Growth Parameters of DK8031 Maize Variety as Affected by Varying Irrigation and Nitrogen Fertilizer Rates in Embu County, Kenya

Determination of crop growth parameters of maize helps assess the performance of the crop for food security. A study was conducted in two seasons covering 2012 and 2013 to establish optimal irrigation and nitrogen fertilizer rates for drought tolerant hybrid maize （Zea mays L.）, DK8031 variety, in sandy loam soils using furrow irrigation. Four additive irrigation levels （119.05 mm, 238.10 mm, 357.15 mm and 476.2 mm） were allocated the main plots while five nitrogen fertilizer rates （0 kg/ha, 60, 75 kg/ha, 90 kg/ha and 100 kg/ha） were allocated the sub-plots. Both irrigation and nitrogen fertilizer treatments significantly enhanced crop growth parameters under consideration. Stand count per treatment plot, plant height and number of leaves per ranged from 45-59 plants/plot, 215-238 cm and 14-16 leaves respectively. It was concluded that use of supplementary irrigation and phased nitrogen fertilizer rates for maize growing in areas such as Embu can greatly promote crop growth.

Use of Several Plant Materials and Chemicals to inhibit Soil Urease Activity and Increase Nitrogen Recovery Rate of Urea by Plant

Effects of residues of 9 plants, lemon eucalyptus (Eucalyptus citriodoraHook., P_1), robust eucalyptus (E. robusta Smith, P_2), Nepal camphortree (Cinnamomum glanduliferum(Wall.) Nees, P_3), tea (Camellia sinensis (Linn.) O. Ktze. f., P_4), oleander (Nerium indicum Mill,P_5), rape (Brassica campestris L., P_g), Chinese tallow tree (Sapium sebiferum L., P_7), tung(Vernicia fordii (Hemsl.), P_8), and croton (Croton tiglium L., P_9), 7 chemicals, boric acid (C_1),borax (C_2), oxalic acid (C_3), sodium oxalite (C_4), sodium dihydrogen phosphate (C_6), sodiumsilicate (C_7) and sodium citrate (C_8), and a natural organic substance, humic acid (C_5), onurease activity of a neutral purple soil and recovery of urea nitrogen by maize were studied throughincubation and pot experiments. Hydroquinone (HQ) was applied as the reference inhibitor. Afterincubation at 37℃ for 24 h, 7 inhibitors with higher ability to inhibit urease activity wereselected and then incubated for 14 days at 25℃. Results of the incubation experiments showed thatsoil urease activity was greatly inhibited by them, and the inhibition effect followed an order ofP_2>P_4>C_3>C_2>P_3>C_1>HQ>P_1. The 7 selected materials reduced the accumulative amounts of Nreleased from urea and the maximum urease activity by 11.7%～28.4% and 26.7%～39.7%, respectively,and postponed the N release peak by 2～4 days in the incubation period of 14 days under constanttemperature, as compared to the control (no inhibitor). In the pot experiment with the 7 materialsat two levels of addition, low (L) and high (H), the C_1 (H), C_3 (H), C_1 (L), P_4 (L) and C_2 (L)treatments could significantly increase the dry weights of the aboveground parts and the totalbiomass of the maize plants and the apparent recovery rate of urea-N was increased by 6.3%～32.4% ascompared to the control (no hibitor).

Root characteristics and yield of rice as affected by the cultivation pattern of strong seedlings with increased planting density and reduced nitrogen application

To address the relationships between the amount of nitrogen fertilizer application and the yield of double cropping rice systems,we investigated the effects of a cultivation pattern of strong seedlings with increased planting density and reduced nitrogen application(SDN)on the morphological and physiological characteristics of double cropping rice.Our results indicated that the effects of SDN on the morphological characteristics of the single plant roots of double cropping rice were not significant,but the morphological characteristics of the population roots were largely different.Specifically,SDN significantly increased the morphological indexes of the root population such as root fresh weight,root volume,root number,root length and root dry weight.The effects of SDN on the total root absorption areas and root active absorption areas of the single plants were non-significant,but it dramatically enhanced the total root absorption areas and root active absorption areas of the plant population during the tillering,heading and mature stages.In addition,SDN significantly increased the root bleeding intensity and elevated the soluble sugar and free amino acid contents of root bleeding sap.Compared to the traditional cultivation pattern(CK),SDN significantly increased root bleeding intensity at the heading stage by 4.37 and 8.90% for early and late rice,respectively.Meanwhile,SDN profoundly enhanced the soluble sugar contents of root bleeding sap by 12.85 and 10.41% for early and late rice,respectively.In addition,SDN also significantly enhanced free amino acid content of root bleeding sap by 43.25% for early rice and by 37.50% for late rice systems compared to CK.Furthermore,SDN increased the actual yield of double cropping rice mainly due to the higher effective panicle number and the larger seedsetting rate.The actual yields of early rice under SDN were higher than CK by 9.37 and 5.98% in 2016 and 2017,and the actual yields of late rice under SDN were higher than CK by 0.20 and 1.41% in 2016 and 2017,respectively.Correlation analysis indicated that the significant positive correlations were observed between the majority of the root indexes and the actual yield across the four different growth stages.

