Extractable Micronutrients Research Articles

Effects of storage on the sequential extraction of micronutrients and trace elements in fruit and vegetable residue flour

Sequential extraction consists of the use of a number of extractors with different chemical properties that are progressively applied to a sample. The objective of this study was to evaluate the influence of sequential extraction of Cu, Fe, Mn, Mg and Zn from fruit and vegetable residue flour during storage for up to 60 days. The following extractors were applied: 1M calcium chloride, 0.1M acetic acid/5% ammonium acetate (pH 5.0), 0.5M acetic acid and 0.5M hydrochloric acid; the storage times were 0, 30 and 60 days. Storage for up to 60 days did not affect the total content of the metals. However, changes were observed in the chemical structure of the sample, which influenced the profile extraction of the metals. At least five distinct chemical species of each metal were analysed, which could influence the bioavailability and metabolic processes inherent in the sample itself.

Ashwagandha (Withania somniferaL. Dunal) crop as Affected by the application of FYM and inorganic phosphorus in typic torripsamments of Hisar

The vegetative parameters of ashwagandha (viz. plant height, number of primary branches, plant spread and dry weight of shoot) were enhanced significantly with the application of 12.5 mg P2O5 kg−1 soil, whereas; dry weight of roots was enhanced up to the application level of 25 mg P2O5 kg−1 soil. FYM at the rate of 12.5 t ha−1 in combination with 12.5 mg P2O5 kg−1 soil significantly improved all the vegetative parameters, whereas, FYM at the rate of 12.5 t ha−1 in combination with 25 mg P2O5 kg−1 soil significantly enhanced the dry weight of the roots. The alkaloids yield (mg pot−1) in ashwagandha roots increased significantly with the application of 25 mg P2O5 kg−1 soil. The application of FYM at the rate of 12.5 t ha−1 improved the alkaloids yield (mg pot−1) but the significantly highest yield of total alkaloids (mg pot−1) was found in treatment combination of 12.5 t FYM ha−1 + inorganic-P at the rate of 25 mg P2O5 kg−1 soil as compared with other eleven treatments. Nutrients (NPK) uptake by ashwagandha shoot increased significantly with the application level of 12.5 mg P2O5 kg−1 soil over control whereas in case of ashwagandha roots, the increase in nutrients uptake at the level of 25 mg P2O5 kg−1 soil over control. Application of FYM at the rate of 12.5 t ha−1 + 12.5 mg P2O5 kg−1 soil was the best treatment combination for ashwagandha roots in terms of nutrients uptake. Application of fertilizer-P significantly improved the status of organic carbon, Available-P in post harvest soil but decreased the Available-N, Available-K and DTPA extractable micronutrients (Fe, Cu, Zn and Mn) up to the level of 25 mg P2O5 kg−1 soil. FYM at the rate of 12.5 t ha−1 helped in maintaining the soil fertility status after harvest of the crop alone or in combination with fertilizer-P.

Kalmegh (Andrographis paniculata Wall. Ex Nees) crop as influenced by the application of farmyard manure (FYM) and inorganic phosphorus in typic torripsamments of Hisar

The growth attributes of kalmegh (plant height, number of primary branches, plant spread and dry weight of shoot) were enhanced significantly with the application of 12.5 mg P2O5 kg-1 soil. Application of farmyard manure (FYM) 12.5 t ha-1 significantly improved all the growth attributes significantly over control. However, 12.5 mg P2O5 kg-1 soil along with FYM 12.5 t ha-1 resulted in significantly the highest values of growth attributes as compared to the other treatments and the results were on a par with higher level of fertilizer phosphorus (P) or FYM application. Application of FYM improved the andrographolide content significantly up to the level of 12.5 t ha-1 FYM in combination with fertilizer P 25 mg P2O5 kg-1 soil when compared with other treatments. Application of FYM 12.5 t ha-1 + 12.5 mg P2O5 kg-1 soil was found to be the best treatment combination for the highest nutrients uptake by kalmegh. Application of fertilizer-P alone significantly improved the status of organic carbon, available-P in post harvest soil, but decreased the available-nitrogen (N), available-potassium (K) and diethylene triamine pentaacetic acid (DTPA) extractable micronutrients (iron (Fe), copper (Cu), zinc (Zn) and manganese (Mn)) up to the level of 25 mg P2O5 kg-1 soil. Use of FYM 12.5 t ha-1 helped in maintaining the soil fertility alone or in combination with fertilizer-P. Key words: Kalmegh, phosphorus, farmyard manure (FYM), quality, nutrients uptake, soil fertility status.

