Available soil nutrients and water content affect leaf nutrient concentrations and stoichiometry at different ages of Leucaena leucocephala forests in dry-hot valley

Purpose

The carbon (C), nitrogen (N), and phosphorus (P) concentrations of leaves can reflect soil nutrient supply conditions and changes in soil. An understanding of species adaptability and nutrient use efficiency in extreme ecosystems can help land managers choose effective methods to improve management and community structure of introduced plants which may induce biological invasion and limit the regeneration of native species.

Materials and methods

We selected the Leucaena leucocephala forests in three ages (9, 15, and 26 years old) in the Jiangjiagou Gully to study the relationships between (i) soil factors and forest age and (ii) leaf nutrient concentrations. Soil factors and leaf nutrients were measured in nine sampling quadrats of 10?×?10 m of each plot. We used ANOVA to examine differences in leaf variables and soil factors at different ages of L. leucocephala forest. Pearson’s correlation analysis and linear regression analysis were conducted to identify the relationships between soil factors and leaf variables. Then, we used analysis of covariance to examine combined effects of forest ages and soil factors on leaf variables.

Results and discussion

Leaf N was significantly correlated with available P, while leaf P was significantly correlated with both available P and available N. Leaf N and P had no significant relationship with soil total N and P. Leaf C:N:P stoichiometries had a higher significant correlation with total N, available N, and soil water content.

Conclusions

Our findings illustrate that available N and available P are the main limitations for L. leucocephala, though available P imposed a stronger limitation than available N. Moreover, soil water content played an indispensable role on nutrient accumulation and the soil ecological environment. Our results provide useful information to improve L. leucocephala community structure and reduce soil degradation in a dry-hot valley.

     

Variation within sunflower cultivars and inbred lines in leaf chemical composition

Abstract

Plant species, as well as cultivars within species, have been shown to vary in response to soil nutrient levels due to variation in tissue requirements and variation in ability to absorb nutrients from the soil. In order to study this latter aspect in sunflowers (Helianthus annuus L.), two field trials were conducted in which nutrient concentrations in the topmost nature leaf were determined. At two growth stages, 16 cultivars differed significantly in leaf nutrient levels of N, K, Ca, Mg, Mn, Cu, Zn, and B. Seed yields were highly significantly correlated with leaf nutrient levels, variation in nutrient concentrations accounting for 43% of the observed variation in seed yield. On this soil which was low in B, variation in B concentration alone accounted for 28% of the variation in seed yield in spite of 2 kg B/ha having been applied. Marked differences were observed in the leaf nutrient concentrations of 40 inbred lines tested.     

Beneficial effects of glycine on growth and leaf nutrient concentrations of coriander (Coriandrum sativum) plants

Abstract

In this study, the effect of glycine amino acid was evaluated on growth characteristics and nutrient uptake of coriander plants under greenhouse conditions. The treatments were soil application of glycine in two concentrations of 300 and 600?mg kg^?1 soil, foliar application of glycine (in 0.05% concentration), soil application of mix NPK fertilizer and no fertilizer control. The growth parameters of plant height, leaf SPAD value, shoot and root fresh weights were significantly improved by soil application of glycine, particularly in higher concentration. Soil application of glycine also reduced the number of flowered plants, while it increased soluble solids (TSS) and vitamin C of plant leaf extracts than control plants. Leaf nutrient concentrations of nitrogen (N), calcium (Ca), potassium (K), phosphorus (P), iron (Fe), and zinc (Zn), but not magnesium (Mg) and manganese (Mn), were significantly increased by soil application of glycine, whereas soil applied NPK significantly increased P and Ca of leaves than unfertilized control plants.     

