Daily macronutrient uptake patterns in relation to plant age in hydroponic lettuce

A greenhouse experiment was conducted to study and quantify the daily uptake rate of nitrate, ammonium, phosphoric acid, potassium, calcium, magnesium, and sulfate (NO₃^?, NH₄⁺, H₂PO₄^?, K⁺, Ca²⁺, Mg²⁺ and SO₄^2?) and to characterize the uptake daily pattern at different plant ages in a lettuce crop. The uptake rates per gram of plant fresh weight were calculated at 2-hour intervals through sampling the nutrient solution and analyzing it by NO₃^?/NH₄⁺ conductivity and inductively coupled plasma atomic emission spectrometry (ICP-AES). The uptake rate of nitrogen, phosphorus and potassium (N, P and K) per unit mass of plant decreased with plant age following a reduction in plant relative growth rate. No significant differences were found in the absorption of Ca, Mg and sulfur (S) between the different weeks of growth. The daily absorption patterns showed no preference for the absorption of any of the ions during the daytime. A significant reduction in the absorption peaks of all the ions with increasing plant age was observed.     

上海地区典型设施菜地的生菜适宜施氮量研究

在设施大棚种植条件下,采用田间小区试验方法研究了不同施氮处理对生菜产量、品质及氮素利用率的影响。结果表明,与农民习惯施氮量150 kg·hm-2相比,减少20%的氮素用量能保持生菜的产量和氮素利用率,维持蔬菜品质。施氮120 kg·hm-2能使大棚生菜产量增加至5 353 kg·hm-2,氮素利用率达17.8%,净收入达12 091元·hm-2。生菜的叶片数、株高、生物量以及可溶性糖含量也在施氮120 kg·hm-2时最高。生菜叶片中的硝酸盐的积累与施氮量呈明显的正相关性,减少施氮能有效抑制生菜叶片中硝酸盐的积累。综合产量效益和经济效益等因素,对上海地区土壤含氮量较高的大棚,推荐生菜适宜施氮量为120 kg·hm-2。     

宁夏引黄灌区春小麦不同生育期吸收氮、磷、钾养分的特点

选择宁夏引黄灌区中等肥力灌淤土,设置施肥与不施肥处理,在相距约5km的3个试验点进行了肥料田间试验,研究春小麦不同生育期氮、磷、钾养分的吸收特点。结果表明,在供试土壤条件下,施肥可明显提高小麦产量、干物质累积量、体内氮、磷、钾含量及其累积量。施肥或不施肥,小麦地上部干物质的累积量随生育期呈典型S型曲线增长,其中拔节期和灌浆期出现两个高峰期,各占总累积量的30%左右。植株氮、磷、钾含量随生育期呈曲线下降趋势,特别是从拔节到灌浆中期下降幅度较大;而在分蘖期以前和灌浆中期以后变化幅度较小。植株氮、磷、钾累积吸收量随生育期的延长和施肥水平的提高而增加,但各生育期相对累积吸收比例,施肥与否差异不大。苗期氮、磷、钾的吸收量约占总吸收量的4%～5%,分蘖期占20%～23%,拔节期分别占30%、41%、34%,抽穗期分别占14%、12%、10%,灌浆期分别占29%、20%、26%,成熟期占1%～3%,其中拔节期是养分吸收的高峰时期。不论施肥与否,地上部氮、磷、钾累积吸收量与其干物质累积量之间均呈极显著正相关,而与植株氮、磷、钾含量之间呈极显著负相关。     

