Foliar Analysis Research Articles

Efecto del yeso sobre las características químicas de un Oxisol de la Orinoquia colombiana cultivado con lima ácida Tahití

La lima acida Tahití [Citrus latifolia (Yu Tanaka) Tanaka] es una de las especies de cítricos con potencial de producción para consumo interno y exportación en los llanos Orientales de Colombia. Con el propósito de evaluar los efectos del uso de yeso agrícola sobre las propiedades químicas, absorción de nutrientes y producción de frutos de lima Tahití, se realizó un experimento en un suelo Oxisol de terraza alta del Piedemonte Llanero. Los tratamientos consistieron de cinco niveles de yeso (0,5 - 1,0 - 1,5 - 2,0 y 2,5 t ha-1). Se utilizó un diseño de BCA con 4 repeticiones. La producción de fruto fue evaluada durante cinco años consecutivos y al sexto año se realizó el análisis químico del suelo y análisis foliar. Se encontró un efecto positivo sobre el aumento en el contenido y la distribución de Ca, Mg, y S en el perfil del suelo, disminución de la acidez intercambiable y aumento del pH con las aplicaciones crecientes de yeso agrícola. Las aplicaciones de yeso aumentaron la absorción de Ca y S y redujeron los niveles foliares de N, K, Mg y Zn, sin alterar la productividad del cultivo. La mayor producción acumulada de frutos (141,41 t ha-1) fue obtenido con la aplicación de 2,5 t ha-1 de yeso. Se demostró los efectos positivos del yeso agrícola en la distribución de bases en el suelo, en la reducción de la acidez y el incremento de pH en profundidad, mejorando la productividad de lima Tahití.

Edaphic and climatic factors and the nutrient dynamics in Uapaca kirkiana dominated miombo woodland agroforestry ecosystems

Soil and foliar analysis were used to investigate influence of edaphic and climatic factors on the soil–plant nutrient dynamics in Uapaca kirkiana dominated woodland ecosystem in Zimbabwe. Examination of the relationship between soil factors and foliar nutrient concentrations as analysed by multiple regression analysis showed that between 60 and 97% of the variations in foliar nutrient concentrations during the wet period, with the exception of nitrogen, could be explained by soil factors: soil nutrient content, texture and pH. In the dry winter period, influence of these soil factors on foliar nutrient content was in the range between 48 and 97%. Factors that had significant influence (P < 0.05) were particularly exhibited during the wet period and these were those influencing foliar P, Fe, Mn and Zn. Multiple regression analysis between climatic factors and foliar nutrients showed temperature had a statistically significant negative relationship with Fe whilst precipitation had a highly significant positive relationship with Fe during the dry winter period. Correlation between foliar Fe and rainfall was negatively statistically significant during the rainy period (P < 0.05) and became positively statistically highly significant during the dry period (P < 0.01). There was also a highly statistically significant negative relationship between the total annual rainfall and foliar nitrogen during the dry winter period. Findings of the study highlight importance of both soil and climatic factors on soil–plant nutrient dynamics in the miombo ecosystem, and should therefore be taken into consideration when establishing U. kirkiana in an agroforestry system.

English

An experiment was conducted in the agricultural year 2014/2015, aiming to evaluate the management of anticipated nitrogen fertilization, applied with a slow-release source in maize crop with two plant covers, in a Dystrophic Red Latosol. Matching the Oxisols in Soil Taxonomy and Ferralsols FAO/United States WRB (Unesco soil classification and the World Reference Base for Soil Resources. Pennisetum glaucus (Pennisetum glaucum (L.) R. Br.) and Raphanus sativus (Raphanus sativus L.) were used as green cover, keeping a fallow area. In the areas with vegetal cover, N was applied anticipatedly, during planting and in top-dressing, while in the fallow area it was applied during the planting process and in top-dressing. The treatments were distributed according to a random block design with four replicates. The anticipated N application was made 38 days before planting and top-dressing application 27 days after planting. Leaves were collected for foliar analysis during the tasselling stage of the plants. The harvest and threshing were done manually, and the grains were weighed. Grain yield and leaf N contents were evaluated. The maize crop responded to nitrogen fertilization regardless of the cover used. Nitrogen fertilization using a slow-release N source can be managed in an anticipated stage, without damaging crop yield. Key words: Soil, slow-release nitrogen, Zea mays L.

