指数施肥对美国山核桃幼苗生长及叶片养分含量的影响

为探究施肥对美国山核桃幼苗生长和叶片养分状况的影响,以美国山核桃1年生实生苗为试验材料,共设置0 (CK)、100、200、400、600、800 mg/株6个不同的施氮处理,运用指数施肥法研究了6种氮素施肥处理下美国山核桃生长和叶片养分含量的变化。结果表明:美国山核桃幼苗的苗高、地径、生物量随着施氮量的增加均呈现出先增加后减小的趋势,分别在N600处理(600 mg/株)达到最大值,分别为33. 4 cm、5. 08 mm和9. 33 g/株。运用临界浓度法确定出美国山核桃幼苗叶片氮、磷、钾含量的临界值分别为22. 58、1. 89和12. 71 g/kg,最适含量范围分别为22. 58～32. 73、1. 89～3. 15和12. 72～22. 05 g/kg。综合3种养分的最适含量范围,推断出美国山核桃幼苗的最适施氮量为600 mg/株。     

施氮水平对不同干旱程度夏玉米生长的影响

在田间小区遮雨条件下,采用有交互作用的双因素试验方法,设置了连续干旱0～32 d等7个水分处理及N 0、140、280 kg/hm2 等3个氮肥处理,研究施氮水平对不同干旱程度夏玉米生长的影响。结果表明,轻度干旱条件下,随着施氮量的增加,夏玉米的株高、叶长、叶宽、茎粗等形态指标,生物量和产量都增加;中度干旱时,适量施用氮肥,夏玉米的形态指标、生物量及产量均高于不施氮肥和大量施用氮肥;严重干旱时,随着施氮量的增加,夏玉米的形态指标、生物量和产量都呈逐渐下降趋势。本试验结果说明,施氮水平对不同干旱程度夏玉米生长有不同影响,应根据干旱程度选择合理的施氮量,以减小干旱带来的损失。     

Effect of seaweed sap as foliar spray on growth and yield of hybrid maize

Seaweeds are important marine renewable resources. Use of seaweeds as fertilizers has allowed for substitution in place of conventional synthetic fertilizers. This study was conducted to examine the effect of seaweed liquid extract (SLE) on growth, yield, and nutrient uptake by hybrid maize. The experiments were conducted in ZARS, Vishweshwaraiah Canal farm, Mandya (Karnataka, India) during the rabi season of 2011–2013 to study the effect of foliar applications of Kappaphycus alvarezii (K sap) and Gracilaria edulis (G sap) sap on growth and yield response of hybrid maize “NAH 1137”. Three foliar sprays of both saps were applied at the rate of 2.5, 5.0, 7.5, 10, and 15.0% (v/v) along with water spray as a control at different stages of the crop. It was found that grain yield increased significantly by 18.54% and 26.04% for plants receiving 10% concentrations of both K. alvarezii and G. edulis sap respectively, over control. The increase in yield was attributed to increase in the number of rows in cob, cob length, and 100 grain weight. This investigation concludes that application of both the saps at 10% increased the nutrient uptake, grain, and stover yield over control.     

Influence of foliar application of manganese on growth,pigment content,and nitrate reductase activity of Vigna radiata (L.) R. Wilczek under salinity

The effect of the micronutrient manganese (Mn) on the physiological performance of green gram [Vigna radiata (L.) R. Wilczek] under saline condition was studied in the present work. Green gram was grown under controlled conditions and treated with different concentrations of sodium chloride (NaCl): 100, 200, and 300 mM. The plant samples were analyzed from 25 to 65 days of plant growth at every 10-day interval. Significant difference was observed in leaf area index, membrane stability index, nitrate reductase enzyme activity, total chlorophyll, and carotenoid content in treated plants. A drastic reduction was recorded at 200 and 300 mM NaCl treated plants in the parameters. The concentration 100 mM resulted in a slight increase of the parameters. Foliar application of Mn as manganese chloride (MnCl₂) was found to improve the physiological parameters in green gram at 200 and 300 mM salinity level and was useful in alleviating the detrimental effects of NaCl.     

Effect of foliar bio-fertilization on growth and biochemical parameters of olive trees at flowering

Growth and biochemical parameters of leaves, flower buds and flowers of olive (Olea europaea L. cv. Chemlali) treated by foliar biofertilization (T0: untreated trees; T1: rich in nitrogen (N), phosphorus (P), potassium (K); T2: rich in calcium (Ca); T3: application of T1 and T2) were analyzed during the flowering stage. The results showed that T1 resulted in higher contents of leaf N, K, and Na. T1 and T3 resulted in an increase of pigment concentration in leaves. All foliar treatments affected negatively the contents of total polyphenols and orthodiphenols in leaves and flower buds. Lower amounts of individual phenolic compounds were detected in the leaves under all foliar bio-fertilizations and in flower buds of olive trees sprayed with T2 and T3. This decrease is explained by the lower enzymatic activity of l-phenylalanine ammonia-lyase. In flowers, T1 exhibits the highest levels of total polyphenols, o-diphenols, and individual phenolic compounds compared to T0.     