Effects of Increased Planting Density with ReducedNitrogen Application on Yield Formation and NitrogenUtilization of Autumn Maize

With the change of cropping system in the middle reaches of the Yangtze River,the planting area of autumn maize is gradually increasing.However,the cultivation techniques are still under improvement for higher yield and nitrogen efficiency of autumn maize.Increase in planting density with reduced nitrogen fertilizer application is one of the important paths to achieve high yield and high nitrogen utilization efficiency.Meanwhile,the effect needs to be verified for autumn maize.The semi-compact autumn maize variety Qinyu 58 was planted under different planting densities and nitrogen fertilizer amounts with the split plot design.Different nitrogen application rates were arranged in the main plots,including the conventional nitrogen application(N300,300 kg/hm^2),30%reduction from the conventional treatment(N210,210 kg/hm^2)and no nitrogen application(N0).Different planting densities were arranged in the sub-split plots,including the conventional planting density(D60,60000 plants/hm2),medium density(D78,78000 plants/hm^2)and high density(D93,93000 plants/hm2).The effects of nitrogen fertilizer,planting density and their interaction effects on canopy structure,dry matter accumulation,yield and nitrogen use efficiency of autumn maize were studied.The nitrogen application rate and planting density had obvious interaction effects on the yield formation of autumn maize.Compared with the conventional cultivation(N300D60),increasing the planting density with 30%reduction in nitrogen application(N210)can obviously increase the canopy light interception rate,LAI,dry matter accumulation and yield.However,there was no significant change in canopy light interception rate,LAI,dry matter accumulation,grain weight and yield between D93 and D78.Compared with N300D60,nitrogen translocation efficiency and nitrogen contribution proportion to grain nitrogen did not change significantly in autumn maize grown under N210 and D78 treatments,whereas nitrogen partial productivity,nitrogen agronomic efficiency and recovery and utilization efficiency of nitrogen fertilizer increased significantly.Moreover,high density(D93)planting at N210 plots significantly improved nitrogen transport efficiency and utilization efficiency in autumn maize.Therefore,the suitable planting density of the autumn maize variety Qinyu 58 in Hubei Province is recommended a value of 78000 plants/hm^2,with the nitrogen application rate of 210 kg/hm2,which can achieve the target of higher yield by increasing density and reducing nitrogen.

Water,Nitrogen and Plant Density Affect the Response of Leaf Appearance of Direct Seeded Rice to Thermal Time

Field experiments were conducted in the Ebro Delta area （Spain）, from 2007 to 2009 with two rice varieties： Gleva and Tebre. The experimental treatments included a series of seed rates, two different water management systems and two different nitrogen fertilization times. The number of leaves on the main stems and their emergence time were periodically tagged. The results indicated that the final leaf number on the main stems in the two rice varieties was quite stable over a three-year period despite of the differences in their respective growth cycles. Interaction between nitrogen fertilization and water management influenced the final leaf number on the main stems. Plant density also had a significant influence on the rate of leaf appearance by extending the phyllochron and postponing the onset of intraspecific competition after the emergence of the 7th leaf on the main stems. Final leaf number on the main stems was negatively related to plant density. A relationship between leaf appearance and thermal time was established with a strong nonlinear function. In direct-seeded rice, the length of the phyllochron increases exponentially in line with the advance of plant development. A general model, derived from 2-year experimental data, was developed and satisfactorily validated; it had a root mean square error of 0.3 leaf. An exponential model can be used to predict leaf emergence in direct-seeded rice.

