Effects of Controlled-Release Fertilizer on Leaf Area Index and Fruit Yield in High-Density Soilless Tomato Culture Using Low Node-Order Pinching

To further development of a simplified fertigation system using controlled-release fertilizers (CRF), we investigated the effects of differing levels of fertilizers and plant density on leaf area index (LAI), fruit yields, and nutrient use in soilless tomato cultures with low node-order pinching and high plant density during spring-summer (SS), summer-fall (SF), and fall-winter (FW) seasons. Plants were treated with 1 of 3 levels of CRF in a closed system, or with liquid fertilizer (LF) with constant electrical conductivity (EC) in a drip-draining system. Two plant densities were examined for each fertilizer treatment. In CRF treatments, LAI at pinching increased linearly with increasing nutrient supply for all cropping seasons. In SS, both light interception by plant canopy at pinching and total marketable fruit yield increased linearly with increasing LAI up to 6 m²·m⁻²; the maximization point was not reached for any of the treatments. In FW, both light interception and yield were maximized at an LAI of approximately 4. These results suggest that maximizing the LAI in SS and FW to the saturation point for light interception is important for increasing yield. In SF, however, the yield maximized at an LAI of approximately 3, although the light interception linearly increased with increasing LAI, up to 4.5. According to our results, the optimal LAI at pinching may be 6 in SS, 3 in SF, and 4 in FW. In comparing LAI values with similar fruit yield, we found that nutrient supply was 32−46% lower with the CRF method than with LF. In conclusion, CRF application in a closed system enables growers to achieve a desirable LAI to maximize fruit yield with a regulated amount of nutrient supply per unit area. Further, the CRF method greatly reduced nutrient use without decreasing fruit yield at similar LAIs, as compared to the LF method.     

施肥对蓝莓植株生长、叶片叶绿素荧光特性和果实品质的影响

以蓝莓“美登”为试验材料,在我国大兴安岭地区研究了连续3年施肥对蓝莓植株生长、叶片叶绿素荧光参数以及果实品质的影响,为优化我国北方地区蓝莓人工栽培技术提供一些基础数据。结果表明：施肥处理可以明显促进蓝莓植株的生长,7.5 g/株施肥量对蓝莓株高和冠幅度的促进作用最明显,而不同施肥量对蓝莓枝条长度和粗度的影响差异不明显。施肥处理还明显促进了蓝莓叶片的实际光化学效率和电子传递速率,以及PSⅡ反应中心的开放程度,并且施肥处理下蓝莓叶片PSⅡ反应中心能量分配参数更倾向于光化学反应方向,与生长参数相似,施肥处理对蓝莓叶绿素荧光参数的影响也表现为7.5 g/株的施肥量作用效果最优。施肥处理还改变了蓝莓果实的品质,虽然不同处理下蓝莓果实的维生素C和花色素苷含量以及pH值没有发生明显的改变,但其总糖含量却明显增加,而总酸含量除10 g/株施肥处理外,均呈降低趋势,表现为糖酸比的增加,但与生长和叶绿素荧光参数的变化不同,以5 g/株的施肥量对蓝莓果实品质的提高更有利。因此,施肥虽然可以明显促进蓝莓植株的生长,改善其光合能力和果实品质,但控制施肥量时要综合考虑其生长和品质等因素。     

缓/控释肥料对辣椒生长及养分利用率的影响

采用盆栽试验方法,连续3年研究了不同缓/控释肥料在辣椒上的施用效果.结果表明：与常规分次施肥处理（T¹）相比,一次性施用聚合物包膜控释肥处理（T²）提高了辣椒的单果质量和维生素C含量,改善了根系活力,产量平均提高8.4％,但可溶性糖含量没有明显变化;施用磷酸铵镁包膜控释肥处理（T₃）的单果质量和维生素C含量与T₁无显著差异,但可溶性糖含量提高了5.67%,根系活力在生育前期旺盛,后期较弱,平均产量略有降低;而3种缓释肥处理则提高了果实的可溶性糖含量,显著改善了根系活力,但平均产量与T₁无显著差异.在养分利用方面,除T₂处理氮钾利用率提高、磷素利用率降低外,其他缓/控释肥料处理的氮、磷、钾利用率均明显提高.表明合理施用缓/控释肥料能改善辣椒的根系活力,提高养分利用率.     

