两种钾肥不同用量对商薯19生长和产量的影响

以甘薯品种"商薯19"为试验材料,研究了两种钾肥(硫酸钾、氯化钾)不同用量对甘薯生长和产量的影响。结果表明,甘薯施用两种钾肥均能提高单株块根鲜重,对甘薯干物率无明显影响。施用钾肥有利于提高甘薯商品薯率,显著提高商品薯及鲜薯产量。试验条件下,硫酸钾和氯化钾均在施钾(K_2O)135 kg/hm~2时,商品薯和鲜薯产量达到最高,最高商品薯产量分别为31 690.8和30 363.4 kg/hm~2;最高鲜薯产量分别为33 439.7和32 740.4 kg/hm~2。在施钾量(K_2O)为90~135 kg/hm~2范围内,钾肥品种对产量无明显影响。     

盐化潮土中硫酸钾对玉米产量及氮钾交互作用的影响

通过田间试验探讨了轻度盐渍化潮土中施用硫酸钾对夏玉米干物质产量及氮钾养分吸收和再利用的影响。在速效钾含量较高的供试土壤中，施钾对高产夏玉米具有明显的增产效果和促进植物对氮钾的吸收，但明显降低了生长后期植物体中钾和氮的再循环率。     

有机钾肥和钾硅钙矿物肥对烤烟生长及烟叶产量质量的影响

为了探讨有机钾肥和矿物钾肥在河南省烤烟上的施用效果,采用大田试验,研究了施用有机钾肥、钾硅钙矿物肥替代15%硫酸钾对烤烟生长及烟叶产量、质量的影响。结果表明,施用有机钾肥、钾硅钙矿物肥替代15%硫酸钾处理比全部施用硫酸钾处理显著提高了圆顶期叶片SPAD值,起到了延缓叶片衰老,保证叶片有足够成熟时间的作用;与全部施用硫酸钾处理相比,用有机钾肥、粒状钾硅钙矿物肥、粉状钾硅钙矿物肥替代15%硫酸钾的3个处理,烟叶产量分别提高16.4%、21.1%和13.0%,产值分别增加5 037.3、10 975.0和3 306.6元/hm2。施用有机钾肥、粉状和粒状钾硅钙矿物肥的3个处理间相比,烟叶产量差异不显著,烟叶产值以施用粒状钾硅钙矿物肥替代15%硫酸钾处理最高,上、中、下部烟叶钾含量显著提高,下部叶和中部叶钾氯比达3.5以上。     

Differential potassium buffer behavior of individual soils related to potassium corrective treatments

Abstract

Although the basic chemistry and behavior of potassium in the soil is well understood, little of this knowledge is used in soil testing and practical soil fertility mangement. In this study the K buffer behavior of three individual soils (Hagerstown silt loam (Typic Hapludalf), Gatesburg sand (Entic Haplorthod) and Gilpin channery silt loam (Typic Hapludult)) was investigated. The buffer relationships determined indicated very different K behavior for these soils even though exchangeable K soil tests indicated similar K levels. It was also determined that for these soils the buffer relationship was apparently independent of previous K management, indicating that the K buffer behavior could be included as part of soil characterization data.

The role of nonexchangeable K in determining K buffer behavior was also investigated. It was found that the levels of solution K where the release of nonexchangeable K becomes measurable (0.27 ‐ 0.83 × 10^‐4 M) are similar to solution K levels reportedly required for crop growth (0.02 ‐ 0.95 × 10^‐4 M). It was also found that these soils were capable of maintaining a relatively high level of exchangeable K even after extraction of significant amounts of nonexchangeable K with sodium tetraphenyl boron.

It was concluded that K buffering behavior of individual soils could and should be included in K management decisions involving corrective soil treatments and/or crop removal estimation. Otherwise, based on current soil tests, soils with very different K buffer behavior will be treated similarly.     

