CO2浓度升高与增施钾肥对土壤化学性质的影响

采用土培和开顶箱法,研究了大气CO_2浓度升高与增施K肥共同作用对土壤化学性质的影响.结果表明,土壤中N、P的含量在高CO_2浓度和高K肥水平下下降,K的含量随K肥用量增加而增加.高K(200、300 mg/kg)处理和高浓度CO_2下温室次生盐渍化土壤中的NO_3~(-)、PO_4~(3-)、Ca~(2+)、Mg~(2+) 含量也显著降低.因此,在未来CO_2浓度升高的环境中,更多的K肥供应能促进作物对此生盐渍化土壤中养分的吸收,降低此生盐渍化土壤中盐分的积累.     

设施栽培黄瓜的氮磷钾肥料效应研究

采用"3414"肥料试验方案开展了设施栽培黄瓜的N、P、K肥料效应研究。结果表明,随着N、K肥施用量增加,黄瓜产量呈先增后减的趋势;随P肥施用量增加,黄瓜产量呈下降趋势;N、K肥配施为正交互作用,N、P肥和P、K肥配施均为负交互作用。在中等P、K肥配施水平下,黄瓜硝酸盐含量随施N量的增加而降低。施N量与黄瓜亚硝酸盐含量间存在显著的函数关系,P、K肥的影响较小。不同施肥处理黄瓜蛋白质和Vc含量差异均不显著,且与N、P、K施肥量间的函数关系拟合度较低。每生产100 kg黄瓜需要吸收的养分量为N 0.296kg、P2O50.166 kg、K2O 0.517 kg。供试条件下黄瓜最佳经济施肥量为N 150.0 kg/hm2、K2O 409.5 kg/hm2,不施或少施磷肥。     

养分调控对超积累植物伴矿景天生长及锌镉吸收性的影响

采用四因素三水平正交设计温室盆栽试验研究了N、P、K三因素不同水平对Zn、Cd超积累植物伴矿景天的生长及地上部Zn、Cd吸收性的影响。结果表明,增施N肥是伴矿景天地上部干重增加的主要因素,高N配施低P(200 mg/kg N,60 mg/kg P,不施K)处理的伴矿景天地上部干重达最大值31.2 g/盆(1.5 kg土/盆),是不施肥处理的3.15倍。增施K肥是提高伴矿景天地上部重金属尤其是Cd浓度和吸收量的主要影响因子,高量K处理比不施K处理地上部Cd浓度增加28.1%;低量施P也可提高伴矿景天的Zn吸取修复效率。综合考虑伴矿景天生物量及其对Zn、Cd的吸取效率,本试验条件下低量N、P肥配施高量K肥为最佳施肥处理(N1P1K2),种植伴矿景天一季对Zn、Cd的吸取量分别为11.2 mg/kg±0.1 mg/kg和0.12 mg/kg±0.02 mg/kg。     

CO2浓度升高、氮与土壤水分对春小麦生长及干物质积累的效应

大型人工气候室条件下进行了350μmol/mol和700μmol/mol 2种CO_2浓度,湿润及干旱2种水分处理和0mg/kg_土、50mg/kg_土、100mg/kg_土、150mg/kg_土和200mg/kg_土5种N肥施用量试验结果表明,高CO_2浓度下春小麦分蘖并未增加,低N时分蘖明显降低,因而高CO_2浓度下春小麦分蘖必须补充足够N素。CO_2浓度增高下播后55d施用N肥,春小麦叶宽、叶面积指数均增加,而不施N肥叶宽、叶面积指数未增加。充足N肥和水分有利于促进春小麦叶片生长,明显提高叶面积和分蘖。CO_2浓度增高,春小麦地上部干物质量增加与N肥施用量有关,中N和高N处理地上部干物质量明显增加,而不施N和低N时则增加不明显。干旱条件且高CO_2浓度下地上部干物质量增幅低于湿润条件,因而CO_2浓度升高对N素和水分胁迫无明显补偿作用。且CO_2浓度升高其根干物质量和根冠比未增加,相反湿润条件下不施N处理根干物质量略有降低,而根冠比明显降低。     

