Effects of N,P and K Fertilizers on Growth of Clover Nitrogen-fixing Rhizobia and Soil Fertility after Plantation

In order to develop organic rice and increase paddy soil fertility by cloverorganic rice rotation, the effects of N, P and K fertilizers on growth of clover nitrogen-fixing rhizobia and soil fertility after plantation were investigated, thereby providing certain reference for reasonable cultivation of clover and improvement of soil fertility. A two-year experiment was conducted from 2012 to 2013. The clover was cultivated after rice every year, and different levels of N, P and K fertilizers were applied before winter. In the treatment group, no fertilizer was applied. The effects of different fertilizers and different application amounts on clover yield, nitrogen-fixing rhizobia quantity, nitrogen-fixing rhizobia weight and soil fertility after plantation were analyzed. The results showed that the application of N, P and K fertilizers in the early stage had significantly effect on the growth of clover. When the application amount of N fertilizer was 75 kg/hm^2（N 46%）, the clover yield, nitrogen-fixing rhizobia quantity and nitrogen-fixing rhizobia weight were highest. The soil nitrogen content after plantation increased with the increase of the application amount of N fertilizer, while the P and K content decreased and then increased with the increased application amounts. Soil available P content increased with the increased application amounts of N and P fertilizers, but it did not change significantly with the increased application amount of K fertilizer. Soil available K content increased first and then decreased with the increased application amounts of N and P fertilizers.When the application amounts of N and P fertilizers were 150（N 46%） and 300（P_2O_5 12%） kg/hm^2, soil available K content reached the maximum. Soil organic matter content increased with the increased application amounts of N, P and K fertilizers. Therefore, in the cultivation of clover, appropriate application of N, P and K fertilizers in the early stage can improve clover yield and soil fertility.

Nitrogen and Phosphorus Runoff Losses from Orchard Soils in South China as Affected by Fertilization Depths and Rates

Fertilizers are heavily applied in orchards of the hilly and mountainous topography of South China and may increase nutrient loadings to receiving waters.A simple runoff collecting system was used to measure the effects of different fertilization treatments on total N and P concentrations of surface runoff in a Chinese chestnut (Castanea mollissima Blume) orchard in Dongyuan County,Guangdong Province,China.In such orchards,fertilizer was typically applied in two short furrows or pits on either side of each tree.Treatments included three application depths (surface,10cm and 20 cm),and three application rates (low,median and high).Results showed that 90.5% of the runoff water samples had a total N concentration higher than 0.35 mgL^(-1) and 54.2% had a total P concentration higher than 0.1 mgL^(-1).Fertilizer application at all depths and at all but the lowest rate significantly increased total N and P concentrations in runoff water.Fertilization with chemical compound fertilizer at a soil depth of 20cm produced significantly lower (P<0.05) total N concentration in runoff than both surface and 10-cm depth fertilization,and significantly lower (P<0.05) total P concentration in runoff than surface fertilization.Total N and P concentrations in runoff significantly increased with the application rate of organic fertilizers.With the exception of total P concentrations,which were not significantly different between the control and fertilization at a rate of 119 kg P ha-1 in organic form,all the other fertilization treatments produced significantly higher total N and total P concentrations in runoff than the control.A fertilization depth≥20cm and an application rate≤72 kg N ha^(-1) or 119 kg P ha^(-1) for compound organic fertilizer was suggested to substantially reduce N and P runoff losses from hillslope orchards and to protect receiving waters in South China.

Effects of Nitrogen,Phosphorus and Potassium Application on Growth and Dry Matter Accumulation in Mulberry

In this paper, the effect of different fertilizer treatments on the main indexes of growth and development and dry matter accumulation of perennial mulberry, which is cut and pruned in summer, were studied with ‘3414’ field experiment design. The results showed that N, P, and K at proper amounts could promote mulberry growth and development, improve its dry matter content, increase its dry matter accumulation. The effects of N, P, K on leaf yield per plant were respectively expressed as follows： N2 N3 N1 N0 , P2 P1 P3 P0 , K2 K1 K3 K0 . It can be concluded that the recommended fertilizer amounts of dry matter accumulations in mulberry leaf were 694.36 kg/hm2 of N, 198.15 kg/hm2 of P, and 274.26 kg/hm2 of K and the dry matter achieved the maximum at 8 045.04 kg/hm2 . The recommended fertilizer amounts of accumulated dry matter in branch were 1 000.05 kg/hm2 of N, 242.04 kg/hm2 of P, and 218.01 kg/hm 2 of K, and the dry matter achieved the maximum at 5 969.05 kg/hm2 . The recommended fertilizer amount in young shoots were 883.76 kg/hm2 of N, 204.48 kg/hm2 of P and 426.59 kg/hm2 of K and dry matter achieved the maximum at 1 410.24 kg/hm2 . This paper could provide reference for the construction of highly-qualified mulberry field in Sichuan hilly area.