Influence of soil calcium,potassium, and pH on development of leaf tipburn of cabbage in eastern North Carolina

Abstract

Three hypotheses that involved manipulation of soil calcium (Ca), potassium (K), and pH in relation to the occurrence of leaf tipburn of cabbage in eastern North Carolina (NC) were formulated and tested: 1) adding K to soil will increase (induce) leaf tipburn; 2) adding Ca and K together to soil will block K‐related tipburn induction, and 3) raising soil pH to levels of 6.0 to 6.5 will decrease leaf tipburn. Six experiments were conducted in commercial cabbage production fields in eastern NC in 1996 and 1997 to test these hypotheses. Hypothesis 1 was accepted since higher rates of K significantly (p<0.05) increased leaf K concentration, soil K content and leaf tipburn incidence compared with the control. Total cabbage yield increased as K rates increased, however, significant differences were only observed between the control and the highest rate (365 kg K ha^‐1) in 1996. Hypothesis 2 was accepted since adding increased amounts of Ca and K. did not significantly increase leaf tipburn incidence. Hypothesis 3 was rejected since a range of soil pH from 5.3 to 6.6 did not increase or decrease leaf tipburn incidence, nutrient uptake or total yield. These data suggest that leaf tipburn of cabbage can be increased (induced) with excessive K fertilization and that this practice may be associated with the disorder observed in NC. Also, the addition of Ca with K may potentially reduce the risk associated with K‐related leaf tipburn of cabbage.     

Interaction of soil boron application with leaf B concentration,root length density,and canopy size of citrus affected by Huanglongbing

Abstract

Good and balanced citrus nutrition is important for high fruit yields and improved tree performance. A study was conducted for 2?years to investigate the effect of soil application of boron (B) on leaf nutrient content, canopy size, and root length density (RLD). The study was conducted on 10-year-old Candidatus Liberibacter asiaticus (CLas)-infected Vernia sweet orange on Rough Lemon rootstock in a commercial grove east of St. Cloud, FL planted at 375 trees ha^?1 on a traditional soluble dry nutrition and spray programs. Treatments were supplied with various ground-applied controlled-release fertilizer treatments containing B. Boron was applied at 0×, 2×, and 4× current University of Florida recommendation where 1×?=?1.12?kg ha^?1. Data collected included leaf B nutrient content, soil B concentration, trunk diameters, canopy volumes, soil electrical conductivity, and soil pH. The 0×, 2×, and 4× application rates corresponded with leaf nutrient contents ranging from 56?mg kg^?1 and 88?mg kg^?1 in March 2017, 162?mg kg^?1 and 288?mg kg^?1 in September 2017, and 122?mg kg^?1 and 320?mg kg^?1 in May 2018. Temporary, RLD decreased with time from March to September 2017 by 13, 30, and 37% at the 0, 2.24, and 4.48?kg B ha^?1 and increased by 309, 258, and 306% at the 0, 2.24, and 4.48?kg B ha^?1, respectively, from September 2017 to May 2018. No consistent pattern was established between soil B application with canopy size.     

Effects op high rates op fertilizer N,P, and K on corn,Zea Mays L., leaf nutrient concentrations

Abstract

The leaf concentrations of N, P, and K were primarily influenced by the respective fertilizer nutrient, except P, vhich also was influenced by the fertilizer N. Increasing rates of the nutrients well above those recommended for normal corn production increased the leaf nutrient concentrations, but not yields after the first increment of fertilizer. The effect of dry veather reduced yields 0.7 quintals per hectare per day and also vas negatively correlated with the leaf N and leaf P concentrations (0.01 probability level).     

Decomposition and nutrient mineralisation of leaf litter in smallholder cocoa agroforests: a comparison of organic and conventional farms in Ghana

Purpose

Although litter decomposition and nutrient release patterns have been studied in cocoa agroforestry systems in general, studies focusing on organic and conventional cocoa systems are lacking which is critical as organic farms are particularly dependent on nutrient returns from decomposing litter.

Materials and methods

Dynamics in leaf litter decomposition and the mineralisation of macro- and micro-nutrients in organic and conventional cocoa agroforestry systems were studied using the litterbag technique for 12 months.