Pedogenic impacts on the distribution of total and available Fe, Mn, Cu, Zn, Cd, Pb and Co contents of vertisols and vertic inceptisols of the Bale Mountain area of Ethiopia

5.9 to 41.5, 0.07 to 0.37, 0.70 to 1.73, 0.07 to 0.83, 0.04 to 1.31 and 0.0 to 0.02 ug/g, respectively. Available indices of the micronutrients studied are believed to be sufficient for plant growth except Zn, which is inadequate. Available heavy metal contents are below tolerable levels that can pose danger to man and livestock. Extractable micronutrients and heavy metals generally showed a decrease in concentration with depth associated with decreasing organic carbon contents and increasing pH and CaCO3 contents that exert a major influence on the availability of the micronutrients and heavy metals. Multiple linear and quadratic regression equations generally improved the predictive abilities for available Fe, Mn, Cu, Zn and Co over simple linear relationships when pH, EC, OC and CaCO3 were used as independent variables. Regression relationships developed constitute useful predictive indices for estimating micronutrients and heavy metals from existing soil survey reports of the Bale Mountain area.

Nutrient extraction and exportation by common bean cultivars under different fertilization levels: II - micronutrients

Where the level of agricultural technology is higher, common bean cultivars with a higher yield potential possibly require greater amounts of micronutrients. In Brazil however, there is a lack of information about the micronutrient extraction and exportation by the main grown cultivars. The objective of this study was to evaluate micronutrient (B, Cu, Fe, Mn, and Zn) extraction and exportation by common bean cultivars Pérola and IAC Alvorada, under different levels of NPK fertilization, on a dystroferric Red Nitosol, in Botucatu, São Paulo State, Brazil. The experiment was arranged in a randomized complete block (split plot) design with four replications. The plots consisted of six treatments based on a 2 x 3 factorial model, represented by two cultivars and three NPK levels (PD0 - 'Pérola' without fertilization, PD1 - 'Pérola' with 50 % of recommended fertilization, PD2 - 'Pérola' with 100 % of recommended fertilization, AD0 - 'IAC Alvorada' without fertilization, AD1 - 'IAC Alvorada' with 50 % of recommended fertilization, and AD2 - 'IAC Alvorada' with 100 % of recommended fertilization) and subplots sampled seven times during the cycle. Higher levels of NPK fertilization increased micronutrient extraction by both cultivars, and treatments with 100 % of recommended NPK fertilization extracted on average 167 g B, 58 g Cu, 1,405 g Fe, 1,213 g Mn and 211 g Zn per hectare. Regardless of the treatment, the highest demand period for B, Cu, Fe, Mn and Zn in both cultivars occurred at the R7 stage (pod formation), i.e. 42 to 55 days after emergence (DAE). The amount of B, Cu, Fe, Mn and Zn exported depended mainly on the level of NPK fertilization used, with values per hectare ranging from 38 to 90 g of B, 12 to 26 g of Cu, 222 to 568 g of Fe 234 to 467 g of Mn, and 40 to 96 g of Zn.

