Influence of temperature on the expression of manganese toxicity by two soybean varieties

Summary Two soybean varieties (Glycine max) were grown in nutrient solution to investigate their response to manganese toxicity at two different temperature regimes. Dry matter yields of both varieties were markedly reduced by lower temperature (21°C day/18°C night). At these temperatures leaf crinkle symptoms of Mn toxicity were very severe on Bragg and moderate on Lee at high levels of Mn in solution (15 ppm). However increasing the temperature to 33°C day/28°C night completely eliminated symptoms on both varieties. High levels (15 ppm) of Mn in nutrient solution decreased yields of both varieties at low temperature with Bragg showing the greater reduction. At high temperature neither variety showed yield reductions at 15 ppm Mn. Higher concentrations of Mn in shoots and roots were obtained at higher temperature, indicating that increased tolerance was not associated with lower plant Mn levels. Lee consistantly contained higher levels of Mn in the shoots than Bragg in the 15 ppm Mn solution at both temperatures although appearing to be more tolerant at low temperatures. The implications of these results for environmental effects on the expression of Mn toxicity in the field are discussed. re]19751202     

Effects of phosphorus and iron fertilizers on the growth of two soybean varieties at two soil temperatures

The influence of FeEDDHA (0, 0.2 and 2 μg Fe g⁻¹ soil) and NaH₂PO₄·H₂O (0 and 120 μg Pg⁻¹ soil) on the growth of two Fe-ineffective soybean (Glycine max L. Merr.) varieties (anoka and T203) on a calcareous soil at two soil temperatures (16 and 24°C) was compared under greenhouse conditions. The two soybean varieties differed in the following respects: (a) T203 accumulated smaller concentrations of Fe in washed tops than Anoka under comparable conditions; (b) T203 was more susceptible to Fe deficiency and its accentuation by high levels of fertilizer P than Anoka; (c) T203 accumulated lower quantities of Mn in tops than Anoka under comparable conditions; (d) T203, but not Anoka, developed Mn deficiency symptoms when treated with P and 2 μg Fe g⁻¹ at 16°C. Fe deficiency was more severe in both varieties at the higher soil temperature due apparently to: (a) greater plant concentration of P in tops at 24°C; and/or (b) an increased rate of plant growth and greater dilution of Fe in young tissue at 24°C. Foliar P concentration was increased much more than foliar Fe concentration by an increase in soil temperature. Severely Fe deficient T203 plants grown without FeEDDHA at 24°C accumulated less foliar Mn than their FeEDDHA counterparts. Comparisons of Fe effectiveness of various soybean cultivars based on relative responses to FeEDDHA can be influenced by differential effects on Mn nutrition.     

Effect of soil sodicity on the growth,yield and chemical composition of groundnut (Arachis hypogaea Linn.)

Summary A replicated field experiment was conducted to study the effect of exchangeable sodium percentage (ESP) on the yield, chemical composition, protein and oil content and uptake of nutrients by groundnut (Arachis hypogaea Linn.) variety M-13. ESP over 15 delayed germination and emergence of flowers. There was continuous decrease in dry matter yield at 30 and 60 days of growth, grain and straw yield after harvest and protein, oil and kernel percent with increase in soil ESP. A 50 per cent reduction in groundnut yield was observed at an ESP of 20. Increasing soil ESP, increased Na and decreased K, Ca and N contents, but had no effect on the Mg, P, S, Fe, Mn, Zn and Cu contents of the plant. Sodium content of the plant increased, while potassium and nitrogen decreased with age of the plant. The uptake of all the nutrients decreased with increase in soil ESP. The results showed that groundnut is a relatively sensitive crop to soil sodicity.     

微生物多样性对土壤氮磷钾转化、酶活性及油菜生长的影响

采用灭菌土壤分别接种不同稀释倍数(1、10~(-2)、10~(-4)和10~(-6))未灭菌土壤悬浊液的方法,研究了土壤微生物多样性降低对油菜生长和养分吸收、土壤养分有效性和酶活性的影响。结果表明:(1)随着接种土壤悬浊液稀释倍数增加,油菜生物量逐渐降低,10-4的油菜生物量显著低于1和10~(-2),10~(-6)仅为1的26%;(2)油菜氮、磷和钾的吸收量与油菜生物量呈现相同的变化规律;(3)土壤铵态氮浓度随接种土壤悬浊液稀释倍数增加而降低;而土壤硝态氮则以10~(-4)为最高,其它处理间没有显著差异;土壤有效磷未发生显著变化;有效钾反而有上升趋势;(4)土壤多酚氧化酶(PhO X)活性随接种土壤悬浊液稀释倍数增加逐渐升高;β-1,4-葡萄糖苷酶(βG)活性以10~(-6)为最高,而其它处理差异不显著;土壤亮氨酸酶氨肽酶(LAP)活性和酸性磷酸酶(AP)活性变化不显著;(5)相关分析表明,油菜生物量与土壤铵态氮浓度的对数显著正相关;与多酚氧化酶、葡萄糖苷酶和亮氨酸氨肽酶活性显著负相关。研究表明,微生物多样性降低主要通过抑制土壤氮素释放影响植物生长。     