土壤干旱条件下锰肥对夏玉米光合特性的影响

在盆栽条件下进行了土壤干旱时夏玉米施用微量元素锰的试验。通过测定拔节期玉米叶片气孔导度(Cs)、细胞间隙CO2浓度(Ci)、蒸腾速率(Tr)、光合速率(Pn)和水分利用效率(WUR)等指标,探讨了干旱胁迫下外源锰对夏玉米光合特性的影响。结果表明,施用锰肥能降低光合作用的气孔限制和非气孔限制,显著提高夏玉米光合能力。锰肥对夏玉米光合作用的影响在土壤干旱时尤为显著。土壤干旱情况下,锰肥可使玉米叶片Cs增加58.11%,Pn和WUR分别增加42.07%和50.00%,从而减轻了土壤干旱对玉米光合作用的抑制。     

Effects of exogenously applied salicylic acid on the induction of multiple stress tolerance and mineral nutrition in maize (Zea mays L.)

Abstract

It has been proposed that salicylic acid (SA) acts as an endogenous signal molecule responsible for inducing environmental stress tolerance in plants. In this study, the effects of seed soaked (1.0 mM for 24 h) and soil incorporated (0.1 mM and 0.5 mM) salicylic acid (SA) supply on growth and mineral concentrations of maize (Zea mays L., Hamidiye F₁) grown under either salt, boron toxicity or drought-stressed conditions were investigated. Exogenously applied SA either with seed soaked (SS) or soil incorporated (SI) increased plant growth significantly in all the stresses conditions. Salicylic acid inhibited Na and Cl accumulation in saline conditions, and 0.5 mM of soil incorporated SA decreased B significantly in boron toxicity treatment. Except in drought condition, SA treatments stimulated N accumulation in plants. And P, K, Mg and Mn concentrations of SA received plants were increased in the stress conditions. These results suggest that SA regulates the response of plants to the environmental stresses and could be used as a plant growth regulator to improve plant growth and stimulate mineral nutrient concentrations under stress conditions.     

Leaf morphology explains the disparity between annual bluegrass and creeping bentgrass growth under foliar fertilization

On golf courses planted to creeping bentgrass, invasion of annual bluegrass is a constant concern. To analyze if nitrogen fertilization manipulation could bias growth to creeping bentgrass, both grasses were fertilized either through foliar or soil application with either urea or ammonium sulfate and the impact on shoot and root growth measured. Ammonium sulfate resulted in greater overall growth for both species. Foliar application resulted in greater shoot growth for annual bluegrass and soil application resulted in greater root growth for creeping bentgrass. Leaf samples, as well as multiple leaf samples collected from golf courses, were examined microscopically for potential routes for foliar nutrient uptake: stomata and aqueous pores. No statistical difference was observed in the stomatal number between the two species but annual bluegrass possessed more aqueous pores. The enhanced ability of annual bluegrass to benefit from foliar fertilization may aid in its encroachment on highly managed golf greens.     

一次性根区穴施尿素提高夏玉米产量和养分吸收利用效率

为了明确氮肥一次施用对作物产量和肥料利用率的影响,探寻夏玉米全生育期一次性施氮技术,该文通过2a(2015-2016)在安徽省太和县砂姜黑土和东至县红黄壤的田间试验,研究了农民习惯分次施氮(SSB)、一次性根区穴施尿素(RZF)和一次性条施尿素(BDP)对夏玉米产量、氮磷钾养分吸收和利用的影响。结果表明,各处理玉米产量的顺序为RZFSSB≈BDPCK,RZF比SSB和BDP分别显著增产8.8%和9.8%。RZF的氮磷钾素积累均为各处理最高,氮肥表观利用率为50.1%~58.9%,比SSB和BDP分别提高8.3和12.4个百分点,并且氮肥农学利用率和偏生产力均最高。RZF的磷肥表观利用率为17.5%,比SSB和BDP分别显著提高18.1%和27.2%。同一施氮水平下,太和点的产量、生物量和氮素积累量比东至点分别高31.5%、25.2%和46.3%。一次性根区穴施尿素提高了氮肥在耕层土壤的集中度,降低了氮素释放速度,达到缓控释肥的效果,能够显著增加玉米产量、提高氮肥利用率。可见,一次根区施肥能够替代当前习惯的分次施肥,实现作物高产稳产,对于化学氮肥减量施用、提高肥料利用率具有很大的潜力和空间,值得进一步研发施肥机械和推广应用。     