营养元素N、P、K对Pb超富集植物吸收能力的影响

为了探索提高Pb(铅)超富集植物吸收能力的方法，该文通过温室土培方法，研究了单一营养元素N、P、K对Pb超富集植物羽叶鬼针草(Bidens maximowicziana)、绿叶苋菜(L.Amaranthus tricolor)和紫穗槐(Sophora japonica)3种植物Pb吸收的影响。营养元素的设计水平为N 0、0.06、0.12、0.18、0.24、0.30 g/kg，P₂O₅ 0、0.06、0.12、0.18、0.24、0.30 g/kg，K₂O 0.08、0.16、0.24、0.32、0.40 g/kg，其他2种元素恒定为0.12 g/kg，土壤铅浓度为800 mg/kg土。结果表明土壤中施入不同水平的营养元素显著影响植物Pb迁移总量。18个处理中羽叶鬼针草、绿叶苋菜与紫穗槐Pb迁移总量最大值与最小值的比值分别为：11.6、10.6、11.9。该试验表明通过调节土壤营养的方法可以提高植物的重金属的迁移总量，利用Pb超富集植物修复Pb污染土壤。3种营养元素对植物的效应不一致，少量的N和K可促进富集植物干质量的增加，促进植物对Pb的吸收，随着N和K水平的增加，植物对Pb的吸收能力降低，但K的抑制作用不如N的显著；土壤供P会降低植物对Pb的吸收，且下降极显著。     

不同氮磷钾配方施肥对紫叶莴笋产量及品质的影响

采用"3414"设计方案设置氮磷钾肥的田间试验,旨在研究不同氮磷钾组合对紫叶莴笋的产量与品质的影响。结果表明,合理施肥对紫叶莴笋具有显著增产效果,其中处理N_2K_2P_2增幅最大,增产量为10 401.3kg/hm~2,并且氮磷钾增产效应为钾氮磷;合理配方施肥处理能显著提高紫叶莴笋叶与茎中氨基酸、还原糖及Vc的含量,降低硝酸盐的含量,提高紫叶莴笋的品质;紫叶莴笋叶花青素含量的增加在一定范围内与施肥量成正比,其中花青素含量最高的为处理N_2P_1K_1,为41.28 mg/100 g,随着氮、磷的增加花青素含量呈现先增加后降低趋势。结合紫叶莴笋产量与品质的多个指标综合评价表明:效果最优的为处理N_2P_1K_2及N_1P_2K_2,氮、磷、钾施肥量分别为276.0、45.0、153.0 kg/hm~2与138.0、90.0、153.0 kg/hm~2。     

Nitrogen and water uptake patterns and growth of plants at various minimum solution nitrate concentrations

Increasing fertilizer and energy costs, as well as awareness of environmental quality, require greater fertilizer use efficiency. Providing plant nutrients in the quantity and at the time needed, possibly through fertigation, should lead to more efficient fertilizer use. Knowledge on crop nutrient requirements and minimum nutrient concentrations in the root zone at different stages of growth is important. Hydroponic greenhouse experiments were conducted using tomato and lettuce plants to determine minimum solution nitrogen concentrations which would allow maximum plant growth for a system of frequent nitrogen application and to quantitatively measure nitrogen uptake rates as a function of time. Minimum N levels for the tomato experiment were 2, 10, and 20 mg/1. Solutions were analyzed three times a week to determine N uptake and sufficient KNO₃ was added each time to supply the plant N demand so that the targeted minimum N concentration would be achieved at the next sampling time. The minimum N concentrations in the lettuce trial were 5, 10, 20 and 50 mg/1. A control consisting of 105 mg/1 N was used for both crops. There was no significant effect of N concentration on N uptake throughout the experiment for lettuce and during the early stages of tomato growth. Higher N uptake during the latter stages of tomato growth occurred for the control as compared to the other treatments. The latter observation was probably caused by N diffusion gradient development because of the dense root system and inadequate solution stirring. Plant growth results were comparable to N uptake results. The ratio of N to water uptake was fairly constant throughout the growth period with a trend toward decrease in the ratio with time for tomatoes. Low N concentrations can occur at the root surface without limiting plant growth.     

Assessment of mineral nutrient concentrations of lettuce in response to cultivar selection and fertilization in greenhouse production

Mineral nutrient contents in vegetable-based foods are a concern in human diets, and depleted soil fertility and high-yielding cultivars are associated with low nutrient contents. This study explored if mineral nutrient concentrations of lettuce (Lactuca sativa L.) can be increased though selection of cultivars and nutritional regimes in greenhouse production. Cultivars including butterhead, romaine, and loose-leaf phenotypes of heritage and modern origins were studied. Hoagland solution, a commercial inorganic fertilizer, and a commercial organic fertilizer were the nutrient regimes. Heritage cultivars had about 10% higher phosphorus, potassium, calcium, magnesium, and zinc (P, K, Ca, Mg, and Zn) concentrations than modern cultivars. Differences in elemental concentrations occurred among phenotypes and nutritional regimes but with no consistent trend among elements for phenotypes or regimes. Some cultivars had twice the concentrations of nutrients of other cultivars. This work suggests that cultivars can be selected for production of mineral nutrient-rich lettuce.     

