苹果树体钾含量与钾累积量的年周期变化

以“富士”苹果树为试材，对树体生物量及不同器官钾含量和钾累积量的变化规律进行了研究。结果表明，03—26～09—21，果树地上部和整株的生物量逐渐增加，果实成熟期（09—21）之后趋于平稳；03—26～07—30，根系生物量几乎没有变化，07—30以后快速增加。果树新生器官（果实、叶片和新梢）中钾含量均表现为物候期前期较高，中后期较低；成龄器官（枝、干、根系）中钾含量基本呈降低的趋势，但变化幅度较小。03—26～04—30，果树主要利用贮藏的钾素建造器官；04-30～09-21，果树生长所需的钾素主要依靠根系从土壤中吸收，且钾素分配随生长中心的变化而转移。03—26～07—30，整株钾累积量逐渐增加，于07—30达最大，之后降低；年周期内根系钾累积量变化较小。不同时期各器官中钾累积量差异较大。07—30～09—21，果实中钾累积量增加幅度最大，建议果实膨大前适当增施钾肥以提高苹果产量。

施钾方法对土壤供钾能力及烤烟钾累积的影响

为探明钾肥施用方法、土壤供钾能力和对钾的吸收之间的内在关系 ,为烤烟生产合理分配和施用钾肥提供依据 ,以湖南烟区主要植烟土壤——石灰岩母质发育的红壤性水稻土为供试土壤 ,采用盆栽土培方法 ,研究了施钾方法对土壤供钾能力及烤烟钾累积的影响 .结果表明 :烟苗移栽后 30 d施用总施钾量的 40 % ,能够使土壤对生长发育中后期的烤烟维持较高的供钾能力 ,土壤速效钾和缓效钾含量比钾肥一次性作基肥施用的处理分别提高了5 7.4%～ 6 0 .9%和 5 .7%～ 6 .2 % ,同时可促进烤烟对钾的吸收与累积 ,使烟株的总吸钾量提高 5 .0 %和 15 .5 % ,烟叶的含钾量提高了 4.6 %和 12 .2 % .

富士苹果T337自根砧和中间砧幼树生长和钾累积研究

以T337自根砧和山定子/T337中间砧富士苹果幼树为试材,在年生长周期内主要物候期进行整株解析,分别测定主干粗度、树高、根长、根尖数等树体形态指标,并将整树解析为根木质部、根韧皮部、侧根、砧木木质部、砧木韧皮部、主干木质部、主干韧皮部、叶片和新梢等9部分,分别测定各部位不同时期的生物量和钾含量。结果表明,T337中间砧富士苹果幼树生长势明显强于T337自根砧。不同砧木类型影响富士苹果幼树钾的吸收运输,对树体不同部位钾的累积分配影响较小。2种砧木类型富士苹果幼树不同时期钾累积增长量均较高,建议定植前施足钾肥。

供钾水平对烟苗生长及钾累积的影响

通过水培法研究了不同供钾水平对烟苗生长和钾累积的影响。结果表明,与对照相比,在一定范围内钾供应水平的提升能显著改善烟苗的生长状况。供钾水平在0～10.00 mg/L范围内,烟苗的干重、钾累积量都随着供钾水平的增加呈先增加后降低的趋势,烟苗的干重、钾累积量在供钾水平为4.00 mg/L时达到最大。说明在一定范围内,增加营养液中的钾含量有利于烟苗干物质及钾的累积,供钾超过一定的水平则会起抑制作用。

小麦灌浆期籽粒累积钾特性研究

以小麦品种Soissons为试验材料,探讨灌浆期钾在籽粒中的累积特性以及籽粒与旗叶叶片、旗叶叶鞘、节、节间、穗轴和颖壳钾含量的相关性。结果显示,随着灌浆时间延长,籽粒钾含量逐渐降低。在灌浆16 d时,籽粒钾累积速率达到最高,钾总量接近最大值。叶片、叶鞘、节间、穗轴和颖壳钾含量呈现先升高后下降趋势。相关分析显示,籽粒钾含量与叶鞘、节、节间和穗轴的钾含量呈负相关,与旗叶和颖壳钾含量呈正相关。表明小麦籽粒钾主要来自根系吸收和转运,并非旗叶钾的再利用。

丛枝菌根真菌对烟草钾素吸收的研究

在盆栽条件下研究了接种AM真菌Glomus Dlosseae对烤烟K素吸收的影响.结果表明,施钾量与AM真菌对烤烟K累积量与分配有明显的影响,对烤烟不同时期生长、不同叶位含钾量影响显著(P<0.01).菌根菌与施钾量二者组合对烤烟烟叶含钾量的提高作用在生长中、后期最为显著.接种AM真菌对烤烟整株烟叶含钾量的影响,主要是提高了上、中、下位叶的含钾量,进而提高了整株烟叶的含钾量;接种AM真菌提高了钾在叶中的分配比例,降低了K在茎中的分配比例.比较而言,在0.75～1.125 g·kg-1施钾(K2O)水平,AM真菌对烤烟K的累积与分配及含钾量的作用效果最佳.