Effect of exogenous proline application on maize yield and the optimum rate of mineral nitrogen under salinity stress

Abstract

Salinity is a negative abiotic stress that produces drastic disorders on soils and plants causing a critical reduction in plant growth and yield parameters, particularly maize plant, which considers a moderately sensitive plant to soil and water salinity. Although proline and nitrogen are well known to protect plants and improve their tolerance against various abiotic stresses including salinity, the interaction between proline and nitrogen fertilizer under saline conditions remained unclear. Two field experiments were conducted, on a clay saline soil in a split-plot design with four replicates. The main plots were arranged to study the effect of exogenous of proline applications at 0, 50 and 100?mM during seedling and vegetative stages, and mineral of nitrogen fertilization rates were 0, 140, 280, and 420?kg N ha^?1 occupied the subplots. A significant response to fertilizer N was observed at 420?kg ha^?1, while the optimum N rate of 50?mM of proline was 410.3?kg ha^?1 and the economic optimum dose was 403.43?kg ha^?1. Therefore, we recommend using 403.43?kg N ha^?1 to get an optimum economic yield of maize, especially in saline soil, when used 50?mM exogenous of proline at seedling and vegetative stages.     

变量施肥对玉米产量及土壤养分影响的试验

采用自主开发设计的基于GPS和GIS技术的自动变量施肥系统,于2003、2004年间进行了玉米种植条件下变量施肥田间试验。与相邻传统施肥地块相比,变量施肥在一定程度上增加了玉米产量,在合理控制化肥用量的情况下,可以达到既减少投入又增加产量的目的。土壤养分分析结果表明：两年试验前后,变量区与传统施肥区土壤中的碱解氮含量均有所增长,但变量区碱解氮含量的变异系数较传统区减少;变量区和传统施肥区速效磷的含量都有所下降,且变量区较传统区下降明显,变异系数减少;速效钾含量均增加,增加幅度基本一致,但变量区变异系数下降。说明变量施肥具有一定均衡土壤养分的作用。     

Effects of silicon on the growth of maize seedlings under normal,aluminum, and salinity stress conditions

The effects of silicon on seed germination and growth parameters of maize seedlings under normal, aluminum (Al), and sodium chloride (NaCl) stress conditions were investigated. The results indicated a dose-dependent relationship between silicon and growth parameters, except for germination attributes.Application of silicon (2 mM) accelerated amylase activity, decreased abscisic acid content, and increased indoleacetic acid and gibberellic acid contents of seedling, The results suggest that the beneficial effects of silicon, at least in part, are mediated by the balance of phytohormones. Exposure to Al (10 mM) significantly decreased all growth parameters of maize seedlings. Application of 2 mM silicon, however, alleviated Al stress and restored almost all growth attributes. Decrease of Al absorption, increase of fructan content, and improvement of amylase activity were considered as the mechanisms of ameliorative function of silicon in Al-stressed maize seedlings. Exposure to silicon, however, did not show beneficial effects on growth parameters of maize seedlings under salt stress conditions.     

Effect of phosphorus,nitrogen fertilization and foliar applied manganese on yield and nutrient concentration of soybean

Abstract

A greenhouse experiment was conducted on clay loam soil of pH 7.8 to evaluate the effect of P, N fertilization and foliar applied Mn on yield and nutrient concentration in leaves and seeds of soybean. A significant yield increase was obtained for each added increment of P fertilizer up to 30 kg P₂O₅/acre. At application rates of 0, 15, 30 & 45 kg P₂O₅/acre, the seed yield was subsequently 27.8, 65.8, 82.8 & 83.6% of the maximum yield obtained at the maximum calculated P level. The yield increase accounted 14.2 and 10.2% for N and Mn applications. In all treatments, in which P was combined with N, the seed yield was relatively higher than with P or N applied alone.

Phosphorus, N and Mn content in leaves and seeds were positively correlated with the applied nutrient fertilizers. At any given level of applied P and Mn, P content was significantly higher in +N than ‐N treatments. By Mn application, P content in leaves and seeds was decreased. Phosphorus and Mn applications did not influence N content in leaves and seeds.     