Effect of Plant Growth-Promoting Rhizobacteria at Various Nitrogen Rates on Corn Growth

Plant growth-promoting rhizobacteria (PGPR) colonize plant roots and promote plant growth by producing and secreting various chemical regulators in the rhizosphere. With the recent interest in sustainable agriculture, an increasing number of researchers are investigating ways to improve the efficiency of PGPR use to reduce chemical fertilizer inputs needed for crop production. Accordingly, greenhouse studies were conducted to evaluate the impact of PGPR inoculants on biomass production and nitrogen (N) content of corn (Zea mays L.) under different N levels. Treatments included three PGPR inoculants (two mixtures of PGPR strains and one control without PGPR) and five N application levels (0%, 25%, 50%, 75%, and 100% of the recommended N rate of 135 kg N ha−1). Results showed that inoculation of PGPR significantly increased plant height, stem diameter, leaf area, and root morphology of corn compared to no PGPR application under the same N levels at the V6 growth stage, but few differences were observed at the V4 stage. PGPR with 50% of the full N rate produced corn biomass and N concentrations equivalent to or greater than that of the full N rate without inoculants at the VT stage. In conclusion, mixtures of PGPR can potentially reduce inorganic N fertilization without affecting corn plant growth parameters. Future research is needed under field conditions to determine if these PGPR inoculants can be integrated as a bio-fertilizer in crop production nutrient management strategies.

N-Exponential Fertilization Could Affect the Growth and Nitrogen Accumulation of Metasequoia glyptostroboides 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).

增密与减氮对青贮玉米产量的影响

以郑青贮1号、北农青贮368和郑单958为试验材料,研究了施氮量、种植密度及品种互作对青贮玉米鲜草产量和干物质生物产量的影响。结果表明:品种(郑青贮1号、北农青贮368、郑单958)、施氮量(N_(1)、N_(2)、N_(3)分别为240、216、168 kg/hm^(2))和密度(D_(1)、D_(2)、D_(3)、D4分别为6.75万、7.50万、8.25万、9.00万株/hm^(2))对青贮玉米干物质生物产量和鲜草产量均有显著的影响,在相同的密度水平下,3个玉米品种的干物质生物产量随施氮量的减少,总体呈下降趋势,但是N_(1)和N_(2)处理之间无显著差异;在相同施氮水平下,3个玉米品种的干物质生物产量随密度的增加,总体呈现先上升后下降的趋势;在不同施氮量和种植密度条件下,正常施氮量且高密度种植条件下(N_(1)D_(3)、N_(1)D4)的产量表现为郑青贮1号>北农青贮368>郑单958;在正常施氮量且低密度种植(N_(1)D_(1)、N_(1)D_(2))和减氮条件下(N_(2)、N_(3))的产量表现为北农青贮368>郑青贮1号>郑单958。因此,综合考虑减氮增产高效的目标,氮肥减施10%(N_(2))的条件下,郑青贮1号和北农青贮368的推荐栽植密度为8.25万株/hm^(2),郑单958不推荐作为青贮玉米种植。

4种氮肥用量对‘紫嫣’茶树生长发育的影响

【目的】研究氮肥用量对‘紫嫣’茶树生长和生化成分含量的影响,为‘紫嫣’茶树高产高效栽培体系的建立提供理论依据。【方法】试验设置4个尿素水平(0、375、525、675 kg/hm^(2)),比较不同氮肥用量下‘紫嫣’茶树产量、品质成分和氮磷钾含量的差异。【结果】不同施氮量处理均能不同程度地促进‘紫嫣’茶树新梢生长、芽叶品质成分含量及氮磷钾的积累,提高土壤酶活性,以560 kg/hm^(2)尿素处理效果显著。此处理下,‘紫嫣’茶树春茶产量显著增加27.44%,春梢的水浸出物、氨基酸和茶多酚含量显著提高10.41%、27.38%、10.09%,叶绿素、类胡萝卜素和花青素显著提高37.35%、25.00%、19.57%。而夏梢的水浸出物、茶多酚含量和叶绿素总量较不追肥处理仍显著提高。【结论】适量氮肥利于‘紫嫣’茶树生长,使产量和品质提高,但随着氮肥用量增加,氮肥的促进效应降低。因此,对‘紫嫣’茶园(黄壤土pH=4.66,有机质27.43 g/kg,全氮1.24 g/kg,速效磷32.05 mg/kg,速效钾81 mg/kg)宜追施525 kg/hm^(2)尿素。