不同供钾水平下转AtCIPK23基因烟草钾吸收特征的研究

采用砂培和水培的方法,以导入AtCIPK23基因的K326品种、未转化的K326以及常规品种NC89三个基因型烟草为材料,研究了转AtCIPK23基因烟草品系的干物质和钾积累特征,以及根系生理特性差异。结果表明,在低供钾水平下,转AtCIPK23基因烟草的干物质积累以及各器官钾含量高于未转化的K326和NC89,并且具有较强的根系活力。钾吸收动力学研究结果表明,转AtCIPK23基因烟草的米氏常数(KM)和最低浓度(Cmin)低于未转化的K326和NC89,而不同基因型烟草间最大吸收效率(Vmax)无明显差异。

不同光强下单叶蔓荆的光合蒸腾与离子累积的关系

同步分析了生长在滨海滩涂沙地的灌木单叶蔓荆钠和钾离子的累积量与植物的水分累积消耗量与光合产物累积量的日变化特点和累积的关系,并比较了单叶蔓荆在晴天和阴天的木质部溶液离子浓度与植物水势的关系和水分利用效率的差别,结果表明:单叶蔓荆在光强度较高的晴天的水分利用效率高于阴天,在晴天的光合产物累积达到了阴天的约4倍,却只消耗了约为阴天3倍的水。随着植物体水势的降低,单叶蔓荆木质部溶液的钠离子的浓度和钾离子浓度呈降低趋势但不明显。木质部溶液的钾离子浓度和钾离子累积量无论在晴天和阴天都明显低于钠离子的浓度和累积量。单叶蔓荆的高浓度的钠离子吸收有可能在液泡累积并降低细胞的渗透势,增加细胞的吸水能力和植物的抗旱抗盐能力。

耕作方式和钾肥用量对旱作马铃薯产量及水肥利用率的影响

2019年,在宁夏南部旱作马铃薯种植区,通过田间试验研究了传统耕作与粉垄耕作下不同钾肥用量(0、45、90、135、180 kg/hm^(2))对马铃薯干物质累积、产量及水肥利用率的影响。结果表明:与传统耕作相比,粉垄耕作马铃薯的干物质累积量明显提高,干物质最大累积速率和平均累积速率分别提高了33.3%和31.0%,施钾90kg/hm^(2)的马铃薯干物质累积总量显著高于其他施钾处理的;相同的施钾量处理,粉垄耕作显著提高了马铃薯单株薯质量、单薯质量、商品薯率,显著降低小薯率,产量提高了23.3%,其中,施钾90 kg/hm^(2)的马铃薯产量最高,达45122.5 kg/hm^(2);2种耕作方式下均以施钾90 kg/hm^(2)时钾肥利用率最高,分别达46.0%、55.0%;相同的施钾量处理,粉垄耕作显著提高了马铃薯的水分利用效率,比传统耕作的提高了29.7%~39.8%。可见,粉垄耕作结合适宜钾肥用量可显著促进马铃薯生长,提高马铃薯产量和水肥利用效率。

深圳福田红树林无瓣海桑+海桑群落N、P、K累积和循环

研究了深圳福田红树林无瓣海桑 +海桑群落的 N、P、K元素的累积和循环。结果表明 ,该群落 N、P、K元素的现存累积量分别为 :3 8694.92、 5 848.62、 5 0 861 .47mg/m2 ,其中地下部分分别占 2 8.5 9%、41 .77%、 42 .0 8%。该群落氮、磷、钾元素生物循环中 ,年吸收量分别为 :1 3 2 40 .0 95、 1 887.70 5、 2 0 73 6.1 1mg/m2 ;年归还量分别为 :62 70 .5 85、 979.1 75、 63 5 3 .948mg/m2 ;年存留量分别为 :6969.5 1、 90 8.5 3、 1 43 82 .1 62 mg/m2 ;周转期分别为 :7a、6a、9a。群落各组分的氮含量最高 ,磷含量最低。