不同浓度CO2与化肥配施对番茄生长和养分吸收的影响

为阐明CO_2气肥在番茄种植中的最佳施用浓度,本试验通过在不同CO_2浓度(300、600、800、1 000、1 200、1 400μL/L)处理下配施不同浓度化肥[不施肥(CK),常规施肥,常规施肥基础上减施20%,常规施肥基础上增施20%]来探究CO_2气肥对番茄生长和养分吸收的影响。结果表明,CO_2浓度在800μL/L时,4种化肥处理下的番茄产量提高9. 11%～67. 76%,Vc含量增加12. 52%～38. 60%,可溶性糖含量增加45. 77%～85. 92%,硝酸盐含量下降7. 78%～38. 18%,并且CO_2浓度在800μL/L时,CK与减施化肥处理的番茄产量高于常规施肥处理与增施化肥处理,具有明显的减肥增效效应。因此,施用800μL/L的CO_2气肥能显著增加番茄产量,促进N、P、K养分的积累,同时对改善番茄品质,以及提高矿质元素的吸收利用有良好的促进作用。     

菊科花卉常见缺素症及植株养分含量变化探讨

通过溶液培养的方法,研究了3种主要菊科花卉（金盏菊、孔雀草、万寿菊）在缺N、P、K、Ca 、Mg、S条件下的缺素症状及其生物量与营养元素变化情况。结果表明,金盏菊、万寿菊缺N,孔雀草缺K时症状最为明显;缺N对金盏菊、孔雀草、万寿菊的植株生物量影响最大;与全素（CK）相比,金盏菊和万寿菊缺K处理植株N浓度增加,3种花卉缺N、缺K处理均增加植株的P含量,但缺P处理降低植株K浓度,缺K处理增加含Ca量,缺Ca处理增加含K量和含Mg量,金盏菊缺Mg处理的含K量增加,3种花卉缺S处理植株S含量降幅不大,孔雀草和万寿菊缺N、P、K、Ca处理均可导致植株S含量增加。     

CO2浓度升高和氮素供应对黄瓜叶片光合色素的影响

本文通过N供应浓度[2(低N),7(中N)和14(高N)mmol/L]和CO_2浓度[400(C1),625(C2),1 200(C4)μmol/mol]处理的水培试验一,以及硝铵比[14/0(N1),13/1(N2),11/3(N3)和8/6(N4)]和CO_2浓度[400(C1),800(C3),1 200(C4)μmol/mol]处理的水培试验二,共同研究黄瓜叶片光合色素对CO_2升高、N供应浓度和形态的响应。研究结果表明:苗期时,低、中和高N下,C4处理使得植物干物质都明显增加;而初果期干物质提高程度下降,植株生长速率降低。中等CO_2浓度(C3)显著增加植物在各硝铵比处理的干物质量,但最高CO_2浓度(C4)有提高N3处理的干物质量的趋势。苗期时,在低N和中N供应时C4处理显著降低叶片叶绿素a、叶绿素b和胡萝卜素含量;但高N时,C3处理提高总色素含量,C4处理提高叶绿素b含量;初果期时CO_2浓度处理对色素含量无显著影响;N2硝铵比处理,中等CO_2浓度(C3)下叶片的3种色素含量最高。因此当苗期N素供应浓度较低时,CO_2浓度升高会显著降低叶片3种色素的含量,这主要可能与苗期植物生长速率显著提高产生的稀释作用有关。当N浓度为14 mmol/L时,CO_2浓度适当提高显著促进色素合成,其合成速率大于植物生长速率,导致色素含量提高,提高光合能力;初果期时,CO_2浓度升高的促进作用降低缓和了色素浓度的下降。适当提高NH4+-N供应比例也能达到提高色素含量的效果,但CO_2浓度不宜过高。故而植物光合色素含量可能受到CO_2浓度升高导致的植物干物质增加速率和光合色素合成速率改变的双重调节。中N和高N供应时,叶绿素a/b在苗期随着CO_2浓度的升高而降低,在初果期仅在高N时有显著降低。而在硝铵比试验中,植株种植稀疏时,C4处理提高叶绿素a/b。因此,CO_2浓度升高下的植物捕光能力的提高,可通过适当降低叶片光照强度和提高N供应浓度来实现。从实际生产角度出发,使用中等浓度CO_2施肥,提高N肥供应浓度和NH4+-N比例,结合植株的适当密植更有利于光合色素含量提高,优化其组成,从而有利于黄瓜生物量的提高。     