The effect of foliar nutrition on yield of greenhouse tomatoes and quality of the crop

Tomatoes grown in traditional mediums such as peat moss are usually supplied with essential nutrients by preplant fertilization and in the later growth stages by top dressing application to the root zone. According to the data from literature the efficient method of nutrient supply during the intensive stage of growth may be estimated as by foliar spraying. In the greenhouse experiment conducted in 1998–1999 a preplant fertilization by multicomponential fertilizer MIS-4 was applied to peat moss growing medium in full (4 kg per m³) and half (2 kg per m³) of recommended rate. Supplemental fertilization during the growing period was provided to the root zone or by using liquid multicomponential fertilizers Ekolist S and Mikrosol U in 5 sprays conducted at two week intervals. Results of the study proved that advantageous effect of foliar tomato nutrion grown in eat substrate was observed only in treatments with restricted supply of fertilizers to the growing medium. The maximum fruit yield was received from plots provided by the reduced preplant MIS-4 dose to 50 % of recommended rate combined with foliar sprays by Ekolist S. Such system of fertilization enhanced the marketable yield of fruit by 9.8 % and early yield by 11.3 % as compared to that obtained with preplant and top dressing soil application. Foliar nutrion did not change dry matter and vitamin C content and increased total and reducing sugars accumulation in tomato fruits.     

供肥对小麦间作蚕豆群体产量及根系的调控

利用田间,池栽,盆栽等方法,对不同N,P水平下小麦间作蚕豆群体根系的时空分布及产量效应进行了研究。结果表明,供P对小麦-蚕豆间作系统有明显的增产作用,与不供P相比,田间试验中供P处理间作小麦和蚕豆分别提高了48.39%和16.69%,池栽试验中群体产量增产幅度为20.07%-43.14%。间作蚕豆经济产量增幅为58.46%-78.78%,小麦间作蚕豆多作系统2种作物根密度生长高峰期交错出现,小麦的峰值出现早于蚕豆,其中,小麦和蚕豆根干重最大值分别出现在抽穗期和成熟期,而根长的最大值分别出现在拔节期和成熟期,这在一定程度上减轻了共生期2种作物对水肥的竞争,也是此群体增产增效的原因之一,施P处理间作小麦的根重,根长和根表面积分别比不施P处理提高54.33%,48.88%和47.00%;施N处理间作小麦的根重,根长和根表面积分别比不施N的增加15.25%,11.61%和11.46%。间作小麦根重的57.61%和蚕豆的69.20%分布在0-30cm土层,随施P水平的提高,总根干重及根密度都趋于增加,且深层土壤中根系增加明显。     

氮肥运筹对免耕水稻根系生长、根际土壤特性及产量的影响

为探索氮肥运筹对免耕条件下水稻根系生长以及对根际土壤特性、产量的影响,以金优253为材料进行试验。结果表明：平衡施肥显著提高单株根系干重、根长、单株生物量、根半径、单株根表面积、根长密度及根系活力,实收单产高于重穗肥和重基肥处理,且与重基肥差异达95％的显著水平,主要是有效穗数、结实率的增加。平衡施肥显著提高0~10 cm土层的0~2 mm根际土壤有机质、碱解氮含量及脲酶、蔗糖酶活性。因此平衡施肥能明显促进免耕水稻根系生长和有效穗数的增加,对提高水稻产量具有促进作用。     

Effect of Optimal Daily Fertigation on Migration of Water and Salt in Soil,Root Growth and Fruit Yield of Cucumber (Cucumis sativus L.) in Solar-Greenhouse