Influence of ca concentration on growth,tissue concentration,and nutrient uptake of in vitro propagated plums and lovell seedlings

Seedlings of ‘Lovell’ peach [Prunus persica (L.) Batsch], and in vitro propagated plums, ‘St. Julien A GF 655–2’ [Prunus institia (L.) Bullace] (655–2), ‘Damas GF 1869’ [Prunus domestica (L.)] (D1869), and ‘Clark Hill Red Leaf’ [Prunus saliciana (Lindl) x Prunus cerasifera (EHRH)] (CH redleaf) were grown in the greenhouse 45 or 51 days in nutrient solutions containing 2, 6, 22, 200, and 400 μM Ca. Terminal length, number of laterals, trunk cross‐sectional area, and root volume were increased by the 22 μM Ca treatments at harvest 1. The CH redleaf and 655–2 plums had the largest increase in growth for harvest 1, but the ‘Lovell’ peach seedlings and D1869 plum had the largest increase in growth for harvest 2. There were no leaf symptoms of Ca deficiency when the leaf Ca concentration in the tissue exceeded 2500 μg/g (dry wt.) Calcium concentration was increased from 1406 to 4109 μg/g (dry wt.) in the stems, and from 540 to 2633 μg/g (dry wt) in the roots by Ca treatments of 400 μM after 45 days of growth. Calcium uptake rate for ‘Lovell’ seedlings was greater than were rates for CH redleaf and 655–2 plums at all solution concentrations during the first 45 days of growth. The Ca uptake rate for D1869 plum was greater than the rate for ‘Lovell’ seedlings during the second growth period. An interaction between Ca concentration and plant species occurred for P, K, and Mg uptake rates at both harvest dates. The in vitro propagated D1869 plum was equal to the ‘Lovell’ seedlings in growth, tissue Ca concentration, and Ca uptake rates.     

黑龙江大豆-玉米轮作体系氮磷调控的产量效应与养分平衡

为探究适宜于黑龙江垦区大豆-玉米轮作体系下最优的施肥模式,在黑龙江省九三管局鹤山农场科技园区进行田间定位试验,以大豆-玉米轮作体系作为研究对象,为保证一个轮作周期施肥总量不变,于大豆茬口实施减氮增磷方案,玉米茬口实施增氮减磷方案,来研究不同氮磷调控处理对大豆-玉米轮作体系作物生长、养分累积量、土壤收支平衡及经济效益的影...     

氮磷钾肥对紫云英产量及养分积累的影响

通过田间试验,研究了NPK肥对紫云英生长、产量及养分积累的影响.结果表明,NPK配施能促进紫云英生长,显著提高产量和养分积累量.NPK处理(施N 75 kg/hm2 、P2O5 60 kg/hm2和K2O 60 kg/hm2)的紫云英茎数、株高和每茎复叶数分别是不施肥处理的3.77、1.81和1.60倍,是施PK处理的2.19、1.23和1.16倍,是施NK处理的2.11、1.16和1.11倍,是施NP处理的1.44、1.19和1.16倍.NPK配施的鲜草产量分别比不施肥、PK配施、NK配施及NP配施处理增加26.47、14.22、7.18和10.74 t/hm2.不同施肥处理都能使紫云英的养分积累量显著提高,其中NPK配施处理的紫云英地上部N、P2O5、K2O和C的积累量最大,分别是不施肥处理的3.66、3.27、2.85和2.80倍.试验结果说明,合理施用N、P、K肥能明显促进紫云英的生长,提高产量和养分积累量,有利于提高紫云英种植效益.     