Potential potassium buffer capacity of Kamchatka volcanic soils

The volcanic soils of Kamchatka are characterized by low and very low values of their potential potassium buffer capacity. The largest amount of readily exchangeable potassium (-ΔK ₀) is observed in the surface layers of the natural soils and is due to the active biogenic accumulation. The soddy horizons have a high content of strongly fixed potassium (K _X ). The main factors determining the content of the labile potassium and its mobility are the contents of physical clay, humus, and exchangeable potassium. The extremely nonuniform distribution of all the potassium status parameters throughout the soil profile reflects the discrete character of the volcanic pedogenesis. The low values of the potential buffer capacity for the potassium (PBC^K) at the high values of the equilibrium potassium potential (AR ₀) and the medium content of the labile potassium in the light-textured synlithogenic soils simultaneously indicate both the good potassium supply of the plants and the incapability of the soils to resist potassium exhaustion under agricultural production conditions for a long time.     

Effect of increasing potassium levels for alleviating sodium chloride stress on the growth and yield of tomato

Abstract

The efficacy of using various levels of potassium (K) (4, 8, and 16 mM) under saline conditions to alleviate the detrimental effects of salt‐stress were studied using five tomato (Lycopersicon esculentum Mill) cultivars, ‘Strain 19’, ‘Pearson’, ‘Montecarlo’, ‘Maruthuam’, and ‘Pusa Rub’. Results of the study revealed that 50 mM sodium chloride (NaCl) in a Hoagland nutrient solution significantly reduced stem height, fruit weight, and whole plant dry weights, but increased number of fruits/plant and improved fruit quality by increasing total soluble solids. It did not significantly affect leaf count, percent fruit set, or dry weight. The addition of 4, 8 and 16 mM potassium nitrate (KNO₃) to the nutrient solution containing 50 mM NaCl resulted in sodium/potassium (Na/K) ratios of 12.5, 6.3, and 3.1, respectively. The Na/K ratios of 12.5 and 6.3 produced significant improvement in stem height, percent fruit set, number of fruits/plant, fruit weight, and whole plant dry weight. The Na/K ratio of 3.1 was found to be detrimental as it resulted in sharp reduction of plant dry weight compared to the control. Percent total soluble solids was not significantly affected by the addition of any level of K to the saline nutrient solution. The performance of the tomatoplant grown under saline conditions supplemented with K in the nutrient solution indicated a higher response at the lowest K concentration used in this study.     

双季稻秸秆还田下减施钾肥对水稻生长和产量的影响

探明秸秆还田和减施钾肥对水稻生长和产量的影响,为双季稻稻作区秸秆还田和钾肥的合理运用提供理论依据,2018 ～ 2019 年在江西进行了2 年试验,早稻和晚稻均按不同施钾量设6 个处理。秸秆还田结合减施钾肥,对植株的生长性状影响不明显;减施钾肥,水稻穗数、粒数略有下降,在生产上减少10% 到30% 的施钾量,对水稻实际产量无明显影响。减施钾肥在一定程度上减少秸秆和籽粒中全氮、全钾的含量,而对全磷含量影响不大,植株的吸钾量有所减少,但钾素稻谷生产效率和农学钾素利用效率有增加的趋势。     

Effect of nitrogen and potassium fertilizer on growth,yield and chemical composition of sweet fennel

Abstract

In this study, the effect of different levels of nitrogen (N) and potassium (K) fertilizers on vegetative fresh bulb yield, quality and biochemical attributes of sweet fennel were investigated in spring 2017 and 2018. Treatments consisted of 0, 50, 100, or 150?kg ha^?1 of N and K in a randomized complete block design with three replications. Results showed that, the bulb fresh yield increased with application of N and K in both years, while the higher level of K had significant adverse effect in first year. Results also showed that sweet fennel bulb treated by N and K exhibited higher vitamin C, total phenols and flavonoid contents, and antioxidant capacity, especially in first year. In both years, alone or combined application of N and K increased total soluble solids (TSS) content as compared to control, and this effect was more pronounced in 2017 season. Macronutrient contents of bulb including magnesium (Mg), phosphorus (P), K, N, and calcium (Ca) were significantly enhanced by NK fertilizer, however an alone application of K decreased Ca and Mg nutrient contents. Therefore, to improve fresh bulb yield, quality and antioxidant capacity in sweet fennel, 150?kg ha^?1 K and 100?kg ha^?1 N is recommended.     