Efficiency of Phosphogypsum and Mined Gypsum in Reclamation and Productivity of Rice–Wheat Cropping System in Sodic Soil

In this study, efficacies of mined gypsum and phosphogypsum (PG), when applied at equivalent doses, were compared for sodic soil reclamation and productivity of rice–wheat system. Application of PG, followed by karnal grass as first crop, resulted in the greatest reduction of soil pH and exchangeable sodium percentage (ESP) followed by PG applied at 10 Mg ha−1 alone. Application of PG at 10 Mg ha−1 resulted in greater yields of both rice and wheat than other treatments. Ditheylenetriaminepentaacetic acid (DTPA)–extractable micronutrients of PG-treated soil were greater than in mined gypsum–treated soil. A greater portion of applied P entered the calcium (Ca)–phosphorus (P) fraction in PG-treated soil, which also resulted in more soluble P than the mined gypsum–treated soil. Phosphogypsum effected greater increase in aggregation, soil organic carbon, microbial biomass carbon, and aggregate associated carbon and decrease in zeta potential, leading to increased hydraulic conductivity and moisture retention capacity in soil over mined gypsum–treated soil.

LONG-TERM EFFECT OF ORGANIC AND INORGANIC FERTILIZERS ON RICE (Oryza sativaL.)–WHEAT (Triticum aestivumL.) YIELD, AND CHEMICAL PROPERTIES OF AN ACIDIC SOIL IN THE WESTERN HIMALAYAS

SUMMARYIn a field experiment initiated in 1991kharifseason (April–October) on an acidic soil in the Western Himalayas of India, 25% and 50% of the recommended doses of nitrogen were substituted through different organics, viz. farmyard manure (FYM), wheat cut straw andSesbania aculeata(as green manure) in rice, followed by use of chemical fertilizers in wheat each year. The aim of this work was to study the long-term integrated effect of organics and chemical fertilizers on grain yield of rice–wheat system and soil quality. Based on five years’ moving average values, continuous cropping without fertilization or manuring (control) gave the lowest grain yields of both rice and wheat. Application of 50% N through FYM plus 50% NPK through chemical fertilizers to rice followed by 100% NPK through chemical fertilizers to wheat (T3) maintained the highest productivity of rice and wheat at about 3.4 Mg ha−1and 3.3 Mg ha−1, respectively, as found from the pooled grain yield over the years. The highest values of organic carbon, cation exchange capacity and available N, P, K were also recorded under this treatment (T3). Soil pH was marginally affected by different treatments, while Diphenyl Triamine Penta Acetic acid extractable micronutrient cations increased over control when chemical fertilizers were applied in conjunction with different organics.

Comparison of Two Sequential Extraction Methods and the DTPA Method for the Extraction of Micronutrients from Acidic Soils

Two sequential extraction methods (the modified BCR—Community Bureau of Reference, now the Standards, Measurement and Testing Program, of the European Commission—and the original Tessier) were compared for the assessment of various forms of copper (Cu), zinc (Zn), iron (Fe), and manganese (Mn) in 29 cultivated acidic soils of northern Greece. In addition, the different forms of the micronutrients extracted by the two methods were compared to the plant-available micronutrients extracted by diethylenetriaminepentaacetic acid (DTPA) and their relation to certain soil physicochemical properties was examined. Because the soils were acidic, the second step of the original method of Tessier (related to micronutrients bound to carbonates) was omitted. Consequently, four micronutrient fractions were assessed by both methods, namely water-soluble + exchangeable, bound to Fe-Mn oxides, bound to organic matter, and residual. Each of the two methods extracted different amounts of the same micronutrients in similar fractions, which amounts were significantly and positively correlated. The order of Fe and Mn distribution in the various fractions was similar in the two methods, within the same element, whereas Zn was slightly different and Cu was detectable only in the residual fraction of both methods. Clay and Fe-Mn oxide–bound Fe, cation exchange capacity (CEC), and organic matter–bound Fe were significantly and positively correlated in the case of the original Tessier method. In the modified BCR method, organic matter–bound Fe and Zn were significantly and positively correlated with CEC. In both methods, significant and positive correlation coefficients were found for the following relations: clay and Mn in the water-soluble + exchangeable fraction, organic C and organic matter–bound Mn, CEC and Mn in the three first fractions. The DTPA-extractable micronutrients were significantly and positively correlated with the respective micronutrients in the fractions bound to Fe-Mn oxides and bound to organic matter of the original method of Tessier for Zn; the fraction bound to Fe-Mn oxides of the same method for Fe; and the three first fractions of both sequential extraction methods for Mn.