Effects of adding wood vinegar to nutrient solution on the growth,photosynthesis, and absorption of mineral elements of hydroponic lettuce

This study was conducted to determine whether using wood vinegar instead of nitric acid to adjust the pH of nutrient solution in hydroponics had any effects on the lettuce. Photosynthesis, mineral elements, water absorption, and the growth of the lettuce were all comparable to those of lettuce in the control group, in which nitric acid was used to adjust the pH. Nitric acid was added to half a unit of Enshi formula to adjust the pH of the control group. The rates of growth, water and mineral element absorption, and photosynthesis were low in lettuce plants grown in nutrient solution with 1 ml L^?1 wood vinegar. However, the lettuce grown in solutions with 0.25 ml L^?1 wood vinegar showed no significant differences from the control group. Therefore, wood vinegar concentration of 0.25 ml L^?1 was found to be sufficient to keep the pH of the nutrient solution within the optimum range for growth.     

灌水频率和施肥量对滴灌马铃薯生长、产量和养分吸收的影响

【目的】针对陕北榆林风沙土马铃薯灌水施肥不合理及水肥利用效率低的问题,通过研究滴灌施肥条件下不同的灌水频率和施肥量对马铃薯生长、产量及养分吸收利用的影响,以期科学地对马铃薯进行水肥调控,为实际生产提供参考依据。【方法】试验于2016年5—10月在陕西省榆林市农业科技示范园区内进行,试验设置了3个灌水频率D1 (4 d)、D2 (8 d)、D3 (10 d)和3个施肥量(N、P_2O_5、K_2O)水平,即F1 (100、40、150kg/hm^2)、F2 (150、60、225 kg/hm^2)、F3 (200、80、300 kg/hm^2)组合,共9个处理。在生育期对马铃薯生长指标进行观测,收获时统计产量及产量构成因素。【结果】1)同一灌水频率下,F3处理的株高、茎粗、叶面积和产量显著高于F1和F2处理,肥料偏生产力在F1处理下最高,而水分利用效率受施肥量的影响不显著,养分利用效率随着施肥量的增加而减小。F3处理的产量达41518 kg/hm^2,比F1和F2处理分别提高11.75%和8.52%,F1处理下肥料偏生产力为128.12 kg/kg,比F2和F3处理的高出45.67%和78.99%。2)在同一施肥量下,马铃薯的生长指标、产量和肥料偏生产力均在D2处理达到最大值,D2处理下的产量和肥料偏生产力分别为42932kg/hm^2和105.88 kg/kg,而D1处理下水肥利用效率最高,但D1和D2之间水分利用效率差异不显著。从水肥交互作用来看,D2F3的产量和水分利用效率最高,分别为44870 kg/hm^2,107.39 kg/(mm·hm^2),D2F1的肥料偏生产力最高,为142.02 kg/kg。【结论】合理的灌水频率与施肥量不仅能维持马铃薯较好的生长特性,而且能获得较大的经济效益。综合产量与节水节肥因素,D2F3处理(8 d,N 200 kg/hm^2、P_2O_5 80 kg/hm^2、K_2O 300kg/hm^2)可作为基于本试验条件下较适宜的灌水施肥组合。     

大气CO2浓度升高对黄花蒿生长和氮磷钾养分吸收的影响

Annual wormwood (Artemisia annua L.) is the only viable source of artemisinin, an antimalarial drug. There is a pressing need to optimize production per cultivated area of this important medicinal plant; however, the effect of increasing atmospheric carbon dioxide (CO₂) concentration on its growth is still unclear. Therefore, a pot experiment was conducted in a free-air CO₂ enrichment (FACE) facility in Yangzhou City, China. Two A. annua varieties, one wild and one cultivated, were grown under ambient (374 μmol mol^-1) and elevated (577 μmol mol^-1) CO₂ levels to determine the dry matter accumulation and macronutrient uptake of aerial parts. The results showed that stem and leaf yields of both A. annua varieties increased significantly under elevated CO₂ due to the enhanced photosynthesis rate. Although nitrogen (N), phosphorus (P), and potassium (K) concentrations in leaves and stems of both varieties decreased under elevated CO₂, total shoot N, P, and K uptake of the two varieties were enhanced and the ratios among the concentrations of these nutrients (N:P, N:K, and P:K) were not affected by elevated CO₂. Overall, our results provided the evidence that elevated CO₂ increased biomass and shoot macronutrient uptake of two A. annua varieties.     