不同结荚习性夏大豆种质的农艺表现及其与产量的相关分析

以533份不同结荚习性大豆种质为试验材料,研究了不同结荚习性大豆种质在黄淮夏播生态区的农艺性状表现,并对主要农艺性状和产量的相关性进行了分析。结果表明:大豆种质的营养期、株高、有效分枝、单株荚数、倒伏性、株型等性状的平均值随无限-亚有限-有限结荚习性递减,生殖期、单株粒重、百粒重、小区产量等性状平均值的变化趋势则相反。相关分析表明,无限结荚习性种质的产量与株高、单株粒重呈极显著正相关,偏相关系数分别为0.602**、0.566**,与有效分枝、倒伏性呈显著负相关,偏相关系数分别为-0.384*、-0.451*。亚有限结荚习性种质的产量与生殖期、单株粒重呈显著、极显著正相关,偏相关系数分别为0.156*、0.536*,与有效分枝呈极显著负相关,偏相关系数为-0.323**。有限结荚习性种质的产量与单株粒重、株高呈极显著正相关,偏相关系数分别为0.433**、0.262**,与株型、单株荚数呈显著、极显著负相关,偏相关系数分别为-0.149*、-0.198**。结合不同结荚习性品种的生长特点,本研究认为,无限结荚习性品种株高较高且株高与产量呈极显著正相关,适合干旱地区种植;亚有限结荚习性品种生殖期与产量呈正相关,生殖期内生长旺盛需要较多的养分供应;有限结荚习性品种的营养生长持续时间短,株高较矮,吸收光能有限,实现高产主要依赖各性状器官间的平衡。生产中,有限结荚习性品种的营养生长期间既需要充足的肥水促其生长,又要防止旺长。     

Influence of interactions of barley cultivars with soil and fertilizer K,and soil pH on grain yield and quality

Summary The interaction of exchangeable soil K with cultivars resulted in differences in grain production by five barley cultivars. The cultivars differed in the amount of exchangeable soil K required to produce maximum yield. Bonanza attained its maximum yield at 183 kg K₂O ha^–1, but Galt did not reach its maximum yield until a high level of exchangeable soil K was reached (252 kg K₂O ha^–1). The other cultivars were within this range. The cultivars also differed in their yield response to applied K fertilizer. Under conditions of growth-limiting K supply, Galt and Gateway were slightly more responsive to the addition of K fertilizer than were Centennial and Conquest, and much more responsive than Bonanza. The interactions of exchangeable soil K and soil pH or soil NO₃–N and soil pH with cultivars indicated differences in acid tolerance of the cultivars. Galt was more pH sensitive than Bonanza.     

Effects of soil pH and associated cations on growth of apple trees planted in old orchard soil

Summary Trunk circumferences were measured on apple trees which had been grown for 5 to 10 years on land previously in apple orchard. Soil beneath each tree was analysed for soil acidity characteristics and basic cations. Tree growth (trunk circumference), was generally retarded but highly variable, but correlated well with the soil measurements in four of the six orchards investigated. Size of Delicious, Tydeman and Rome Beauty cultivars correlated positively with soil pH and negatively with 0.02M CaCl₂-soluble Al and Mn, while that of McIntosh grown adjacent to the Delicious and Tydeman trees in two of those orchards correlated little or not at all with these soil acidity characteristics. However, in the three orchards where McIntosh trees were grown, their size correlated (r=0.72^**, 0.71^**, 0.54^**) well with exchangeable soil Mg. The effects of soil acidity and associated nutrient deficiencies on growth of young apple trees is discussed.Contribution No. 602.     

Effects of salinity, external K+/Na+ ratio and soil moisture on growth and ion content of Sesbania rostrata

Growth of Sesbania rostrata was decreased gradually with increase in root medium salinity (mixed salts or NaCl alone). Soil moisture or anoxia did not affect plant growth significantly. Higher K⁺/Na⁺ ratios in plant tissues compared to those in the root medium were found under different salinities. This indicated a high K⁺-Na⁺ selectivity, a characteristic generally considered unique to halophytes. S. rostrata is moderately salt tolerant and may be utilized as forage crop and green manure on saline land. This revised version was published online in July 2006 with corrections to the Cover Date.     