酸性土壤中丛枝菌根真菌菌剂多样性对玉米产量及其磷钾吸收的影响

【目的】明确酸性土壤中丛枝菌根真菌(arbuscular mycorrhizae fungi,AMF)菌剂多样性在玉米籽粒产量和磷、钾养分吸收方面的作用,能够为农田微生物肥料配施、养分利用率提高等方面提供理论依据。【方法】2019和2020年玉米生育期,选用4种不同种丛枝菌根真菌类型(摩西斗管囊霉Funneliformis mosseae,A;扭形球囊霉Glomus tortuosum,B;地表球囊霉Glomus versiforme,C;地斗管囊霉Funneliformis geosporum,D),设置不接菌处理(CK),接种单一AMF菌剂、2种AMF混合菌剂、3种AMF混合菌剂和4种AMF混合菌剂共16个处理,研究玉米籽粒产量、植株各器官生物量及其磷、钾累积量对不同菌剂类型以及菌剂多样性的响应。【结果】与对照相比,两个试验年度所有接菌处理均能增加玉米籽粒产量及其磷、钾累积量,其中接种A、B、C、D 4种单一菌剂处理的玉米籽粒产量均值分别增加57.9%,26.9%,40.5%和32.9%;磷累积量增加77.8%,48.2%,26.2%和75.8%;钾累积量增加85.5%,62.1%,59.0%和63.5%。随AMF菌剂多样性增加,两个试验年度玉米籽粒产量呈增加趋势,表现为4种混合菌剂>3种混合菌剂>2种混合菌剂>单一菌剂,其中4种混合菌剂处理籽粒产量比单一菌剂处理均值高12.3%;籽粒磷累积量表现为2种混合菌剂>4种混合菌剂>3种混合菌剂>单一菌剂,其中2种混合菌剂处理籽粒磷累积量比单一菌剂高23.2%;但AMF菌剂多样性处理之间玉米籽粒钾累积量差异不显著。【结论】在酸性土壤条件下玉米接种不同类型丛枝菌根真菌均能显著增加籽粒产量及其磷、钾累积量,其中Funneliformis mosseae改善玉米籽粒产量及其磷钾累积量的作用最佳。丛枝菌根真菌菌剂多样性增加能显著提高玉米籽粒产量和磷累积量,其中4种混合菌剂处理的增产效果较好,而2种混合菌剂处理的养分吸收积累量较高。生产上应根据高产优质不同目的,选择接种合适的丛枝菌根真菌类型并进行菌剂之间合理的搭配。

Effects of Application Modes of Potassium Fertilizer on Sorghum Grain Yield and Dry Matter Accumulation

[Objective] This study was conducted to investigate the effects of application modes of potassium fertilizer on sorghum grain yield and dry matter accumulation. [Method] Sorghum hybrids Jiza 305 and Jiza 87 were used as materials, and four treatments were designed （Ko： applying potassium at 0 kg/hm^2, K1： applying potassium as base fertilizer at 120 kg/hm^2, K2： applying potassium as base fertilizer at 90 kg/hm^2 and as additional fertilizer at 30 kg/hm^2, and K3： applying potassium as base fertilizer at 60 kg/hm^2 and as additional fertilizer at 60 kg/hm^2） to investigate the effects of application modes of potassium fertilizer on dry matter accumulation and grain yield, so as to determine the best application mode of potassium fertilizer. [Result] The results showed that after the application of potassium, the leaf area, dry matter accumulation, grain starch content, yield and economic coefficient of sorghum plants were improved. The leaf area values of the two sorghum cultivars showed the order of K0〈K1〈K2〈K3. The economic coefficients were in order of K0〈 K3〈K2〈K1. The amounts of dry matter accumulation, grain starch contents and grain yields showed the order of K0〈K3〈K1〈K2. For Jiza 305, the grain yields of K1, K2 and K3 were higher than that of Ko by 9.3%, 15.6% and 9.3%, respectively. As to Jiza 87, the grain yields of K1, K2 and K3 were higher than that of K0 by 8.1%, 12.5% and 8.1%, respectively. [Conclusion] Comprehensively, the best application method was 90 kg of potassium as base fertilizer and 30 kg of potassium as additional fertilizer per hectare.

Effects of Amino Acids Replacing Nitrate on Growth,Nitrate Accumulation,and Macroelement Concentrations in Pak-choi (Brassica chinensis L.)

