Impact of fertilization on chestnut growth, N and P concentrations in runoff water on degraded slope land in South China

Growing fruit trees on the slopes of rolling hills in South China was causing serious environmental problems because of heavy application of chemical fertilizers and soil erosion. Suitable sources of fertilizers and proper rates of applications were of key importance to both crop yields and environmental protection. In this article, the impact of four fertilizers, i.e., inorganic compound fertilizer, organic compound fertilizer, pig manure compost, and peanut cake （peanut oil pressing residue）, on chestnut （Castanea mollissima Blume） growth on a slope in South China, and on the total N and total P concentrations in runoff waters have been investigated during two years of study, with an orthogonal experimental design. Results show that the organic compound fertilizer and peanut cake promote the heights of young chestnut trees compared to the control. In addition, peanut cake increases single-fruit weights and organic compound fertilizer raises single-seed weights. All the fertilizers increased the concentrations of total N and total P in runoff waters, except for organic compound fertilizer, in the first year experiment. The observed mean concentrations of total N varied from 1.6 mg/L to 3.2 mg/L and P from 0.12 mg/L to 0.22 mg/L, which were increased with the amount of fertilizer applications, with no pattern of direct proportion. On the basis of these experiment results, organic compound fertilizer at 2 kg/tree and peanut cake at 1 kg/tree are recommended to maximize chestnut growth and minimize water pollution.

Effect of nitrogen and phosphorus addition on leaf nutrient concentrations and nutrient resorption efficiency of two dominant alpine grass species

Nitrogen(N)and phosphorus(P)are two essential nutrients that determine plant growth and many nutrient cycling processes.Increasing N and P deposition is an important driver of ecosystem changes.However,in contrast to numerous studies about the impacts of nutrient addition on forests and temperate grasslands,how plant foliar stoichiometry and nutrient resorption respond to N and P addition in alpine grasslands is poorly understood.Therefore,we conducted an N and P addition experiment(involving control,N addition,P addition,and N+P addition)in an alpine grassland on Kunlun Mountains(Xinjiang Uygur Autonomous Region,China)in 2016 and 2017 to investigate the changes in leaf nutrient concentrations(i.e.,leaf N,Leaf P,and leaf N:P ratio)and nutrient resorption efficiency of Seriphidium rhodanthum and Stipa capillata,which are dominant species in this grassland.Results showed that N addition has significant effects on soil inorganic N(NO_(3)^(-)-N and NH_(4)^(+)-N)and leaf N of both species in the study periods.Compared with green leaves,leaf nutrient concentrations and nutrient resorption efficiency in senesced leaves of S.rhodanthum was more sensitive to N addition,whereas N addition influenced leaf N and leaf N:P ratio in green and senesced leaves of S.capillata.N addition did not influence N resorption efficiency of the two species.P addition and N+P addition significantly improved leaf P and had a negative effect on P resorption efficiency of the two species in the study period.These influences on plants can be explained by increasing P availability.The present results illustrated that the two species are more sensitive to P addition than N addition,which implies that P is the major limiting factor in the studied alpine grassland ecosystem.In addition,an interactive effect of N+P addition was only discernable with respect to soil availability,but did not affect plants.Therefore,exploring how nutrient characteristics and resorption response to N and P addition in the alpine grassland is important to understand nutrient use strategy of plants in terrestrial ecosystems.

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.

GENERALIZED FORELLI-RUDIN TYPE OPERATORS BETWEEN SEVERAL FUNCTION SPACES ON THE UNIT BALL OF C^(N)

In this paper,we investigate sufficient and necessary conditions such that generalized Forelli-Rudin type operators T_(λ,τ,k),S_(λ,τ,k),Q_(λ,τ,k)and R_(λ,τ,k)are bounded between Lebesgue type spaces.In order to prove the main results,we first give some bidirectional estimates for several typical integrals.

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.

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.

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.

Influence of Deformation on CVC p-n-Junction in a Strong Microwave Field

This paper investigates the current-voltage characteristics (CVC) strain of p-n-junction in a strong microwave (MW) field and shows that the deformation increases the current generated in the p-n-junction. We analyze the current-voltage characteristics of p-n-junction in which three-dimensional space (I,U,e) gives more complete information than the two-dimensional.