Organic P in temperate forest mineral soils as affected by humus form and mineralogical characteristics and its relationship to the foliar P content of European beech

Phosphorus (P) deficiency of beech (Fagus sylvatica L.) is widespread in Europe. However, it is difficult to determine at which sites trees are prone to P deficiency, since foliar analysis is the only tool widely accepted for assessing the P nutritional status of beech. Our central objective was to identify the main influencing factors on organic P in forest soils and to test its usefulness as a predictor of the foliar P content of beech. Our hypotheses were: (1) stocks of total organic P (TOP) and microbial biomass P (MBP) in the mineral soil are higher at mull than at moder/mor sites, (2) the TOP content and the soil organic carbon (SOC):TOP ratio are affected by soil mineralogical characteristics, such as oxalate-extractable iron and aluminum (Feox, Alox) and clay, (3) multiple regression models that include the TOP stock, soil mineralogical parameters and the humus form as predictors are useful to explain the variability of the foliar P content of beech. We sampled the mineral soils of 9 mull and 11 moder/mor sites at 0–50 cm depth and took foliar samples of beech trees in three subsequent years. In contrast to our hypothesis (1), we did not find significantly higher TOP or MBP stocks, but determined lower SOC:TOP ratios at mull compared to moder/mor sites. In line with our hypothesis (2), the TOP content was positively related to Feox, Alox and clay contents, while the SOC:TOP ratio was negatively related to Feox, Alox and clay contents, suggesting strong effects of clay, Al and Fe on the accumulation of TOP. In partial agreement with our hypothesis (3), the TOP stock was included as a positive and the clay content as a negative predictor in a multiple regression model of the foliar P content, suggesting decreasing bioavailability of TOP with increasing clay content. Across all sites, the model consisting of these two parameters better explained the foliar P content (R2 = 0.60) than the stocks of Bray-II- (R2 = 0.37) or Olsen-extractable P (R2 = 0.53) as single predictors. Overall, our results suggest that the accumulation of TOP in forest mineral soils and its potential availability to beech are strongly affected by soil mineralogical parameters, which may be included in statistical models to improve the predictability of P availability to trees.

Silver vase bromeliad: Plant growth and mineral nutrition under macronutrients omission

The present study aimed to evaluate the effects of N, P, K, Ca, Mg and S deficiencies on the growth, mineral contents of silver vase bromeliad [Aechmea fasciata (Lindley) Baker], a species native to Brazil. Plants were maintained on modified Hoagland & Arnon nutrient solution with omission of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), sulfur (S) or complete solution (CS) totalizing seven treatments. Leaf nutrient contents of the treatments were analyzed to confirm the deficiencies. The first leaf deficiency symptoms appeared in cultivated plants from which nitrogen (N) was omitted. In fact, nitrogen was found to be the growth-limiting nutrient of silver vase bromeliad. Phosphorus-deficient plants had reddish leaves and showed necrosis in young leaves. K, Ca, Mg and S deficiency can only be determined by foliar analysis. The limiting nutrients to silver vase bromeliad growth were N > P = K > Ca = Mg > S in ascending order.

WATER TREATMENT SLUDGE AS POTENTIAL SOIL AMENDMENT FOR NATIVE PLANTS OF THE BRAZILIAN CERRADO

This work evaluates the effect of 5 mixtures of water treatment sludge, soil from the Cerrado region (Brazil) and a commercial substrate on the growth of 4 species of native plants (Copaifera langsdorffii, Astronium fraxinifolium, Peltophorum dubium and Tabebuia roseo-alba) from the Brazilian Cerrado. A randomized design was setup with four repetitions and WTS loading rates of 0, 204, 417, 638 and 869 g/kg. Plant sampling for analysis was performed at 30, 60, 90, 120 and 150 days after planting, totalling 400 experiments. The results on morphological parameters and foliar analysis showed good results for the sludge loading rates of 204 and 417 g/kg (18,75 and 37,5% of sludge, respectively), for the Copaifera langsdorffii, Astronium fraxinifolium and Tabebuia roseo-alba growth, which presented the highest values for plant diameter, height and total dry matter weight at the 90th and 120th day of experiments. These loading rates seem to provide suitable buffer conditions and nutrients for plant growth. For sludge loading rates of 638 and 869 g/kg the development of all species was reduced, suggesting that plant growth was probably affected by both the higher concentration of Al and the poor mixture structure due to excess of sludge.