Inappropriate and excessive irrigation and fertilization have led to the predominant decline of crop yields, and water and fertilizer use efficiency in intensive vegetable production systems in China. For many vegetables, fertigation can be applied daily according to the actual water and nutrient requirement of crops. A greenhouse study was therefore conducted to investigate the effect of daily fertigation on migration of water and salt in soil, and root growth and fruit yield of cucumber. The treatments included conventional interval fertigation, optimal interval fertigation and optimal daily fertigation. Generally, although soil under the treatment optimal interval fertigation received much lower fertilizers than soil under conventional interval fertigation, the treatment optimal interval fertigation did not statistically decrease the economic yield and fruit nutrition quality of cucumber when compare to conventional interval fertigation. In addition, the treatment optimal interval fertigation effectively avoided inorganic nitrogen accumulation in soil and significantly (P<0.05) increased the partial factor productivity of applied nitrogen by 88% and 209% in the early-spring and autumn-winter seasons, respectively, when compared to conventional interval fertigation. Although soils under the treatments optimal interval fertigation and optimal daily fertigation received the same amount of fertilizers, the treatment optimal daily fertigation maintained the relatively stable water, electrical conductivity and mineral nitrogen levels in surface soils, promoted fine root (<1.5 mm diameter) growth of cucumber, and eventually increased cucumber economic yield by 6.2% and 8.3% and partial factor productivity of applied nitrogen by 55% and 75% in the early-spring and autumn-winter seasons, respectively, when compared to the treatment optimal interval fertigation. These results suggested that optimal daily fertigation is a beneficial practice for improving crop yield and the water and fertilizers use efficiency in solar greenhouse.     

5种叶面肥对草莓光合特性及品质的影响

为探讨不同叶面肥对大棚草莓光合特性、果实品质及产量的影响,并筛选出适宜的叶面肥,以甘肃省兰州市西固区牟家台草莓温室大棚内栽植的草莓品种‘蒙特瑞’为试材,在施肥充足的情况下,在4个生育期追肥喷施经典750倍液（T1）、花仆1500倍液（T2)、润亮750倍液(T3)、艾德拉果500倍液（T4）及磷酸二氢钾1500倍液（T5）5种叶面肥,清水作为对照（CK）,测定了处理植株光合参数、果实品质、生物量及产量等指标。结果表明：（1）喷施不同叶面肥处理后草莓植株生物量、叶绿素含量显著增加,叶片的净光合速率和蒸腾速率显著上升,喷施叶面肥后的草莓植株胞间二氧化碳浓度均高于CK;（2）对果实品质而言,T2和T3处理能够显著改善草莓果形指数,T1和T5可以显著增大果实体积和重量。其中,T1的平均单果重较CK增加了5.89 g,T5的果实横径和纵径分别较CK增加了1.22 cm和1.15 cm。（3）实硬度、可溶性固形物含量、维生素C含量和还原糖含量有很明显的提高,并以T1施用效果最佳,较CK分别增加了3.3%、17.25 mg/g、2.71%。处理T1和T3可溶性蛋白含量分别较CK提高了0.097 mg/g和0.070 mg/g;（4）喷施叶面肥能够显著提高草莓单位面积产量,且以处理T1处理产量最高,较CK增长了13.65%。可见,施用适宜的叶面肥均能有效改善草莓营养生长状况,提升草莓果实品质,显著提高产量,并以经典750倍液叶面肥施用综合效果最佳。     

不同施肥方式对稻麦轮作田土壤杂草种子库的影响

为揭示不同施肥方式(纯施化肥、有机肥配施化肥、秸秆还田配施有机无机肥、有机无机复合肥)对稻麦两熟制地区农田土壤杂草种子库的影响, 在江苏常州金坛区进行了固定施肥试验。经过连续4年试验处理后, 对不同施肥处理下农田土壤杂草种子库杂草种子种类及密度进行了调查, 并对杂草种子多样性、数量、分布与施肥措施的关系进行了分析。结果表明, 与不施肥相比, 施肥有减少稻麦轮作田土壤杂草种子库杂草种子种类数、杂草种子群落均匀度指数和物种多样性指数的趋势, 并使稻麦轮作田土壤杂草种子库杂草种子总密度明显降低。施肥明显提高了土壤杂草种子库菵草(Beckmannia syzigachne)、日本看麦娘(Alopecurus japonicus)、看麦娘(A. aequalis)种子的密度, 施用猪粪堆肥配施化肥处理提高程度更为显著; 秸秆还田配施化肥、秸秆还田配施有机肥化肥、有机无机复合肥施用处理有减少菵草、日本看麦娘、看麦娘杂草种子密度的趋势。施肥明显降低了土壤杂草种子库阔叶杂草种子密度; 施用有机肥有增加土壤杂草种子库水苦荬(Veronica undulata)、蛇床(Cnidium monnieri)种子密度的趋势; 施用猪粪堆肥有增加土壤杂草种子库鸭舌草(Monochoria vaginalis)种子密度的趋势。因此, 不同种类杂草对不同肥料存在偏好性差异, 不同施肥方式造成了土壤杂草种子库优势物种组成的差异。     

