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。     

生物有机肥对作物生长、土壤肥力及产量的效应研究

通过7年的生物有机肥试验表明:施用生物有机肥可以使作物保持良好的生长发展态势,促进干物质的积累;长期施用生物有机肥可以显著提高土壤有机质含量与土壤全氮、碱解氮的含量,提高土壤肥力,其中施用生物有机肥15000kg/hm2的处理有机质含量上升的最快,从1996年的1 26%升高到2001年的1 96%。施用生物有机肥可以持续稳定的提高作物产量。施用生物有机肥15000kg/hm2的处理冬小麦年平均产量比常规施肥和对照分别增产1808 14kg/hm2和3652 39kg/hm2;夏玉米产量分别增产2668kg/hm2和5062kg/hm2。     

Nutrient mobilization and nutrient contents of Zea mays in response to EDTA additions to heavy‐metal‐contaminated agricultural soil

Enhanced phytoextraction of heavy metals (HMs) using chelating agents and agricultural crops is widely tested as remediation technique for agricultural soils contaminated with less mobile HMs. Nutrients are complexed by chelating agents simultaneously to HMs. In this study, the effect of EDTA (ethylenediaminetetraacetic acid) application on nutrient mobility in the soil and nutrient contents of Zea mays was tested on the laboratory and on the field scale. EDTA effectively increased the mobility of total water‐soluble macronutrients (Ca, K, Mg, P) and micronutrients (Fe, Mn) in the soil solution. Thereby nutrient co‐mobilization did cause competition to target HMs during the phytoextraction process. Mobilization was caused by complexation of nutrient cations by negatively charged EDTA and by dissolution of oxides and hydroxides. Increased concentrations of negatively charged P indicate the dissolution of metal phosphates by EDTA. Higher total water‐soluble nutrient concentrations enhanced bioavailability and plant contents of all determined nutrients especially that of Fe. Mobilization of nutrients may result in leaching and loss of soil fertility.     

平衡施肥对玉米养分吸收、产量及效益的影响

采用田间试验方法,探讨了平衡施肥对玉米养分吸收、产量和经济效益的影响.结果表明,平衡施肥能促进玉米对养分的吸收和利用,在OPT施肥水平下,每形成100 kg玉米籽粒吸收1.95 kg的N、1.05 kg的P2O5、1.96 kg的K2O,玉米吸收NPK的比例约为1∶0.54∶1;平衡施肥较农民习惯施肥增产5.6%,增收714元/hm2;在本试验条件下,钾是玉米产量的第一限制因子.因此,必须科学合理地调配氮磷钾施用比例,加大钾肥的施用量,才能实现玉米高产.     

施肥对玉米养分吸收利用、产量及肥料效益的影响

分别于2006年和2007年,通过田间小区试验,研究了施肥对玉米养分吸收利用及产量的影响.结果表明,2006年测土推荐施肥处理(NPK)植株的N、P2O5、K2O吸收量分别比不施肥处理提高54.94%、41.87%、67.72%,每形成100 kg子粒的养分吸收量N 3.15 kg、P2O5 0.71 kg、K2O 3.90 kg.施肥对玉米增产效果显著,NPK处理的增产率达到28.90%,氮、磷、钾肥对玉米产量的贡献率分别是6.18%、20.69%、12.42%,每千克N、P2O5、K2O对玉米的增产效益分别是2.83、27.45、36.15 kg.两年的试验都表明磷素是供试土壤的第一养分限制因子,氮素的增收效益较小,因此要重视磷、钾肥的施用,减少氮肥的用量,均衡土壤养分比例来提高化肥施用的效益.     

Responses of photosynthesis,chlorophyll fluorescence,and grain yield of maize to controlled‐release urea and irrigation after anthesis