USE OF YIELD AND TOTAL SOLUBLE SOLIDS/TOTAL TITRATABLE ACIDITY RATIO IN ORANGE ON GROUP DEFINITION FOR STANDARD DRIS

ABSTRACT The nutritional quality of orange influences directly on its juice quality. Therefore, the DRIS (Diagnosis and Recommendation Integrated System) allows the verification of nutrients balance in plants as well as determine if its growth is associated or not to nutritionals restrictions. Thus, this research applied the total soluble solids/total titratable acidity to identify the standard group and to define the DRIS. The experiment was carried out in an orange orchard (1 ha) of the Monte Parnaso variety, in Southern Brazil. Twenty trees were geo-referenced, aiming to collect samples for foliar analysis and quantify fruits quality parameters. Therefore, it was possible to observe that total soluble solids/total titratable acidity presented the best ratio with the nutritional balance index, when compared to yield. Hence, it presents the best response when choosing standard group for DRIS calculations.

Carbon footprint of oil palm planted on peat in Malaysia

The carbon footprint of palm oil on mineral soils based on primary data from Malaysia was published in 2011, but a study for palm oil grown on peat is missing. The estimation of greenhouse gas emissions (GHG) of oil palm planted on peat in Malaysia was divided into three main components, namely GHG emissions from land use change, peat oxidation due to the establishment of oil palm plantations, and operations during cultivation and milling processes. The study collected comprehensive primary data for the latter and derived a best estimate for the other emissions to provide guidance for the most appropriate values and uncertainty range for oil palm planted on peat. The study highlights uncertainties and gaps in knowledge and provides recommendations for reducing GHG emissions for oil palm planted on peat. GHG emissions were estimated based on published data (LUC and peat oxidation) as well as from comprehensive primary data from operations at plantations mainly on peat in Sarawak and the palm oil mills for the period of 3 years. For this study, the data is partitioned into three case scenarios: (a) base case, where oil palm plantation is assumed from previously logged-over (PSF) with medium level of peat oxidation and 50% of the mills have the facilities to capture methane; (b) best-case scenario, where oil palm is assumed planted from previously degraded PSF or land with lowest estimation of peat oxidation and mills with methane capture facilities; and (c) worst-case scenario, where oil palm is assumed planted from previously virgin PSF with the highest estimation of peat oxidation and mills with methane capture facilities. GHG emissions from cultivation and milling stage were modeled using the System for Integrated Environmental Assessment of Product (SimaPro, version 8) with Ecoinvent database (ver 3). Total GHG emissions for oil palm planted on peat for three scenarios arising from three main components range from 12.4 t CO2 eq ha−1 (best case) to 76.6 t CO2 eq ha−1 (worst case). These variations depend on C stock of previous vegetation, depth of drainage, length of time of drainage, amount of nitrogen fertilizer used, and use of methane capture facilities at the palm oil mills. GHG emissions for oil palm planted on peat can be reduced by developing plantations from degraded PSF or grassland with low carbon stock, with effective water management coupled with methane capture facilities at the mill and judicious application of nitrogen fertilizers using precision application according to requirement of the site based on diagnosis of nutrient requirement from soils and foliar analyses. In Malaysia, only 13% of the areas planted with oil palm are on the peat soil. Therefore, the overall GHG emission at the national level (13% planted on peat and 87% on mineral soils) can be further reduced by around 4.1 t CO2 eq ha−1 year−1.