施肥对菜园土壤养分淋溶流失浓度的影响

利用盆栽种植空心菜和菜心并收集测定土壤渗漏水氮磷钾养分浓度,研究了不同施肥水平对土壤氮磷钾淋溶流失浓度的影响。试验表明,在较大施肥量或化肥当季损失量范围内,土壤渗漏水硝态氮、总磷和钾浓度与氮、磷、钾施肥量或损失量之间呈非线性关系,但在中低施肥量时则表现为线性关系。化肥当季损失量与土壤渗漏水养分浓度呈显著水平的线性正相关,由此提出“双速率转折点”概念用以评价土壤养分流失潜力。当施肥量或化肥当季损失量超过双速率转折点X0后,土壤淋溶排水养分浓度将以非线性形式急剧增加。因此,从环保角度看,施肥量不应超过X0。盆栽试验表明,以化肥当季损失量为基础的灰泥土、灰黄泥土和黄泥土的氮肥X0分别为每盆N 0.35、0.32和0.34 g,磷肥X0分别为每盆P 0.06、0.06和0.09 g,灰泥土和灰黄泥土的钾肥X0则分别为K 0.17和0.18 g;与土壤渗漏水养分浓度为基础所确定的氮、磷、钾X0有显著水平的线性正相关。以环保为目标的氮磷钾用量X0大多数低于以产量为目标的经济施肥量。化肥当季损失量参数较易获得,可作为环保施肥的依据。     

施用钾肥对叶菜产量和品质的影响

Over a period of two years, field experiments were conducted on four silty loam soils grown with foliar vegetable crops including Chinese cabbage (Brassica pekinensis Rupr., cv.Lu-Bai 3), autumn greens (B. chinensis L., cv.Piao-Geng-Bai), winter greens (B. var.rosularis Tsen et Lee, cv.You-Dong-Er), and summer greens (B. chinensis L., cv.Zao-Shu 5), respectively. Each experiment included one CK treatment without K, N and P fertilizers applied, and four treatments with from low to high doses, 0~300 kg hm^-2 for Chinese cabbage, 0~150 kg hm^-2 for autumn and winter greens and 0~180 kg hm^-2 for summer greens, of K fertilizers in the form of sulfate of potash (SOP) applied together with N and P fertilizers. One treatment of K fertilizer in the form of muriate of potash (MOP) applied at high levels (150 or 180 kg hm^-2) together with N and P fertilizers was included in the experiments of autumn, winter and summer greens, respectively, in order to compare the effects of SOP and MOP. The market yields of the tested crops increased significantly with the increasing rate of K application. The crops supplied with K fertilizers yielded more stably as the CV% of their yields decreased with the rate of K application. K fertilization increased not only K contents but also the amounts of N, P and K absorbed in shoots of autumn, winter and summer greens, which were statistically significantly correlated to their yields. It can also be found that potassium improved the quality of the foliar vegetable crops as their dry mater contents were generally increased and Vc contents obviously increased and nitrate contents markedly decreased. As compared to MOP, SOP was more effective on the yields and quality of autumn, winter and summer greens at the high levels of fertilization.     

春旱背景下春玉米苗情对产量的影响及减产评估模式

为建立基于苗情的玉米春旱指标和春旱减产即时定量评估模式,2010－2011年春季在中国东北玉米主产区开展玉米分期播种-土壤水分控制试验。每年设3个播期和4个水分胁迫处理,用雨棚和人工灌水控制土壤水分,观测土壤湿度、玉米出苗期、保苗率、7叶前后的株高、叶龄、生物量和单产。采用回归方法分析玉米产量对出苗期、保苗率及幼苗长势的响应,建立春旱评估模式。 结果表明,在春旱背景下,玉米产量与出苗期、出苗率、苗期株高、叶龄和生物量相关性显著。出苗期延迟导致产量下降,出苗期每推迟1d,玉米单产下降2.9%;出苗率下降10%,玉米减产9.2%;株高、叶龄和植株干质量每下降10%,玉米单产依次下降13.4%、11.1%和5.5%。用出苗期、保苗率、叶龄和株高等苗情要素建立玉米春旱损失评估模式,可以定量评估（或预测）春旱对玉米产量的影响,模式检验和实际应用表明评估误差在6.5%左右。该研究提供多个评估模式,便于根据不同时间和不同观测要素选择适当的模式开展玉米春旱减产的即时定量评估,为制定减灾对策和开展玉米春旱损失保险业务提供科学依据。     

Short-Term Effect of Drought and Salinity on Growth and Mineral Elements in Wheat Seedlings