Distribution of Available Macro and Micronutrients in Cashew Growing Soils of Dakshina Kannada District of Coastal Karnataka

Available macro and micronutrient status of soils of cashew growing regions of Coastal Karnataka was carried out in Dakshina Kannada district to help in determining the potential of the soils to supply nutrients for crop growth. Six pedons viz., Pala hillock, NRCC-Shanthigodu, Muchipadavu, Mulia, ARS Ullal and Palikudel were studied throughout the major cashew growing areas of Dakshina Kannada district representing the major climatic zones. The macro and micronutrients status of collected soil samples were analyzed by using standard analytical procedures. Results indicated that the available nitrogen status was found to be varying from low to medium in all the pedons. Further, the soils were low in available phosphorus, low to medium in available potassium and low to medium in available sulphur. Among the DTPA extractable micronutrients, iron and manganese were sufficient in most soils, available copper was sufficient and available zinc was deficient. The available macronutrient and micronutrient status was found to decrease with increasing depth of the soils. Phosphorus and zinc were highly deficient in all the pedons.

Availability and fractionation of trace elements in arid calcareous soils

Thirty seven soil samples were collected from seven agricultural regions in Saudi Arabia to investigate trace element availability and fractionation distribution. Di-ethylene tri-amine penta acetic acid extractable micronutrients ranged from 1.1 to 11.5 µg g-1 for Fe, 0.2-3.7 µg g-1 for Zn, 0.48-13.0 µg g-1 for Mn, and 0.2-3.7 µg g-1 for Cu. Based on published critical levels, Cu was sufficient for most crops in all soils. Four soil samples were low in Mn, 28 were low in Zn, and 31 were low in Fe. Fractionation of micronutrients (Fe, Cu, Zn, and Mn) in selected seven soil samples revealed that the exchangeable fractions were the smallest, with Zn and Cu below detection limits. Carbonate bound fractions showed the micronutrient concentrations in the order Mn>Fe>Cu>Zn. Oxide and hydroxide bound fraction was higher than the previous two fractions; the order of the metals was Fe>Mn>Zn>Cu. For the organic bound fractions, the order was Fe>Mn>Cu>Zn. The residual fraction was the largest. The order of residual micronutrients was Fe>Mn>Zn>Cu. Overall, and considering the total amount of the four micronutrients within each fraction, the five fractions followed the order: Residual> oxide bound>CO3 bound>organic bound>exchangeable. Based on the data, it is recommended that Fe and Zn applications should be included in balanced fertilization programs. Mn and Cu are sufficiently available in the studied soils, and may not need to be supplied to crops

Extractable micronutrients status in relation to other soil properties in Billiri Local Government Area

A study of the micronutrient status of soils of Billiri was carried out at 55 different locations. The objective of the study was to evaluate the status of micronutrients and their relationship with soil properties. Soil sample were collected at 0 to 30 cm depth and analyzed forDiethylenetriamine penta acetic acid DPTA extractable micronutrients (iron, Fe, manganese, Mn, zinc, Zn, and copper, Cu). The DPTA extractable Fe, Cu, Zn ranged from 10.31 to 20.17, 4.04 to 8.43, 2.63 to 7.02 and 10.8 to 26.74 mgkg-1 soil respectively. All soil samples had adequate amount of micronutrients. DPTA extractable Fe gave negative non significant correlation with soil properties; Mn gave negative significant correlation with pH, clay, CEC and organic carbon while Cu and Zn were positively significantly correlated with pH, clay, cation exchange capacity (CEC) and organic carbon. Since all values were above the critical limits, there is no threat of Fe, Cu, Zn and Mn deficiency in the soils. Deficiency is however likely to develop with continuous cropping and poor fertilizer management. Key words: Micronutrients, soil properties, pedogenic, geologic.

