坡度与施肥密度对毛竹林氮素流失的影响

为研究坡度与施肥密度对笋用毛竹(Phyllostachys edulis)林氮素流失的影响,在典型的笋用毛竹林内建立径流场,收集并检测不同类型毛竹林径流水中的NH_(4)^(+)-N、NO_(3)^(-)-N、TN和TP含量。结果表明,施肥后短期内,毛竹林径流水中的NH_(4)^(+)-N、NO_(3)^(-)-N和TN含量升高,之后缓慢下降。坡度对NH_(4)^(+)-N、NO_(3)^(-)-N和TN含量的影响较大;随着坡度的增加,NH_(4)^(+)-N、NO_(3)^(-)-N和TN在径流水中的含量及年流失总量均增加;30°坡毛竹林中的NH_(4)^(+)-N、NO_(3)^(-)-N和TN年流失总量均最高,分别为69.72、136.13和413.50 g·hm^(-2)·a^(-1)。施肥密度对养分流失也有较大影响;随着施肥密度的增加,NH_(4)^(+)-N、NO_(3)^(-)-N和TN在径流水中的含量及年流失总量均增加,最高年流失总量分别为64.47、132.74和364.94 g·hm^(-2)·a^(-1)。在整个试验周期内,TP在径流水中的含量和年流失总量均无显著变化。施肥是毛竹林径流水中NH_(4)^(+)-N、NO_(3)^(-)-N和TN含量升高的原因之一。

不同肥料以及不同施肥密度对黄樱椒的影响

1肥效试验 1．1试验处理 试验地点为湖州市八里店镇义山村“中味”公司黄樱椒基地，供试氮肥为国产尿素，钾肥为以色列氯化钾。黄樱椒于3月12日播种育苗，5月6日移裁，种植密度为9万株／hm^2。试验处理采用二因素三水平裂区设计，

节水灌溉条件下施肥与密度对双季晚稻‘丰源优299’产量和稻米品质的影响

本试验采用裂区设计对节水灌溉条件下不同施氮量和栽植密度对双季晚稻‘丰源优299’的产量和品质的影响进行了研究。试验结果表明：随着施氮量的增加,稻米垩白粒率、垩白度和蛋白质含量分别增加8.5%-20.0%、0.8%-1.8%、7.0%-43.4%,胶稠度、直链淀粉含量分别降低5.8%-20.3%、3.7%-6.6%。随着栽植密度的增加,碾米品质和稻米蛋白质含量先增加后降低,垩白粒率、胶稠度及稻米直链淀粉含量有减少的趋势,而垩白度有增加的趋势。施氮量为135 kg/hm2,密度为30万穴/hm2时,增产1.0%-34.7%,为最优的施肥与栽植密度组合。

栽培密度与施肥对尾巨桉中大径材生长的影响

对广西东门林场13年生尾巨桉(E.urophylla×E.grandis)中大径材密度与施肥试验进行研究,经方差分析表明,不同密度对尾巨桉生长影响的差异达到极显著水平,而早期不同施肥处理对尾巨桉后期生长影响的差异不显著,以883株/hm2和667株/hm2两种栽培密度是比较适合尾巨桉中大径材的培育。

栽培密度和施肥量对甜玉米金玉甜1号农艺性状和产量的影响

研究了不同的栽培密度和施肥量对甜玉米金玉甜1号的农艺性状和产量的影响,结果表明:金玉甜1号的最适栽培密度为4.20万株/hm2,氮肥施用量为225 kg/hm2。

密度与施肥对白肋烟香味物及品质的影响

采用同时蒸馏萃取、顶空分离前处理方法及气相色谱-质谱联用分析鉴定技术,对不同种植密度与施肥水平组合生产的原烟进行了定量测定,并对其主要化学成分和鲜叶的腺毛密度也做了测定,结果表明:密度与施肥对香味物质的成分与含量、主要化学成分和腺毛密度都具有一定影响,以A2B2处理的较好,其次是A2B3,A1B2和A1B3.因此,在当地TN86以种植密度18000株/hm2,施氮300?/hm2,N∶P2O5∶K2O=1∶11∶.5的栽培组合,有利于烟叶香吃味的形成.