The Application of Fertilizer and AMF Promotes Growth and Reduces the Cadmium and Lead Contents of Ryegrass (<i>Lolium multiflorum</i> L.) in a Copper Mining Area

Heavy metal-polluted soil was collected from the Pulang copper mine in Shangri-La City, Yunnan Province, Southwest China. The effects of fertilizer (organic and inorganic) and arbuscular mycorrhizal fungi (AMF) on ryegrass (Lolium multiflorum L.) growth, root morphology, mineral nutrition and cadmium (Cd) and lead (Pb) contents were investigated by pot experiments. The results showed that both fertilizer and AMF significantly ameliorated the root morphology and mineral nutrition, reduced the Cd and Pb contents, and promoted the growth of ryegrass. Among all treatments, the combined application of organic–inorganic compound fertilizer with AMF had the highest effect, resulting in increases in root length, surface area and branch number by 2.3, 1.1, and 3.9 times, respectively; an 88% increase in plant biomass; a nitrogen content increase of 2.3 and 1.2 times, and phosphorus content increase of 62% and 68% in shoots and roots, respectively was also recorded as well as decreases in Cd content by 34% and 62% and Pb content by 47% and 34% in shoots and roots, respectively. Two-factor analysis showed that both fertilizer and AMF significantly promoted ryegrass growth (plant height, biomass, chlorophyll content, root length, nitrogen and phosphorus content) and reduced the Cd and Pb contents in roots, and there was a synergistic effect between them. Moreover, the nitrogen and phosphorus contents were very significantly positively correlated with the shoot and root biomasses but very significantly negatively correlated with the Cd and Pb contents of ryegrass. Thus, the application of fertilizer and AMF synergistically improved ryegrass growth on polluted soils in the copper mining area.     

施肥对红豆树苗木生长、根系结瘤和矿质营养的影响

探讨几种市售肥料对红豆树(Ormosia hosiei)苗木各器官生长发育及养分含量的影响,为培育红豆树优质苗木选用肥料提供参考。以红豆树当年生大田苗为试材,采用3种常见肥料(复合肥、缓释肥和尿素)分3个施肥水平进行施肥试验,测定苗高、地径、根系指标、根系结瘤指标、各器官生物量及N、P、K含量,对不同施肥处理苗木质量进行综合评价。不同施肥处理对红豆树苗木生长、结瘤和矿质营养均有显著或极显著影响。施缓释肥和复合肥的处理表现为随施肥量的增加苗木的生长和生理指标均表现出先增后降趋势,施尿素则表现为随施肥量增加呈逐渐递减趋势。通过隶属函数对苗木质量进行综合评价,表明缓释肥30 g·m^-2为最佳施肥处理,其苗高增量、各根系质量指标、各生物量指标、结瘤数量以及根、茎、叶的N、P、K含量均为最大。红豆树当年生苗木密度为50 株·m-2时,施用缓释肥(N-P-K: 30-6-7) 30 g·m^-2可以有效提高红豆树的苗木质量。     