Both drought and salinity cause nutrient disturbance, albeit for different reasons: a decrease in the diffusion rate of nutrients in the soil and the restricted transpiration rates in plants for drought and extreme soil sodium (Na)/calcium (Ca), Na/potassium (K), and chloride (Cl)/nitrate (NO₃) ratios for salinity. The objective of this study was to examine short-term effects of drought and salinity on nutrient disturbance in wheat seedlings. Wheat was grown in a greenhouse in soil under drought and saline conditions for 26 days after sowing. At harvest, shoot biomass and length, and fresh weight and dry weight of the blade and sheath in expanded leaves 3 and 4 and expanding leaf 5 were determined. Mineral elements (K, Ca, magnesium (Mg), phosphorus (P), nitrogen (N), Na, sulphur (S), iron (Fe), zinc (Zn), and manganese (Mn)) in leaf blades and sheaths were also analyzed. At harvest, the reduction in plant height, shoot biomass, and accumulative evapotranspiration under drought was similar to that under salinity as compared with control plants. However, drought decreased the accumulation of all ions in the blade of the youngest leaf 5 compared with the control, whereas there was either an increase or no difference in all ion concentrations under saline conditions. The change in concentration for most ions in the blade and sheath of expanded leaves 3 and 4 varied among control, drought, and salinity plants, which indicated a different competition for nutrients between the sheath and blade of expanded leaves under drought and saline conditions. It can be concluded from this study that ion deficiency might occur in expanding leaves under drought but not saline conditions.     

气候变化下干旱对中国玉米产量的影响

了解干旱的时空变化特征及其对农业生产的影响对于维护农业可持续发展具有重要意义。该研究以中国五大主要玉米种植区中241个地级行政单元作为研究对象,采用AquaCrop作物模型分别对rcp2.6、rcp4.5、rcp8.5,3种代表性浓度路径情景中玉米在不同灌溉条件下的受到的水分胁迫及相应产量进行模拟,在此基础上通过建立回归模型评估干旱强度对玉米产量损失的影响。结果表明,1）未来中国的干旱强度分布及玉米产量损失在空间上均呈现由西北至东南递减的趋势;2）未来时期全国大部分地区干旱水平相比于历史时期有所上升;3）玉米干旱损失率随干旱指数的变化特征符合Logistic曲线,回归结果的R2为0.96。4）未来北方春播玉米区和黄淮海夏播玉米区的玉米产量对干旱强度反应最敏感,应当引起格外重视。     

Wood biochar produces different rates of root growth and transpiration in two maize hybrids (Zea mays L.) under drought stress

This study investigated the effects of wood-derived biochar (BC) applied at 1% to a C-poor silty-loam soil in the drought-tolerant (D24) and in the drought-sensitive (P1921) Pioneer Hi-Bred maize hybrids in pot and field trials (NE Italy). D24 had better growth than P1921 under rain-fed conditions without irrigation and soil amendment. The addition of biochar increased root growth in D24 (+38% root area) and decreases it in P1921 (?9%) at the silking stage, while the fraction of finer roots (<250 µm diam.) was reduced in D24 and increased in P1921. This led both hybrids to maintain the maximum transpiration at a lower fraction of transpirable soil water (from 82% to 45% in D24, and from 46% to 22% in P1921). There were no significant variations in plant nutrient contents, productivity and in the protein and starch contents of the grains, whereas the lipid content was reduced by biochar, particularly in P1921 (2.6% vs. 3% DW, ?13%).

We conclude that biochar can be profitably used to enhance drought tolerance in maize, possibly due to improvements in the physicochemical characteristics and the water content of treated soils, although maximum benefits are expected in drought-tolerant hybrids through increased root elongation and transpiration.     

The effect of winery solid waste compost application on maize growth,biomass yield,and nutrient content under greenhouse conditions

A greenhouse study was conducted to assess the fertilizer value and determine the optimum application rate of five winery solid waste (WSW) composts containing varied filter material (FM) mixed proportions with grape marc and pruning canes using maize. The composts comprised of 4, 10, 20, 30, and 40% FM (w/w) designated C4FM, C10FM, C20FM, C30FM, and C40FM, respectively. Application rates of 5, 10, 20, 40, and 80 t ha^?1 were used; while unamended control and inorganic NPK fertilizer treatments were included as references. The results showed that application of composts with 20% FM or more at 80 t ha^?1 significantly increased the dry matter yield more than NPK fertilizer but full potential was not reached due to inadequate nitrogen supply. Maize shoot K content from compost treatments exceeded the critical nutrient level while the shoot Zn content from compost treatments with 20% FM or less also exceeded the critical level. The results revealed that these composts could serve as potential good sources of K and Zn for maize production, particularly, in sandy soils where these nutrients are often reported to be deficient. Quantitative estimate of the optimum rate of the composts for dry matter production ranged from 75 to 307 t ha^?1.