玉米栽培中密度与施肥的重要性

我国是农业生产和出口大国,农业种植直接影响着我国经济的发展以及人们的生活水平。我国政府对农业的发展非常重视,为此出台了一系列的政策支持和鼓励农业种植的发展。我国作为粮食生产大国对粮食作物的关注度极高,玉米作为我国主要的粮食产物之一,对我国农业的发展更是有着深远的影响。如何提高玉米的粮食产量一直是农业科学家们思考的问题,也是限制我国农业经济发展的关键因素。影响玉米产量高低的因素很多,既包括玉米种子这一决定性的内在因素,还受自然环境、种植间距、玉米施肥程度等许多外在因素的影响。本文主要从玉米栽培的植株密度和玉米成长过程中的施肥频率2个角度进行研究,了解玉米栽培密度和施肥对产量的影响。

玉米栽培密度与施肥对种植效果的影响及管理要点研究

玉米栽培过程中,若出现密度与施肥不够科学合理的情况,势必会对玉米生长高度、玉米产量和质量带来极大的影响,因此要对玉米栽培管理引起高度重视,并结合地区玉米种植实际情况,对玉米栽培的密度进行科学控制,同时根据玉米不同生长时期给予肥料支持,真正提高玉米栽培的产量与质量。本文联系玉米栽培密度与施肥对种植效果产生的影响,对当前玉米栽培中密度与施肥方面存在的问题进行细致分析,并围绕实际案例提出几点有效应对策略,希望可以发挥参考作用。

浅议油菜不同栽培密度与不同施肥方案

油菜是泸西县小春的主要经济作物。它的栽培密度和施肥技术一直得不到统一,作为科技推广部门,如何寻求适合本地的油菜栽培技术方案,不断总结成功的经验,通过提高单产,增加总产。具有十分重要的意义,本文通过试验,对泸西县的油菜种植,在种植密度和施肥方案方面提出了一个技术措施。

密肥水平对川西平原春(播)小麦产量与品质的影响

以密度为主处理(基本苗22,27,33万/667m^23个水平),施氮量为副处理(纯氮0,4,8,12kg/667m^24个水平),对川西平原春播小麦进行密肥试验,结果表明:(1)低密度平均产量显著低于中密度,但中高密度之间、低密度与高密度之间差异均不显著;副处理以无氟处理产量最低,显著低于4kg和8kg纯氮,但无氮与12kg纯氮之间,以及4kg,8kg,12kg纯氮之间的差异均不显著。表明,中等密度和较高施氮量(4～8kg)利于高产。(2)增施氮肥对春播小麦品质没有显著影响,而过高密度(33万/667m^2)则显著降低品质。

苦荞高产优质栽培技术研究与集成

本文以国家燕麦荞麦产业技术体系凉山综合试验站近2年所做的系列荞麦栽培、品种比较和展示等试验为依据，总结彝家农户在长期荞麦种植中的栽培技术和经验，形成一套简单、易行、有效的栽培技术，提升凉山荞麦产区生产。