NaCl处理对海滨锦葵N、P和Na^+、K^+含量及其化学计量特征的影响

为更好的开发利用耐盐经济植物海滨锦葵(Kosteletzkya pentacarpos),以了解盐处理下其N、P及Na+、K+吸收,本研究以海滨锦葵幼苗为材料,研究了不同盐浓度(0、2、4、8、12、16 g·L-1Na Cl)处理对海滨锦葵N、P和Na+、K+离子含量及其化学计量特征的影响,处理50 d后采样分析。结果表明:海滨锦葵在高盐环境(16 g·L-1Na Cl)下,增强了对N的吸收,其中茎中N增加尤为明显。同时,茎、叶和全株的含P量也明显增加。相关分析表明,叶片P含量与盐梯度显著正相关(P<0.05)。茎、叶和全株的Na+含量随着盐梯度的增加而增加,尤其叶中Na+含量增加最为明显。叶中Na+含量与盐梯度呈极显著正相关(P<0.01)。茎、叶中K+含量随着盐梯度的增加表现明显下降趋势,其中叶中K+含量下降较为平缓,盐梯度与叶中K+含量表现显著负相关。盐梯度与植株N/P呈一定正相关,Na Cl盐梯度处理并没有对K+/Na+产生明显影响,植株保持相对较为稳定的K+、Na+离子平衡状态(即相对稳定的K+/Na+)。海滨锦葵叶中N与P显著正相关(P<0.05),与叶N/P极显著正相关(P<0.01),而与叶K+/Na+极显著负相关(P<0.01),说明对栽培海滨锦葵的滨海滩涂盐碱地施加氮肥,可以很好地促进植株对P的吸收。盐碱地一定量的Na Cl对海滨锦葵的生长无害,并有益于增强对P的吸收与积累。本研究结果对指导实践栽培具有重要的现实意义。

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

一个水耕法的实验被执行决定在小白菜(Brassica chinensis L.) 在氮(N) ，磷(P) ，和钾(K) 的生长，硝酸盐累积，和集中上用 20 单个氨基酸在营养液代替 20% nitrate-N 的影响射击。20% nitrate-N 什么时候与完整的硝酸盐处理，新鲜的小白菜射击和干燥重量相比被精氨酸( Arg )代替，但是20% nitrate-N 什么时候被丙氨酸(翼)代替，显著地增加了( P ≤ 0.05 )，缬氨酸(瓦尔)，白氨酸(列伊)，异白氨酸( Ile )，脯氨酸(专业版)，本氨基丙酸( Phe )，蛋氨酸(相遇)，天门冬酸(毒蛇)， glutamic ( Glu )，离氨酸( Lys )，甘氨酸( Gly )，丝氨酸(重量的单位)，苏氨酸( Thr )，半胱氨酸( Cys )，和酷氨酸( Tyr )，新鲜的射击和干燥重量显著地减少了( P ≤ 0.05 )。在用天门冬素(Asn ) 和夫酸安(Gln ) 代替 20% nitrate-N 以后，新鲜的射击和干燥重量是未受影响的。比作完整的硝酸盐处理，氨基酸代替处理除了 Cys， Gly，组氨酸(他的) ，并且 Arg，显著地减少了(P ≤ 0.05 ) 在植物射击的硝酸盐集中。显著地除了 Cys，列伊，专业版，和在另外的氨基酸处理的植物组织的遇见的、全部的 N 集中增加了(P ≤ 0.05 ) 。氨基酸也影响了全部的 P 和 K 集中，但是效果不同取决于单个氨基酸。改进小白菜射击质量， Gln 和 Asn 由于他们小白菜生长上的不足道的效果，他们在硝酸盐集中的重要减小，和他们宏元素的增加在植物满足，可以被用来部分代替 nitrate-N。

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、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。

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。

硝态N累积与菠菜有机N形成及P、K吸收的关系

在低N(0.3g·kg-1土)和高N(0.6g·kg-1土)2个水平下,采用土壤盆栽试验,研究了30个菠菜品种硝态N累积情况及其与植株生长,有机N形成,P、K吸收的关系。结果表明:施N水平低时,30个菠菜品种的硝态N含量与生长量、有机N总量和P、K吸收量之间均无显著的相关关系;高N时,菠菜品种间硝态N含量表现出显著的差异,硝态N含量最高与最低相差242mg·kg-1,与生长量、有机N总量和P、K吸收量之间亦呈极显著正相关关系。

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.