麦秸还田对水稻产量及地表径流NPK流失的影响

在大田试验条件下,以水稻品种运2645为供试材料,设置常规处理(A)、麦秸还田(B)、麦秸还田减肥(C)、肥料运筹(D)和旋耕(E)5个处理组合,研究不同处理对水稻产量及农田地表径流NPK流失的影响。结果表明:(1)麦秸还田使水稻产量比常规处理增加3.0%左右;(2)试验年度稻季农田总地表径流水量为4.3×103m3·hm-2;(3)麦秸还田减肥和麦秸还田处理比其处理明显降低农田地表径流水体NPK流失量,不同处理地表径流总N流失量由低到高依次为麦秸还田减肥、麦秸还田、常规处理、肥料运筹和旋耕,不同处理地表径流总P和K的流失量由低到高依次为麦秸还田减肥、麦秸还田、肥料运筹、常规处理和旋耕;(4)麦秸还田能够降低稻田地表径流NPK的流失率,但麦秸还田减肥处理由于流失量减小幅度远低于肥料施用量的减小幅度,其NPK流失率均表现为最高;(5)麦秸还田使水稻产量略有增加,使稻田地表径流水体NPK流失量和流失率均明显降低。

N、P、K肥对香根草修复土壤镉、锌污染效率的影响

通过盆栽试验研究在30 mg/kg镉(Cd)污染土壤条件下N[CO(NH2)2:100、200、300 mg/kg土]、P(P2O5:50、100、200 mg/kg土)和K(KCl:100、200、300 mg/kg土)处理对香根草修复土壤Cd和锌(Zn)污染效率的影响。结果表明:3种N处理能促进香根草地上部生长,而且显著提高地上部特别是叶的Cd和Zn含量,导致其修复效率成倍显著增加;200 mg/kg K处理显著提高Zn修复效率,但300 mg/kg K和50、200 mg/kg P处理却显著降低Cd、Zn修复效率。因此,为改善香根草对较贫瘠土壤中Cd、Zn污染的修复效率,应对香根草适施N肥,并控制或者不施P、K肥为佳。

N、P、K营养元素不同配比对马占相思苗期生长的影响

采用N、P、K 3营养元素 5个水平配比试验 ,分析不同配比对马占相思苗期生长的影响 ;通过正交试验 ,确定马占相思苗木对各营养元素的实际需求水平。结果表明 ,P素对马占相思苗期生长影响最大 ,其次为K素 ,而N素的影响相对较小。不同水平的N、P、K配比对试验苗有不同的影响 ,其中 ,N∶P∶K最佳配比为 :190∶2 5∶16 0 (mg·L- 1)。

滴灌施肥条件下107杨幼林N、P、K养分吸收量与施肥量研究

杨树以其生长迅速、产量大、分布广、适应性强、易繁殖、易更新等特性，成为我国主要的速生造林树种，常作为短轮伐期工业用材来经营；同时，它在解决我国用材短缺和生态问题等方面也起着不可忽视的作用。在营造速生丰产林的过程中，施肥是一项关键措施，多项研究结果表明，施肥对杨树树高、胸径的生长具有促进作用，不同施肥处理对杨树生长的影响不同。水和肥（主要是N肥）是影响杨树生长的重要因素，一直以来，

专用缓释肥料对黄瓜产量品质及N,P,K养分吸收利用的影响

采用土培试验研究了黄瓜专用缓释肥对黄瓜产量品质及N,P,K养分吸收利用、土壤酶活性的影响.结果表明:2种专用缓释肥(CSRF1和CSRF2)显著提高了黄瓜果实干物质量和总干物质量,CSRF1和CSRF2处理黄瓜果实干物质量较CCF,MSRF,OCF处理分别增加了23.3%~37.2%和16.5%~31.6%.2种专用缓释肥(CSRF2和CSRF1)提高了黄瓜果实的维生素C质量分数和氨基酸的质量分数,降低了硝酸盐质量分数.黄瓜根、茎、叶和果实的N,P,K养分质量分数均以CSRF2最高.黄瓜N,P,K积累量从大到小依次为CSRF2、CSRF1、MSRF、CCF、OCF,专用缓释肥处理的N,P,K积累量较MSRF,CCF和OCF处理分别提高了27.45%~46.55%,33.17%~56.20%和67.61%~102.13%.与普通复合肥相比,2种专用缓释肥处理的N,P,K相对养分利用效率分别增加了18.53%~24.20%,19.27%~20.02%和18.54%~35.69%.