Extractable Micronutrients Status and Their Relationship with Some Inland Valley Soil Properties in Delta State, Nigeria

The study was conducted in some inland valley soils of Delta State, Nigeria. The aim was to evaluate the status of extractable plant micronutrients of Iron (Fe), Zinc (Zn), Manganese (Mn), and Copper (Cu), and their relationship with some soil properties using 0.1 N dilute HCl andDTPA solutions. Four mapping units designated as pedons A, B, C and D were randomly selected for the study and in each of them, a standard profile pit representative of the pedon was dug, examined and described. Soil samples were collected from each of the horizons for the study of the soil’s physical and chemical properties. The results of the study showed that 0.1 N HCl extracting solution has better affinity for extraction with mean values of 18.36 ppm for Fe; 9.12 ppm for Zn, 8.59 ppm for Mn and 2.36 ppm for Cu as against 13.62 ppm 5.71 ppm; 7.18 ppm; and 1.86 ppm for the corresponding DTPA extractable Fe, Zn, Mn and Cu. Relationship between micronutrients and some soil properties showed positive correlation between 0.1 N HCl extractable Zn and soil pH (0.3548X). and DTPA extractable Mn with organic carbon (0.4217X) and total nitrogen (0.3643X). There was also significant correlation Mn ad Fe (0.684XX), CU and Mn (0.667 XX) and Hcl extractable Cu and Mn (0.524 XX) DTPA extractable Mn (r = 0.684XX ) and Cu (r = 0.347X ). 0.1 N HCl therefore has better affinity for extraction of plant available micronutrients of Iron (Fe), Zinc (Zn), Manganese (Mn), and Copper (Cu) in the inland  valley soils of Delta State, Nigeria.Keywords: Extractable micronutrients, inland valley and soil properties.

Crescimento e extração de micronutrientes em abacaxizeiro 'vitória'

No presente estudo, foram avaliadas a produção de massa seca e a extração de micronutrientes do abacaxizeiro 'Vitória', adubado com micronutrientes aplicados via solo e por adubação foliar. O experimento foi instalado em abril de 2009, em uma área de 0,178 ha localizada no Perímetro Irrigado Baixo Acaraú, na região norte do Estado do Ceará. O delineamento estatístico empregado foi o de blocos casualizados, no arranjo de parcelas subsubdivididas, com quatro doses de FTE-12 (parcelas), quatro níveis de adubação foliar (subparcelas), quatro avaliações trimestrais (subsubparcelas) e cinco repetições. Foram feitas avaliações de produção da massa seca da parte aérea e de extração de micronutrientes. A produção da massa seca e a extração de Fe, Zn, Mn e B foram influenciadas pela idade fisiológica e pelas doses de micronutrientes aplicadas tanto no solo como nas folhas. As maiores doses de micronutrientes resultaram em maior crescimento da planta, o que levou a maiores extrações de micronutrientes, porém não chegando ao ponto de máximo, indicando que a cultura pode responder a doses maiores de micronutrientes.

Impact of Marble Mining on Soil Properties in a Part of Guinea Savanna Zone of Southwestern Nigeria

The effects of marble mining activities on the properties of soils of Igbeti marble area, Oke-Ogun, Southwestern Nigeria were investigated. Sample plots of 10 x 10 m2 were established at 150 m intervals from the factory site up to a distance of 600 m and with a sample plot at 10 km to serve ascontrol in four cardinal directions. A total of 84 composite soil samples from 21 established plots were taken for soil physico-chemical properties. No plot falls under agricultural crops. The results show that there is drastic deterioration in the quality of soil as a result of mining activities. There was increase in total porosity and decrease in bulk density of the soil as you move away from the mining site. The soil pH changed greatly from 5.90 in the control site to 8.20 in highly polluted soils. Soil organic matter,total nitrogen and available phosphorus decreased with increase in dust particulate from the mining sites. Except for Ca2+ and Mg2+ that decreased with distance from the mining site, Na+ and K+ increased slightly. The availability of the extractable micronutrients (Fe2+, Mn2+, Cu2+ and Zn2+) increased as the soil acidity increased, though Cu2+ availability dropped slightly at control site. It is concluded that there is the need for close monitoring of marble mining activities in Nigeria as deposit of marble particulates may result to soil nutrients’ imbalance and hence poor soil health especially in areas polluted with marble particulates.Key words: Mine waste, pollution monitoring, soil deterioration, soil pollution, soil nutrients’ imbalance.