Controlled‐release urea (CRU) is a new type of urea, which may increase crop nitrogen (N)‐use efficiency compared with conventional urea (CU), but the conditions where it outperforms urea are not well defined. A field experiment assessing responses of plant growth and grain yield of maize to CRU and irrigation was conducted on a typical agricultural farm in Shandong, China. Five treatments of the two types of urea (75, 150 kg N ha^–1, 0 kg N ha^–1) were applied as basal fertilizer when sowing maize, and two water treatments (W₀ and W₁) were used 23 d after anthesis. Net photosynthetic rate (P_N) and chlorophyll concentration as well as leaf‐area index (LAI) increased significantly by both CRU and CU application, with the increases being larger in CRU‐treated plants than in CU‐treated plants at grain filling and maturing stages. CRU significantly enhanced the maximum photochemical efficiency (F_v / F_m), PSII coefficient of photochemical fluorescence quenching (q_P), and actual quantum yield of PSII electron transformation (Φ_PSII) but decreased the nonphotochemical quenching (NPQ). Cob‐leaf N concentration of CRU‐treated plants was significantly higher than that of CU‐treated plants under no irrigation, but not in the irrigation treatment 30 d after anthesis. Significant positive correlations were found between cob‐leaf N concentration and P_N both with and without irrigation. Grain yield of maize was significantly higher in the CRU treatment than in the CU treatment under both irrigation conditions. In conclusion, CRU as a basal application appeared to increase the N‐use efficiency for maize relative to CU especially by maintaining N supply after anthesis.     

Nitrogen use efficiency and nutrient partitioning in maize as affected by blends of controlled-release and conventional urea

ABSTRACT

Blends of controlled-release urea (CRU) and conventional urea can be an alternative to conventional fertilization to improve nitrogen use efficiency (NUE) and reduce costs when applied as a single application to agricultural crops. Different indexes of NUE, grain yield, nutrient uptake and partitioning in maize (Zea mays L.) were investigated in field experiments. The treatments consisted of a single rate of 180 kg N ha^?1 with different proportions of polymer-sulfur coated urea (PSCU) and conventional urea (U) applied incorporated at sowing (0.05 m below and 0.1 m to the side of the seed row) at two tropical sites (Site 1, Typic Haplustox; Site 2, Rhodic Haplustox) in Brazil. A control treatment (without urea-N) and a treatment with conventional urea management (UCM: 20% of urea-N applied as basal fertilizer and 80% of N applied as top dressing) were also included. This study demonstrates that blends of PSCU and U are efficient in supplying N throughout the maize cycle at a Typic Haplustox site when applied in a single application incorporated at sowing, resulting in high yields and adequate macronutrient uptake. PSCU improved NUE index compared to U and UCM. There was not response for N fertilization in the Rhodic Haplustox site.     

适宜滴灌施肥量促进河西春玉米根系生长提高产量

针对河西地区水资源短缺、作物水肥利用效率低等问题,研究不同滴灌施肥条件下河西地区春玉米根系生长与产量对水肥的响应关系,以期探索提高水肥利用效率的滴灌施肥模式。利用2 a的田间小区试验,以春玉米"强盛51号"为试验材料,设置4个灌水水平,2015年和2016年分别为I_(60)(60%ET_c)、I_(75)(75%ET_c)、I_(90)(90%ET_c)、I_(105)(105%ET_c)和I_(60)(60%ET_c)、I_(80)(80%ET_c)、I_(100)(100%ET_c)、I_(120)(120%ET_c),ET_c为玉米需水量;4个N-P_2O_5-K_2O施肥水平(kg/hm~2):F_(60)(60-30-30)、F_(120)(120-60-60)、F_(180)(180-90-90)和F_(240)(240-120-120),共16个处理。在生育期内对春玉米的根长、根表面积、根质量、根体积、根长密度进行观测,并统计地上部干物质量和产量。结果表明:灌水量为105%ET_c(2015年)和100%ET_c(2016年)与施肥量180-90-90 kg/hm~2组合的处理根长、根表面积、根质量、根体积均较高;相关性分析显示,各生育期根系特征参数与产量和地上部干物质量相关系数按大小排序表现出灌浆期大喇叭口期成熟期小喇叭口期的规律;在河西地区膜下滴灌施肥条件下,综合考虑根系生长、节水节肥及高产等因素,该地区灌水量90%ET_c~100%ET_c、180-90-90(N-P_2O_5-K_2O)kg/hm~2处理为最佳滴灌施肥策略。     

