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Agronomic biofortification, encompassing the use of mineral and organic nutrient resources which improve micronutrient concentrations in staple crops is a potential strategy to promote the production of and access to micronutrient-dense foods at the farm level. However, the heterogeneity of smallholder farming landscapes presents challenges on implementing agronomic biofortification. Here, we test the effects of zinc (Zn)- and selenium (Se)-containing fertilizer on micronutrient concentrations of wheat (Triticum aestivum L.) and teff (Eragrostis tef (Zucc.) Trotter) grown under different landscape positions and with different micronutrient fertilizer application methods in the western Amhara region of Ethiopia. Field experiments were established in three landscape positions at three sites, with five treatments falling into three broad categories: (1) nitrogen (N) fertilizer rate; (2) micronutrient fertilizer application method; (3) sole or co-application of Zn and Se fertilizer. Treatments were replicated across five farms per landscape position and over two cropping seasons (2018 and 2019). Grain Zn concentration ranged from 26.6 to 36.4 mg kg−1 in wheat and 28.5–31.2 mg kg−1 in teff. Grain Se concentration ranged from 0.02 to 0.59 mg kg−1 in wheat while larger concentrations of between 1.01 and 1.55 mg kg−1 were attained in teff. Larger concentrations of Zn and Se were consistently attained when a foliar fertilizer was applied. Application of ⅓ nitrogen (N) yielded significantly larger grain Se concentration in wheat compared to a recommended N application rate. A moderate landscape effect on grain Zn concentration was observed in wheat but not in teff. In contrast, strong evidence of a landscape effect was observed for wheat and teff grain Se concentration. There was no evidence for any interaction of the treatment contrasts with landscape position except in teff, where an interaction effect between landscape position and Se application was observed. Our findings indicate an effect of Zn, Se, N, landscape position, and its interaction effect with Se on grain micronutrient concentrations. Agronomic biofortification of wheat and teff with micronutrient fertilizers is influenced by landscape position, the micronutrient fertilizer application method and N fertilizer management. The complexity of smallholder environmental settings and different farmer socio-economic opportunities calls for the optimization of nutritional agronomy landscape trials. Targeted application of micronutrient fertilizers across a landscape gradient is therefore required in ongoing agronomic biofortification interventions, in addition to the micronutrient fertilizer application method and the N fertilizer management strategy. [ABSTRACT FROM AUTHOR]

Background: Supplement of balanced nutrition is required for the growth and development of crops and humans, particularly essential amino acids, vitamins and minerals. The application of mineral micronutrient fertilizers to soil or plant leaves to increase micronutrient content in edible parts of crop. Therefore, this study is focused to evaluate the effect of agronomic biofortification with different nutrient levels on maize. Methods: A field experiment was conducted on sandy clayey loam soil during the Rabi season of 2020-21 Perambalur, Tamil Nadu to study the effect of agronomic biofortification through integrated nutrient management for improving maize (Zea mays L.) yield and quality under Cauvery delta condition. Two hybrids in main-plots both, QPM and non-QPM were sown by direct method on ridges at a spacing of 60 x 20 cm under split plot design (SPD) with 6 treatments of nutrient management in sub-plot combination under three replications. Result: The results revealed that the nutrient level treatments containing 50% RDF through NPK + 50% RDF through FYM with Fe and Zn as foliar application @ 0.5% conc led to highest growth and yield attributes, grain yield (8.52 t ha-1) and stover yield (10.35 t ha-1) and also resulted in maximum crude protein content (14.93%), starch content (63.85 mg g-1), Fe (36.25 mg kg-1) and Zn (29.35 mg kg-1) in maize grain. It was observed that agronomic biofortification through integrated nutrient management enhanced the vegetative growth and yield components of non-QPM hybrid, whereas it improved the grain quality content of the QPM hybrid. [ABSTRACT FROM AUTHOR]