Nutritional diagnoses of oriental beech trees in damaged Caspian forest sites, using the diagnosis and recommendation integrated system (DRIS)

Oriental beech established in the Hyrcanian forests, is a valuable tree whose habitats are constantly exposed to destructive factors which change the nutritional status of soil and leaves. Analysis of foliar elements is a commonly used method for studying tree nutrient status that indicates site's quality. Foliar analysis of beech (Fagus orientalis Lipsky) was carried out in Kojour (Mazandaran) in order to assess the nutritional balance of trees in a damaged forest site (a direct result of livestock grazing and anthropogenic perturbations). Sunny leaves of dominant trees were taken in August and foliar concentration of macroelements, N, P, Ca, K and Mg were measured. The diagnosis and recommendation integrated system (DRIS) analysis was applied for evaluating the nutritional state. The results showed deficiency with K and P in disturbed stands. Nutrient Balance Index (NBI) indicated imbalance in nutrient status. These results suggest the usefulness of DRIS for foliar tissue analysis as an indicator of nutritional status and elemental stress in natural forests.

Effectiveness of native arbuscular mycorrhiza on the growth of four tree forest species from the Santa Marta Mountain, Veracruz (Mexico)

Aim of the study: The aim of this work was to isolate consortia of arbuscular mycorrhizal fungi (AMF) associated to Liquidambar styraciflua in soils of the Santa Marta Mountain in Veracruz, and to select highly effective mycorrhizal consortia on promoting the growth of four tree forest species with economic and ecological importance.Area of study: Santa Marta Mountain, inside the buffer area of the Los Tuxtlas Biological Reserve in Veracruz (México).Materials and methods: Ten composite samples of rhizosphere soil were collected from L. styraciflua trees of 13-15 cm DBH (diameter at breast height). Roots were fixed in FAA solution to determine the mycorrhizal colonization percentage, the abundance of morphospecies, and its effectiveness in promoting the growth of L. styraciflua, Terminalia amazonia, Cordia alliodora, and Cojoba arborea. Soil physical and chemical characteristics were also analysed, and soil type recognition was performed with the Reference Base for Soil FAO-ISRIC World-SICS. Mycorrhizal colonization was determined by the method of clearing and staining roots with trypan blue; total percentage of colonization was estimated by the Linderman-Biermann method. Spores were extracted for counting and identifying morphospecies from each soil sample, those with more effectiveness were selected and inoculated in the four tree species, based upon a completely random design there were evaluated height, number of leaves, total dry weight and foliar area.Main results: Average mycorrhizal colonization percentage was 45% from natural conditions, samples one and four showed 80% of AMF-colonization. Average number of spores was 617 in 100 g-1 of dry soil. Forty-seven AMF-morphospecies were identified. After eight months significant differences were observed in root colonization, height, number of leaves, total dry weight, leaf area and foliar analysis of N5+, P5+ and K+ on plants inoculated with rhizosphere samples of L. styraciflua. Terminalia amazonia and Cojoba arborea showed greater response to the inoculation of AMF, they showed more height, number of leaves and more total dry weight; whereas C. alliodora appears to be low dependent on AMF.Highlights: Diversispora aurantia and Glomus aggregatum are reported by the first time from Mexican humid tropics. Native AMF have potential biotechnological application. The mycorrhizal consortium six (Glomus and Acaulospora) was the more effective in promoting the development of the four tree species used in the experiment.

Determination of diagnostic standards on saturated soil extracts for cut roses grown in greenhouses.

This work comprises the theoretical determination and validation of diagnostic standards for the analysis of saturated soil extracts for cut rose flower crops (Rosa spp.) growing in the Bogota Plateau, Colombia. The data included 684 plant tissue analyses and 684 corresponding analyses of saturated soil extracts, all collected between January 2009 and June 2013. The tissue and soil samples were selected from 13 rose farms, and from cultivars grafted on the 'Natal Briar' rootstock. These concurrent samples of soil and plant tissues represented 251 production units (locations) of approximately 10,000 m2 distributed across the study area. The standards were conceived as a tool to improve the nutritional balance in the leaf tissue of rose plants and thereby define the norms for expressing optimum productive potential relative to nutritional conditions in the soil. To this end, previously determined diagnostic standard for rose leaf tissues were employed to obtain rates of foliar nutritional balance at each analyzed location and as criteria for determining the diagnostic norms for saturated soil extracts. Implementing this methodology to foliar analysis, showed a higher significant correlation for diagnostic indices. A similar behavior was observed in saturated soil extracts analysis, becoming a powerful tool for integrated nutritional diagnosis. Leaf analyses determine the most limiting nutrients for high yield and analyses of saturated soil extracts facilitate the possibility of correcting the fertigation formulations applied to soils or substrates. Recommendations are proposed to improve the balance in soil-plant system with which the possibility of yield increase becomes more probable. The main recommendations to increase and improve rose crop flower yields would be: continuously check pH values of SSE, reduce the amounts of P, Fe, Zn and Cu in fertigation solutions and carefully analyze the situation of Mn in the soil-plant system.