Results

The average monthly mass loss was more than two times higher on organic farms (9.2–14.4 g month^?1) compared to conventional farms (4.2–7.3 g month^?1) in the first five months. The annual rate of decomposition (k) was higher on organic farms (1.9) compared to conventional systems (1.4). The time required for 50% (t₅₀) and 99% (t₉₉) decomposition of leaf litter was both lower on organic farms (t₅₀?=?0.4 years, t₉₉?=?2.6 years) than conventional farms (t₅₀?=?0.5 years, t₉₉?=?3.5 years). The estimated k values for macro- and micro-nutrients on organic cocoa systems ranged from 2.3 for calcium to 4.5 for potassium compared to 1.6 (Ca) to 2.8 (K) on conventional farms. The k values of all nutrients (except nitrogen and phosphorus) were significantly greater on organic farms than conventional systems. The estimated k values for both litter decomposition and nutrient mineralisation correlated with soil pH and moisture content, but not initial litter chemistry.

Conclusions

Organic management of smallholder cocoa agroforestry systems enhanced leaf litter decomposition and nutrient mineralisation through improved soil conditions. Thus, organic management of cocoa agroforestry systems may contribute to sustainable cocoa production in smallholder systems through enhanced nutrient return from litter decomposition.

     

Effects of magnesium and potassium soil applications on yields and leaf nutrient concentrations of red raspberries and on soil analyses

Abstract

Magnesium and potassium applications did not affect yield of Willamette raspberries in a study conducted between 1974 and 1977 in British Columbia. Potassium increased berry size but only in one of the three years that berry size was recorded. Leaf Mg, K, Ca and P concentration plateaus were established using biweekly sampling in 1977 and comparison with literature data of studies on a similar soil and with the same raspberry cultivar. New cane leaf K was relatively stable between August 10 and September 25, Mg between July 10 and August 15 and P between September 1 and 20. A relatively stable concentration plateau for Ca occurred between July 10 and August 5 but was not as consistent from year to year as were Mg, K and P concentration plateaus. Correlations between soil nutrient extraction values and corresponding leaf nutrient concentrations (during the established concentration plateaus) were found for both Mg and K, with Mg being better than K.     

Nutrient status of apple orchards in Canterbury,New Zealand. 1. Levels in soil,leaves and fruit and the prevalence of storage disorders

Abstract

The nutrient status (N, P, K, Ca, Mg, K, Fe, Mn, Zn and Cu) of 26 Cox's Orange Pippin and 20 Braeburn apple orchard sites in the Canterbury region of New Zealand was evaluated by soil, leaf and fruit analysis. Concentrations of available nutrients in soils ranged widely but those in leaves and fruit were generally confined to a relatively narrow range. Concentrations of leaf N were high in the study area, as were levels of extractable soil P, and it is suggested that reductions in fertilizer additions of these nutrients would generally be appropriate.

Soil, leaf and fruit nutrient contents were generally not well correlated with one another. The only highly significant correlations (P≤0.001) were between leaf and fruit Ca for Cox's and soil and fruit Mg for Braeburn. The poor correlations were attributed to the empirical nature of soil tests, the presence of large nutrient reserves within the tree framework and the effects of cultural and environmental factors on nutrient uptake and translocation by the trees.

The storage disorders bitter pit and senescent breakdown in Cox's and lenticel blotch pit in Braeburn were observed in apples harvested from some of the study sites. Such disorders were generally associated with low concentrations of Ca (≤.2.5 mg/100 g) in samples of cortical plugs taken from fruit at harvest.     