不同株型小花生品种氮素养分吸收利用特性

南方小花生植株高大的地方良种与矮化改良的品种并存。为探明其需氮规律,实现差异化施肥的高产管理,以湖南主栽的高秆地方良种安化小籽、矮秆现代品种湘黑小果为材料,设置4个基施复合肥用量0、450、600、750 kg/hm^(2),分别代表土壤背景(CK)、低肥(F30)、中肥(F40)、高肥(F50)水平,于4个生育时期测定并分析植株各器官氮含量、积累与分配状况。结果表明:氮含量以高秆品种果>叶>根>茎为序;矮秆品种则以叶>果>根>茎为序。叶、根氮含量表现为高秆<矮秆,而茎、果反之。增施肥料对氮含量的影响程度总体趋势为茎>叶>根>果,利于营养器官的氮素同化吸收。氮积累量两品种各器官以叶>果>茎>根为序。除苗期外,其余时期的全株、叶、茎氮积累量表现为高秆>矮秆;根在苗期、结荚期为高秆<矮秆,其余时期相反;果则为高秆<矮秆。施肥利于营养器官前期的氮素积累。氮素分配率两品种均以叶最高,荚果和茎其次,根最少。地上部为高秆>矮秆,而地下部反之,说明矮秆植株吸收的氮素更利于转运到荚果。氮素利用效率均为矮秆>高秆,氮素生产效率、氮肥偏生产力两品种均以F40、F30最高,过度施肥降低氮素利用效率。综上,矮秆品种氮素积累量对增肥的响应度较低,总积累量虽然较少而在荚果中分配较多,并具有更高的氮素利用效率;品种株型特点应作为南方典型贫瘠酸性红壤区小籽花生生产上确定施肥量的主要依据。

绿洲灌区密植对氮肥减量玉米产量的补偿潜力

【目的】针对绿洲灌区玉米生产氮肥用量过高的问题,探究通过密植补偿氮肥减量对玉米产量负效应的可行性。【方法】2019—2021年,以施氮水平为主区,设地方习惯施氮(N_(2),360 kg·hm^(-2))、减量25%施氮(N_(1),270 kg·hm^(-2))两个水平;以种植密度为副区,设传统(M_(1),7.8万株/hm^(2))、中(M_(2),10.4万株/hm^(2),增密33%)、高(M3,12.9万株/hm^(2),增密66%)3个密度水平,进行裂区试验,重点研究氮肥减量条件下增密对玉米产量及其构成因素的影响。【结果】(1)氮肥减量导致玉米籽粒产量、生物产量分别降低4.0%、4.9%。减氮条件下,中密度可以产生籽粒产量补偿效应,N_(1)M_(2)较对照N_(2)M_(1)提高4.1%;高密度处理N_(1)M3生物产量补偿效应最大,较对照提高14.2%。(2)通过回归分析模拟得到:减氮条件下,当种植密度提高至8.4万株/hm^(2)可以与对照N_(2)M_(1)籽粒产量持平,并在10.6万株/hm^(2)时获得最大产量13537kg·hm^(-2),较对照提高4.9%。(3)氮肥减量引起穗数、穗粒数和千粒重分别降低5.0%、3.3%和3.4%;中、高密度分别较传统密度提高穗数27.9%、49.7%,降低穗粒数3.8%、8.4%,降低千粒重5.2%、8.9%。中密度较传统密度对收获指数无显著影响,而高密度使收获指数降低14.2%。N_(1)M_(2)较对照N_(2)M_(1)通过穗数增加补偿了减氮引起穗数、穗粒数及千粒重的下降,从而实现丰产。(4)氮肥减量降低拔节期至抽雄吐丝期的玉米生长率7.2%—8.4%;中、高密度较传统密度提高苗期至大喇叭口期玉米生长率27.3%、60.3%。(5)氮肥减量条件下,N_(1)M_(2)较对照提高叶、茎和鞘干物质转运量达9.6%、13.6%和3.7%,提高叶和茎对籽粒产量的贡献率5.3%和9.0%。【结论】通过合理密植可以补偿减氮引起的玉米产量下降,在施氮量270 kg·hm^(-2)的基础上增密至10.4万株/hm^(2),能够最大化产量补偿效应,是绿洲灌区玉米节氮稳产丰产的可行措施。