施钾对夏玉米子粒发育过程中糖代谢相关酶活性的影响

选用高淀粉玉米品种费玉3号及低淀粉玉米品种豫玉22为材料,研究了钾肥不同用量对玉米开花后子粒淀粉积累、淀粉合成关键酶活性的影响;分析不同处理对直、支链淀粉含量的影响以及淀粉合成关键酶活性与直、支链淀粉积累的关系。结果表明,施K2O 225kg/hm2的处理显著比不施钾肥处理提高了两品种子粒中腺苷二磷酸葡萄糖焦磷酸化酶（ADPG-PPase）的活性与尿苷二磷酸葡萄糖焦磷酸化酶 （UDPG-PPase）,显著提高了费玉3号子粒中可溶性淀粉合成酶（SSS） 的活性;施钾降低了豫玉22子粒SSS、束缚态淀粉合成酶（GBSS）的活性。施K2O 225kg/hm2提高了两品种穗位叶蔗糖含量和蔗糖合成能力,促进了子粒淀粉的合成;显著提高子粒直链、支链及总淀粉含量及积累速率,收获时总淀粉含量分别提高13.6%和8.2%,施钾更容易提高费玉3号子粒淀粉含量。中、高量钾提高了高淀粉玉米费玉3号子粒可溶性糖含量,有利于淀粉的合成;而对低淀粉玉米豫玉22子粒可溶性糖含量没有显著影响。除可溶性糖含量外,品种与施钾的交互作用对以上各指标的影响均达到显著性水平。     

A comparison of a pasture ley with a maize monoculture on the soil fertility and nutrient release in the succeeding crop

Specialization within agriculture has been a key factor in increasing farm income. The production systems have become increasingly simple, since farmers only grow a small number of crops which have a favourable market price. However, monocultural systems require increasing use of agrochemicals leading to unsustainable environmental costs. In this work, the soil fertility of two plots in a crop rotation previously grown for 5 years as pasture or maize monoculture was evaluated. In the pasture, the upper 0–20 cm soil layer sequestered 17.4 Mg organic C ha^?1 and accumulated 403 kg N ha^?1 more than under maize monoculture. Analytical data from pot experiments showed that soil samples from the pasture plot released significantly more mineral N than soil samples from the maize monoculture. Maize dry matter (DM) yields in 2012 and 2013 were 15.3 and 10.0 Mg ha^?1 in the pasture plot and 8.8 and 8.4 Mg ha^?1 in the maize monoculture plot. Nitrogen recoveries by maize were 175.4 and 68.0 kg ha^?1 in the pasture and 78.3 and 50.3 kg ha^?1 in the maize monoculture plot. The pool of organic matter accumulated during the pasture phase immobilized important nutrients which benefited the succeeding crop as the organic substrate was mineralized.     

长期不同施肥措施下黑土作物产量与养分平衡特征

为了明确长期不同施肥措施下黑土作物产量及养分平衡特征,利用开始于1979年的哈尔滨黑土肥力长期定位试验,以小麦-大豆-玉米轮作(3a)为一个周期,选取对照(不施肥,记作CK)、常量氮磷钾化肥配施(小麦施N、P2O5量分别为150、75 kg/hm2,大豆施N、P2O5量分别为75、150 kg/hm2,玉米施N、P2O5量分别为150、75 kg/hm2,K2O共施75 kg/hm2,记作NPK)、常量有机肥(施肥18 600 kg/hm2,记作M)、常量化肥有机肥配施(化肥施量同NPK,有机肥施量同M,记作MNPK)和二倍量氮磷化肥有机肥配施(小麦施N、P2O5量分别为300、150 kg/hm2,大豆施N、P2O5量分别为150、300 kg/hm2,、玉米施N、P2O5量分别为300、150 kg/hm2,有机肥共37 200 kg/hm2,记作M2N2P2)5个处理,研究了不同作物的平均产量、产量年际变化和土壤养分表观平衡。结果表明:1)较CK,长期平衡施用化肥或化肥配施有机肥提高了作物产量,多年平均增产率分别在82.5%~91.6%(小麦)和35.6%~40.9%(玉米)之间。长期不同施肥措施增产效果表现为M2N2P2MNPKNPKM,有机无机肥配施与单施化肥处理间作物产量差异不显著。2)长期不施肥处理小麦和玉米产量随试验年限推移呈下降趋势,降幅分别为13.93和42.61 kg/(hm2·a),大豆则以7.409 kg/(hm2·a)的速率增加。施肥处理小麦、大豆和玉米产量随试验年限的增加呈总体上升的趋势。3)在该试验条件下,长期施用常量化肥处理(NPK)和常量化肥有机肥配施处理(MNPK)土壤氮亏缺量分别为29.7和17.5 kg/hm2,磷盈余量分别为33.4和61.2 kg/hm2。各处理土壤中钾素均表现为亏缺,亏缺量在30.4~73.0 kg/hm2之间。MNPK处理氮、钾供应状况有所改善,较NPK处理分别增加12.2和27.6 kg/hm2。4)作物产量与土壤有机质、碱解氮、有效磷、降雨量、生育期日平均气温呈显著正相关关系(P0.05)。5)在黑土小麦-大豆-玉米典型轮作制度下,基于土壤养分平衡特征提出"稳氮、减磷和增钾"的施肥策略。该研究为评价和建立长期施肥模式、促进粮食持续生产提供依据。     

