Effects of N, P and K on Output and Nutrient Cycle of Vegetables in Greenhouses

ObjectiveThe aim was to increase farmers’ income and reduce the waste of fertilizer by exploring effects of N, P and K fertilizations on vegetable yields and the accumulation of N, P and K in vegetable and soils. MethodThe fertilization tests were conducted on tomato, cauliflower and celery in greenhouses. ResultWhen N, P and K were not applied in tomato, cauliflower or celery, the yields reduced in 6.0%-13.8% and total annual income reduced by 39 220, 36 902 and 22 023 yuan/hm 2 respectively, suggesting that N, P and K are limiting factors of yield. The absorbed N amounts of tomato and cauliflower were higher compared with celery; the absorbed P amount of cauliflower was higher compared with tomato and celery; the absorbed K amount of tomato was the highest, followed by celery and cauliflower. The absorbed N in tomato fruit was lower than that of cauliflower and the absorbed N amount of other parts of tomato was also lower. Furthermore, the absorbed amounts of P and K by tomato and cauliflower fruits were higher than it absorbed by the other parts, especially the absorbed of K was significantly high. Total absorbed amounts of N, P and K from high to low were cauliflower, tomato and celery. After harvesting of tomato, cauliflower and celery, N, P and K in soils were all higher compared with soils before planting. Influenced by fertilizers, residual N content in soils grown with tomato and residual P content in soils grown with celery both doubled compared with base soils. Cauliflower plants were not applied with organic fertilizer, and residual N and K contents in soils were lower compared with tomato and celery. ConclusionResidual P content in soils is higher, which is a kind of waste and would cause pollution on soils. It is necessary to improve the proportion of organic and inorganic fertilizers in fertilization.

Plant Biomass, Primary Production and Mineral Cycling of a Mixed Oak Forest in Linnebjer, Sweden

Plant biomass, primary production and mineral cycling were studied in a mixed deciduous forest (Quercus robur L., Tilia cordata L. and Corylus avellana L.) in southern Sweden. Plant biomass amount above and below ground was 201 and 37 t&middotha-1, respectively. Primary production above and below ground was an estimated 13.3 and 2.3 t&middotha-1, respectively. Carbon was the dominant element in the forest ecosystem, comprising 133 t&middotha-1. Other major elements were: N > Ca > K > Si > Mg > S > Mn > P > Fe and Na (range 1123 to 18 kg&middotha-1), followed by some trace elements. Yearly litterfall restored 6.0 t&middotha-1 organic matter or 2.3 t&middotha-1 carbon. Approximately 45% decomposed and returned to the soil during the year. Monitoring of other elements revealed that the ecosystem received inputs through dry and wet deposition, in particular 34.4 kg&middotha-1 S and 9.4 kg&middotha-1 of N yearly as throughfall. Determination of yearly biomass increase showed that the oak forest ecosystem was still in an aggradation or accumulation phase.

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.

Effects of Regulation of C/N Ratio Wheat Straw Application on Nitrogen,Phosphorus and Potassium Uptake in Tobacco

[Objective]The aim was to study the effects of regulation of C/N ratio wheat straw application on tobacco nitrogen,phosphorus and potassium uptake. [Method]Effects of regulation C/N ratio wheat straw application on the flue-cured tobacco yield,output value,nitrogen,phosphorus and potassium content and cumulative uptake of the upper,middle and bottom leaf were studied by using the field plot experiments at Banqiao town,Qujing city,Yunnan Province during the 2008-2009 summer growing seasons. [Result]The results showed that the application of wheat straw alone or after C/N regulation,could significantly increase tobacco production,potassium content,the potassium and nitrogen accumulation amount of leaf,and was more conducive to the potassium uptake of tobacco leaf with wheat straw application after C/N regulation. Compared with non-straw application,the yield of tobacco increased by 6.59%,3.58%,5.98%,8.80% with application of wheat straw alone,wheat straw and vetch,wheat straw and oilseed cake,wheat straw and urea nitrogen,the potassium content in tobacco leaf increased by 3.85%,7.76%,8.82%,11.21%,respectively,the total potassium cumulative amount of leaf increased by 10.71%,11.62%,15.32% ,21.01% and the total nitrogen cumulative amount increased by 9.76%,1.22%,8.14%,14.00%. However,the differences of tobacco leaf nitrogen content among the different treatments were not significant,the phosphorus uptake of tobacco leaf decreased. [Conclusion]application of high C/N ratio wheat straw in flue-cured tobacco production,which should be concerned not only to adjust C/N ratio by adding nitrogen,but also considering additional phosphorus application.

