Micronutrient Fertilizers Research Articles

Toxic heavy metals content in different agrochemicals available in markets of Bangladesh and their loads to the agricultural lands.

A study was conducted to determine the concentration of toxic heavy metals in various agrochemicals available in Bangladesh and to assess the burden of these metals on agricultural soils. An atomic absorption spectrophotometer (AAS) was used to measure the content of 4 toxic metals (Cd, Pb, Cr, and Ni) in the aqueous extract of various agrochemicals. There were significant differences in the amounts of Cd, Pb, Cr, and Ni in different brands of insecticides (mean < 0.01, 3.16, 17.32, and 47.33 µgg-1), fungicides (mean 12.42, 10.19, 9.63, and 243.34 µgg-1), phosphatic fertilizers (mean 25.43, < 0.01, 206.33, and 210.69 µgg-1), micronutrient fertilizers (mean 0.68, < 0.01, 43.43, and 65.79 µgg-1), and plant hormones (mean < 0.01, < 0.01, 9.90, and 43.08 µgg-1). The concentrations of Cd and Ni were on anaverage higher in phosphatic fertilizers, which exceeded the maximum acceptable limit of fertilizers in Bangladesh by 2.5 and 4.2 times, respectively. The study also revealed that the burden of toxic heavy metals from agrochemicals on farm soils was in the following order: phosphatic fertilizers > fungicides > micronutrient fertilizers > plant hormones > insecticides. Among the toxic heavy metals, Ni posed the highest burden on Bangladeshi farm soils due to a single application of different agrochemicals in a year. The average total burden of each metal in the soils of Bangladesh showed a decreasing trend in the order of Ni > Cr > Cd > Pb, resulting in a total metal burden of 22.88gyear-1ha-1. Finally, the study recommended that certification about the content of metals be made mandatory for agrochemical manufacturing firms to ensure that their products entering in Bangladeshi markets are free from toxic metals.

Влияние минеральных удобрений на содержание микроэлементов в агрочерноземе при использовании технологии No-till

The article presents the results of studies on the effect of mineral fertilizers on the content of Zn, Cu in the soil and winter wheat plants using the No-till technology. In the field experiment, ammonium nitrate (N12P52) and potassium magnesium oxide (K32Mg12S20) were applied during sowing against the background of two additional fertilizing with ammonium nitrate (N34) - N30 at the tillering stage, N70 - at the tube emergence stage. Low content of mobile Zn and Cu compounds was found in the agrochernozem of the southern zone of the Rostov region. The application of ammonium nitrate, ammophos, potassium magnesium oxide does not replenish the reserves of biomicroelements in the soil. The balance of Zn and Cu for all experimental variants was negative: Zn - 115–154 g/ha; Cu - 39.0–56.0 g/ha. The obtained results indicate a violation of the microelement cycle in winter wheat agrocenoses and prove the need to use micronutrient fertilizers to obtain stable grain yields of good quality. Keywords: AGROCHERNOZEM, ZINC, COPPER, WINTER WHEAT, FERTILIZERS, NO-TILL TECHNOLOGY

Влияние минеральных удобрений на содержание микроэлементов в агрочерноземе при использовании технологии No-till

The article presents the results of studies on the effect of mineral fertilizers on the content of Zn, Cu in the soil and winter wheat plants using the No-till technology. In the field experiment, ammonium nitrate (N12P52) and potassium magnesium oxide (K32Mg12S20) were applied during sowing against the background of two additional fertilizing with ammonium nitrate (N34) - N30 at the tillering stage, N70 - at the tube emergence stage. Low content of mobile Zn and Cu compounds was found in the agrochernozem of the southern zone of the Rostov region. The application of ammonium nitrate, ammophos, potassium magnesium oxide does not replenish the reserves of biomicroelements in the soil. The balance of Zn and Cu for all experimental variants was negative: Zn - 115–154 g/ha; Cu - 39.0–56.0 g/ha. The obtained results indicate a violation of the microelement cycle in winter wheat agrocenoses and prove the need to use micronutrient fertilizers to obtain stable grain yields of good quality. Keywords: AGROCHERNOZEM, ZINC, COPPER, WINTER WHEAT, FERTILIZERS, NO-TILL TECHNOLOGY

Effect of coating phosphorus with humic acids and micronutrients on yield of soybean and maize in succession

The increasing the efficiency of phosphate and micronutrient fertilization in tropical soils should be better studied to close crop yield gaps. The aim of this study was to evaluate the effect of a soluble P source with or without humic acids (HA) and micronutrients (M) on P-availability and maize and soybean yield in Minas Gerais State, Brazil. The crops were grown under a rainfed and no-till cropping system, with maize grown in the 2016/2017 rainy summer season, wheat grown as a cover crop in the 2017 winter season, and soybean grown in the 2017/2018 crop year. The field trial was organized in a 4 × 2 factorial arrangement [4 sources of P in combination with 2 forms of M supply]. The coated monoammonium phosphate (MAP) P source was supplied in three ways: 1) MAP, 2) MAP + HA, and 3) MAP + HA + M (B, Cu, Mn, and Zn), plus a control for P (no P). The micronutrient supply was 1) Mn + Zn + Cu + B (MZCB) and 2) control for MZCB (no M supply). Coating MAP with HA increased soil P availability but did not increase P content within the soybean leaves. The multivariate approach also showed that soybean yield can increase in response to coating MAP with HA. The study showed that MAP + HA increased soil P content. However, this increase was diminished when micronutrients were included in the same granule (MAP + HA + M). However, P sources raised P in soybean leaves equally compared to control for P. Soybean yield was unaffected by the P source, likely due to adequate leaf P concentrations across all treatments. However, soybean yield generally increased with micronutrient supply. For maize, yields were unaffected by supplying micronutrients with the P source. Conversely, maize yields typically decreased with micronutrient supply, except when using the MAP + HA + M combination granule.