祁连山水源涵养林区水质特征分析

通过祁连山水源涵养林区水质化学元素分析表明降水经青海云杉林林冠层作用后各化学元素总含量呈增加趋势,增幅最大的元素为Zn,其含量高出降水5.580 mg/L,各化学元素含量从大到小为Zn＞Ca＞K＞Mg＞Fe＞P＞Mn＞Cu＞N;降水经灌木林冠层作用后各化学元素中Ca元素的增幅最大,高出降水含量1.737mg/L,各元素含量变化顺序为Ca＞K＞Mg＞P＞Fe＞N＞Mn＞Cu＞Zn;白大板流域径流中Mg、Ca、K的增加幅度较大,分别为158.16 mg/L,85.965 mg/L和9.266 mg/L;Fe、P、Cu的增幅较小,分别为0.335 mg/L,0.033 mg/L和0.013 2 mg/L.     

开放式空气CO2浓度升高对水稻土壤可溶性C、N和P的影响

采用 FACE (Free air carbon dioxide enrichment)技术,研究了不同 N 施肥水平下,大气 CO2浓度升高对水稻/小麦轮作中水稻土壤可溶性 C、N、P 的影响。结果表明,CO2浓度升高使土壤表层可溶性 C 含量增加,土壤 5 ~ 15 cm 的可溶性 C 含量倾向于降低,增加 N 肥施用(常规 N 处理)更易于使土壤可溶性 C 含量降低。CO2浓度升高使水稻土壤中的可溶性 N 含量降低,在低 N 处理和土壤表层降低幅度较大,N 肥施用仍有提高的余地。CO2浓度升高使水稻成熟期土壤可溶性 P 含量增加,但是常规N 处理下会降低水稻生长前期和土壤表层的可溶性 P,增加 N 肥施用有利于水稻对 P 的吸收。     

咖啡-荔枝混农林系统中小粒咖啡营养诊断及平衡施肥效应研究

定位试验研究咖啡-荔枝混农林系统中N、P、K不同用量及配比咖啡营养状况结果表明,缺N对小粒咖啡产量影响最大,其次为K,而P的影响较小;喷施微量元素B、Zn可明显增加咖啡产量。N、P、K肥配比为1∶0.5∶1,咖啡产量随N、P、K用量的增加而提高,鲜果产量为15~30t/hm2。建议思茅地区小粒咖啡营养诊断指标为N25~30g/kg,P1.0~1.5g/kg,K15~25g/kg,Ca10~12g/kg,Mg2.5~5.0g/kg,Zn10~15mg/kg和B40~50mg/kg;N、P2O5和K2O平衡施肥年最佳用量为N50~100g/株、P2O525~50g/株和K2O50~100g/株。     

Soil and plant calibration for cucumbers grown in the mid‐Atlantic coastal plain

Abstract

Few soil test and plant tissue calibration data exist for cucumbers (Cucumis sativus L.). Two years of a singly‐replicated cucumber fertility study were conducted to develop soil and plant data for calibration purposes employing the Boundary Line Approach. Fertility treatments consisting of 4 K levels (as KC1), 3 Mg levels (as MgCl₂), 3 pH levels (as Calcitic limestone), and 4 N rates (as urea ammonium nitrate) were factorilly arranged and completely randomized to give 108 treatments in both 1987 and 1988. Analyses were performed upon leaf samples for N, P, K, Ca and Mg at early bloom and soil samples for Mehlich (M) 1‐ and 3‐ P, K, Ca and Mg, and pH. Cucumber yields were determined on early (two fruit pickings) and total (four fruit pickings) sampling periods. High‐yielding cucumbers were attained at soil K (Ml = 64 mg/kg) and Mg (Ml = 29 mg/kg) levels lower than currently recommended. No significant differences in correlation coefficients between either Mehlich (Ml, M3) extractant and cucumber leaf P, K, Ca and Mg concentrations were found. Co‐efficients of determination (R²) values for the relationships (in 1987, 1988) between Ml‐ and M3‐extractable P (0.53, 0.40), K (0.77, 0.64), Ca (0.81, 0.71) and Mg (0.89, 0.74) were all highly significant (P ≤ 0.01). No significant differences were noted between early and total high‐yielding cucumber leaf concentrations and ratios developed for use as preliminary sufficiency ranges and DRIS norms, respectively. A reevaluation of cucumber coastal plain soil test calibrations, especially with regard to K, appears necessary. This study provides further support for the conversion of Ml to M3 soil extraction methodology.     