Effect of N and K Fertilizers on Yield and Quality of Greenhouse Vegetable Crops

The application of large amounts of fertilizers, a conventional practice in northern China for the production of vegetable crops, generally leads to substantial accumulation of soil nutrients within a relatively short period of time. A fixed field experiment was designed to study the effects of nitrogen （N） and potassium （K） fertilizers applied to optimize the yield and quality of typical vegetable crops. Application of N and K fertilizers significantly increased the yields of kidney bean. The largest yields were obtained in the first and second years after application of 1 500 kg N and 300 kg K20 ha^-1. In the third year, however, there was a general decline in yields. Maximum yields occurred when intermediate rates of N and K （750 kg N and 300 kg K20 ha 1） were applied. However, no significant differences were observed in the concentrations of vitamin C （VC） in kidney bean among different years and various rates of fertilizer treatments. Yields of tomato grown in rotation after kidney bean showed significant responses to the application of N and K in the first year. In the second year, the yields of tomato were much lower. This suggested that the application of N fertilizer did not have any effect upon tomato yield, whereas application of K fertilizer did increase the yield. Application of K fertilizer was often associated with increased sugar concentrations.

Effects of Amino Acids Replacing Nitrate on Growth,Nitrate Accumulation,and Macroelement Concentrations in Pak-choi (Brassica chinensis L.)

A hydroponic experiment was carried out to determine the influence of replacing 20% of nitrate-N in nutrient solutions with 20 individual amino acids on growth, nitrate accumulation, and concentrations of nitrogen （N）, phosphorus （P）, and potassium （K） in pak-choi （Brassica chinensis L.） shoots. When 20% of nitrate-N was replaced with arginine （Arg） compared to the full nitrate treatment, pak-choi shoot fresh and dry weights increased significantly （P ≤ 0.05）, but when 20% of nitrate-N was replaced with alanine （Ala）, valine （Val）, leucine （Leu）, isoleucine （Ile）, proline （Pro）, phenylalanine （Phe）, methionine （Met）, aspartic acid （Asp）, glutamic acid （Glu）, lysine （Lys）, glycine （Gly）, serine （Ser）, threonine （Thr）, cysteine （Cys）, and tyrosine （Tyr）, shoot fresh and dry weights decreased significantly （P ≤ 0.05）. After replacing 20% of nitrate-N with asparagine （Asn） and glutamine （Gin）, shoot fresh and dry weights were unaffected. Compared to the full nitrate treatment, amino acid replacement treatments, except for Cys, Gly, histidine （His）, and Arg, significantly reduced （P ≤0.05） nitrate concentrations in plant shoots. Except for Cys, Leu, Pro, and Met, total N concentrations in plant tissues of the other amino acid treatments significantly increased （P ≤ 0.05）. Amino acids also affected total P and K concentrations, but the effects differed depending on individual amino acids. To improve pak-choi shoot quality, Gln and Asn, due to their insignificant effects on pak-choi growth, their significant reduction in nitrate concentrations, and their increase in macroelement content in plants, may be used to partially replace nitrate-N.

Effects of N,P and K Amounts on Yield Traits of Wheat in Wheat-cotton Intercropping System

[Objective] This study was conducted to investigate the demands for N, P and K by wheat in wheat cotton intercropping system in high-fertility field of Hebei Province. [Method] The experiment adopted randomized block arrangement. Five treatments （0, 75, 150, 225 and 300 kg/hm2） were designed for N, P and K. Wheat tillering, ear number, yield and yield components were investigated. [Result] Wheat yield increased significantly with the application of N fertilizer. The number of ears per unit area, number of grains per ear, 1 000-grain weight and yield were im- proved with N increasing. P fertilizer improved wheat yield at a certain degree, but K had no effect on wheat yield. ]Conclusion] The optimum fertilization for wheat-cot- ton intercropping system was N at 225-300 kg/hm2 and P2Os at 150 kg/hm2; and there is no need to apply K.