Effect of soil zinc,pH, and cultivar on cadmium uptake in leaf lettuce (Lactuca sativa L. var. crispa)

Abstract

Six noncrisphead lettuce cultivars (Lactuca sativa L.) were grown in pots, using soil from field plots that had been amended annually with 90 MT/ha of an industrial sludge as part of a continuous study initiated in 1981. Two greenhouse experiments (each replicated 6 times) were completed—one in the spring and one in the fall. Variables included 6 cultivars, 2 soil pH levels and 2 soil Zn levels. All variables appeared to influence Cd accumulation in the leaf tissue. Uptake of Cd and Zn increased with decreasing soil pH for all cultivars. ‘Grand Rapids’ accumulated the least leaf Cd and ‘Summer Bibb’ the most. A positive correlation between leaf Zn and leaf Cd was observed, but the correlation between soil Zn and leaf Cd was variable.     

Dryland corn response to tillage and nitrogen fertilization. II. P,K, CA,MG

Abstract

Nitrogen fertilization and tillage practices may influence the availability and uptake of essential plant nutrients other than N. This study was conducted to assess the interactive effects of N rate and timing and tillage practices on uptake and concentration of P, K, Ca and Mg in corn grown under dryland conditions. Potassium accumulations in no till (NT) soils were greater than in conventional till (CT) near the surface and lower than CT in the subsoil. Phosphorus and Ca levels decreased with soil depth, while Mg tended to accumulate in the subsoil. Phosphorus uptake and concentration of 5‐leaf stage corn was increased as tillage intensity decreased. Nitrogen rate at planting increased 5‐leaf P uptake but reduced P concentration; however, by silking no effect of tillage or N fertilization practice on ear leaf P concentration was obtained. Increases in 5‐leaf corn K uptake and concentration as tillage intensity decreased may have reduced Mg and Ca concentrations via cation antagonism. Ear leaf Mg and Ca concentrations were increased by N rate, probably as a result of solubilization of Ca and Mg and improved crop growth. Distribution of essential elements in the soil due to tillage in combination with varying N fertilization practices can influence temporal nutrient uptake, thereby altering plant nutrient diagnosis.     

Impact of time of day and time since irrigation on cotton leaf blade and petiole nutrient concentrations

Abstract

Petioles are used in weekly nutrient monitoring programs because they are more responsive to short‐term changes than leaf blades. However, this responsiveness may allow other factors, such as sampling time, to mask genuine changes in nutrient status. The objectives of this study were to measure the influence of time of day and time since irrigation on petiole and blade phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg) concentrations and to compare petiole and blade samples in their stability and usefulness in evaluation of cotton nutrient status. Cotton was grown on a sandy soil in the Coastal Plain region of Georgia. Treatments were K application rates of 0, 55, and 110 kg K₂O/ha. In early bloom, leaf blades and petioles were sampled from the first fully expanded leaf immediately following irrigation at 13: 00 Monday through Friday and on Tuesday at 7: 00, 9: 00, 11: 00, 15: 00, 17: 00, and 19: 00. Blades were separated from petioles, and P, K, Ca, and Mg were measured. Petiole and blade nutrient levels were positively correlated for P, K, Ca, and Mg. The difference in K rates was not as well reflected in the blade K levels as in the petiole K levels. As time since irrigation increased and the soil dried out, the petiole K levels of the 55 and 110 kg K₂O/ha treatments became significantly different. Petiole and blade P and K levels declined earlier in the day than Ca and Mg levels as the moisture content of the leaves declined. Blade moisture content dropped earlier than petiole moisture content which led to increased nutrient concentrations. The large daily variation in petiole nutrient levels could result in altered fertilizer recommendations. Therefore, it is of critical importance to sample cotton petioles consistently at the same time of day and the same time in relation to irrigation scheduling in order to differentiate between these timing effects and the timing effect due to crop growth stage.     