Effects of vermicomposts obtained from rose oil processing wastes,dairy manure,municipal open market wastes and straw on plant growth,mineral nutrition,and nutrient uptake of corn

Study aims to investigate the effects of vermicomposts containing oil processing wastes, dairy manure, municipal open market wastes and straw on the growth, nutrient concentrations and nutrient uptakes of corn plant. For this, there different mixtures were prepared. Vermicomposts were applied with the rates of 0, 5000, 10000, and 20000 kg ha^?1 to 2 kg soil containing pots. Study was conducted in growth chamber for 2 months. Vermicompost applications increased plant growth, some plant nutrient concentrations and uptake. Also, vermicomposts showed the variation on parameters depending on their mixtures. Results showed that nutrients taken by the plant increased with the vermicompost until 10000 kg ha^?1 dose. Most of the nutrient concentrations such as phosphorus, potassium, calcium, magnesium, iron, and manganese (P, K, Ca, Mg, Fe, and Mn) were not increased in plant tissues, whereas uptake of them by the plant showed a significant increase. In addition, residual soil nutrients increased with the increase in vermicompost levels.     

磷对不同基因型玉米生长及氮磷钾吸收的影响

采用田间试验法,在高磷和低磷土壤上分别设置施磷和不施磷处理,研究磷对9个玉米基因型生物量、产量、氮磷钾养分吸收量的影响及其各基因型间的异同,为磷肥合理施用提供科学依据。结果表明,在高磷土壤上,不施磷对各玉米基因型的生物量、产量、产量构成因素和多数玉米基因型的氮磷钾吸收量影响不大;在低磷土壤上,不施磷降低各玉米基因型的生物量、穗粒数、产量及氮磷钾吸收量。两个磷水平下,均以蠡玉16的生物量和产量最大,冀单28最小,这与前者具有较多的养分吸收量有关。不同玉米基因型间有明显差异,在玉米生产中应该因地制宜合理施用磷肥。     

K和Al对水稻生长和养分吸收的影响

The effects of K and Al in K-deficient and complete nutrient solutions on the growth and nutrient uptake of rice were studied in the work.The effect of Al on the growth of roots and above-ground part of rice was associated with the concentration of Al in solution .A low level(0.1 mmol L^-1) of Al promtoed but a high level(1 mmol L^-1)of Al inhibited the growth of both the root and the aerial part of rice,and the magnitude of K concentration in the nutrient solution also had an appreciable impact on this,Thus ,in the low-Al solution,the plant treated with K2(80 mg K L^-1)produced much longer roots,showing the presence of interaction between Al and K; in the high-Al solution the K-reated plant had more and longe roots and a considerably greater dry weigh of the above-ground part compared with the plant deficient in K, showing the alleviating effect of K^ on Al toxicity.The mechanism of the Al-K interaction affecting the rice aerial part growth is not yet known,but part of the reason might be that the excessive amount of Al inhibited the uptake of some nutrients such as Ca and Mg and reduced their transfer to the plant aerial organs,whereas K showed its compensating effect on this;therefore,K could relieve Al toxicity at a high level of Al and promoted rice growth at a low level of Al.     

Growth and nutrient uptake of peach seedlings with varying magnesium concentrations at low pH 1