Evaluation of the AB-DTPA multiextractant in Chilean soils of different origin with special regard to available phosphorus

The objective of this study was to evaluate the suitability of the ammonium bicarbonate diethylenetriaminepentaacetic acid (AB-DTPA) multiextractant to estimate the available P, exchangeable cations (K, Ca, Mg, Na) and extractable micronutrients (Cu, Fe, Mn, Zn) in comparison with conventional soil tests (Olsen-P, NH4OAc-exchangeable cations and DTPA-extractable micronutrients) in alkaline, acidic and volcanic acidic soils (n = 50). Exchangeable cations and extractable micronutrients were determined in soil extracts by ICP-OES. Phosphorus was determined colorimetrically in Olsen extracts, while in AB-DTPA extracts, P was determined both colorimetrically (AB-DTPAC-P) and by ICP-OES (AB-DTPAICP-P). In 14 soils, the available soil and plant P were determined in a pot experiment with ryegrass (Lolium multiflorum L). Both the AB-DTPAC-P and AB-DTPAICP-P were highly correlated with Olsen-P in alkaline and acidic soils. All P extractants were highly correlated with plant P concentration and uptake, but in soils with Olsen-P <20 mg kg−1 the AB-DTPA-P showed weaker relationships with P availability. The AB-DTPA method can be recommended to estimate the available P in alkaline and acidic soils, excluding Andisols, which typically contain very low amounts of available P. For K, Mg, Na, Cu, Fe, Mn and Zn, the multiextractant was highly correlated with respective conventional tests in all soils.

Potential Use of Bioorganic Nutrient Source Dynamics on Cropping Behavior, Soil Properties, and Quality Attributes of Apricot

The comparative efficacy of bioorganic nutrients on cropping behavior and soil properties of apricot trees was studied. Bioorganic nutrient sources, namely, vermicompost (VC), biofertilizers (BF), cow urine (CU), and vermiwash (VW), were evaluated in 13 treatment combinations. The treatment application of VC at 50 kg, BF at 60 g, CU at 12.5%, and VW at 12.5% significantly improved cropping and soil properties over nitrogen–phosphorus–potassium (N–P–K) chemical fertilizers. Available macronutrient contents of soil (viz., N, P, and K) increased by 25.50, 70.90, and 6.44%, respectively. Diethylenetriaminepentaacetic acid–extractable micronutrients (Fe, Cu, Zn, and Mn) increased by 15.45, 35.90, 80.36, and 40.12%, respectively. Microbial biomass of Pseudomonas, Bacillus, Azotobacter chroococcum, and arbuscular mycorrhizal (AM) fungi improved 51.83, 122.78, 60.93, and 2.91 times, respectively. This superior combination also resulted in considerably greater amounts of leaf macro- and micronutrients: N (2.34%), P (0.34%), K (3.71%), iron (Fe; 172.83 mg kg−1), copper (Cu; 12.79 mg kg−1), zinc (Zn; 25.49 mg kg−1), and manganese (Mn; 54.32 mg kg−1), which might be responsible for better cropping behavior and productivity in apricot trees.

Influence of Vesicular Arbuscular Mycorrhizal Fungi and Applied Phosphorus on Root Colonization in Wheat and Plant Nutrient Dynamics in a Phosphorus-Deficient Acid Alfisol of Western Himalayas