密度、施肥对旱地春小麦产量、水分利用效率和籽粒养分含量的补偿效应

为了探明旱作条件下无机营养对作物产量和水分利用效率的补偿效应,我们在宁南黄土高原半干旱地区开展了为期两年的春小麦密度与肥料试验。通过4种播种密度和5种肥力水平的综合研究结果表明,在不同处理的籽粒产量和水分利用效率排序中,播种密度为500粒／m^2时,以施肥量90kg／hm^2N和135kg／hm^2P2O5处理的产量和水分利用效率为最大。与不施肥的对照相比,增施肥料与籽粒产量和水分利用效率的提高成显著的正相关关系,相关系数分别达到0．959和0．894,而播种密度则与产量和水分利用效率的相关性不显著。增施肥料虽然能够提高可育小花数,但随着播种密度的增大,穗粒数和千粒重反而呈下降趋势,表明可育小花数对肥料水平反应敏感,而穗粒数和千粒重主要受播种密度的影响。施肥能够促进春小麦根系的生长发育,特别是促进浅层根量的增加,增强了作物的水分养分吸收。另外,不同种类肥料配施的结果表明,单施P肥或者N、P、K配合施用,可使春小麦产量分别提高44．6％和55．4％。N、P、K配合施肥还能够提高品质,使籽粒中的P、N、K含量分别提高18．5％、18．4％和8．1％。上述研究结果说明,控制播种密度、改善土壤肥力对于促进旱地春小麦高效利用有限水分具有明显的补偿效应。     

长期施肥对黄土旱塬农田土壤有机磷组分及小麦产量的影响

研究长期施肥对黄土旱塬农田土壤有机磷组分及小麦产量的影响,可为提高磷素转化利用率及合理利用肥料提供理论支持。本研究依托长武旱塬农田生态系统长期(1984—2016年)定位试验站,选取不施肥(CK)、单施氮肥(N)、单施磷肥(P)、施氮磷肥(NP)、单施有机肥(M)、氮肥配施有机肥(MN)、磷肥配施有机肥(MP)、氮磷肥配施有机肥(MNP)8个处理,研究其对土壤有机磷组分、小麦产量和土壤性质的影响。结果表明: 长期施肥后土壤有机磷含量为244.7～429.1 mg·kg^-1,除N处理外,其余各处理有机磷含量比CK均显著增加了15.4%～47.9%。长期施用磷肥改变了黄土旱塬农田表层土壤(0～20 cm)各有机磷组分含量,MP、MNP处理显著提高了活性有机磷及中活性有机磷含量;N、P和NP处理显著降低了中稳性有机磷含量;N、P、NP、MN、MP、MNP处理均显著提高了高稳性有机磷含量。各处理土壤有机磷组分与总有机磷含量比值为:中活性有机磷>高稳性有机磷>活性有机磷>中稳性有机磷。长期施肥后,与CK相比,氮、磷肥配施,尤其是与有机肥配施,显著增加了小麦生物产量和籽粒产量。土壤指标中,有机质、速效磷和无机磷与小麦产量呈显著正相关。MP、M处理可以显著提高黄土旱塬黑垆土中的速效磷、总磷、总无机磷、活性有机磷和中活性有机磷含量,表明有机肥与磷肥配施可以提高该地区更容易被作物吸收的磷组分。总之,氮磷肥配施并配施有机肥可以提高该地区磷供给,对小麦增产有促进作用,对提高黄土旱塬地区土壤质量有重要意义。     

增温、施肥与种内竞争的交互作用对云杉根系属性的影响

增温、施肥与种内竞争的交互作用对云杉根系属性的影响 物种竞争、气温和土壤养分是青藏高原东部高寒地区影响树木生长的重要因素。虽然已开展了大量关于物种竞争、气温、施肥单因素对树木生长的影响研究,但关于这三者的交互作用对根系生长的影响还知之甚少。因此,本研究拟通过测量根系属性(细根长、根表面积、比根长、比表面积、根尖数、根系分支数等)、根生物量,以及根系养分吸收,研究施肥和增温对物种竞争的影响,并进一步探讨施肥、增温与物种竞争的交互作用对云杉(Picea asperata)生长的影响机制以及所采取的适应策略。研究结果表明,增温、施肥和竞争均提高了细根的氮、钾浓度,但并未影响细根生物量和根长、根表面积、根尖数和根分支数等根系特征。然而,无论是增温、施肥,或是它们的联合作用,与物种竞争进行交互时,均增加了根长、根表面积、根尖数、根系分支数和养分吸收。此外,施肥降低了根比表面积、比根长和单位面积的根尖数和根分支数,增温和竞争的交互作用使根比表面积、比根长下降,其他参数不受温度和竞争的影响。该结果表明,云杉在物种竞争、气候变暖、施肥及其交互作用下保持着保守的营养策略。该研究加强了对树木应对全球变化的生理和生态适应性的理解。     