The objective of this study was to investigate the spatial variability and the degree of abundance and deficiency of medium and micronutrient element contents in typical paddy soils of China, and to develop the best fertilization management for improving rice yields. Based on 289 monitoring points of paddy soils distributed across the northeast, Yangtze River delta, the middle of the Yangtze River, the southwest and south of China, soil samples collected in 2016 were determined for the contents of available medium and micronutrient elements (calcium, magnesium, sulfur, iron, manganese, copper, zinc, boron and molybdenum) in paddy soils. The spatial variability of these elements across the five regions was assessed. Combined with the critical values for limiting rice growth due to deficiency of available medium and micronutrient elements, the abundance and deficiency degree of available medium and micronutrient elements in the paddy soils were evaluated. The results showed that the contents of exchangeable magnesium and available boron in the northeast of China were much higher than those in the other regions, while the contents of available zinc in paddy soils were the lowest among the five regions. The highest average content of available manganese and the lowest average content of available sulfur in the paddy soils were both found in Yangtze River delta. The highest average content of available copper but the lowest average content of available iron, manganese and molybdenum among paddy soils was observed in middle of the Yangtze River. As compared with the other areas, the exchangeable calcium content of the paddy soils in the southwest of China was significantly higher (P<0.05), while the available copper content was significantly lower (P<0.05). Compared with the other areas, the contents of available iron and molybdenum in the south of China were significantly higher (P<0.05), while the contents of exchangeable calcium and magnesium were significantly lower (P<0.05). Critical values for evaluation of these elements were summarized based on practices and previous studies. The critical values for exchangeable calcium, exchangeable magnesium and available sulfur were 400, 50 and 16 mg/kg, respectively. The critical values for available iron, manganese, copper, zinc, boron and molybdenum were 4.5, 10, 2, 1.5, 0.5 and 0.15 mg/kg, respectively. The soils would be lack of the corresponding element if the contents of these elements were below the critical values and thereby the rice growth may be limited. Based on the critical values, the exchangeable calcium and magnesium contents in paddy soils of the five regions were rich in China. The contents of available sulfur in paddy soils were abundance for rice growth in the northeast, the middle of the Yangtze River, and the southwest of China, while 42.2% and 41.8% of monitoring points in Yangtze River delta and south of China were lack of available sulfur. The contents of available iron, manganese and copper were abundance in all the paddy soils. The proportions of monitoring points with lower contents of available zinc than its critical value were 75.0%, 52.3%, 31.9%, 53.2% and 10.4% in the northeast, Yangtze river delta, the middle of the Yangtze River, the southwest, and south of China, respectively. The proportions of monitoring points with lower contents of available boron than its critical value were 38.5%, 65.2%, 92.2%, 88.6% and 78.3% in the northeast, Yangtze river delta, the middle of the Yangtze River, the southwest, and south of China, respectively. The proportions of monitoring points with lower contents of available molybdenum than its critical value were 28.6%, 60.4%, 82.6%, 42.0% and 33.4% in the northeast, Yangtze river delta, the middle of the Yangtze River, the southwest, and south of China, respectively. It indicated that the contents of calcium, magnesium, iron, manganese and copper in the paddy soils of typical areas in China were abundance for rice growth. Sulfur fertilizer was needed in some areas of Yangtze River delta and southwest of China. The available zinc, boron and molybdenum in most of paddy soils were deficiency, and additional micronutrient element fertilizers were needed for rice growth, especially for zinc in the northeast, zinc, boron and molybdenum in Yangtze River delta, boron and molybdenum in middle of the Yangtze River, boron in southwest, and boron in south of China. And the medium and micronutrient element fertilizers should be included as part of fertilization management in practice for improving rice yields. [ABSTRACT FROM AUTHOR]

Agronomic biofortification is the fastest and less expensive method to overcome micronutrient deficiencies of iron, zinc and selenium. Fertilizers also help in augmenting vitamins and other food qualities. Although fertilizers have contributed vastly toward increase in food production, their misuse or rather abuse has led to severe environmental pollution. These include eutrophication of sea and inland waters, depletion of ozone layer and global warming. Fertilizers also contribute toward an increase in mineral and vitamin content in crops. Micronutrient fertilizers can increase concentration of iron and zinc in grains and vegetables, the deficiencies of which are widespread in Asian and African countries. Nitrogen fertilization can increase content of carotene in carrots. Liming is reported to increase calcium concentration in vegetables. Similarly, sulfur (S) fertilization can increase the content of S-containing amino acids in grains, glucosinolates in many Brassica species and alliin content in garlic and onion. As regards, vitamin C, there are increases as well decreases due to nitrogen reported in literature; the minor decreases are well compensated by an increase in yield. Potassium fertilization is reported to increase vitamin C content in some vegetables. Nitrogen fertilization increases nitrate content in vegetables, which is considered harmful, but some recent reports suggests advantages of this increase. Instead of blaming fertilizer for quality of food and environmental degradation, sincere efforts are needed toward its judicious application and avoiding its overuse or abuse and biofortification is the best suited method. [ABSTRACT FROM AUTHOR]