N concentration of old leaves and twigs is more sensitive to stand density than that of young ones in Chinese fir plantations: a case study in subtropical China

Young leaves are conventionally used in the analysis to study the nutrient status of evergreen plants and their responses to environmental changes, but the role of old leaves remains poorly understood. We selected two stand types in 31-year-old Chinese fir (Cunninghamia lanceolata) plantations with similar soil conditions but different stand densities, to test the hypothesis that nitrogen (N) concentration of old leaves and twigs is more sensitive to stand density than that of young ones. Leaves and twigs were sampled and sorted into young (one-year-old) and old (two- and three-year-old) groups. Significant differences in N concentration and carbon: nitrogen ratio between the low-density stand and high-density stand were only found in the old leaves and twigs but not in the young ones. Although the N resorption efficiency did not vary significantly with stand density, the annual N resorption rates were increased in old leaves and relatively young twigs at high stand density. These results show the potential use of old tissues in the nutrient analysis in Chinese fir plantations. Testing the generality of these results could improve the use of foliar analysis as an indicator of nutrient status and environmental changes in evergreen tree species.

Normas Dris para Porta-Enxertos Limão Cravo e Citrumelo Swingle

Objetivou-se obter um banco de dados de análise foliar para estabelecimento do DRIS e avaliar o estado nutricional de dois porta-enxertos de citros (Limão Cravo e Citrumelo Swingle). Foram realizadas coletas de 180 amostras de folhas para cada porta-enxerto. O banco de dados foi analisado pelo método dos Níveis Críticos ou Faixas de Concentração e pela metodologia DRIS. As Faixas de Concentração diagnosticaram, para o porta-enxerto Limão Cravo, que os nutrientes mais limitantes por deficiência foram Mg e Zn e por excesso P e Fe. Para o Citrumelo Swingle, por deficiência foram K, S, Mn, Cu e Zn e por excesso Fe e N. O Zn é o nutriente com maior frequência de deficiência e o Fe de excesso entre os porta-enxertos. O método DRIS diagnosticou o S como o mais limitante por deficiência e o N como o mais limitante por excesso. Tal método apresenta maior sensibilidade para diagnosticar problemas nutricionais.

NUTRITIONAL DIAGNOSIS IN HYBRID COCONUT CULTIVATED IN NORTHEASTERN BRAZIL THROUGH DIAGNOSIS AND RECOMMENDATION INTEGRATED SYSTEM (DRIS)

ABSTRACT The assessment of the nutritional status of plants by leaf diagnosis such as the Diagnosis and Recommendation Integrated System (DRIS) has stood out among traditional methods of interpreting the results of plant tissue analysis. For coconut, nutritional monitoring through foliar analysis has been pointed as an efficient method for fertilizer recommendation, and the results have been traditionally interpreted using the critical level of sufficiency ranges criteria. The aim of this study was to evaluate the nutritional status and establish nutritional standards for the cultivation of hybrid coconut in the municipality of Moju, Pará, using DRIS. The leaf analysis and productivity results of 134 observations for the period 2001-2011 were used to form the database. The most common deficiencies found were lack of K, and possibly excess of Mg. The order of nutrient limitation was K&gt; P&gt; Ca&gt; Fe&gt; N&gt; O&gt; B&gt; Zn&gt; Cu&gt; Mn&gt; Mg. Ca, Fe and K nutrients are more likely to positively respond to fertilization, since Mg, Cu and Mn were diagnosed as having the greatest likelihood of negative response to fertilization. It was also found that N and P are elements that are in the best nutritional balance condition. Regression equations for the relationship between nutrient content in hybrid coconut leaves and its DRIS indexes were adjusted, which allowed establishing nutrient reference values based on DRIS.