氮肥施用量和种植年限对苜蓿产量和品质影响的Meta分析

为探究氮肥施用量和种植年限对苜蓿(Medicago sativa L.)产量和品质的影响,确定最佳氮肥施用量和最适宜种植年限,以中国为研究区域,通过检索文献收集整理田间数据,将数据按照氮肥添加量(不施氮;0<施氮量≤50 kg/hm^(2),低氮;50<施氮量≤100 kg/hm^(2),中氮;施氮量>100 kg/hm^(2),高氮)和种植年限(1年、2年、3年和3~5年)进行分组,采用整合分析(Meta-analysis)方法系统研究氮肥施用量和种植年限对苜蓿产量和品质(粗脂肪、粗蛋白、酸性洗涤纤维和中性洗涤纤维)的影响。结果表明:随施氮量增加,苜蓿产量和品质指数提高效应呈先升高后降低趋势,中氮水平下产量和品质指数提高效应均最高;施氮显著影响苜蓿品质指标(中性洗涤纤维除外);与低氮和高氮相比,中氮下苜蓿粗蛋白含量提高效应最高、酸性洗涤纤维降低效应最高(P<0.05)。随种植年限延长,苜蓿产量提高效应呈先升高后降低趋势,种植3年苜蓿产量提高效应最高。综上所述,从区域尺度上来看,为获得高产优质的苜蓿,建议最佳氮肥施用量为50~100 kg/hm^(2),最适宜种植年限为3年。在实际生产中,应基于生产目标,结合当地气候特征、土壤特性和苜蓿品种等实际情况,确定适宜氮肥施用量和种植年限。

氮肥运筹对小麦籽粒灌浆、花后干物质转运及植株糖含量影响

【目的】为了明确不同氮肥运筹对安徽省长江中下游小麦干物质转运、籽粒灌浆特性、植株糖含量及产量等影响。【方法】以小麦白湖麦1号为试验材料,不同施氮水平和基追比(3个施氮量:180、210、240 kg/hm^(2);3个基追比:5∶1∶4、7∶1∶2、5∶4∶1)对安徽省长江中下游小麦干物质转运、氮肥利用、籽粒灌浆特性以及植株糖含量的影响。【结果】随着施氮量的增加,小麦开花期与成熟期干物质分配量呈上升趋势,而小麦花后干物质转运则呈现先高再低的趋势,以210 kg/hm^(2)的施氮量为最高;相同施氮水平,基追比7∶1∶2(基肥∶分蘖肥∶拔节肥)条件下小麦的干物质积累量、氮肥利用率以及产量为最高。在相同基追比处理下增加施氮量能提高小麦灌浆持续时间与推迟最大灌浆速率出现日,而小麦籽粒干重、理论千粒重以及平均灌浆速率有逐渐降低的趋势。在施氮量一定的条件下,基追比5∶1∶4有利于提高籽粒最大灌浆速率,且将籽粒灌浆速率维持在较高水平,以及较高的籽粒干重。施氮提高了叶片的同化物生产能力,提高叶片可溶性糖和蔗糖的含量。对成熟期茎秆碳水化合物含量的进一步分析,增施氮肥降低了茎秆蔗糖浓度,提高茎秆可溶性总糖含量。【结论】在长江中下游地区,白湖麦1号小麦高产的氮肥施用量应以210 kg/hm^(2)为最佳,而基追比应参考7∶1∶2。

青贮玉米应用现状以及其栽培措施研究进展

青贮玉米营养丰富、适口性好,是畜牧业发展中重要的饲草作物。近年来,随着我国畜牧业的迅速发展和“粮改饲”政策的不断推进,我国青贮玉米产业发展迅速,产量和品质均得到很大提升。青贮玉米种植面积有限,且品种多为传统品种。如何在有限的资源条件下提高青贮玉米产量和品质,是目前青贮玉米产业亟待解决的问题。目前,对于青贮玉米的栽培措施已开展了许多深入的研究,文章综述了青贮玉米的发展现状和近年来青贮玉米高产优质栽培的研究成果,主要包括品种选择、种植方式、种植密度、氮肥施用和收获时期等栽培措施对青贮玉米产量和品质的影响,以及青贮玉米与动物生产应用相关的研究,旨在为青贮玉米优质生产提供重要参考。