To evaluate the effect of different micronutrients (Mn, Fe, Zn) and farmyard manure (FYM) on the vegetative, phenological, and achene yield components of sunflower a field experiment was conducted in Maragheh, North West of Iran during the growing season 2018–2019. The treatments were arranged in a split-plot design- with three replicates. The main plots assigned to two levels of FYM (0 and 20 t ha−1) and sub plots assigned to the recommended dose of three micronutrients (Mn, Fe, Zn). The results revealed significant improvements in the growth and yield of sunflower due to the main and interaction effects of farmyard manure and inorganic fertilizer application. The highest number of leaves and the highest leaf area was observed in a plant grown by FYM + Zn. However, there was no significant difference between micronutrients under inorganic condition (without FYM application). The highest leaf relative water content (RWC), plant height, internode distance, and chlorophyll was recorded for plants grown by Fe or Zn under FYM applied condition. Application of FYM and micronutrients reduced the number of days to flowering. However, the application of FYM significantly delayed plant maturity. Achene number per head, 100-achene weight, achene length, achene width, achene oil percent, achene yield, and harvest index significantly increased with the application of FYM and the best performance was in a plant grown by FYM + Zn and FYM + Fe. The percentage of hollow and empty achene was significantly reduced by the application of FYM. Combined applications of FYM and micronutrients has become an increasingly common practice. [ABSTRACT FROM AUTHOR]

In many parts of the world, soils deficient and/or toxic in micronutrients reduce potential soybean (Glycine max) yields. The objective of our study was to grow plants in low to high concentrations of boron (B) and zinc (Zn) to determine how B and Zn deficiencies and toxicities affect soybean growth and interact with other essential nutrients in roots, leaves, and seeds. We found that B significantly affected levels of all essential nutrients except manganese and iron, while Zn significantly affected all essential nutrients in at least one plant tissue tested. Some of the physiological responses and nutrient interactions were cultivar-dependent. This study showed how deficiencies and toxicities of B and Zn affect plant growth and how B and Zn fertility interacts with many of the other essential nutrients. [ABSTRACT FROM AUTHOR]

Deficiencies of secondary and micronutrients (SMNs) are major causes of low maize yields in poorly responsive soils. This phenomenon minimizes the agronomic efficiency of N, P and K fertilizers and consequently result in a dwindling economic benefit associated with their use. Therefore, 18 on-farm trials were conducted in western Kenya during two cropping seasons to assess maize response to three NPK amendments; (i) N, P, K, Ca, Zn and Cu (inorganic and organic); (ii) N, P, K, Ca, Zn and Cu (inorganic) and (iii) N, P K, Zn and Cu (inorganic) and evaluate the profitability of their use compared to additions of only N, P and K fertilizers. In this set of experiments, maize response to any amendment refers to a yield increase of x2 t ha-1 above control and could be categorized in three clusters. Cluster 1, comprising of nine sites, maize responded to all amendments. Cluster 2, holding six sites, maize responded only to one amendment, N, P, K, Ca, Zn and Cu (inorganic). In this cluster, (2), emerging S, Mg and Cu deficiencies may still limit maize production. Cluster 3; consisting of three sites, maize responded poorly to all amendments due to relatively high soil fertility (≤17 mg P kg-1). Profitability of using NPK amendments is limited to Cluster 1 and 2 and the largest Value Cost Ratio (VCR) of 3.1 is attainable only when soil available P is below 4.72 mg kg-1. These variable responses indicate the need for developing site-specific fertilizer recommendations for improved maize production and profitability of fertilizer use in poorly responsive soils. [ABSTRACT FROM AUTHOR]

The effect of seed priming and foliar application with micronutrients zinc and iron (in both nano- and chemical formulations) on quality of forage corn (Zea mays L.) under field and greenhouse conditions was studied during two years. Seed priming and foliar spraying were performed with six treatments: nano-iron chelate, nano-zinc, chemical iron chelate, chemical zinc fertilizer, distilled water and control. Results indicated that both forms of iron fertilizer increased leaf chlorophyll concentration, compared to other spraying treatments and the control. The highest plant height, total dry biomass, crude protein, soluble carbohydrates and phosphorus uptake were obtained in the nano-iron spraying treatment. Significant improvement in leaf chlorophyll concentration, plant height, total dry matter, crude protein and soluble carbohydrates occurred as a result of spraying with both forms of zinc, but more evident for the nano-zinc treatment, compared with the control. Further studies are needed to elucidate the optimum timing of application, mode of action and critical range of nano zinc and iron concentrations. Aplication of nano-forms of fertilizers, compared to chemical forms of fertilizers, increased the phosphorus concentration, biomass, and crude protein and soluble carbohydrate concentration. [ABSTRACT FROM AUTHOR]