葡萄滴灌施肥的NPK配比研究

应用二次通用旋转组合设计,在沙壤质棕漠土上进行了葡萄滴灌施肥条件下的氮、磷、钾配比试验,获得了相应的函数模型;通过对葡萄产量和经济效益的分析,得出了葡萄适宜的NPK滴灌用量配比,在葡萄萌芽—开花期滴灌追施氮、磷、钾的比例以N∶P2O5∶K2O=1∶0 26∶0 12为好,在葡萄果实生长期滴灌追施氮、磷、钾的比例以N∶P2O5∶K2O=1∶1 54∶1 97较佳。

水磷耦合对甘蔗叶片NPK含量的影响

以新台糖22号为试材,采用2因素(供水量、施磷量)随机区组设计,研究不同水磷耦合对甘蔗叶片NPK含量的影响。结果表明,在高水条件下,甘蔗叶片全N、全P含量总体水平均较高,而全K含量则随供水量增加而降低;高磷条件下,甘蔗叶片全N、全K含量总体水平均较高,而全P含量则以低磷处理表现较好。水磷耦合比较结果显示,甘蔗叶片全N含量综合水平较高的是高水高磷组合,全P含量总体水平较高的是高水低磷组合,全K含量总体水平较高的是低水高磷组合。

NPK用量对露地西兰花产量、养分累积及肥料效率的影响

为了探讨露地西兰花的NPK合理施用量,提出科学的施肥配比。在宁夏引黄灌区通过田间试验研究了不同NPK供应水平对露地西兰花产量和地上部NPK吸收累积的影响,并评价了其肥料效率。结果表明:施用N、P肥对西兰花有显著增产作用,而施K处理间无显著差异。相对于N0和P0处理,增施N、P肥可分别提高23.6%～36.2%和7.6%～11.5%的经济产量。适当增施NPK肥能显著提高西兰花的地上部NPK养分累积。西兰花的肥料利用率、农学效率和偏生产力都随施肥量增加而降低。每施用1 kg N、1 kg P_2O_5、1 kg K2O分别可生产50.9～184.7、89.3～369.1、53.9～220.2 kg西兰花经济产量,其随施肥量增加呈显著降低趋势。西兰花经济产量与施N量(R2=0.886)、施P量(R2=0.906)和施K量(R2=0.794)都呈二次曲线关系。综合考虑蔬菜产量、养分累积和肥料效率,建议宁夏引黄灌区露地西兰花的施肥量分别为N 189.8～200.0 kg/hm^2、P_2O_579.8～86.8 kg/hm^2和K2O 80.2～112.5 kg/hm^2,其施肥配比为1:0.42～0.43:0.42～0.56。

N、P、K配方施肥对1年生黄芩生长的影响

[目的]研究N、P、K配方施肥对1年生黄芩生长的影响。[方法]采用3因素2次D-饱和度最优试验,考察N、P、K配比对黄芩生长的影响,筛选出商洛黄芩的最佳施肥方法。[结果]各施肥处理中,黄芩各项指标均高于空白对照组,说明3种元素的配合施用有助于黄芩的生长。总体上看,N、P、K 3种元素配合施用的处理组要优于2种元素配比,更优于单质元素处理组。优选出的最佳的施肥条件为N 79.41 kg/hm2、P2O5 150.00 kg/hm2;在此条件下,黄芩多糖的含量为7.4%。[结论]优选出了最佳施肥方法,为黄芩的生产提供了依据。

河西走廊加工型胡萝卜N、P、K肥配施数学模型构建与优化方案研究

采用三因素二次回归通用旋转组合设计,研究氮肥、磷肥、钾肥对加工型胡萝卜产量的影响,结果表明:3因素影响加工型胡萝卜产量的顺序为:N肥>K肥>P肥,各因素间存在交互作用。经过计算机模拟,得到加工型胡萝卜产量达到最高值80.11t.hm-2时,其相对应N、P、K肥用量分别为1041.90kg.hm-2,177.15kg.hm-2和4059.45kg.hm-2。通过验证表明,模型选优所得N肥、P肥和K肥配比的产量最高,施肥成本、施肥利润、肥料投资效率分别为0.78万元.hm-2、1.50万元.hm-2和1.92,效果明显优于其他配比,证明构建的模型准确可靠。

提高龙眼重回缩修剪树N,P,K营养水平和抽穗率的技术

对树体高大、交叉封行的龙眼树作重回缩修剪;剪后施用多效唑、乙烯利调节生长、控梢促花;测定叶片的N,P,K含量;调查翌年枝梢抽穗率。结果表明:①重回缩修剪对叶片N,P,K水平有明显影响,但对各次梢影响程度不同;②适当施用多效唑及乙烯利对提高重回缩修剪树叶片N,P,K营养水平及枝梢抽穗率有良好作用。

