4.15和4.82,含铋剂四联相对于标准三联方案增量成本-效果比为1.02。结论:Hp根除率含铋剂四联方案较标准三联方案高,可推荐为经济、高效的一线治疗方案。

线粒体ATP敏感性钾通道开放剂改善大鼠心脏冷保存

目的:探讨线粒体ATP敏感性钾通道开放剂二氮嗪(DE)对离体大鼠心脏冷保存效果的影响及作用机制。方法:SD大鼠随机分成对照组、DE组、DE+5-HD组。利用Langendorff离体鼠心灌注法,各组心脏在4℃条件下分别保存3h和8h后,复灌60min,观察各组大鼠血流动力学的恢复情况、冠脉流出液中心肌酶漏出量、心肌水含量的变化及心肌超微结构改变。结果:在Celsior心麻痹液中添加30μmol/L的DE后,能明显改善冷保存3h心脏的左心室发展压力的恢复,降低心肌酶(LDH、CK)在某些复灌时间点上的漏出,但对保存后左心室舒张末期压力的抬高和冠脉流量的恢复及心肌水肿程度无明显作用;而相同浓度的DE添加到Celsior心麻痹液中,可明显降低冷保存8h心脏左心室舒张末期压力的抬高,改善左心室发展压力和冠脉流量的恢复,降低心肌酶(LDH、CK、GOT)的漏出,缓解心肌水肿,对心肌的超微结构也有较好的保护作用,其中30和45μmol/LDE组对冷保存8h心脏的保护作用优于15μmol/LDE组,而30及45μmol/LDE组之间并无显著性差异。DE的上述作用可被线粒体ATP敏感性钾通道的特异性阻断剂5-HD所取消。结论:DE可通过激活线粒体ATP敏感性钾通道显著改善离体大鼠心脏冷保存效果。

Cromakalim保护培养的心肌细胞耐受缺氧－复氧损伤

目的：探讨Ｋ＿（ＡＴＰ）通道开放剂Ｃｒｏｍａｋａｌｉｍ（ＣＲＫ）的直接细胞保护作用。方法：利用培养心肌细胞缺氧－复氧损伤模型观察ＣＲＫ的保护作用。结果：ＣＲＫ显著降低缺氧－复氧心肌细胞的ＬＤＨ漏出率及细胞内钙含量，而且呈浓度依赖性。上述作用可被选择Ｋ＿（ＡＴＰ）．通道阻滞剂Ｇｌｙｂｅｎｃｌａｍｉｄｅ（ＧＬＢ）所消除。结论：ＣＲＫ具有直接的心肌细胞保护作用，其机制表现为膜稳定作用及抑制细胞钙超载。

钾通道开放剂对抗原诱发大鼠肥大细胞释放组胺的抑制作用

本文报道钾通道开放剂米诺地尔（Min）、二氮嗪（Dia）和钙拮抗剂硝苯啶（Nif）对抗原诱发大鼠腹腔肥大细胞（PMC）释放组胺的影响。以卵清蛋白免疫大鼠并触发PMC释放组胺。给大鼠Min200mg／kg灌胃；用含有Dia的孵化液预处理；或用Nif125mg／kg灌胃后，触发剂诱发PMC的组胺释放率与对照组比较均有显著差异（P＜0.01）。结果提示，肥大细胞可能存在钾通道，钾通道开放剂可能具有治疗过敏性疾病的前景。

中药对维持血透的慢性肾衰患者血钾的影响

本文观察了应用中药治疗的15例维持血透慢性肾衰患者血钾的变化.结果是:血透前有7例患者并发高血钾症,经血透和中药治疗后,15例患者的血清钾均值都维持在正常血钾值范围,没有一例因服中药而引起高血钾症的发生。因而提出:应用中药治疗维持血透慢性肾衷惠者,只要在辨证基础上使用通畅大小便药物,注意饮食和某些药物,避免感染,一般是不会有引起高血钾症发生的观点。

(1–x)(K_(0.48)Na_(0.48)Li_(0.04))NbO_3–x(Na_(0.8)K_(0.2))_(0.5)Bi_(0.5)TiO_3无铅压电陶瓷的相变行为及其压电性能

采用固相法应法制备了(1–x)(K0.48Na0.48Li0.04)NbO3–x(Na0.8K0.2)0.5Bi0.5TiO3无铅压电陶瓷,研究了不同x(0,0.5%,1.0%,1.5%,2.0%,3.0%)对材料的相结构、介电性能以及压电性能的影响。结果表明:随着x增加,样品的Curie温度TC与正交到四方相变温度TO–T均逐渐降低,而压电常数d33与机电耦合系数kp均先升高后降低;该体系在0.5%<x<1.5%形成了典型的多晶型相变(polymorphic phase transition,PPT),当x=1.0%的样品不仅具有最佳的压电性能(d33=226 pC/N,kp=0.41),而且其Curie温度TC(437℃)保持在较高水平,在PPT附近样品的压电性能对温度非常敏感。