Micronutrients are essential for plant development; however, micronutrient content in soil often is not sufficient. This study compared availability of boron (B), copper (Cu), manganese (Mn), and zinc (Zn) in the soil and their effect in developing maize plants, supplied from a physical mixture of nitrogen, phosphorus, and potassium (NPK) granules and micronutrients or from a granulated mixture of NPK coated with these micronutrients. The experiment was conducted in a greenhouse, with a Rhodic Acrustox soil and the formulation 4-30-10 [nitrogen-phosphorus pentoxide-potassium oxide (N-P2O5-K2O)] with 0.1% B, 0.2% Cu, 0.2% Mn, and 0.3% Zn. A randomized block design with four replicates was used and the NPK formula doses used were 0, 150, 300, 600, 1200, and 2400 kg/ha. Coated NPK increased Zn levels in soil in 0.5 mg/dm3in relation to its initial content, also causing an increase in plant dry matter. Compared with mixture, this increase was more than three times greater. Cu and Zn accumulation and Zn absorption were greater when their supply was made via coated granules. The larger dose of B via coated granules resulted in a greater B accumulation in comparison to the mixture. No differences were observed for the other variables when comparing both sources. Coating NPK granules with micronutrients was better than the mixture when comparing B, Cu, and Zn concentrations in the soil. Dry matter production of maize shoots and the accumulation of B, Mn, Cu, and Zn in it was greater when the fertilizer was coated with micronutrients. [ABSTRACT FROM AUTHOR]

In order to investigate the influence of biological and chemical fertilisers on morphological traits, yield and yield components of safflower (Carthamus tinctorius L.), a field experiment was conducted in Maragheh (37°23' N; 46°16' E), in north western Iran, for one year in the 2014 growing season. The effect of seven treatments was evaluated: T1 - control (no fertiliser application), T2 - seed inoculation with P biofertiliser (contains phosphate solubilising bacteria; Pantoea agglomerans strain P5 and Pseudomonas putida strain P13), T3 - seed inoculation with N biofertiliser (contains Azotobacter vinelandii strain O4), T4 - foliar application of iron chelate, T5 - soil application of complete NPK, T6: foliar application of manganese chelate, and T7 - foliar application of zinc sulphate. The result showed that although application of N biofertiliser did not have a significant effect on the evaluated traits, P biofertiliser slightly improved grain yield. However, the application of complete NPK fertiliser improved most of the traits, compared to the control and biofertiliser treatment. The best performance was obtained by foliar application of manganese chelate and zinc sulphate. The results showed that micronutrient-deficiencies have to be managed to unlock the potential yield of safflower in semiarid production systems. [ABSTRACT FROM AUTHOR]

Phosphorus is a key nutrient for increasing productivity of legumes. It is required for plant growth and root development. Phosphorus deficiency in soil is widespread and crops grown under deficient situation show significant response to fertilizer phosphorus. At several places normal yield of crops could not be achieved despite judicious use of NPK fertilizers due to deficiency of micronutrients in soil, in general, that of Zn in particular. The knowledge regarding the use of optimum dose of nutrients especially Phosphorus and Zinc is of serious concern. The literature about the performance of fodder cowpea (Vigna unguiculata) in relation to phosphorus and zinc nutrition is reviewed in this paper. [ABSTRACT FROM AUTHOR]

In the present paper, the novel environmentally friendly micronutrient fertilizer biocomponents produced via biosorption and based on the biomass of seaweed were introduced. The utilitarian properties of new preparations were examined in germination tests on Lepidium sativum. The application of micronutrient biocomponents with zinc resulted in the higher mass of plant and higher content of zinc in comparison with the untreated group and reference materials, leading to the biofortification of plants with this micronutrient (a more than 20-fold increase in zinc level was obtained). It was observed that the dosage of zinc influenced plant mass and element content of plants. Statistically significant correlations between zinc and other microand macronutrients were observed. Also, a strong positive correlation (0.55) between zinc and plant mass was found. The micronutrient biocomponents produced via the biosorption process can constitute an alternative tool for micronutrient fertilization as preparations characterized by high bioavailability of nutrients and high biodegradability constituting an "eco-friendly" method for micronutrient biofortification of plants. [ABSTRACT FROM AUTHOR]