The Effects of Water and Fertilizer Coupling on Plant and Soil Nitrogen Characteristics and Fruit Growth of Rabbiteye Blueberry Plants in a Semi-Arid Region in China

To evaluate the effects of nitrogen (N) and irrigation coupling on the soil N distribution, plant N utilization, and fruit yield of rabbiteye blueberries (Vaccinium virgatum), a field experiment was designed using two factors (water and fertilizer application) with four levels of irrigation and three levels of fertilization, and a control. Under the different water and fertilizer combinations, N primarily accumulated in the leaves. Irrigation and N application within appropriate ranges (pure N ≤ 29 g/plant and irrigation volume ≤ 2.5 L/plant) significantly improved the blueberry fruit yield. Increases in water and N within these ranges promoted the effective accumulation of N in various organs and the absorption and utilization of N in the plants, which ultimately promoted blueberry yield. With increased N application rate, the nitrate N content of the 0–20 cm and 20–50 cm soil layers increased. With increased irrigation volume, the nitrate N content of the 0–20 cm soil layer decreased, while the nitrate content in the 20–50 cm soil layer increased. Low N and moderate water treatments resulted in high fruit yields and reduced nitrate N retention in the soil. Under these conditions, the economic input-output ratio was high and the soil N accumulation was low, and thus the economic and ecological benefits were maximized.

     

干旱胁迫对花生根系生长发育和生理特性的影响

以花育17号和唐科8号两个花生品种为试验材料,在防雨棚栽培池内进行土柱栽培试验,研究了中度干旱胁迫和正常供水处理下花生生育后期根系形态发育特征和生理特性.结果表明: 唐科8号具有较发达的根系及较高的产量和抗旱系数,花育17号根系对干旱胁迫的适应性小于唐科8号.两品种根长密度、根系生物量均主要分布于0～40 cm土层中,但同一土层内两品种根系性状存在差异.与正常供水处理相比,干旱胁迫处理使花育17号各生育期总根长、根系总表面积和总体积均降低,而唐科8号除花针期显著降低外,其余生育期均明显升高;干旱胁迫增加了两品种20～40 cm土层内根系生物量、根系表面积和体积,而降低了40 cm以下土层内各根系性状;干旱胁迫处理使两品种饱果期40 cm以下土层内根系活力降低,且花育17号降低幅度高于唐科8号.干旱胁迫下两品种生育后期根系发育和生理特性的差异表明其根系在干旱胁迫下对水分吸收和利用存在差异.     

The role of chemical and organic fertilizers on yield, yield variability and carbon sequestration— results of a 19-year experiment

Fertilization practice in the North China Plain has been changing since the late 1970s. To evaluate how organic and chemical fertilizers contribute to yield, yield variability and soil carbon sequestration, we analyzed wheat (Triticum aestivum L.) yield data in a long-term fertilization experiment that began in 1989, conducted pot experiments using soils from the long-term fertilization experiment plots, and simulated the soil organic carbon (SOC) dynamics of individual treatments in the long-term experiments. Wheat yield results showed that when organic fertilizer was used as an alternative nutrient source for chemical fertilizers, it was neither directly beneficial to crop yield, nor decreased yield variability when compared to a balanced chemical fertilizer. However, there was a linear relationship between yield trend and SOC change rate (r = 0.951, P?<?0.01). The use of organic fertilizer increased SOC and soil fertility and consequently resulted in a larger yield trend when compared to a balanced chemical fertilizer. Roth-C model simulation and pot experimental results indicated that soils with higher SOC had a higher root/shoot ratio. Therefore, the long-term use of organic fertilizer not only directly increases SOC, but indirectly contributes to carbon sequestration by favoring root development. We found that yield variability was determined by the relative contributions of soil fertility and fertilizer to yield (the contribution of fertilizer to yield is the yield difference between fertilized and unfertilized treatments). The contribution of balanced chemical fertilizer to yield was higher than that of organic fertilizer, resulting in less yield variability in balanced chemical fertilizer treatment. However, if organic fertilizer was used as a complementary nutrient source with chemical fertilizers, it would increase the contribution of fertilizers to yield, thus decreasing yield variability.     