A hydroponic experiment was carried out to determine the influence of replacing 20% of nitrate-N in nutrient solutions with 20 individual amino acids on growth, nitrate accumulation, and concentrations of nitrogen （N）, phosphorus （P）, and potassium （K） in pak-choi （Brassica chinensis L.） shoots. When 20% of nitrate-N was replaced with arginine （Arg） compared to the full nitrate treatment, pak-choi shoot fresh and dry weights increased significantly （P ≤ 0.05）, but when 20% of nitrate-N was replaced with alanine （Ala）, valine （Val）, leucine （Leu）, isoleucine （Ile）, proline （Pro）, phenylalanine （Phe）, methionine （Met）, aspartic acid （Asp）, glutamic acid （Glu）, lysine （Lys）, glycine （Gly）, serine （Ser）, threonine （Thr）, cysteine （Cys）, and tyrosine （Tyr）, shoot fresh and dry weights decreased significantly （P ≤ 0.05）. After replacing 20% of nitrate-N with asparagine （Asn） and glutamine （Gin）, shoot fresh and dry weights were unaffected. Compared to the full nitrate treatment, amino acid replacement treatments, except for Cys, Gly, histidine （His）, and Arg, significantly reduced （P ≤0.05） nitrate concentrations in plant shoots. Except for Cys, Leu, Pro, and Met, total N concentrations in plant tissues of the other amino acid treatments significantly increased （P ≤ 0.05）. Amino acids also affected total P and K concentrations, but the effects differed depending on individual amino acids. To improve pak-choi shoot quality, Gln and Asn, due to their insignificant effects on pak-choi growth, their significant reduction in nitrate concentrations, and their increase in macroelement content in plants, may be used to partially replace nitrate-N.

Determination of Nutrient Uptake Characteristic of Black Pepper （Piper nigrum L.）

The relationship between the growth and nutrient uptake by perennial crop such as pepper is poorly understood and improved understanding of such relationship is important for the establishment of rational crop management practices. In order to characterize the growth performance and quantify the nutrient removed, this study presents results of three consecutive cropping years, fertilized with 1, 2 and 3 ton ha1 of NPK fertilizer respectively. Plant biomass accumulated was evaluated every two months, separating plant into stems, branches, leaves, berries, fruit spikes and flowers. Total biomass of pepper increased linearly and reach maximum at 22 months after planting. Thereafter, a decrease in dry matter was observed due to fruit export and fallen leaves at harvest. However, at the 28 months of planting, the biomass of pepper vine showing some increasing trend indicating the vegetative growth was reassumed for the next flowering. At 30 months, the pepper had removed 293.08 kg of nitrogen, 46.41 kg of phosphorus, 264.95 kg of potassium, 35.4 kg of magnesium and 74.82 kg of calcium. Based on data obtained, the nutrient uptake rates were lower than nutrient applied suggested that fertilizer had been overused for pepper production. In light of these results obtained, the optimum fertilizer dosage would be 62-10-62-6-18 kg/ha, 237-22-246-22-65 kg/ha and 390-62-352-47-100 kg/ha of N-P-K-Mg-Ca for the year 1, year 2 and year 3 of cropping year.

Influence of Long-Term Fertilization on Selenium Accumulation in Soil and Uptake by Crops

Continuous applications of organic and inorganic fertilizers can affect soil and food quality with respect to selenium （Se） concen- trations. A long-term （over 20 years） experimental field study, started in 1989, was conducted to investigate the changes in soil Se fractions and its uptake by crops, as affected by different fertilizer practices, in the North China Plain with an annual crop rotation of winter wheat and summer maize. The long-term experiment was arranged in a complete randomized block design consisting of 4 replications with 7 fertilizer treatments： 1） organic compost （OC）, 2） half organic compost plus half N-P-K chemical fertilizers （OC ＋ NPK）, 3） N-P-K fertilizers （NPK）, 4） N-P fertilizers （NP）, 5） P-K fertilizers （PK）, 6） N-K fertilizers （NK）, and 7） an un-amended control. Soil samples from the surface （20 cm） were collected in 1989, 1994, 1999, 2004 and 2009 to characterize Se and other soil properties. In 2009, the average soil Se concentrations in the treatments （149 ± 8 beg kg-1） were higher than those in the soil samples collected in 1989 at the beginning of the experiment （112 4- 4 beg kg-1）, and decreased in the order of OC 〉 OC ＋ NPK 〉 NPK NP 〉 PK NK 〉 control. Sequential extraction showed the oxidizable fraction （50.06%± 3.94%） was the dominant form of Se in the soil, followed by the residual fraction （24.12% ± 2.89%）, exchangeable fraction （15.09% ± 4.34%） and Fe-Mn oxides fraction （10.73%±4.04%）. With an increase of soil K, the exchangeable Se concentrations in the soil increased. The Se concentrations in the soil tillage layer （0-20 cm） were mainly related to soil organic carbon （SOC）, although different contributions came from atmospheric deposition, irrigation and fertilizers. With the accumulation of SOC, the uptakes of soil Se by two crops were inhibited. For the OC and OC ＋ NPK treatments, Se concentrations in wheat grains were lower than the critical standard of Se in stable food （100 μg kg·1]. Additionallv. Se concentrations in grains were also decreased by the deficiencies of major soil nutrients, especially P.