More than 60% of the world population suffers from iron deficiency, and over 30% of the global population has zinc deficiency. Micronutrient deficiency leads to compromised health and economic losses and is prevalent in populations depending on non-diversified plant-based diets. Increasing mineral content of staple food crops through biofortification is the most feasible strategy of combating micronutrient malnutrition. Additionally, it will also enhance the agronomic efficiency of crops on mineral poor soils. A multipronged strategy towards enhancing mineral content of cereal grains should involve increased uptake of minerals from soil, enhanced partitioning towards grain and improved sequestration in the edible tissues of grains. At the same time, it is essential to improve mineral absorption in vivo from cereal-based diets. Both conventional and modern breeding approaches and genetic engineering are being employed for biofortification of crop plants. With increased understanding of mineral uptake and transport mechanisms in plants, it is becoming ever more possible to engineer biofortified crop plants with the ultimate goal of overcoming hidden hunger. [ABSTRACT FROM AUTHOR]

Restricted supply of micronutrients is a common constraint for plant growth worldwide, especially in organic farming systems where nutrients supply to crops mostly depends on the mineralization of native soil organic matter, decomposition of applied manures and crop residues. A laboratory incubation study was therefore conducted to investigate the potential release of copper (Cu), manganese (Mn) and zinc (Zn) from the rock mineral flour (RMF) and city waste compost (CWC) as compared to inorganic micronutrient fertilizers for 140 days. Release of the micronutrients from RMF and CWC showed different trends. The results showed that about 4.6% of Cu added as RMF was released irrespective of the quantity of the RMF applied. However, Cu release from CWC increased from 0.7 to 3.5% as the amount of compost added was increased. Copper recovery from copper sulphate was 98%. Manganese release from RMF decreased from 114 to 103% as the RMF level was increased, while the corresponding decrease in Mn release from CWC was from 14 to −3%. Manganese recovery from manganese sulphate was 100%. Zinc release from RMF increased from 5.8−15.5%, with an increase in the amount of RMF applied, while no Zn was released from CWC. Recovery of Zn from zinc sulphate was 98%. These results show that RMF and CWC could be used to meet Cu, Mn and Zn requirements of organically grown cereals. The results of the investigation have general applicability in organic farming. [ABSTRACT FROM AUTHOR]

Leaching of copper (Cu), zinc (Zn), and manganese (Mn) from a soil contaminated by metallurgy waste (used as a micronutrient source) was carried out in a column experiment. The main objective was to evaluate the effect of the chelates ethylenediaminetetraacetic acid (EDTA), ethylenediaminedisuccinic acid (EDDS), and citrate at doses of 2, 4, and 8 mmol kg-1. The two synthetic chelating agents increased metal contents in the lower part of the column, which was filled with an uncontaminated sample of the same soil. No Cu or Zn was present in the leachates. Although Mn could be detected, values were not related to treatments. Water by itself was also able to mobilize metal inside the soil column. The retention of metals by the uncontaminated soil layer was explained by its large adsorptive capacity, as demonstrated by the corresponding adsorption isotherms. [ABSTRACT FROM AUTHOR]

Mathematical models of micro-nutrient uptake by plants have been based on models designed for uptake of major nutrients. This poses a number of problems, as the behaviour of micro-nutrients in the rhizosphere is different, particularly with respect to interactions between solid and solution compartments. There is no standard procedure for the measurement of soil parameters that affect the supply of micro-nutrient from the soil. The Dynamic Plant Uptake Model (DPUM) presented here can use soil parameters for micro-nutrients that are measured under similar conditions to those that apply during plant uptake, as, for example, by the technique of DGT (Diffusive Gradients in Thin-films). The construction and practical applications of the model are discussed in the context of mathematical simulations of realistic situations. The simulations have been used to investigate conditions under which uptake of zinc by a zinc hyperaccumulator ( Thlaspi caerulescens), and a non-accumulator plant ( Thlaspi arvense), is limited by either processes occurring in the plant or in the soil. The size of the solid phase reservoir of zinc, and the rate at which the solid phase reservoir responds to zinc depletion in the solution phase, are important in determining the soil solution concentration at which the plant uptake kinetics begin to limit the uptake of the metal. The relative importance of advective transport of zinc from the surrounding soil to the root–soil interface depends on both the size of the solid phase reservoir and the speed at which the soil responds to zinc depletion in the pore water. These results have been used to assess conditions where DGT is likely to behave as a reliable surrogate for the transport and metal release processes that affect plant uptake. [ABSTRACT FROM AUTHOR]