Soil Characteristics and Mineral Nutrient in Wild Jatropha Population of India

Abstract

Mature leaves of naturally occurring Jatropha curcas plants and soils samples were collected from four different populations to determine the soil characteristics, soil‐available nutrients, and leaf nutrient contents. This study provides a reliable account of the endogenic concentrations of nutrients present in jatropha leaves. Soil manganese [diethylenetriamine pentaacetic acid (DTPA)‐Mn] was the only soil‐available nutrient significantly correlated with its content in the plant. Relationships between soil characteristics, available nutrient in soil, and their content in plant leaves were also attempted.     

Production of Chinese cabbage in relation to nitrogen source,rate, and leaf nutrient concentration

Abstract

Chinese cabbage (Brassica rapa L. Chinensis group) production is expanding in the U. S., and guidelines regarding its production under Western cultural practices are needed. The objectives of this study were to investigate the effects of N source and rate on Chinese cabbage yield, marketability, and wrapper leaf nutrient concentrations, and to estimate the critical wrapper leaf‐N concentration associated with maximum yield and marketability. Chinese cabbage was grown in five sequential plantings using raised‐bed, polyethylene mulch culture with subsurface irrigation on a sandy soil. Nitrogen fertilizer was applied at rates of 0, 67,112, and 157 kg/ha using the following sources: 1) ammonium nitrate. 2) calcium nitrate, 3) urea‐ammonium nitrate solution (Uram, 32% N), 4) urea, and 5) a urea‐calcium solution (18% N). Mature Chinese cabbage wrapper leaf concentrations of P, Ca, and Mg increased with increasing N rate, while leaf‐K concentration decreased. Leaf‐N concentration increased in response to N rate, but was not affected by N source or harvest date. Leaf‐P, K, Mg, and B concentrations were sufficient or high according to established standards, but leaf‐Ca was low. Leaf‐Ca and Mg concentrations were lowest with N sources containing only urea, and highest where at least part of the N was applied as NO₃ ^‐. Chinese cabbage head weight and percentage marketable heads increased as N rate increased. Yield and quality were highest with N sources which contained NO₃ ^‐, and were smallest where N was applied entirely as urea, which may have been due to plant sensitivity to NH₄ ⁺. The critical value of mature cabbage wrapper leaf‐N concentration above which yield or marketability was not limited was estimated to be 36 to 41 mg/g, which agrees well with established standards.     

Effects of bark mulch and npk fertilizer on yield,leaf nutrient status and soil mineral nitrogen during three years of strawberry production

The effects of bark mulch and NPK fertilizers on yield and leaf and soil nutrient status of ‘Korona’ strawberry plants (Fragaria×ananassa Duch.), were studied over a period of three years. A significant effect of mulching was found in the first harvest year, but additional fertilizer did not affect total yield. Bark mulch slightly decreased the level of leaf nitrogen, but increased the level of leaf phosphorus and potassium in all years. Bark had a significant, negative effect on soil nitrate and ammonium content in the two first seasons. Mulching increased the soil moisture content in all years.     

Use of routine soil tests in predicting corn leaf zinc

Abstract

Zinc of index corn leaves samples from 91 Minnesota sites on numerous soil types was correlated with soil Zn extracted by four routine procedures. The EDTA?(NH₄)₂CO₃ ‐ extractable soil Zn was more closely correlated with leaf Zn than soil zinc extracted by 0.1N HCl, EDTA‐NH₄OAc, or by NH₄OAc ‐ dithizone. Soil pH, CaCO₃ equivalent, extractable P, and organic matter of both acid and calcareous soils were negatively correlated with leaf Zn. When EDTA ? (NH₄)₂CO₃ ‐ extractable Zn was included with routine soil tests, a prediction equation for corn leaf Zn was formulated and compared with analytical values. However, the use of 1.4 ppm EDTA ? (NH₃)₂CO₃, ‐ extractable soil Zn alone as a critical value was equally effective in predicting leaf Zn.     