Effects of potassium supply on growth and yield of safflower as compared to sunflower§

Safflower may have a certain production potential under German conditions, particularly in organic farming where the putatively low nutrient requirement is highly welcomed. However, current knowledge regarding the nutrient requirements of safflower as compared to similar oil crops is limited. It was thus the aim of this study to determine the growth and yield response of safflower (Carthamus tinctorius L.) as compared to sunflower (Helianthus annuus L.) with respect to potassium (K) supply. Three safflower and two sunflower plants were cultivated in 5 L Mitscherlich pots. Both species responded strongly to increasing K supply with respect to plant growth and yield. Growth and yield of safflower increased up to 1 g K per pot, while the optimum for sunflower was 3.0 g K per pot. Safflower out‐yielded sunflower at low K supply, while at high K level, the opposite was observed. Supply of K affected virtually all yield components in both species, though to different degree. The number of capitula in safflower was only slightly affected, and the number of achenes per capitulum was only reduced under severe K deficiency, while single‐achene mass increased with increasing K supply. In sunflower, the number of achenes per capitulum strongly responded to the K supply, as did the single‐achene mass. Oil yield in safflower was affected by K deficiency mainly due to reduced achene yield, not oil concentration. However, oil yield in sunflower was severely affected by low K supply due to both reduced achene yield and lowered oil concentration. Multiple‐regression analyses indicate that in sunflower, the stem dry matter (DM) and the total amount of K accumulated in the aboveground biomass were most important, while in safflower the total amount of K and N accumulated had the highest impact. It is concluded that sunflower is more sensitive to inadequate K supply than safflower.     

钾素水平对二年生三七全生育期光合特性及产量的影响

选取二年生三七[Panax notoginseng(Burk.)F.H.Chen]作试验材料,通过田间试验研究了不同钾水平(K_2O 0、337.5、450、675、1 012.5 kg/hm~2)对三七不同生长时期叶绿素Chl(a+b)含量、光合特性及收获期块茎产量的影响。结果表明,施钾处理均显著增加了三七叶片Chl(a+b)含量,提高了净光合速率(Pn)、气孔导度(Gs)、蒸腾速率(Tr),降低了胞间CO_2浓度(Ci),增加了光合产物的生产和积累,提高了三七块茎产量。不同钾用量条件下,三七块茎产量以K3处理(675 kg/hm~2)最高,较K0处理增产17.17%。不同钾用量条件下,三七叶片光合参数对钾肥的响应存在显著差异,在同一生长时期,随着钾素水平的提高,三七叶片Chl(a+b)含量、Pn、Gs、Tr均表现为先升高后降低趋势,Ci先降低后升高。全生育期三七叶片Chl(a+b)含量,Pn、Gs和Tr均与三七块茎产量呈显著正相关,Ci与三七块茎产量呈显著负相关。本试验条件下,施钾量为K_2O 675 kg/hm~2的K3处理时三七块茎的经济产量最高。     

不同钾水平对温室番茄生长、产量和品质的影响

采用营养液砂培试验技术,研究开花期一次施用不同钾水平营养液处理对番茄生长、产量和品质的影响.结果表明:在番茄植株拉秧时,高浓度钾水平T1 (K+:9 mmol/L)和T2(K+:12 mmol/L)茎粗显著大于对照(K+:6 mmol/L),分别比对照增加10.03％和9.08％;在处理后第8d,T2比T1和对照的净光合速率分别增加4.58％和12.96％,且差异显著;T1单株产量最高,比对照增加4.65％;T1和T2果实Vc的含量较对照分别显著增加15.25％和14.46％,T2显著降低了果实中硝酸盐含量,T1显著增加了果实中可溶性固形物含量,T1和T2糖酸比分别比对照高9.67％和10.70％.     