盐胁迫下大气CO2浓度升高对黄瓜幼苗生长、光合特性及矿质养分吸收的影响

采用营养液培养和开顶箱法,研究了盐胁迫下CO2浓度升高对黄瓜幼苗生长、光合特性及矿质养分吸收的影响。结果表明,黄瓜生长在80mmol/L NaCl下,其生物量、光合速率、气孔导度、蒸腾速率均显著下降,而胞间CO2浓度明显升高;CO2浓度升高可增加盐胁迫下黄瓜幼苗生物量,使光合速率、气孔导度、蒸腾速率升高。表明CO2浓度升高能减轻盐胁迫对光合功能的不利效应。80mmol/L NaCl可使黄瓜幼苗体内总N和K 的浓度降低,而使Na 浓度增加;CO2浓度升高具有提高盐胁迫下总N和K 浓度,降低Na 浓度的效应,说明CO2浓度升高可减轻盐胁迫的毒害作用,提高黄瓜幼苗生物量。     

Nutrient distribution in a Norway spruce stand after long-term application of ammonium nitrate and superphosphate

The distribution of nutrients between soil layers and above-ground tree components was examined in a Norway spruce stand that had received ammonium nitrate (annually) and superphosphate (about every third year) for 22 years. Four treatments were included in the study; control (n = 4), N1P1, N2P2 and N3P2 (n = 2), which had received a total of 0, 730, 1700 and 2550 kg nitrogen (N) ha^-1, 0, 130, 300 and 300 kg phosphorus (P) ha^-1 and 0, 340, 784 and 784 kg calcium (Ca) ha^-1, respectively. Compared with the control, stem-wood growth had been three times higher in N1P1 and three and a half times higher in N2P2 and N3P2. Amounts of N, P, Ca, potassium (K) and magnesium (Mg) in the above-ground tree biomass increased (p<0.05) with the fertilizer dose, whereas manganese (Mn) did not. The recovery of fertilizer N and Ca in soil and above-ground tree biomass was negatively related to the fertilizer dose, although there had been a buildup of the N and Ca pools in the mor layer. This strongly indicates that at least the higher doses of N addition caused substantial nitrate leaching. Soil pools of K, Mg and Mn decreased as the fertilizer dose increased. However, the system total amounts (above-ground tree biomass plus soil) of K and Mg did not differ between treatments suggesting that no extra losses of these ions induced by nitrate leaching have occurred. Thus, in an aggrading forest ecosystem, N additions are likely to be followed by increased uptake of K, Mg and Ca. This may to some extent prevent extra leaching of these ions, which otherwise would be expected when there is an increase in nitrate leaching.     

Growth, carbon dioxide exchange and mineral accumulation in potatoes grown at different magnesium concentrations