Calibration of the mehlich 3 soil test for potassium using leaf analyses and potassium deficiency symptoms in cotton plants

Abstract

A new calibration of the Mehlich 3 soil test for potassium (K) is proposed for the Mississippi Delta area, based on leaf analyses and K deficiency symptoms in cotton plants. The calibration reflects the need to supply adequate K concentrations to plants during the fruiting period of greatest K demand. The lowest levels and highest percent of sites exhibiting K‐deficiency symptoms were associated with the fifth week of flowering; or at the peak bloom stage of plant growth. The fifth week of flowering was selected to base soil and plant evaluations for K needs. A 1.5% leaf K level was selected as the critical leaf K level (the level that plants experience a nutrient deficiency and yield reductions), based on visual leaf K‐deficiency symptoms observed in plants 95% of the time. Leaf K concentrations below 1.51% identifies K‐deficiency symptoms in the upper leaves through eight weeks of flowering. A simplified equation [Topsoil K (lb/A) = 480 + 5 x CEC (Milliequivalents/100g soil)] defines critical soil test K concentrations with respect to the cation exchange capacity (CEC) in soils. This equation can be used to determine present topsoil K needs for cotton in the Mississippi Delta area based on a 1.5% critical leaf K level during the fifth week of flowering.     

Dominant effects of litter substrate quality on the difference between leaf and root decomposition process above- and belowground

Initial decomposition rates, changes in organic chemical components (acid-insoluble fraction, holocellulose, polyphenols, soluble carbohydrates) and nutrient dynamics (K, Mg, Ca, P, N) were examined for fine roots and leaves of Japanese cypress (Chamaecyparis obtusa). Litterbag experiments designed to evaluate the relative effects of litter type and position of litter supply in the soil were carried out, considering that root and leaf litter typically occupy different locations and have different substrate qualities. Litterbags of roots and leaves were placed at two positions (on the soil surface and in the humus layer), and collected every 3 months over one year. The mass loss rate and N release were slower during root decomposition in the humus layer than during leaf decomposition on the soil surface. These differences between root and leaf decomposition were mainly caused by the litter type, and the effect of the position on decomposition was relatively small. Root litter was less influenced by position related effects, such as differences in humidity, than leaf litter, and this recalcitrant trait to environmental effects may be responsible for the slower mass loss rate and N release in root decomposition. The results of the present study suggest that fine roots are persistent in the soil and serve an important role in N retention in forest ecosystems because of their litter substrate quality.     

A comparison of the chemical composition of the corn leaf and the grain sorghum leaf

Abstract

Leaf samples were taken from corn and grain sorghum being grown in adjacent fields with the same soil type and with the same cultural practices insofar as possible. The samples were analyzed for N, P, K, Ca, Mg, Fe, Zn and Mn. Results show that the nutrient composition of the leaves of corn and grain sorghum were consistently different for most nutrients. The differences were sufficiently great and consistent to strongly suggest that critical nutrient levels need to be established for grain sorghum instead of using diagnostic criteria established for corn.     

Effects of Soil Application of Amino Acids,Ammonium, and Nitrate on Nutrient Accumulation and Growth Characteristics of Sweet Basil

ABSTRACT

The use of organic or reduced form of nitrogen (N) can have various beneficial effects in terms of plant nutrient uptake, metabolism, and environmental issues. In this study, the influence of soil application of reduced N-forms (ammonium, glycine, and glutamine) compared to nitrate and a no fertilizer treatment was evaluated on growth characteristics of sweet basil (Occimum basilicum L.) under a moderate lime soil conditions. The basil growth traits including root and shoot biomass were increased under application of reduced N-forms mainly glycine and glutamine compared to no fertilizer treatment. Application of reduced forms of nitrogen (ammonium, glycine, and glutamine) increased the leaf concentrations of potassium (K), magnesium (Mg), calcium (Ca), iron (Fe) and zinc (Zn), whereas the leaf N concentration was increased by ammonium and nitrate fertilization compared to unfertilized control plants. The results indicate that soil application of reduced N-forms particularly glycine and glutamine is superior to nitrate application.