菜子饼肥等氮替代化肥雪茄烟叶产质量及土壤有效养分含量变化

为了探索施用不同比例的有机肥氮对雪茄烟叶生长及产质量的影响,采用大田试验方式,以雪茄烟叶品种CX80为材料、菜子饼肥为有机肥氮源,按有机肥氮、化肥氮不同配施比例设置4个处理,分别为CK(0∶100%)、T1(10%∶90%)、T2(20%∶80%)、T3(30%∶70%),研究各处理对植烟土壤pH和养分含量、雪茄烟叶生长和品质的影响。结果表明,随有机肥氮替代比例的增加,呈现出土壤速效钾、碱解氮、有效硼含量逐步下降,有效钼持续增加,pH、有机质含量、交换性钙含量、交换性镁含量、阳离子交换量先上升后下降;与CK相比,T2株高、叶数分别增加12.02%和3.09%,T3中部最大叶面积增加7.69%,T2、T3烟叶产量显著增加(P<0.05),烟叶均价分别提高7.64%、7.57%;随有机肥氮替代化肥氮比例的增加,晾制后烟叶烟碱、总糖、总氮含量呈先增加后减少趋势,糖碱比和钾氯比上升;感官评吸呈波动增加趋势,其中T3最高,其次是T1、T2。

种植密度和施氮量对贵州地区爱沃燕麦产量、品质和经济效益的影响

为了解种植密度和施氮水平对爱沃燕麦产量、品质和经济效益的影响,试验采用完全随机区组设计,设3个种植密度150、180、210 kg/hm^(2)(分别记作D1、D2和D3),4个施氮量0、80、110、145 kg/hm^(2)(分别记作N0、N1、N2和N3)。结果显示,同一施氮量下,爱沃燕麦的茎粗、株高、叶片数、叶宽、粗蛋白含量和粗脂肪含量随种植密度的增加而降低,不同种植密度间干草产量差异不显著(P>0.05)。同一种植密度下,施氮有利于提高爱沃燕麦的干草产量、粗蛋白含量和经济收益。在3个种植密度和4个施氮量的双因素试验中,D1N2的干草产量、粗蛋白含量及净收入最高。研究表明,贵州地区爱沃燕麦的最佳种植方式为种植密度150 kg/hm^(2)、施氮量110 kg/hm^(2)。

不同施肥方式对玉米种植区氮、磷流失的影响

研究不同施肥处理方式下山东泰安地区夏玉米种植体系下氮、磷的流失规律,能够为该地区的农田种植面源污染防控提供依据和技术参考。本试验设置当地农民常规施肥处理、主因子优化施肥处理、综合优化施肥处理3种方式,采用自然降雨野外观测方法,分析不同施肥处理对山东泰安地区玉米种植径流淋溶氮磷流失的影响。结果表明:地表径流和降雨量密切相关。与常规处理和主因子优化处理相比,综合优化处理减少了径流水量,在监测期间,综合优化处理径流水量减少20.75%。氮在径流和淋溶水中均以可溶态的形式存在,并且淋溶水中氮、磷的浓度高于径流。径流和淋溶水总氮、硝态氮、氨氮和总磷的平均浓度总体表现排序为常规处理>主因子优化处理>综合优化处理,主因子优化处理后,径流水中总氮浓度降低38.58%,总磷浓度降低46.88%,淋溶水中总氮浓度降低26%,总磷浓度降低73.07%。研究表明,综合优化处理是试验区夏季农田防控氮、磷流失和保证作物产量理想的施肥方式。

复合肥高氮原料尿素装置的精益管理与效益提升

文章以河南晋开集团复合肥高氮原料尿素装置为例,详细介绍了精益管理的理念,并结合企业实际,提出了“精、准、细、严”四字方针的管理模式,从稳产增产、节支降耗、质量提升等方面进行技术改造,进而提高经济效益。将精益管理落实到复合肥高氮原料尿素装置具体工作中,有效促进了企业高质量发展。