Seed Yield Potential of Five Wheat Species/Cultivars without and with Phosphorus Fertilizer Application on a P-Deficient Soil in Northeastern Saskatchewan

In the Canadian Prairies, many soils on organic farms are low in available phosphorus (P). Previous research has shown that wheat species/cultivars vary in their sensitivity to P deficiency, yield response to applied P fertilizer, P uptake and P use efficiency on P-deficient soils. A 3-year field experiment was conducted from 2012 to 2014 on a P-deficient soil at Kelvington, Saskatchewan, Canada, to determine the potential of five wheat species/cultivars (Spelt and Kamut representing “ancient”, Red Fife representing “old”, and Unity and Goodeve representing “modern” wheat species/cultivars) for seed yield, protein concentration (PC) in seed, partial factor of productivity (PFP, kg seed kg-1 of N applied), total N and P uptake, P use efficiency (PUE, kg seed kg-1 of P applied) and % recovery of applied P in seed under zero-P and with P fertilizer (triple superphosphate) applied at 20 kg P ha-1. Seed yield, PFP and PUE were determined in all 3 years, but PC, total N and P uptake, and % recovery of applied P in seed were determined only in 2012. There was a marked and significant response of seed yield and PFP of all wheat species/cultivars to P fertilizer in all 3 years, but the actual seed yield and PFP, without and with applied P fertilizer, as well as PUE, varied with species/cultivar in different years. On the average of 3 years, seed yield and PFP were greatest for Unity in both without and with applied P fertilizer treatments. Seed yield increases from applied P were 1111, 773, 890, 1810 and 2028 kg·ha-1, respectively, for Spelt, Kamut, Red Fife, Unity and Goodeve. Total N and P uptake were lowest for Kamut and greatest for Unity or Goodeve, in both without and with applied P fertilizer treatments. Percent recovery of applied P in seed was greatest for Goodeve or Unity and lowest for Spelt or Kamut. Protein concentration in seed usually decreased with P fertilizer, and wheat species/cultivars with higher PC in seed usually showed greater reduction in PC with P application. In conclusion, the findings suggest that the “modern” wheat species/cultivars Unity or Goodeve might be more suitable for high sustainable seed yield and total P or N uptake than the “ancient” wheat species Spelt and Kamut or the “old” wheat cultivar Red Fife, especially when adequate amount of P fertilizer is applied to optimize crop production on a P-deficient soil.

Effect of Fertilizer N Forms on Physiological Metabolism and Potassium Uptake of Flue-Cured Tobacco

The growth, chlorophyll composition, photosynthesis, respiration, K uptake and root K+ secretion offlue-cured tobacco as thected by different concentrations of N supplied as urea, NaNO3 and NH4NO3 werestudied under the experimental condition of sand culture. The results showed that the content of K in thefiue-cured tobacco was not merely related with root vitality and uptake but also closely related with root cellmembrane structure and K+ secretion.

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。

A Preliminary Study on Dynamics and Models of N,P,K Absorption for High-Yield Cotton

The field experiments were carried out to investigate the dynamics and models of N, P and K absorption for the cotton plants with a lint of 3 000 kg ha-1 in Xinjiang. The main results were as follows: The contents of N, P2O5, K2O in cotton leaves, stems, squares and bolls decreased obviously with the time over the whole growth duration and the falling extent was greater in high-yield cotton than in CK. Contents of N in leaves, squares and bolls, in particular in the leaves of fruit-bearing shoot was higher in high-yield cotton than in CK. Contents of P2O5 in squares and bolls and that of K2O in stems were higher in high-yield cotton than in CK during the whole growing period. The accumulations of N, P2O5 and K2O in the cotton plants could be described with a logistic curve equation. There was the fastest nutrient uptake at about 90 d for N, 92 d for P2O5 and 85 d for K2O after emergence, respectively. Total nutrient accumulation of N, P2O5 and K2O was 385.8, 244. 7 and 340.3 kg ha-1, respectively. Approximately 12. 5 kg N, 8. 0 kg P2O5 and 11.1 kg K2O were needed for producing 100 kg lint with the leaves and stems under the super high yield condition of 3 000 kg ha-1 in Xinjiang.