杨梅的需钾特性及施钾对杨梅的增产效应

钾对杨梅产量和品质的影响仅次于微量元素硼。杨梅对N：P2O5：K2O的需要比例分别为1：0．5：2．69。浙江省杨梅主产区土壤（0-20cm）的全钾和速效钾含量分别为1．81-2．41g／kg和83-121mg/kg。施钾能显著提高杨梅产量和改善果实品质。株产50kg果实的杨梅树以施用1．0～1．5kg氯化钾并配施50g硼砂的效果较好，杨梅进行叶面施钾时以喷施0．5％KCl或0．5％磷酸二氢钾的效果较佳。     

施钾时期对甘薯产量及钾肥利用率的影响

为了明确不同时期施用钾肥对甘薯块根产量及钾肥利用率的影响,以济徐23为材料,进行大田试验。研究钾肥施用时期对甘薯块根干物质积累特性、干物质分配、钾肥利用率的影响。结果表明,不同时期施用钾肥均可提高块根产量,基施增产幅度最大,为26.09%,封垄期追施次之,高峰期追施最小。与对照处理相比,施用钾肥提高了块根膨大速率,基施和封垄期追施处理块根膨大前期增幅较大,而高峰期追施钾肥块根膨大后期增幅略高;基施处理显著降低全时期甘薯茎叶鲜重与块根鲜重的比值(T/R值),而封垄期追施处理显著降低生长中后期T/R值;施肥处理均可提高收获期块根干物质分配率,基施钾肥处理达到显著水平。基施钾肥处理钾肥产块根效率、钾肥收获指数、钾肥农学利用率和钾肥偏生产力显著高于其他施钾处理。基施钾肥通过提高钾肥农学利用率、偏生产力和钾肥收获指数,降低T/R值,促进块根膨大,最终获得高产。     

根区施用钾肥对烤烟产量、钾含量及钾素吸收的影响

为了探讨根区施用钾肥对黄淮烟区石灰土烤烟产量和钾素吸收利用的影响,采用田间试验,研究根区枸溶性钾肥与硫酸钾配施对烟叶产量、钾含量以及钾素吸收利用的影响。试验共设9个处理,分别为CK、CP_1、CP_2、WP_1、WP_2、CW_(1-50%)、CW_(2-50%)、CW_(1-75%)与CW_(2-75%)(CK表示对照,CP表示只施用枸溶性钾肥,WP表示只施用硫酸钾,CW表示枸溶性钾肥与硫酸钾配施;数字1、2表示施用量分别为225、300 kg/hm~2,百分数表示硫酸钾的配施比例)。结果表明,烟叶钾含量随生育期推进呈下降趋势,不同施肥处理各时期烟叶钾含量均高于CK;不同施肥处理下土壤钾素在垂直和水平方向上迁移距离较小,根区钾肥施用可直接有效的增加根区土壤速效钾含量;施钾(K_2O)300 kg/hm~2与225 kg/hm~2相比,可显著提高烟叶钾含量和钾肥利用效率(P0.05);CW_(2-75%)处理下烟叶钾含量、土壤速效钾含量和钾肥利用率最高,而CW_(2-50%)处理下烟叶产量最高。综上所述,根区施用含75%硫酸钾的枸溶性钾肥300 kg/hm~2(CW_(2-75%)处理)可有效改善黄淮烟区石灰土钾素养分,提高该区烤烟产量、钾含量与钾肥利用效率,达到优质高产。     

氮磷钾化肥与有机肥不同配比对油菜生长及产量、品质的影响

运用田间小区试验探讨了氮磷钾化肥与有机肥不同配比对油菜生长及产量、品质的影响,以期为油菜大田生产科学、适量施肥提供依据。研究结果表明,在本试验条件下,施N 180 kg/hm2、P2O5108 kg/hm2、K2O144 kg/hm2、谷壳粉1 800 kg/hm2时,油菜的经济性状和产量表现最佳。     