Vesicular arbuscular mycorrhizal (VAM) fungi symbiosis confers benefits directly to the host plant's growth and yield through acquisition of phosphorus and other macro- and micronutrients, especially from phosphorus (P)–deficient acidic soils. The inoculation of three VAM cultures [viz., local culture (Glomus mosseae), VAM culture from Indian Agricultural Research Institute (IARI), New Delhi (Glomus mosseae), and a culture from the Centre for Mycorrhizal Research, Energy Research Institute (TERI), New Delhi (Glomus intraradices)] along with P fertilization in wheat in a P-deficient acidic alfisol improved the root colonization by 16–24% while grain and straw yields increased by 12.6–15.7% and 13.4–15.4%, respectively, over the control. Uptake of nitrogen (N), P, potassium (K), iron (Fe), manganese (Mn), zinc (Zn), and copper (Cu) was also improved with VAM inoculation over control, but the magnitude of uptake was significantly greater only in the cases of P, Fe, Zn, and Cu. Inoculation of wheat with three VAM cultures in combination with increasing inorganic P application from 50% to 75% of the recommended P2O5 dose to wheat through the targeted yield concept following the soil-test crop response (STCR) precision model resulted in consistent and significant improvement in grain and straw yield, macronutrient (NPK) uptake, and micronutrient (Fe, Mn, Zn, Cu) uptake in wheat though root colonization did not improve at P2O5 doses beyond 50% of the recommended dose. The VAM cultures alone or in combination with increasing P levels from 50% to 75% P2O5 dose resulted in reduction of diethylenetriaminepentaacetic acid (DTPA)–extractable micronutrient (Fe, Mn, Zn, Cu) contents in P-deficient acidic soil over the control and initial fertility status, although micronutrient contents were relatively greater in VAM-supplied plots alone or in combination with 50% to 75% P2O5 dose over sole application of 100% P2O5 dose, thereby indicating the positive role of VAM in nutrient mobilization and nutrient dynamics in the soil–plant system. There was significant improvement in available N and P status in soil with VAM inoculation coupled with increasing P levels upto 75% P2O5 dose, although the greatest P buildup was obtained with sole application of 100% P2O5 dose. The TERI VAM culture (Glomus intraradices) showed its superiority over the other two cultures (Glomus mosseae) in terms of crop yield and nutrient uptake in wheat though the differences were nonsignificant among the VAM cultures alone or at each P level. Overall, it was inferred that use of VA-mycorrhizal fungi is beneficial under low soil P or in low input (nutrient)–intensive agroecosystems.

Optimizing organic and mineral amendments to jatropha seed cake to increase its agronomic utility as organic fertilizer

The agronomic utility of an organic residue, jatropha cake (Jc) was assessed according to the NPK requirement of selected crops. Fertilizer combinations were made by mixing jatropha cake (Jc), bone meal (Bm), tobacco dust (Td) and inorganic supplements ammonium Bi-carbonate (NH4HCO3), dicalcium phosphate (CaHPO4 · (H2O)2) and potassium chloride (KCl). The effects of combinations on the chemical and biological properties of soil and the growth of Jatropha curcas (used for non-edible oil or biofuel) and Cymbopogon martinii (essential aromatic oil used for anti septic, anti viral, bactericide, cytophylactic, digestive, febrifuge and hydrating properties) were studied. The combination of Jc with other residues turned it into an appropriate soil amendment to increase soil fertility. Utilization of these residues can also solve disposal related issues of these residues. Jc + CaHPO4 · (H2O)2 + KCl, Jc + Bm + Td, Jc + Bm and Jc + Td were most efficient combinations in terms of increasing soil fertility and growth of J. curcas and C. martinii. Most optimal organic combination of Jc + Bm + Td provided 182.4 kg N ha−1, 102.8 kg P ha−1 & 50 kg K ha−1 for J. curcas and 83.7 kg N ha−1, 19.8 kg P ha−1, 33.1 kg K ha−1 for C. martinii. The fertilizer combination gave significantly highest increase of 1.78 and 5.79 mg N g−1, 14.12 and 10.3 mg P g−1, 9.38 and 26.40 mg K g−1 and 9.06 and 4.42 mg C g−1 of experimental soils of J. curcas and C. martini, respectively. The combination also increased the extractable micronutrient content and soil enzymatic activity. Total plant biomass increased 5.9 and 10.5 times higher to control due to Jc + Bm + Td fertilizer combination in test crops of J. curcas and C. martini, respectively.

Status and distribution of extractable micronutrients in Haplustults in Yamaltu-Deba Local Government Area, Gombe state, Nigeria.