N、P、K营养元素的不同配比对红藤苗期生长的影响

红藤(Daemonorops margaritac)是我国华南地区主要商品藤种之一,天然资源供不应求,人工种植面积日益扩大,随之栽培技术的研究也在不断深入。施肥是促进藤苗生长,提高栽培经济效益的一项重要措施。探讨红藤苗期对N、P、K三要素的实际需求,是合理施肥的一个重要依据。但这方面的研究国内外尚缺少资料。本试验用砂培法探讨了 N、P、K营养元素对红藤苗期生长的合理配比,为栽培中的苗期施肥提供科学依据。

晋南冬麦区N、P、K肥单配施对强筋小麦部分加工品质的影响

小麦加工品质是测定优质小麦品质的关键指标,施肥对小麦加工品质有较大影响,深入探讨施肥对小麦加工品质的影响,对于晋南地区优质小麦生产具有重要的意义.试验以优质强筋小麦临汾145为材料,设计N、P、K单因子施肥及其相互配施共8个处理,研究对强筋小麦加工品质性状的影响.结果表明:单施N、P肥均可提高小麦容重,尤以施N肥效果显著,单施K肥对容重无明显影响;单施N、P肥可提高小麦出粉率,尤以N肥效果显著;单施P、K肥可提高籽粒硬度,而单施N肥对硬度无明显影响;NPK平衡施肥籽粒容重为792.6 g/L、出粉率72.1%、硬度67.6%,高于其他处理.单施N肥对面包体积和面包评分影响较大,而单施P、K肥对其影响不显著;肥料配施各处理与单施N肥相比面包评分、面包体积差异不显著.

盐渍土区棉花N、P、K肥效应研究

应用盆栽和田间试验对盐渍土棉花N、P、K肥效应进行了研究。结果表明 ,合理施用P、K肥能提高棉花体内过氧化物酶 (POD)活性 ,减少丙二醛 (MDA)含量 ,改善P、K营养 ,维持K+ 、Na+ 平衡 ,显著增强棉花耐盐性 ;合理增施N、P肥 ,可显著提高盐渍土棉花产量 ,有利于改善棉纤维品质 ,以N用量 1 95kg/hm2 、P2 O5用量 1 65kg/hm2(N1 95P1 6 5)

土壤施N、NP、NPK肥对越桔生长、产量及叶片元素含量的影响

对暗棕色森林立上栽培的6年生“美登”矮丛越桔，连续2年土壤施人N、NP和NPK复合肥，研究结果表明：土壤施入纯N肥，促进了树体生长，但百果重和产量降低，果实成熟延迟，且有贪青和越冬抽条加重现象;;土壤施入NP和NPK复合肥，既可以促进树体生长，又增加了百果重和产量，尤以NPK复合肥效果明显。经叶分析表明，施入N、NP和NPK肥均提高了叶片中N、K、Mn含量而降低了Ca、Mg含量;;增施N肥降低了叶片P含量，增施NP肥增加了叶片P含量。根据2年的研究结果认为，在暗棕色森林土壤上栽培越桔时单施N肥对生长不利，增施肥料以NP肥和NPK复合肥为宜，较适宜的施肥量为500～1000kg／hm2。

水肥条件对小麦、玉米N、P、K吸收的影响

水、N是影响作物N、P、K吸收的重要因素。通过对 6个水分等级和 5个N肥等级相互搭配的研究结果表明 ,高水、高N处理不利于小麦N吸收 ,而玉米是耐肥作物 ,相同灌水条件下 ,玉米的吸N量随施N量的增加而增加。在低灌水条件下 (W 0、W 1处理 ) ,玉米子粒吸N量很低 ,变幅为 0～ 17 3kg/hm2 ,并且不受施N量的影响 ;而小麦子粒吸N量仍达 36 6～154 2kg/hm2 。小麦与玉米吸P量的变化趋势与吸N量的变化趋势非常接近。但是 ,作物的吸K量随灌水量增加有明显增加的趋势 ,在玉米上表现尤其明显 ,并且作物的吸K量主要存在于茎秆中 ,因此 。

不同N,P,K配比的沼液肥对叶菜产量及品质的影响

试验以原沼液作对照,设置了4个不同N、P、K配比的沼液叶面肥共计5个处理,分别喷施在白菜、甘蓝及油白菜3种叶菜上。通过比较各处理对叶菜产量,VC,硝酸盐及农残含量的影响,探究出最佳的沼液叶面肥配方。结果表明:向沼液中加入不同比例的氮、磷、钾化肥后,其增产效果均高于原沼液,但叶菜中硝酸盐含量也相应提高。综合比较各处理的产量及VC含量,以N∶P∶K比例为2∶1∶4相对较好,为最佳配方,其次为5∶1∶7。