土壤化学性质对Cu的植物吸收效应和土壤有效Cu测定的影响

在华北平原石灰性土壤中,盆栽小麦的生物相关性检验证明,常用的SB/D联合浸提剂或AB/D联合浸提剂,与植物的吸Cu量均无显著相关关系,不适合直接用来测定土壤有效Cu.校正土壤pH和有机质含量之后,SB/D侵提剂与吸Cu总量的相关性则达到P＜0.01的极显著水平,可用于土壤有效Cu的评价.土壤pH越高则小麦吸收的Cu越少;土壤pH升高1个单位,则土壤有效Cu吸收量平均减少19μg·盆^-1.土壤pH升高和有机质含量增加,土壤有效Cu的测定结果分别减小和增大.     

Influence of soil waterlogging on subsequent plant growth and trace metal content

Summary The uptake of trace metals by two plant species (French bean and maize) has been measured on two soils subjected to various waterlogging regimes. Uptake of both manganese and iron was increased due to soil waterlogging, although reoxidation of the soil affected iron more than manganese. Zinc and copper uptake was influenced by a species factor; French bean (Phaseolus vulgaris) showed preferential uptake of zinc, whereas maize (Zea mays) took up copper preferentially. Uptake of cobalt by both species was increased due to waterlogging, following the pattern of manganese.The abilities of these species to take up trace metals from soil followed the pattern predicted by selective extraction of soil for manganese, iron and cobalt, but not for zinc and copper.     

Influence of potassium and manganese on growth and uptake of magnesium by soybeans (Glycine max (L.) Merr. cv. Bragg)

Summary Soybean (Glycine max (L) Merr. cv. Bragg) seedlings were grown in nutrient solutions to evaluate the response to manganese nutrition as affected by potassium supply. In solutions containing 275 M manganese, increasing the solution concentration of potassium from 1 mM to 10 mM alleviated symptoms of manganese toxicity, decreased manganese concentrations in the leaves and increased dry matter yields of the plants. The reduction in manganese toxicity was brought about by a reduced rate of root absorption of manganese at high potassium supply levels.Increasing the supply of either potassium or manganese decreased the leaf concentration of magnesium although there were no apparent symptoms of magnesium deficiency in any treatment. The reduced concentration of magnesium in the leaves was due to effects of potassium and manganese on the rate of root absorption of magnesium.Under manganese deficiency conditions, growth was reduced and manganese concentrations in plant parts were very low; there was no effect of potassium supply when manganese was absent from the nutrient solution.     

Influence of salt stress on propagation,growth and nutrient uptake of typical aquatic plant species

Anthropogenic activities and natural causes contribute to an increase in the area and degree of degraded saline wetlands in arid/semi‐arid and coastal regions. The objective of this study was to determine the salt tolerance of the seven aquatic plant species Phragmites australis, Arundo donax, Canna indica, Scirpus validus, Alternanthera philoxeroides, Phyllostachys heteroclada and Potederia cordata during asexual reproduction and continuous growth. The species were exposed to five salinity treatments from 0.3 (control) to 20 dS m^?1 during a 30 day experiment. Data were collected on asexual reproduction and growth, chlorophyll content in leaves, Na⁺ and K⁺ concentrations, total nitrogen (TN) and total phosphorus (TP) concentrations in above‐ground biomass (AGB) and below‐ground biomass (BGB). The results showed that: 1) increase in salinity (especially at a salinity level of EC ≥15 dS m^?1) generally inhibited the capacity for asexual reproduction and reduced the chlorophyll content of leaves; 2) total dry biomass of plants was significantly negatively related to asexual reproduction; 3) species‐specific salt tolerance mechanisms were reflected by the Na⁺ and K⁺ concentrations and Na⁺/K⁺ ratios in different parts of the plants; and 4) the absorption of TN and TP were inhibited at high salinity (i.e. EC = 20 dS m^?1) in AGB and BGB of most tested plant species. However, salinity may enhance plant uptake of TN and TP under certain conditions (e.g. EC at 5, 10 and 15 dS m^?1). In general, as compared to the other species tested, giant reed A. donax and alligator weed A. philoxeroides showed relatively high asexual reproduction and growth capacity under high salt stress, and these species should thus be considered as candidates for restoration of degraded saline wetlands and/or for decontaminating saline wastewater.     