A study was conducted to determine the status and distribution of extractable Zn, Cu, Fe and Mn in Haplustults in Yamaltu-Deba Local Government Area (LGA) of Gombe State, Nigeria. Composite soil samples representative of the soils in the LGA were collected from 0 - 15 and 15 - 30 cm depths of five locations (Hinna, Kanti, Jangargari, Gidan Waya and Dadin Kowa) and analyzed. Results indicate that the soils were dominantly sandy loam, very strongly to moderately acidic (pH = 4.7 - 5.9) and low in CEC (mean = 7.21 cmolkg-1), exchangeable bases (Means for Ca = 3.34, Mg = 0.71, K = 0.21, Na = 0.10 cmolkg-1) and organic carbon (mean = 7.27 g kg-1). Extractable Zn, Cu, Fe and Mn (in mgkg-1) were 0.48 - 0.75 (mean = 0.58), 0.18 - 0.26 (mean = 0.21), 18.40 - 21.91 (mean = 19.96), and 30. 54 - 38.58 (mean = 33.00), respectively. The micronutrients were neither significantly (P = 0.05) influenced by the depths nor locations. The Fe and Mn contents were above the critical limits for crop production in all the locations. Copper was low in soils from Hinna and Jangargari and will consequently benefit from its application. Zinc was, however, generally low and its application in all the locations are recommended for successful crop production in the area. Key words: Haplustults, micronutrients, distribution.

Diethylenetriaminepentaacetic Acid–Extractable Micronutrients Status in Soil under a Rice–Wheat System and Their Relationship with Soil Properties in Different Agroclimatic Zones of Indo‐Gangetic Plains of India

Available micronutrient status of zinc, copper, manganese, and iron (Zn, Cu, Mn, and Fe) in surface soil samples under a rice–wheat system collected from farmers' fields in 40 districts representing different agroclimatic zones of the Indo‐Gangetic Plain (IGP) were determined. The selection of farmers, villages, blocks, and districts within an agroclimatic zone was made on the basis of a multistage statistical approach. In Trans‐Gangetic Plains, the diethylenetriaminepentaacetic acid (DTPA)–extractable Zn ranged from 0.11 to 5.08, Cu ranged from 0.22 to 4.72, Mn ranged from 2.9 to 101.2, and Fe ranged from 1.05 to 97.9 mg kg−1. In the Upper Gangetic Plains, the DTPA‐extractable Zn ranged from 0.04 to 2.53, Cu ranged from 0.06 to 4.32, Mn ranged from 11.1 to 421.0, and Fe ranged from 3.48 to 90.2 mg kg−1. In the Middle Gangetic Plains, the DTPA‐extractable Zn ranged from 0.17 to 8.60, Cu ranged from 0.09 to 7.80, Mn ranged from 3.0 to 155.1, and Fe ranged from 9.22 to 256.7 mg kg−1. In the Lower Gangetic Plains, the DTPA‐extractable Zn ranged from 0.04 to 3.46, Cu ranged from 0.21 to 4.38, Mn ranged from 9.54 to 252.2, and Fe ranged from 3.60 to 182.5 mg kg−1. The intensively cultivated Trans‐Gangetic transect representing the midplain and Siwalik had more available micronutrients than the arid plain. Midplain and arid plain showed 17 to 20% of soil samples were low to medium in Zn and 5 and 8% were low in Fe. In the Upper Gangetic Plains, only 25% samples were deficient in Zn, especially in central and southwest plains. In the Middle Gangetic Plains, 20 to 30% of samples were deficient in Zn, and very few samples were deficient in other micronutrients. In the Lower Gangetic Plains, a majority of the samples were medium to high in micronutrients except in Barind and Rarh Plains where 30% of samples were deficient in Zn. In the Lower Gangetic Plains, the available micronutrients were plentiful. Available micronutrients increased with increase in organic C content and decreased with increase in sand content, pH, and calcium carbonate. These soils are alluvial in nature, and there was no definite pattern of micronutrient distribution with depth in the profile. However, there was more accumulation in the Ap horizon than in the B horizon.