Foliar Diagnosis Indexes for Corn by the Methods Diagnosis and Recommendation Integrated System (DRIS) and Nutritional Composition (CND)

ABSTRACTFoliar analysis has been an important method for diagnosing the nutritional status of plants. Therefore, this work aimed to determine benchmarks (norms) for interpretation of results of foliar analysis by the methods of Diagnosis and Recommendation Integrated System (DRIS) and Nutritional Composition (CND) and to determine the order of nutritional limitation and the potential response to fertilization (PRA) of corn cultivations. Leaves were sampled and the productivity was determined in 64 different sites in the crop season 2011/2012, and 66 sites were sampled in the crop season 2012/2013. The yields were divided in two sub-populations: high productivity (equal or above 11.795 kg ha−1) and low productivity (less than 11.795 kg ha−1). The normal ranges obtained by DRIS and CND methods were similar. The amplitudes of ideal ranges were smaller when compared to the sufficiency ranges found in the Brazilian literature. The development of benchmarks (norms) at regional levels increases reliability in diagnoses.

Extractants for available boron in limed acid soils and its correlation in crops with high carbon storage capacity (Tectona grandis)

ABSTRACTThe objective of this work was to evaluate the efficiency of six extractants for available boron in acid soils undergoing to liming, and to correlate the results of soil analysis with foliar response seen in the teak plants in greenhouse conditions. Acid soil samples were collected and their chemical characterization was performed using standard analysis protocols. Later, agricultural lime was added to the experimental units in greenhouse conditions in order to control the soil acidity and these were incubated for 30 days. Six extracts for available boron were evaluated and correlated with response in the plant by foliar analysis. It is concluded that a high dissolution power of boron extractant solution produces a high sensitive in the determination of the changes of boron concentration in the limed acid soil. These methods are seen to be not adequate for the determination of available boron contents at high concentrations.

Impact of Compost Application during 5 Years on Crop Production, Soil Microbial Activity, Carbon Fraction, and Humification Process

ABSTRACTCompost amendment is considered as a practical tool to increase the soil organic matter (SOM), which contributes to agricultural sustainability. The objective of the present work was to evaluate the impacts of organic soil management over 5 years on orchard prune production (Prunus salicina), microbial activity, soil carbon (C) fraction, and stabilization degrees of soil humification. Plot experiment was designed with two different soil managements: i) for minimizing anthropogenic disturbances, only mulching of orchard residues derived from prune tree plot area was applied to soil surface (S + V); and ii) the amendment of composted manure was annually practiced in addition to the utilization of orchard residues inside the plot area (S + V + C). After 5 years, the soil with the continuous compost application (S + V + C) showed higher productivity of Prunus salicina (21.4%), greater fruit diameter (7.8%), and heavier fruit weight (22.4%) than the soil without compost application (S + V). Nutrient content in foliar analysis showed no difference between the two treatments (S + V and S + V + C). By contrast, the amended soil by compost (S + V + C) increased the SOM and water-soluble C fraction in parallel with the increase of microbial parameters (microbial biomass C, adenosine triphosphate (ATP), basal respiration, and dehydrogenase). Analyzing soil humic acid character by chemical spectra techniques of Fourier-transform infrared (FT-IR) spectra and 13C nuclear magnetic resonance (13C-NMR), gradual reformation of a more stabilized structure was shown in both soils (S + V and S + V + C), due to the selective biodegradation and humification process after the amendments over 5 years. Especially, in the soil treated with compost application (S + V + C), the increase of functional C groups (aromatic and carboxylic groups), which reinforce the recalcitrant character of soil humified fraction, was clearly observed. The continuous application of composted manure for the duration of 5 years improved the orchard soil fertility as well as productivity.Abbreviations: ATP, adenosine triphosphate; CPMAS, cross-polarization magic angle spinning; EC, electrical conductivity; FT-IR, Fourier-transform infrared; HA, humic acid; HS, humic substance; INTF, iodonitrotetrazolium formazan; K, Potassium; LSD, least significant differences, N, nitrogen; NMR, nuclear magnetic resonance; O, oxygen; OM, organic matter; MBC, microbial biomass C; P, phosphorous; SD, standard deviation; SE, standard error; SOM, soil organic matter; TOC, total organic carbon; WSC, water-soluble C; WS-Ch, water-soluble carbohydrate