Optimal Technique for High Yield of Purple Flesh Sweetpotato in Chongqing

[Objective] The aim was to obtain the best planting density and the best fertilizer of purple flesh sweetpotato so as to provide theoretical basis for breeding of high yield and quality of purple flesh sweetpotato in Chongqing.[Method] The effects of fertilization,planting density and variety on yield of purple flesh sweetpotato were studied by orthogonal test of L9（34）.Residential treatment was：fertilization（A）,300 kg/hm2（A1）,600 kg/hm2（A2）,900 kg/hm2（A2）;density（B）,45 000 Plants/hm2（B1）,60 000 Plants/hm2（B2）,75 000 Plants/hm2（B3）;species（C）,Wanzi 56（C1）,Yuzi 43（C2）,Yuzi 263（C3）.[Result] The yield of Wanzi 56 was the highest among three purple flesh cultivars on conditions that planting density was 75 000 plants/hm2,and fertilization was 300 kg/hm2.The influence of planting density for yield of purple flesh sweetpotato was higher than that of fertilization.The orders of different levels of various factors on the test results was A factor column,K1〉K2〉K3;B factor column,K3〉K1〉K2;C factors column,K1〉K3〉K2.[Conclusion] The yield of Wanzi 56 was highest,follow by the yizi263 and yuzi43.The optimum planting density was 75 000 plants/hm2,and the most reasonable amount of fertilizer was 300 kg/hm2.

Effect of Fertilizing Level and Planting Densities on Yield and Nitrogen Utilization in Maize

Elite maize hybrid Guidan0810 was selected as material, and the effects of fertilizing level and planting densities on yield and nitrogen utilization were dis- cussed in the study. In field experiments as per double-cropping system, 4 main plots （fertilization levels） and 6 subplots （planting densities） were set in a split plot design. The results suggested that yield had close relationship with fertilization levels and planting densities. Different fertilization levels and planting densities significantly affected yield. With the increase of nitrogen fertilization, nitrogen use efficiency, nitrogen agronomic efficiency and nitrogen physiological efficiency declined. Under the same fertilization level, nitrogen use efficiency, nitrogen agronomic efficiency and nitrogen physiological efficiency grew a little with the increase of planting density, so nitrogen efficiency could be improved by regulating planting density. The results also showed that A2 （including N 225.0 kg/hm2, P205 75.0 kg/hm^2, K20 187.5 kg/hm^2） matching to B3 （52 500 plants/hm^2） or B4（60 000 plants/hm^2） was a better design, which could obtain a higher yield in the range of 7 913.2-8 207.8 kg/hm2, respectively.

"扬麦11号"密肥试验初报

"扬麦11号"是里下河地区农科所育成的具有较好的品质、较佳抗性、较高产量潜力的小麦新品种.本试验拟从密度、氮肥施用量、氮肥前、中、后期的施用比例三方面加以研究,以期为以后"扬麦11号"的大面积生产提供科学依据.

不同肥密水平对垦啤麦8号及垦啤麦9号产量的影响研究

通过对垦啤8号及垦啤9号2个啤酒大麦新品种不同密度与施肥量级对其产量的影响试验,结果分析表明,在黑龙江省西部雨养农业区种植垦啤麦麦8号垦啤麦9号施肥量氮磷钾纯量为160 kg/hm2量级和密度水平在500万/hm2左右,在平丰年份优质啤酒大麦产量水平可达6 000 kg/hm2～7 000 kg/hm2。

冬寒时节话护花

入冬以后．天气渐变寒冷，盆栽花木长势亦减慢．这段冬寒时间，怎样才能使盆花安全越冬及春节时花，时果培育成花繁、菜多叶茂呢?需要注意下面几个问题。

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.

Effect of CO_2 enrichment on competition between Skeletonema costatum and Heterosigma akashiwo

We investigated the effect of CO2 enrichment and initial inoculum density on competition between Skeletonema costatum and Heterosigma akashiwo,two common algae seen in algal blooms.The initial inoculum density(0.2×104,0.4×104,0.8×104 cells/ml) had a significant effect on population growth and competition between H.akashiwo and S.costatum.The time required for population growth to reach the exponential growth phase and stationary phase decreased significantly as the initial density increased.When the two species were cultured together,S.costatum tended to outcompete H.akashiwo,especially when present at higher initial ratios.CO_2 enrichment(5 000μl/L CO_2) increased the maximum population density and carrying capacity of H.akashiwo but decreased these measures for S.costatum.Thus,CO_2 enrichment favored the growth of H.akashiwo over S.costatum.