外源水杨酸对镉胁迫下两种菊芋品系幼苗的缓解作用

研究了不同浓度Cd(0、50、100 μmol·L-1)及水杨酸(SA)(0、10、100和1000μmol·L-1)处理下2种菊芋(南芋5号和南芋2号)的生物量变化情况,测定了叶片色素(叶绿素和类胡萝卜素)含量及光合作用参数,并比较了2种菊芋对Cd的吸收转运差异性.结果表明:外源SA处理不同程度地缓解了Cd对菊芋幼苗生长的毒害效应,提高了色素含量,改善了光合作用参数,增大了Cd的生物富集系数(BCF)和转运系数(TF),与此同时减少了植株不同器官对Cd的累积量,但最佳SA浓度因品种及器官不同而有所区别.研究表明,适当浓度的SA处理可以有效增强2种菊芋对Cd的耐性.     

Frankia strains of soil underBetula pendula: Behaviour in soil and in pure culture

A K/Rb isotope dilution method was used to determine the uptake of K from undisturbed subsoils. Rb was applied to the topsoil (0–30 cm) to trace the K taken up from the topsoil by crops. The K/Rb ratio in the crops increases when roots contact the Rb-free subsoil. This change in the K/Rb ratio enables the calculation of the uptake of K from the subsoil. Results of 34 field experiments on loess-parabrown soils in N. Germany showed that the subsoil (>30 cm) supplied, on average, 34% of the total K uptake by spring wheat (range 9–70%). The range between the experimental sites is considered in relation to the contents of K in the top and subsoils (as extracted by 0.025 N CaCl₂ solution), the proportion of the total root length in the subsoils, and competition for K between roots in the top and subsoil. In subsoils with similar K contents, uptake from the subsoil decreased significantly from 65 to 21% of total K uptake, as K contents in the topsoils increased from 4 to 8 mg K/100 g. On sites with the same K contents in topsoils (9 mg K/100 g), the subsoil supplied 12 to 61% of total K uptake as the K contents of the subsoil increased from 2 to 27 mg K/100 g. The contribution of uptake of K from the subsoil increased with the development of the crop, from 8% at first node stage to 35% at ear emergence, as the proportion of total root length in the subsoil increased. High root length densities in the topsoil (9 cm/cm³) resulted in competition for K between roots and increased uptake of K from the subsoil.     

土壤水分对温室嫁接和非嫁接黄瓜生长与生理特性的影响

观测了黄瓜生长动态与生理特性对土壤水分状况的反应。结果表明,日光温室嫁接与未嫁接黄瓜分别在土壤相对含水量70％和80％时株高,叶面积和产量增长最快,土壤水分过高与过低均不利于黄瓜的生长;随土壤含水量降低;叶片光合速率,气孔导度,水势与根系活力的下降。     

Gopher mound soil reduces growth and affects ion uptake of two annual grassland species

Summary Portions of an annual serpentine grassland community in California are subject to frequent gopher mound formation. Consequently, studies were undertaken to characterize the effects of mound soils on plant growth and ion uptake. For two of the dominant annual species (Bromus mollis L. and Plantago erecta Morris), growth was reduced in gopher mound soil relative to that in inter-mound soil. A similar reduction in growth was found for plants grown in soils collected at a depth corresponding to the depth of gopher burrowing. This reduction in growth was associated with lower total P and N contents of the soil which were reflected in lower shoot contents of N and P. Additional experiments, however, showed that reduced N and P availabilities in mound soil were not entirely responsible for the growth reduction. Similarly, shoot Ca/Mg ratios were reduced in mound soil but additions of Ca improved the Ca/Mg ratio without improving growth. Growth reductions were associated with altered shoot concentrations of microelements, particularly elevated levels of Mn. A competition experiment between Plantago and Bromus showed that Bromus was more competitive than Plantago in mound and inter-mound soils and that soil type had only small affects on the nature of the interaction between the two species.     

Comparative study on EUF and other methods of soil analysis for the determination of available potassium in soils from Northern Greece

Summary Twenty-one representative soils from Northern Greece could be grouped into three categories based on the EUF-K curves which displayed marked differences in the magnitude of K release by the soils employed. The cumulative K desorption by EUF within 35 min and the cumulative K-uptake values of ryegrass (10 cuts) were found to be correlated (r=0.87***). Although this correlation is rather close, the K dynamics of a soil can be better characterized by the course of the K-desorption curves. Because the quotient EUF-K-80°C/EUF-K-20°C can give information on the course of K desorption it is therefore sufficient in routine investigations to know the EUF-K-20°C contents and the numerical values of the quotients EUF-K-80°C/EUF-K-20°C.The EUF procedure does not only indicate the close relationship between K extracted and K uptake by plants, but it can also provide information on other nutrients in the same soil sample. With this extra information it was possible to explain why in some of the analysed soils K uptake was low despite high K availability, the reason being that P availability was not optimal in one of the experimental soils and that the Mn concentration of the soil solution was too high in another. At equal K availability the K uptake was also dependent on the amount of EUF-extractable N.