关于K_2O_F的p^n-rank公式

使用Browkin的方法,将Browkin关于MilnorK-群K2OF的2-rank公式推广到pn-rank的情况(p为素数,n≥1为自然数),从而得到了代数数域F的pn-rank公式,其中F包含pn-次本原单位根。

N,P,and K characteristics of different age groups of temperate coniferous tree species in northwestern China

This study chose dominant tree species including Picea crassifolia,Pinus armandii and Pinus tabuliformis which are distributed in Qilian Mountains,Xiaolongshan Mountains,and Bailongjiang River.According to the different tree species,ages and components,we sampled leaves,branches,stems,and roots,and measured the contents of Nitrogen,Phosphorus,Potassium,along with soil fertility.The changes of N,P,and K contents in the different tree species were studied,and the relationship between nutrient content and environmental factors was analyzed.The results indicated that the content of P in all three species was the lowest(0.039–0.28 g kg),while N content was the highest(0.095–1.72 g kg).As the terminal organ of nutrient transport,the nutrient content of leaves was the highest.P.armandii(0.45 g kg) had a higher nutrient concentration than P.tabulaeformis(0.19 g kg) and P.crassifolia(0.29 g kg).The nutrient content of each species was highest in a young forest,but lowest in a mature forest.The nutrient content of all three tree species was significantly affected by soil nutrient content,and negatively correlated with available soil nutrients.

关于图P_n^k和图B(3,2,k),B(4,3,k)的强协调性

证明了图Pkn和B(3,2,k),B(4,3,k)都是强协调图,并给出了它们的强协调标号.进一步讨论了图Pkn(k 3)的强协调性.

The Effects of Manure, Lime and P Fertilizer on N Uptake and Yields of Soybean （Glycine max （L.） Merrill） in the Central Highlands of Kenya

Soybean （Glycine max （L.）） is one of the most important legume crops being introduced in the CHK （Central Highlands of Kenya） expected to increase yields. However, low levels of soil N （nitrogen） and other plant nutrients and soil acidity are seen as the major causes impairing goal achievement. To evaluate the influence of manure, lime, P （phosphorus） fertilizer and their combination on N uptake and soybean performance, an experiment was conducted in Embu ATC （Agricultural Training College） comprising 9 treatments, arranged in a Randomized Complete Block Design with 4 replicates in plots of 4 m×4.5 m. The study included manure （0, 5 and 10 t-ha-1）, lime （0 and 2 t.ha-1） and P fertilizer （0, 30 and 60 kg.P.hal）. The treatments significantly influenced N uptake and soybean yields. Both parameters responded well to application of manure both alone or combined to lime and TSP （triple super phosphate）. From these it was concluded that organic and inorganic resources have potential to enhance N uptake and soybean and other crops yields in CHK.

NP配施对平茬后云南松苗木N、P、K化学计量比的影响

为了解NP配施对平茬后云南松(Pinus yunnanensis)苗木各器官N、P、K化学计量比的影响,分析云南松苗木不同器官(根、茎、叶、萌条)的ω(N)∶ω(P)、ω(N)∶ω(K)、ω(P)∶ω(K)化学计量比的季节变化特征,探讨各器官间N、P、K化学计量比的相关性及其变异来源。采用N、P二因素三水平的3×3回归设计开展不同施肥试验,并对苗木采样测定,研究NP配施对平茬后云南松根、叶、茎及其萌条N、P、K化学计量特征的影响。结果表明:平茬后云南松苗木不同器官的营养元素分配没有统一的规律,展现出丰富的变异。随着施肥季节的变化,ω(N)∶ω(P)在根、茎和萌条中逐渐下降,在叶中先下降后上升,但总体差异不大。单施N肥、P肥和NP配施均对云南松苗木生长的影响产生一定差异,总体来看NP配施更有利于促进苗木的生长,且以处理5(N_(1)P_(1))表现为极显著(P<0.01)。云南松苗木各器官N、P、K化学计量比主要受N×P交互作用的影响,其次是N,影响最小的是P。除在根和叶中ω(N)∶ω(P)与ω(N)∶ω(K)之间相关性发生改变之外,其余两两间的正负相关性均保持不变,而ω(N)∶ω(P)与ω(P)∶ω(K)、ω(N)∶ω(K)与ω(P)∶ω(K)的相关性均随着施肥季节的变化相关性发生改变,且相关系数降低,分别受P和K的调控。平茬改变植株体内的营养元素含量,不同施肥处理促使云南松各器官中N、P、K化学计量特征差异极显著(P<0.01)。NP配施可以有效缓解单施N肥、P肥对植株的限制作用,使养分处于一个平衡状态,从而满足植株对生长的需要。