The benchmark soils collection of Pernambuco state contain 13 of the 14 soil orders of the Brazilian System of Soil Classification. Thus, information on zinc (Zn) and copper (Cu) status in such soils is useful as a reference of micronutrient distribution and availability in a representative set of Brazilian soils. The present work was performed to assess Zn and Cu distribution into operationally defined fractions of benchmark soils of Pernambuco state. In addition, chemical extractants, with contrasting chemical properties, were used to assess the availability of these micronutrients to relate such values with fertility guidelines concentrations and with the fractions defined by the sequential extraction. The results demonstrated that the organic matter was the most important fraction retaining Zn and Cu in the studied soils, as indicated by the sequential extraction. The Zn availability in the majority of the soils (90% of the samples) is sufficient to meet the requirement of the major field crops, although the available Cu concentrations are below the critical levels for plant growth in 46% of the analyzed samples. Mehlich- 1 extractant appeared to be the most efficient in predicting the availability of Zn in the soils because of its better correlation with exchangeable and organic fractions. DTPA and Mehlich-3 were the most efficient extractants for the evaluation of Cu availability, as suggested by the better correlation with organic matter, which is the main pool of available Cu in the soils. [ABSTRACT FROM AUTHOR]

Spent alkaline and zinc-carbon batteries contain valuable elements (notably, Zn and Mn), which need to be recovered to keep a circular economy. In this study, the black mass materials from those spent batteries are pyrometallurgically treated via a series of process steps in a pilot-scale KALDO furnace to produce an Mn–Zn product, a ZnO product, and an MnO (manganese monoxide) product, toward applications of Mn–Zn micronutrient fertilizer, zinc metal, and manganese alloy, respectively. After an oxidative roasting step, an Mn–Zn product, containing 43% Mn, 22% Zn, and negligible amounts of toxic elements (notably, Cd, Hg, and Pb), could be produced, being suitable for the micronutrient fertilizer application. After a reductive roasting step, a ZnO product and an MnO product are produced. The attained ZnO product, containing up to 84.6% ZnO, is suitable for zinc metal production when the leaching steps are taken to remove most of the Cl and F in the product. The attained MnO product, containing up to 91.7% MnO, is of premium quality for manganese alloy production, preferably for SiMn alloy production due to its low phosphorus content. The proposed application scenarios could substantially improve the recovery efficiency of those spent batteries. [Display omitted] • A pilot study is carried out to recover Zn and Mn from alkaline and Zn–C batteries. • Recovery of Mn and Zn toward three application scenarios is presented. • Mn–Zn micronutrient fertilizer, zinc metal and SiMn alloy are the studied scenarios. • The keys to these scenarios are the removal of toxic or undesirable elements. • The identified scenarios can be integrated into existing industrial infrastructure. [ABSTRACT FROM AUTHOR]

Field experiments for 3 years were carried out to assess the efficacy of organic manures (Sesbania aculeata, Leucaena leucocepliala), cowpea (Vigna unguiculara) and mungbean ( Vigna radiata) green manures, wheat straw and FYM (Farm Yard Manure) in enhancing the productivity of rice-wheat cropping system and for their capacity to supply Zn and Cu. Green manuring with Sesbania gave the highest rice yield, whereas lowest yields were recorded with wheat straw incorporation. The organic manures had significant residual effect on succeeding wheat and the high- est yields were recorded with FYM. The percent increase over no organic manure (control) in total rice-wheat productivity was the highest with Sesbania green manuring (19.5%) and lowest with wheat straw (4%). The concentration and uptake of Zn and Cu by individual crops and system was significantly greater with organic manures. The micronutrient status of soil after 3 cycles of rice-wheat cropping system declined over initial values but the decline was the least with FYM followed by green manures. Application of organic manures is desirable for sustained supply of Zn and Cu to rice-wheat cropping system soils. [ABSTRACT FROM AUTHOR]