Plants of Norland potatoes (Solanum tuberosum L.) were maintained for 42 days at Mg concentrations of 0.05, 0.125, 0.25, 1, 2, and 4 mM in a nonrecirculating nutrient film system under controlled environment. With the increased Mg supply from 0.05 to 4 mM, Mg concentrations in the leaves of the 42-day old plants increased significantly from 1.1 to 11.2 mg g-1 dry weight. Plant leaf area and plant and tuber dry weights increased with increased Mg concentrations up to 1 mM in solution or 6.7 mg g-1 in leaves, and then decreased with further increases in Mg concentrations. Rates of CO2 assimilation measured on leaflets in situ at ambient and various intercellular CO2 concentrations were consistently lower at 0.05 and 4 mM Mg than at other Mg treatments, which may indicate decreased photosynthetic activity in mesophyll tissues at the lowest and highest Mg concentrations. Dark respiration rates in leaves were highest at 0.05 and 4 mM Mg, lowest at 0.25 and 1 mM Mg, and intermediate at 0.125 and 2 mM Mg. The different Mg treatments also influenced accumulation of other minerals in leaves. Leaf concentrations of Ca and Mn decreased with increased Mg supply except that Ca and Mn were lower at 0.05 mM than at 0.125 mM Mg. Leaf K concentrations were lower at 1, 2 and 4 mM Mg than at other Mg treatments. Foliar concentrations of P, Fe, Zn, and Cu had small but inconsistent variation with different Mg concentrations. Leaf concentrations of N, S, and B were similar at different Mg concentrations. This study demonstrates that various Mg nutrition, along with altered accumulation of other nutrients, could regulate dry matter production in potatoes by affecting not only leaf area but also leaf carbon dioxide assimilation and respiration.     

钾、镁交互作用对橡胶幼苗生长及养分吸收的影响

  【目的】  我国植胶区砖红壤钾、镁缺乏现象日益突出，研究钾、镁缺乏对橡胶幼苗根系形态和养分吸收的影响，可为橡胶平衡施肥和优质高产栽培提供理论依据。  【方法】  选用‘热研7-33-97’橡胶 (Hevea brasiliensis) 幼苗为研究材料，在人工气候箱内用营养液培养。采用二因素二水平的析因试验设计，设置4个处理:对照 (CK)、缺钾 (–K)、缺镁 (–Mg) 和缺钾镁 (–K-Mg)，培养3个月后，取样测定橡胶幼苗干物质量、根系构型参数、根系活力和养分含量等指标。  【结果】  1) 与CK相比，–K和–K-Mg处理显著降低了单株干物质量和根冠比，干物质量降幅分别为8.4%和27.5%，根冠比降幅分别为20.4%和26.9%，而–Mg处理对干物质量和根冠比均无显著影响；K、Mg交互作用对茎干、根和单株干物质量及根冠比均有显著影响 (P < 0.05)。2) 与CK相比，各缺素处理均显著降低了橡胶幼苗吸收根 (直径 < 2 mm) 的根长、根表面积、根体积、总根尖数及根系活力等根系构型参数，而不同程度增加了平均根粗。方差分析结果表明，K、Mg交互作用对吸收根的根长、根表面积、根体积及总根尖数有极显著影响 (P < 0.01)。3) 各处理下氮和镁、磷和钾以及钙分别在叶片、根系以及茎皮中的平均分配比例高于其他器官。各缺素处理下，地上部的养分占比呈增加趋势。4) 与CK相比，–K处理显著增加了橡胶幼苗单株氮、磷和镁的积累，–K-Mg处理则显著降低了单株氮积累，各缺素处理均显著增加了单株钙的积累；K、Mg交互作用对氮、磷、钙和镁的积累有显著或极显著影响。  【结论】  钾、镁营养显著影响橡胶幼苗对养分的吸收，缺钾、缺镁显著抑制橡胶幼苗特别是根系的生长发育，同时缺钾缺镁加重抑制效果。因此，橡胶生产上不仅要保证培养基质或土壤的矿质营养充足，还要重视钾、镁元素间平衡关系。     