莲雾遮光期叶片SPAD值和C、N、P、K含量的变化及其规律

对大田莲雾成年树进行遮光处理,研究遮光叶片SPAD值及C、N、P、K含量的动态变化及其规律。结果表明:叶片SPAD值受叶龄和遮光互作影响,自然条件下,叶龄40 d左右SPAD值最大,达到63.0±2.49。短时间遮光对叶片SPAD值的影响不大,遮光40 d叶片SPAD值降到最低;长时间遮光会造成叶片早衰,限制树体营养生长。遮光对叶片N、P、K、C含量均有影响,在遮光过程中,叶片的C、N、P、K含量的变化情况不尽相同,但树体对遮光后形成的弱光条件均作出响应,然后通过自身的调节,慢慢使C、N、P、K趋同于自然条件下的含量水平。莲雾叶片的碳氮比(C/N)随着遮光时间的延长而呈增大趋势,遮光40 d左右比值达到顶峰,此时是莲雾栽培上进行催花的一个关键时间点。

Ability of Ectomycorrhizal FUngus Laccaria biclor S238N to Increase the Growth of Douglas FIr Seedlings and Their Phosphorus and Potassium Uptake

Ectomycorrhizal fungus Laccaria bicolor S238N,isolated from a forest soil in central France in 1990s,has demonstrated unequivocally and ability to promote pine growth.In the present nursery bed experiment,the ability of this ectomycorrhizal fungus to increase growth and P and K uptake of Douglas Fir seedlings (Zone 22) was examined.Growth of inoculated seedlings was over twice(plant height) and three times (biomass)that of non-inoculated ones.Similarly,both the concentrations and the amounts of P and K uptake by seedlings were significantly increased by fungal inoculation,indicating the improvement of P and K nutrition in mycorrhizal seedlings.In contrast,Al-P in the soils was decreased obviously by plants,especially by mycorrhizas,suggesting utilization of this soil P pool by plants and more efficient Al-P mobilization by mycorrhizas than by nomycorrhizas.Moreover,K extracted by 1mol/L HCl following consecutive extraction of H2O and CH3COONH4,which may not be plant available,could be utilized by fungus colonied roots.This could be explained by the release of protons and oxalate by hypae which leads to replacement of interlayer K in nonexpanded 2:1 clay minerals and bio-weathering of phyllosilicates.

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。

Macronutrients Uptake in Soybean as Affected by <i>Bradyrhizobium japonicum</i>Inoculation and Phosphorus (P) Supplements

Field and glasshouse experiments were conducted to study the effect of B. japonicum inoculation and phosphorus supplementation on macronutrient uptake by soybean. The treatments consisted of B. japonicum inoculation (with & without), phosphorus supplementation at the levels of 0, 20, 40 and 80 kg P·ha-1. Both treatments were replicated four times in a split plot design. The macronutrients considered were N, P, K, Ca and Mg. Results showed that inoculation with B. japonicum significantly contribute to the uptake of N, P, K, Ca and Mg in roots, shoots, pods and the whole soybean plant. Likewise, phosphorus supplementation significantly enhanced the uptake of N, P, K, Ca and Mg in roots, shoots, pods and the whole plant. The use of effective strains of rhizobia and P supplementation was an effective way of enhancing the growth of soybean, eventually the uptake of macronutrients in plant organs.