灌淤土区长期施钾对作物产量与养分及土壤钾素的长期效应研究

通过在宁夏灌淤土区长达14年的连续施钾和小麦秸秆还田试验, 研究钾素投入对作物产量、养分和土壤钾素状况的影响.结果表明:小麦秸秆还田和长期施用钾肥均可不同程度提高小麦和玉米的经济产量, 其中施钾年平均增产小麦244 kg·hm-2, 玉米397 kg·hm-2, 处理之间产量表现为氮磷钾肥配合秸秆还田>施用氮磷钾肥>氮磷肥配合秸秆还田>只施用氮磷肥.定位后8～10年施钾肥开始显著有效, 玉米显效时间早于小麦;秸秆还田和钾肥的投入均可提高籽粒和秸秆的钾素吸收量, 秸秆含钾丰富, 籽粒钾含量仅占植株钾总量的13%～17%;施用钾肥可提高作物籽粒大中微量元素含量而降低秸秆中、微量元素含量, 促进籽粒对大部分元素的吸收;长期不施钾肥处理(NP和NP+St)0～20 cm土层土壤速效钾和缓效钾含量较定位开始时下降; 所有处理土壤全钾含量均表现下降, 下降幅度为0.8～1.2 g·kg-1.     

The importance of biochar quality and pyrolysis yield for soil carbon sequestration in practice

Biochar is a carbon (C)-rich material produced from biomass by anoxic or oxygen-limited thermal treatment known as pyrolysis. Despite substantial gaseous losses of C during pyrolysis, incorporating biochar in soil has been suggested as an effective long-term option to sequester CO₂ for climate change mitigation, due to the intrinsic stability of biochar C. However, no universally applicable approach that combines biochar quality and pyrolysis yield into an overall metric of C sequestration efficiency has been suggested yet. To ensure safe environmental use of biochar in agricultural soils, the International Biochar Initiative and the European Biochar Certificate have developed guidelines on biochar quality. In both guidelines, the hydrogen-to-organic C (H/C_org) ratio is an important quality criterion widely used as a proxy of biochar stability, which has been recognized also in the new EU regulation 2021/2088. Here, we evaluate the biochar C sequestration efficiency from published data that comply with the biochar quality criteria in the above guidelines, which may regulate future large-scale field application in practice. The sequestration efficiency is calculated from the fraction of biochar C remaining in soil after 100 years (F_perm) and the C-yield of various feedstocks pyrolyzed at different temperatures. Both parameters are expressed as a function of H/C_org. Combining these two metrics is relevant for assessing the mitigation potential of the biochar economy. We find that the C sequestration efficiency for stable biochar is in the range of 25%–50% of feedstock C. It depends on the type of feedstock and is in general a non-linear function of H/C_org. We suggest that for plant-based feedstock, biochar production that achieves H/C_org of 0.38–0.44, corresponding to pyrolysis temperatures of 500–550°C, is the most efficient in terms of soil carbon sequestration. Such biochars reveal an average sequestration efficiency of 41.4% (±4.5%) over 100 years.     