Application of digital images for nitrogen status diagnosis in three Vigna unguiculata cultivars

The SPAD chlorophyll meter is widely used to indirectly monitor the nitrogen (N) status of various crops, which is important to ensure proper management of N fertilizers. Here, we propose that the freely available digital foliar analysis software AFSoft may be used to monitor N status with the same effectiveness as the SPAD meter. To verify the usefulness of AFSoft, we employed both SPAD meter readings and AFSoft note to estimate relative chlorophyll content in cowpea beans exposed to different N fertilization rates. The experiment followed a completely randomized design comprised of four replicates carried out in a factorial scheme, with five N fertilization rates (0, 50, 100, 200 and 300 mg pot -1 ) applied to three cowpea bean cultivars (BRS Itaim, BRS Guariba and BRS Novaera). At 45 days after emergence (DAE) of the plants, SPAD readings were obtained on the second trifoliate leaf. The whole leaf was subsequently digitally photographed and dried for the determination of total N concentration by applying acolour scale using AFSoft ® software. There was no significant interaction observed between N fertilization rate and cultivar for the evaluated variables. For all cultivars, increasing the rate of N fertilization increased the total observed N concentration as determined by both SPAD index and AFSoft note. The AFSoft note value was positively correlated with the total N concentration (r=0.95, P≤0.05; r=0.80, P≤0.01; r=0.86, P≤0.01) and the SPAD readings (r=0.99, P≤0.01; r=0.97, P≤0.05; r=0.97, P≤0.05) for the Itaim, Guariba and Novaera cultivars. These results suggest that N concentration in the leaves of cowpea bean cultivars can be estimated using AFSoft, which may serve as an alternative to SPAD meter readings.

Effect of Organic and Synthetic Fertilizers on the Crop Yield and Macronutrients Contents in Soil and Pepper

ABSTRACTNowadays farmers are interested in moving to organic cultivation. The purpose of this experiment was to compare two organic, with or without effective microorganisms (EM), and one conventional greenhouse pepper cropping systems. We focused on the study of the macronutrients nitrogen, phosphorus, and potassium (N, P, K) concentrations in leaves plants, soil, and soil solution during the full production cycle to detect any plant nutrient deficiencies and differences in crop yield for the three different treatments. Foliar analyses showed good concentrations of nutrients with conventional treatment, but P was low with organic ones. However, P content in soil was high, because this element is easily precipitated in carbonated soil. Pepper yield was higher in conventional treatment and no differences in productivity were found between the two organic treatments. The role of EM was not clear on the development of plants and fruits; however it seems to influence the N mineralization in organic treatments.

Soil and leaf nutritional constraints in major pomegranate growing states of India

Pomegranate orchards grown under hot, semi-arid to arid tropical climate were surveyed to diagnose nutrient constraints through soil and leaf analysis. A total 347 pomegranate orchards covering an area about 60,000 ha were surveyed in major pomegranate growing areas of Maharashtra, Karnataka and Andhra Pradesh states during 2007 to 2013. Physico-chemical analysis of the soil samples revealed that most of the pomegranate cultivation is on shallow and light textured soils having pH (&lt; 8.9), EC (&lt; 1.86dS/m) and CaCO&lt;sub&gt;3&lt;/sub&gt; (&lt; 10% in majority orchards) which is within tolerable limit for pomegranate cultivation. Soil as well as leaf nutrient status indicated that P was the most limiting nutrient, followed by N while K and Ca was in sufficient quantity. Micronutrient constraints through foliar analysis revealed that Fe content was in sufficiency range in almost all the orchards despite its low availability in the soils. Similarly, leaf Cu content was very low in majority orchards despite its availability in the soil in excess range. Zinc content in the leaves was in sufficient quantity in all the orchards located in all the states. The nutrients should be applied in a balance ratio ensuring periodical application of organics to maintain soil health.