Soils of the peach growing region of the Southeastern Coastal Plain are highly leached and excessively acid, with inherently low concentrations of subsoil magnesium (Mg). A greenhouse experiment was conducted to determine the effects of varying Mg concentrations at low pH on growth and Mg uptake of three peach seedling cultivars commonly used as rootstock in the region. Seedlings of ‘Lovell’, ‘Elberta’, [Prunus persica (L.) Batsch] and ‘Nemaguard’ [Prunus persica (L.) Batsch X Prunus davidiana Carriere] were grown for 36 days in nutrient solution containing 9, 21, 42, 84, 167, 333, and 667 μM Mg. Magnesium concentration in solution did not increase lateral length, number of laterals, trunk cross‐sectional area, or root volume. All terminal growth responses were cultivar related. Magnesium concentration in the leaves, stems, and roots were increased either by quadratic or cubic relationship with solution Mg concentration while Mg uptake rate was increased linearly with solution Mg concentration with all three seedling cultivar. Uptake rates of calcium, manganese, and zinc, and tissue concentrations of phosphorus, manganese, and zinc decreased with increasing Mg concentrations in nutrient solution. Predicted Mg uptake rates by‐regression analysis revealed a cubic uptake isotherm for Nemaguard and a quadratic isotherm for Elberta. Predicted tissue Mg concentration followed similar patterns of accumulation for leaves and stems, but root Mg concentration followed a cubic uptake isotherm for all three seedlings. The linear Mg uptake at low pH may be an important physiological characteristic that enables Lovell seedlings to outperform either Elberta or Nemaguard when used as a rootstock in the southeastern soils.     

根区氮钾水平对杂交和常规水稻品种光合作用及根系生长的影响

Root box experiments were conducted to evaluate the effects of N and NK levels in the root zone on shoot photosynthesis and root growth of hybrid an cultivar of rice (Oryza sativa L.) on two paddy soils (clayey and silty).The results showed that dry matter yields in the hybrid and the cultivar were considerably increased by NK supply,bu the effect was greater for the hybrid.Supply of NK in the root zone significantly increased photosynthetic rate of the lower position leaf and the active green leaf area per plant,in which the effects were much more obvious in the hybrid rice than in the cultivar.High NK supply in the root zone stimulated the root growth,and decreased pH and increased the oxidation zone in the rhizosphere in both entries,but to a greater extent in the hybrid .The results indicated that higher NK levels were needed to maintain higher root activity and shoot photosynthetic capacity in rice,particularly in hybrid rice.     

Effect on plant growth and nutrient uptake of a saturated gypsum solution given to a soil rich in CA

Abstract

Barley plants were grown in 201 pots containing a sandy soil rich in exchangeable and watersoluble Ca. Results from earlier experiments have indicated that the mode of action of supplementary Ca may differ according to, for example, the associate anion. In this experiment soil‐Ca was activated by placing NH₄NO₃ at three depths in the soil and by adding solutions of Ca salts. Yields were found to increase with successively deeper placements of NH₄NO₃ in treatments without Ca application, whereas only small differences between placement depths were observed when Ca was added as a saturated gypsum solution or equivalent amounts of CaCl₂. The very pronounced responses to Ca application were in good agreement with visual symptoms of Ca deficiencies later in the season and with the nutrient uptake rates and growth rate over the intire growth period.     

Effect of type of compost and application rate on growth and quality of lettuce plant

Abstract

This study intends to assess the effect of compost types and rates on lettuce growth. A pot experiment was conducted at the greenhouse of the College of Agriculture and Veterinary Medicine experimental station, Saudi Arabia. Three types (chicken residues, animal residues, and mixed organic residues) and four rates (1%, 2%, 4%, and 6%) were added to sandy soil. Lettuce seeds were sown in a nursery. After two weeks, each seedling was transplanted to a pot that contained 15?kg of soil. The lettuce plants were irrigated regularly for 60?days, then harvested following dry weight (DW) and chemical analyses. The results showed great variation in the DW, nutrient content, and heavy metals concentrations between the different compost treatments. It noted that DW of lettuce decreased with increasing rates of compost in certain treatments. Moreover, no plant growth occurred in some treatments derived from the mixed organic residue with higher application rates. The nutrient status of lettuce tissues varies greatly among different types of compost. The concentration of heavy metals and microelements present within the lettuce tissues was significantly affected by the types of compost. Copper (Cu), Zinc (Zn), Lead (Pb), Cadmium (Cd), and Nickel (Ni) concentrations in lettuce tissues ranged between 7.4 and 9.6, 81.5 and 104, 23.3 and 28.2, 3.7 and 5.8, and 27 and 30?mg kg^?1, respectively. It revealed that heavy metals concentration increased in lettuce tissues with an increasing application rate of composts. The content of Zn, Pb, Cd, and Ni in lettuce plants were higher and did not meet the requirement set by national standards.