水钾耦合对花生生理性状及产量的影响

为明确不同水钾耦合对花生生理性状及生殖生长的影响,以‘花育25’为试验材料,采用水分[土壤含水量为35%(水分胁迫,W1)、50%(轻度水分胁迫,W2)、65%(水分适中,W3)、80%(水分过量,W4)田间持水量]和钾肥[0 g(K2O)·kg~(-1)(土)(缺钾,K0)、0.15 g(K2O)·kg~(-1)(土)(低钾,K1)、0.30 g(K2O)·kg~(-1)(土)(中钾,K2)、0.45 g(K2O)·kg~(-1)(土)(高钾,K3)]2因素4水平随机区组设计,通过遮雨棚盆栽试验探讨不同水钾耦合下花生叶片保护酶活性在结荚期后期的差异,以及生殖生长的差异,为干旱半干旱地区花生的高效水肥管理技术提供一定的理论依据。结果表明,水分对花生叶片相对含水量和叶绿素含量的影响极显著,叶片含水量对叶绿素有明显的稀释作用,随灌水量的增加叶片相对含水量(RWC)和叶绿素含量呈现出相反的变化趋势,两者为极显著负相关。水分和钾肥对超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性均存在显著或极显著的正交互效应。3种酶对不同的逆境响应不同,SOD活性在缺钾(K0)或高钾(K3)条件下升高明显,POD酶在水分胁迫(W1)或K3时升高极显著,CAT酶在W1或K0时升高显著。随土壤含水量的升高,叶片CAT活性迅速下降,且与叶绿素含量呈极显著正相关,说明CAT在花生结荚期后期可减缓叶绿素降解,延长叶片功能期。钾肥和灌水对单株开花总量的影响分别达显著和极显著水平,施钾肥能显著推迟始花时间,而减少灌水量能提前终花时间。在中钾(K2)时各水分处理有效花量和有效花率均处于较高水平。在水分适中(W3)时,钾肥对单粒仁重有促进作用,水分轻度胁迫(W2)也有利于单粒仁重的增加。单株荚果数显著增加和双仁果率提高是水分效应增产的重要原因。以中水中钾W3K2处理花期最短(25 d)、有效花率最大,达51.0%,籽仁产量最高。     

冬油菜施钾的增产效果和肥料利用率研究

通过总结2004/2005~2006/2007年3个年度在长江流域冬油菜主产区10个省(市)的72个田间试验数据,以产量、增产率、偏生产力、农学效率、生理利用率及表观利用率等指标分析了长江流域施钾增产效果及钾肥利用率,以期为油菜进一步增产提供依据。分析结果表明,长江流域冬油菜施钾效果显著,与对照不施钾处理相比,施用钾肥油菜籽平均增产量为349 kg·hm-2,平均增产率为19.8%,其中增产率小于5%的试验数占总数的20.8%,另外,油菜籽增产率随着土壤速效钾含量的升高而明显下降;施钾处理油菜地上部钾素积累量比不施钾处理显著增加38.1%;钾肥的平均偏生产力、农学效率、生理利用率和表观利用率分别为21.1、2.9、8.5 kg·kg-1和46.7%。综合结果表明,在施用氮、磷及硼肥基础上增施钾肥能够明显提高油菜地上部的生物量及钾素的累积,从而增加油菜籽产量,且根据基础地力及油菜对钾的需求规律而合理施肥极为重要。     

Effect of top-dressed potassium fertilization on the yield and quality of cucumber

The current study aimed to evaluate the effect of top-dressed potassium (K) application on the production of hybrid cucumber “Sapphire.” The experimental design was a randomized complete block, with five blocks of 0.80 × 0.40 m² each and eight replicate plants per block. The five fertilization rates of K used were 0, 45, 90, 135, and 180 kg K₂O ha^?1. Data collection consisted of the estimation of fruit diameter, fruits length, fruit fresh and dry weights, the number of fruits per plant, and the weight of fruits per plant. The number of fruits per hectare and the fruit fresh weight per hectare were calculated. Fruit tissue was analyzed for determination of macronutrient concentrations, pH, titratable acidity, soluble solids, sugar contents, and protein content. The data were statistically analyzed using regression analysis and analysis of variance (ANOVA). There was a significant effect of the fertilization rate of K on fruit diameter, fruit fresh and dry weights, macronutrients concentrations in fruits, titratable acidity, soluble solids, and reducing sugars. A quadratic equation was adjusted for the number of fruits per plant and per hectare; fruit yield per plant and per hectare, with maximum top-dressing doses, was estimated to be between 60 and 95 kg K₂O ha^?1. A linear increase was obtained in the pH. An increase in the K fertilization rate caused a linear decrease in the fruit length.