减氮施肥结合修剪处理对百香果结果蔓生长及单株产量与品质的影响

【目的】研究减氮施肥措施并结合修剪处理对百香果生长、开花和结果以及单株产量与果实品质的影响,为合理使用氮肥并明确减氮施肥下选择适宜百香果枝蔓修剪的栽培措施提供技术支撑。【方法】以百香果品种台农1号为材料,2021—2022年在百香果大田采用单级结果蔓栽培模式,以100%氮肥施用量(240 kg·hm^(-2))和不修剪措施组合为对照(T1、CK),研究9种不同氮肥施用量和修剪强度措施组合(T1–T9)处理百香果定植苗,测定并分析了百香果结果蔓生长及单株产量与品质相关指标。【结果】合理减氮施肥和修剪措施组合能促进百香果结果蔓生长、开花和结果,增加单株产量,提高果实品质。与T1(CK)相比,80%氮肥施用量结合强修剪措施(T6)可使植株茎粗度、有效叶片数、花蕾数、开花数、坐果数、成花率和坐果率等7项指标值均显著增加,且均达到最高水平,同时使百香果结果蔓平均节间长度显著缩短了19.04%;减氮施肥结合修剪处理的百香果单株产量在2个试验年份均值较对照(CK)各表现显著差异(P<0.05),其中T6处理百香果单株产量显著提高了71.74%,达到最高值,且单株结果数、平均单果重和中大果比率均达到最大,分别提高了48.90%、15.29%和1.65%,总糖含量和糖酸比值分别增加了25.89%和75.24%,酸含量降低了28.18%。【结论】百香果生产中,施用80%氮肥量,即氮施用量减少至192 kg·hm^(-2)时,并采用定植苗生长枝条强修剪措施,可增加单株产量,并使百香果植株生长、开花和结果及品质达到最佳效果。

种植密度和施肥方式对春播鲜食糯玉米产量、品质及氮素吸收利用的影响

【目的】适宜的种植密度和施肥方式是实现玉米高产优质高效的重要措施。为此,我们研究了不同密度和施肥方法组合对春播鲜食糯玉米产量、品质和氮素吸收利用的影响,旨在建立实现鲜食糯玉米高产、优质及轻简施肥的栽培技术体系。【方法】田间试验于2021、2022年在江苏南通进行,供试品种为江苏省主推鲜食糯玉米品种“苏玉糯11号”。试验采用裂区设计,主区为密度水平:4.5×10^(4)(D1)、5.25×10^(4)(D2)、6.0×10^(4)(D3)、6.75×10^(4)(D4)、7.5×10^(4)(D5)株/hm^(2);副区为施肥模式,在总施氮(N)量225 kg/hm^(2)条件下,设置常规基施普通复合肥N 75 kg/hm^(2)+6叶期追施尿素N 150 kg/hm^(2)(CF)、缓释型复合肥一次性基施(SF-b)和6叶期一次性追施(SF-t)3种施肥方式。在玉米吐丝期和鲜食期,测定生物量和氮素积累量,在鲜食期测定鲜果穗产量和鲜籽粒产量,分析籽粒淀粉、蛋白质和可溶性糖含量。【结果】相同施肥模式下,D2、D3、D4、D5密度下的鲜果穗产量分别较D1密度下平均增加了4.14%、7.68%、11.68%、7.17%,鲜籽粒产量平均增加了6.09%、7.48%、12.19%、7.08%。两年D4密度下玉米的平均鲜穗和籽粒产量显著高于其他密度下(P<0.05),D4密度下玉米吐丝前后干物质和氮素积累量、氮肥偏生产力、氮素回收率也达到最高值。籽粒淀粉、可溶性糖和蛋白质含量平均值随密度增加而不同程度地降低,施肥方式提升品质的效果无显著差异。相同密度条件下,SF-t处理鲜果穗和鲜籽粒产量显著高于CF和SF-b处理,而吐丝前后干物质和氮素运转量和运转率显著低于CF和SF-b处理;SF-b处理玉米吐丝前后干物质和氮素积累量、运转量及运转率高于或者与CF处理相近。20个处理组合中,以D4−SF-t组合的产量、氮素利用率最高。【结论】与基施缓释肥或基施复合肥加追施尿素相比,6叶期一次性追施缓释复合肥可显著提高吐丝后玉米的干物质和氮素积累量,进而有效提高鲜食玉米果穗和籽粒产量。适当提高密度有效发挥了玉米的群体增产效应,提高了氮肥吸收和利用效率,最大限度地减少对品质的不利影响。在供试条件下,栽培密度提高到6.75×10^(4)株/hm^(2),配合缓释复合肥6叶期一次性追施可作为江苏春播鲜食糯玉米高产优质高效的技术组合。