Changes in nutrient allocation between roots and shoots of young maize plants during sulfate deprivation

Hydroponically grown maize (Zea mays L.) plants were deprived of the external source of sulfate following an initial period of 13 d during which the sulfur (S) supply was sufficient. The amounts of dry mass (DM), water, sulfate, sulfur, nitrate, ammonium, nitrogen, phosphorus, potassium, magnesium, calcium, boron, iron, copper, zinc, and manganese were monitored in the shoots and the roots for 10 d. The deprivation altered the nutritional balance between them, causing a 70% decrease of sulfate in shoots and roots after 2 d. At 10 d, 95% of sulfate had vanished in both shoots and roots. Total S remained rather constant in shoots or was slightly decreased in roots after 4 d. This coincided with a decrease of Fe in shoots after 4 d. The calculated decreases of S and Fe in –S shoots, up to 6 d were linearly correlated. Kinetic analysis of the changes revealed a sequence in their onset, and we distinguished early and late changes. Among the early changes, we highlight the following ones: (1) an increased amount of Cu in both shoots and roots at 2 d; Fe was 40% decreased in both shoots and roots at 2 d; (2) a decrease in transpiration rate by 35% after 2 d; (3) alterations in boron allocation; in –S shoots the % changes in S were linearly correlated with the corresponding % changes in B; (4) calcium content was not affected by the S deprivation in –S shoots, whilst it increased in –S root after d 2; (5) Mn and Mg decreased from the beginning and in a uniform fashion in both –S shoots and roots. Day 6 may be considered as the boundary between the early and late changes. The root fraction of DM increased progressively after 4 d. Changes in DM seemed to be similar to those of P. Changes of Zn also took place rather late. In –S shoots and for the time interval between 6 d and 10 d, linear correlations were found between the corresponding % changes of the pairs DM–S, DM–P, DM–N, DM–water, S–N, S–P, and N–P.     

Phosphate Solubilization by Several Genera of Saprophytic Fungi and Its Influence on Corn and Cowpea Growth

The aim of this study was to test the ability of several strains of fungi, which were isolated from the Brazilian Amazon, to solubilize calcium phosphate in vitro and to promote corn and cowpea growth under axenic conditions. Each plant species received six treatments: inoculation with strains with high solubilization index (SI) (Haematonectria ipomoeae CML 3249 and Pochonia chlamydosporia var. catenulate CML 3250) and control treatments: inoculation with strain that does not solubilize phosphate on Pikovskaya agar (PVK) (Acremonium polychromum FSA115), and non-inoculated treatments with high concentration of insoluble phosphate (HPins), high concentration of soluble phosphate (HPs) or low concentration of soluble phosphate (LPs). The fungi strains had SI between 1.07 cm and 2.03 cm including species without previous report in the literature of their capacity to solubilize calcium phosphate. The two phosphate-solubilizing strains promoted greater corn and cowpea root growth than the controls FSA115, HPins and LPs, to a level similar to the HPs control.     