Short-term influence of anaerobically-digested and conventional swine manure, and N fertilizer on organic C and N, and available nutrients in two contrasting soils

A three-year (2006-2008) field experiment was conducted at Swift Current and Star City in Saskatchewan to determine the short-term in-fluence of land-applied anaerobically digested swine manure (ADSM), conventionally treated swine manure (CTSM) and N fertilizer on total organic C (TOC), total organic N (TON), light fraction organic C (LFOC), light fraction organic N (LFON) and pH in the 0 - 7.5 and 7.5 - 15 cm soil layers, and ammonium-N, nitrate-N, extractable P, exchangeable K and sulphate-S in the 0 - 15, 15 - 30, 30 - 60, 60 - 90 and 90 - 120 cm soil layers. Treatments included spring and autumn applications of CTSM and ADSM at a 1x rate (10,000 and 7150 L·ha-1, respectively) applied each year, a 3x rate (30,000 and 21,450 L·ha-1, respectively) applied once at the beginning of the experiment, plus a treatment receiving commercial fertilizer (UAN at 60 kg·N·ha-1·yr-1) and a zero-N control. There was no effect of swine manure rate, type and application time on soil pH. Mass of TOC and TON in the 15 cm soil layer increased significantly with swine manure application compared to the control, mainly at the Swift Current site, with greater increases from 3x rate than 1x rate (by 2.21 Mg·C·ha-1 and 0.167 Mg·N·ha-1). Compared to the control, mass of LFOC and LFON in the 15 cm soil layer increased with swine manure application at sites, with greater increases from 3x rate than 1x rate (by 287 kg·C·ha-1 and 26 kg·N·ha-1 at Star City, and by 194 kg·C·ha-1 and 19·kg·N ha-1 at Swift Current). Mass of TOC and TON in soil layer was tended to be greater with ADSM than CTSM, but mass of LFOC and LFON in soil was greater with CTSM than ADSM. Mass of TOC, TON, LFOC and LFON in soil also increased with annual N fertilizer application compared to the control (by 3.2 Mg·C·ha-1 for TOC, 0.195 Mg·N·ha-1 for TON, 708 kg·C·ha-1 for LFOC and 45 kg·N·ha-1 for LFON). In conclusion, our findings suggest that the quantity and quality of organic C and N in soil can be affected by swine manure rate and type, and N fertilization even after three years, most likely by influencing inputs of C and N through crop residue, and improve soil quality.

不同浓度营养液对赤霞珠葡萄N、P、K吸收量的影响

以4年生赤霞珠葡萄为试验材料,栽植于体积比为1∶1∶1的蛭石、珍珠岩、草炭基质中,设置常规、0.5倍、2.0倍3个浓度的改良Hoagland营养液,探讨了不同浓度营养液对赤霞珠葡萄N、P、K吸收量以及光合特性和果实品质的影响。结果表明,赤霞珠葡萄在0.5倍浓度营养液下干物质量最高,2.0倍浓度下叶片N和P含量最高,常规浓度下叶片K含量最高,且果实总酚、单宁、花色苷含量较高,品质最优。

关于p^k元域中的n方元素

设 F为 pk元域 ,n为正整数 .本文建议 F中的 n方元素的概念 ,给出 n方元素的特征性质 .最后 ,给出

藻类爆发对太湖梅梁湾水体中NPK含量的影响

1998～ 2 0 0 0年对太湖梅梁湾的实测结果表明 ,在一定范围内叶绿素a的含量与温度呈现明显的正相关 ;NH4+ N和总氮 (TN)、总磷 (TP)含量在每年的八九月份最低 ,总含量与叶绿素a呈正相关 ,随着叶绿素a含量上升 ,N、P含量呈现下降趋势 ;K的含量与N、P相似 .排污口的 0号点和 6号点的N、P含量相对于湖中心的 8号样点来说极高 ,而且P已不是限制性营养元素 ,在其它水域 ,P依然是限制性营养元素 ,表明微囊藻 (Microcystisspp .)只在TN含量为 1～ 4mg·L-1、TP在 0 .1～ 0 .

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)。