管道输液滴干对核桃生长、果实的影响

为了探索核桃提质增效新途径,该研究采用管道输液滴干技术,对‘辽核’核桃树进行水、肥、药一体化管理,将管道输液滴干处理与土壤施肥处理、常规管理进行对比,测定叶片 SPAD 值、叶面积、新梢长度、新梢粗度、干周、土壤含水量、单株产量、单果重、出仁率、黑果率等指标。结果表明：管道输液滴干处理的叶片SPAD 值比土壤施肥处理和常规管理分别提高了28.37％和53.23％;核桃叶片叶面积值分别提高了18.27％和51.54％;新梢长度分别提高了7.03％和13.73％;新梢粗度分别提高了21.92％和27.14％;干周分别提高了20.52％和24.28％;0~20 cm 土层的土壤含水量分别增加了8.66％和8.52％;单株产量分别提高了21.62％和73.08％;单果重分别提高了14.55％和23.53％;出仁率分别提高了11.45％和12.37％;黑果率分别降低了88.76％和91.55％。这说明管道输液滴干技术可以促进树体生长,提高核桃产量和果实品质以及抗病性,降低果实的黑果率,确保核桃丰产稳产。该研究结果能达到既节水、省工,又高效利用肥料、农药,提高核桃产量和品质的目标,从而为管道输液滴干技术在果木生产上的推广应用提供了依据。     

不同类型保水剂对冬小麦水分利用效率和根系形态的影响

采用田间小区试验,研究5种不同类型保水剂及2个施用水平对冬小麦产量、水分利用效率、根形态的影响.结果表明: 冬小麦茎蘖数、旗叶面积、产量和水分利用效率在不同类型保水剂及施用量处理之间存在显著差异.与对照相比,5种保水剂处理冬小麦产量增加1.3%～7.9%,水分利用效率由对照的17.1 kg·hm^-2·mm^-1提高到18.0～20.7 kg·hm^-2·mm^-1.保水剂对冬小麦根系的平均直径、总根长和总表面积的影响均达到显著水平,在0～20和20～40 cm土层,总根长分别增加3.7%～19.1%和6.3%～27.3%,总表面积分别增加6.5%～21.7%和2.9%～18.5%.冬小麦根系形态特征与冬小麦产量和水分利用效率均呈显著正相关.丙烯酰胺/无机矿物复合型保水剂对提高冬小麦水分利用效率和促进根系生长效果最为明显.     

N-Exponential Fertilization Could Affect the Growth and Nitrogen Accumulation of <i>Metasequoia glyptostroboides</i> Seedling in a Greenhouse Environment

Metasequoia glyptostroboides (M. glyptostroboides) is a unique plant species related to relic flora in China. It plays a positive role in afforestation and its long-term protection with high paleoclimate research value. However, due to the nutrients-supply deficiency, it is a big challenge to cultivate the high-quality seedlings of M. glyptostroboides. In this study, a pot experiment in a greenhouse environment was carried out to identify the effect of N-exponential fertilization on the growth and nutrient distribution of M. glyptostroboides seedling. The M. glyptostroboides rooted seedlings with 12-month growth were chosen. Different N fertilizer levels with conventional fertilization (CF: 5.0 g seedling⁻¹), exponential fertilization including EF1, EF2, EF3 and EF4 were determined. The relevant growth indexes were measured after 210-day growth. The results indicated that non-significant differences in seedlings’ height and ground diameter were found among the above treatments (P > 0.05); At the same time, N-exponential fertilization promoted the M. glyptostroboides’s biomass in different organs (P < 0.05), with the maximum total biomass under EF3 treatment. The N accumulation in root and stem of the N-exponential fertilization treatments were increased in to some extent (P < 0.05). The maximum N accumulation was also found under EF3 treatment. Therefore, steady-state nutrition and superior growth performance of M. glyptostroboides could be obtained by N-exponential fertilization of 5.0 g cutting⁻¹.