施氮时期对超高产夏玉米产量及氮素吸收利用的影响

选用登海661（DH661）和郑单958（ZD958）为试材,研究了超高产条件下施氮时期对夏玉米子粒产量、氮素利用率以及转运特性的影响。结果表明,拔节期一次性施氮较不施氮增产不显著;随着施氮次数的增加产量显著提高,灌浆期施氮可以显著提高粒重,从而提高产量。拔节期、大口期、花后10d按2:4:4施氮,DH661产量可达14188.9 kg/hm2;基肥、拔节期、大口期、花后10d按1:2:5:2施氮,ZD958产量可达14529.6 kg/hm2。生长期内分次施氮及灌浆期施氮可显著提高植株和子粒中氮素积累,延长氮素积累活跃期;同时可以显著提高氮素收获指数、氮肥农学利用率、氮素表观回收率和氮肥偏生产力。DH661和ZD958在2:4:4和3:5:2施肥方式下开花前和开花后氮素吸收比例分别为51:49和60:40。开花前分次施氮可显著提高氮素转运量和转运效率,灌浆期施氮可显著提高花后子粒氮素同化。DH661和ZD958在2:4:4和3:5:2施肥方式下花后氮素同化量分别占子粒吸氮量63.0%和50.5%。本试验条件下,DH661采用拔节期、大口期、花后10d按2:4:4施入,ZD958基肥、拔节期、大口期、花后10d按1:2:5:2施入或拔节期、大口期、花后10d按3:5:2施入可提高氮素利用率,实现高产高效。     

Silage yield and quality of row intercropped maize and soybean in a crop rotation following winter wheat

Maize (Zea mays L.) intercropped with soybean (Glycine max L.) may be a viable option to improve the quality of the silage. In this study, maize and soybean intercropped in different numbers of rows and their monocropping equivalents were tested to determine the best intercropping system in a crop rotation following winter wheat. The treatments were monoculture maize (M), monoculture soybean (S), 75% maize + 25% soybean (3M:1S), 50% maize + 50% soybean (2M:2S) and 25% maize + 75% soybean (1M:3S). The experiment was laid out in a randomized complete block design with three replications in 2011 and 2012 in Antalya, Turkey. Highest fresh forage yields were obtained from maize (53.3 t ha^?1) and 3M:1S (62.8 t ha^?1) treatments in 2011 and 2012, respectively. Maize treatment had highest dry matter yield (21.1 and 22.0 t ha^?1) in both years. Quality analysis of silage revealed that 3M:1S was superior to maize treatment in terms of dry matter (25.23%), crude protein (7.31%), crude fiber (18.27%), neutral detergent fiber (42.56%), acid detergent fiber (25.81%), lactic acid (4.71%) and acetic acid (4.05%). In conclusion, 3M:1S row intercropped production system was a better alternative for silage to monoculture maize in a crop rotation following winter wheat.     

Rock phosphate-enriched organic fertilizer with phosphate-solubilizing microorganisms improves nodulation,growth, and yield of legumes

ABSTRACT

Phosphorus availability from rock phosphate (RP) can be increased via composting with organic fertilizer and phosphate-solubilizing microorganisms (PSMs) in the soil. Incubation and pot experiments were conducted to investigate the comparative efficacy of RP-enriched organic fertilizer with PSMs vs. diammonium phosphate (DAP) as a control to enhance the production of legumes. In incubation studies, RP-enriched organic fertilizer with PSM₂ significantly increased soil aggregate stability (37%) and P-release (2.35 folds) as compared to control, whereas, in pot study, the number and dry weight of nodules plant^?1, shoot length, number of pods plant^?1, and grain yield of chickpea increased by 23%, 13%, 17%, 15%, and 15% with RP-enriched organic fertilizer + PSM₂ compared to control. Similarly, nitrogen and phosphorus contents in straw (11 and 42% respectively) and grains (11 and 13% respectively) and protein contents (16%) of chickpea were also increased. A similar trend was observed regarding the growth and yield parameters of lentil. The use of RP-enriched organic fertilizer with PSM could produce results similar to that of DAP for the optimum production of legumes.     

施肥对烤烟产量、品质及土壤养分、酶活性的影响

田间试验设置不施肥、单施化肥和有机无机配施3种施肥处理,研究了施肥对烤烟产量、质量及土壤养分、酶活性的影响。结果表明,在有机无机配施的处理中,烟叶产量最高,中上等烟比不施肥和单施化肥分别提高了24.6%和13.2%,土壤有效养分的变化与烤烟生理需要相协调。此外,施肥显著增强土壤脲酶活性;有机无机配施显著提高土壤蔗糖酶活性;土壤过氧化氢酶活性有机无机配施最高,单施化肥次之,不施肥最低。在不施肥的处理中,土壤酶活性在烤烟主要生育期无显著差异;但在施肥处理中,土壤酶活性随烤烟生育期的延长而提高,说明肥料养分(或有机质)与土温升高的交互作用可能是土壤酶活性提高的主要原因之一。