影响山核桃林地土壤生产性能的主要肥力因子及其临界区间

【目的】土壤养分是植物生存的必要条件,探讨山核桃(Carya cathayensis Sarg.)主产区林地土壤肥力因子及其对土壤生产性能的影响,为山核桃的栽植和可持续发展、土壤培肥提供科学依据。【方法】在浙江省山核桃主产区,随机选择58个典型乡镇的山核桃林采集土样,测定了pH、有机质、碱解氮、有效磷、速效钾、有效钙、有效镁、有效铁、有效锰、有效铜、有效锌、有效硼12个肥力因子水平,运用主成分分析和回归分析方法,分析了它们对山核桃生长、感病等级、产量等级的影响以及丰缺临界区间。【结果】主成分分析前5个因素(PC1、PC2、PC3、PC4、PC5)的累计贡献率达78.49%。PC1的主要荷载为土壤pH、有效钙和有效镁含量,PC2的主要荷载是微量元素和有效磷含量,PC3是有机质和碱解氮含量,PC4和PC5分别是有效硼和速效钾含量。林分生长性状中,生长势等级与pH、速效钾、有效钙、有效镁、有效铜、有效锌显著负相关(P <0.01),干腐病感病等级与pH、有效钙、有效镁显著负相关(P <0.01),产量等级与pH、有效钙、有效镁、有效磷、有效锌显著正相关(P <0.01)。回归模型分析得出,土壤pH、速效钾和有效钙、有效镁、有效铜、有效锌是当前栽培措施水平下影响山核桃生长的关键土壤肥力因子。综合评价后发现,研究区现有约57%的山核桃林地土壤综合肥力低于平均水平。【结论】对山核桃林地土壤生产性能影响最大的因素是土壤pH、有效钙和有效镁含量,其次是微量元素和有效磷含量,有机质、速效钾含量也有一定的影响。山核桃主产区的林地土壤关键指标丰缺范围:pH 5.19~5.70、速效钾87~129 mg/kg、有效钙817~1374 mg/kg、有效镁93~145 mg/kg、有效铜1.36~4.39 mg/kg、有效锌0.78~2.33 mg/kg。     

Effect of phosphorus‐enriched biochar and poultry manure on growth and mineral composition of lettuce (Lactuca sativa L. cv.) grown in alkaline soil

The use of pyrolysis products of manures gives positive effects on soil fertility, crop productivity and soil carbon sequestration. However, effects depend on soil characteristics, plant species and the raw material from which the biochar is derived, and some negative effects of biochar have been reported. The objective of this study was to evaluate the effectiveness of poultry manure (PM)‐derived biochar on the growth, and P, N, K, Ca, Mg, Fe, Zn, Cu and Mn concentration of lettuce (Lactuca sativa L.) plant. The treatments as follows: control, 20 g/kg poultry manure (PM), 20 g/kg phosphorus‐enriched poultry manure (PM+P), 10 g/kg Biochar (B), 10 g/kg Biochar+P (B+P). Application of biochar and PM significantly increased lettuce growth, and P‐enriched forms of PM and biochar gave the higher growth. PM has no significant effect on the N concentrations but biochar and, P‐enriched PM and biochar treatments significantly increased N concentrations. Phosphorus concentration of the lettuce leaves significantly increased by PM and biochar treatments. Plant K concentrations were also increased by PM and biochar, and their P‐enriched forms. Leaf Ca and Mg concentrations were lower in Biochar and B+P treatments than that of PM and PM+P treatments. Compared to control and PM treatments, biochar applications reduced Fe, Zn, Mn and Cu concentrations of the lettuce plants. The results of this study indicated that application of biochar to alkaline soil is beneficial for crop growth and N, P and K nutrition, but it certainly reduced Fe, Cu, Zn and Mn nutrition of lettuce.     

水肥耦合对温室盆栽黄瓜产量与水分利用效率的影响

采用一种负水头供水控水盆栽装置进行水分精确控制,通过设定装置的不同供水吸力控制不同的土壤含水量,研究不同水肥供应对温室黄瓜生长发育的影响及水肥间的耦合效应。试验分别设3种供水吸力:3 kPa(W1)、5kPa(W2)和7 kPa(W3);3种施肥水平:N 600、P 300、K 300 kg/hm2(F1),N 900、P 450、K 450 kg/hm2(F2)和N 1200、P600、K 600 kg/hm2(F3)。试验结果表明,W1、W2、W3处理控制的土壤含水量分别为26.25%、20.81%、15.35%。在F1、F2和F3的处理下,黄瓜的生长速率和产量随着土壤水分的增加而增加,表现为W1W2W3;在W1与W2处理下,施肥水平越高,黄瓜生长速率、叶片光合速率、干物质积累量以及产量与水分利用效率越高,表现为F3F2F1;且增加施肥对提高水分利用效率并不以增加植株耗水量为代价。而在W3处理下,植株干物质积累量、叶片光合速率和产量的高低顺序为F2F1F3,F3过高的施肥量抑制了植株的生长。试验结果还表明,水肥互作效应对黄瓜产量与水分利用效率有显著的影响。