Agronomic Effectiveness of Zinc Sources as Micronutrient Fertilizers: A Comprehensive Review’

Zinc naturally occurs in the earth's crust as part of rocks and ore minerals. The average concentration of zinc in the lithosphere is 80 mg kg-1. While zinc is relatively immobile in soil, it is moderately mobile in plants. As a vital micronutrient for both humans and animals, zinc plays an essential role in plants as a catalytic, structural and regulatory cofactor for many enzyme reactions. It is necessary for the metabolism of carbohydrates, protein synthesis, the biosynthesis of growth hormones (particularly indoleacetic acid) and the maintenance of cell membrane integrity. Zinc deficiency is a widespread problem affecting both plants and humans in many regions of the world. To address this issue and improve plant zinc nutrition and yields, both soil and foliar zinc fertilizers have been applied. The agronomic effectiveness of Zn fertilizers has been related to the management factors such as placement, source type, seed treatment, foliar spray and biofortification that can affect the effectiveness of Zn fertilizers.

SOIL MICRONUTRIENT CONTENT ANALYSIS AND MAPPING OF AGRICULTURAL SALT-AFFECTED SOILS AROUND ABAYA AND CHAMO LAKES, SOUTH ETHIOPIA RIFT VALLEY

&lt;p&gt;&lt;strong&gt;&lt;span lang="EN-US"&gt;Background.&lt;/span&gt;&lt;/strong&gt;&lt;span lang="EN-US"&gt; Salt-affected soils cause a significant portion of land to become unproductive yearly; its impact is severe in sub-Saharan African nations, especially the arid and semiarid lowlands, and the Rift Valley regions of Ethiopia are typically host to naturally salt-affected areas. &lt;strong&gt;Objective.&lt;/strong&gt; To analyze the micronutrient content and map the micronutrient fertility status of agricultural salt-affected soils around Abaya and Chamo Lakes South Ethiopia Rift Valley. &lt;strong&gt;Methodology.&lt;/strong&gt; A systematic sampling technique was employed to obtain 300 soil samples for the investigation from two depths (0-20 and 20-40cm), with a 600m sampling interval, of which 30 were used. The research data was analyzed using the application of standardized analytical procedures for soil data and descriptive and geostatistical techniques. &lt;strong&gt;Results.&lt;/strong&gt; According to the study, there is low zinc available in the soil but an ample amount of iron, manganese, and copper. In addition, the study's findings revealed that, whereas the remaining micronutrient regional variability is found at long distances, available iron exhibited a regional variation in soil quality at small distances. &lt;strong&gt;Implications.&lt;/strong&gt; The study suggests applying organic matter for better soil structure, water retention, and nutrient availability.&lt;/span&gt;&lt;span lang="EN-US"&gt;Moreover, the results recommend that soils affected by salt might recover using various materials. &lt;strong&gt;Conclusions.&lt;/strong&gt; In the study areas, zinc fertilizer may still be needed for an optimal yield even though the research area has low amounts of zinc fertilizer. The study concluded with management recommendations to minimize the adverse effects of very high micronutrient content on human health and plant growth.&lt;/span&gt;&lt;/p&gt;

Examining the Effect of Agrochemicals on Soil Microbiological Activity, Micronutrient Availability, and Uptake by Maize (Zea mays L.) Plants

Agricultural practices profoundly influence soil microbial populations and physicochemical properties, vital for crop growth and quality. This study aims to explore the impact of diverse agrochemical applications on soil microbial dynamics, physicochemical properties, and maize yield and proximate properties. Topsoil samples, collected at depths of 1 to 15 cm, were transported to Jimma University for maize cultivation. Over 120 days, soil and maize samples were collected at specified intervals for analysis, including soil pH, microbial populations, and nutrient content. Statistical analysis using one-way ANOVA (p &lt; 0.05) was conducted. Soil bacterial and fungal populations were measured on days 5, 10, 20, 40, 80, and 120. The highest total mesophilic bacterial count (TMBC) was in compost-treated pots (G) and the lowest in those receiving macronutrient fertilizers and glyphosates (B). The highest total mesophilic fungal count (TMFC) was in pots with glyphosates and compost (F), and the lowest was in pots treated with macronutrient fertilizers and glyphosates (B). Pots treated with macronutrient fertilizers and glyphosates (B), macronutrient fertilizers (A), and micronutrient fertilizers (C) showed the lowest Fe and Zn levels. Maize in pots treated with macronutrient fertilizer combined with glyphosate (B) exhibited the lowest protein, fats, and carbohydrates. Notably, compost-treated soils showed the highest bacterial and fungal counts, Fe, and Zn concentrations, while micro-mineral fertilizer combined with glyphosate (B) depleted the soil. Agrochemical treatments negatively affected maize yield quality, indicating complex treatment-related changes in soil parameters.

The fate and biostimulant potential of metal lactates in silt loam soil

AbstractConventional farming practices have negatively impacted micronutrient fertility and overall soil health. Metal lactates are an organic micronutrient amendment that provide both a labile carbon substrate as well as mineral nutrition for plant and microbial growth. To determine the ability of metal lactates to provide readily available micronutrients, Zn, Cu, Mn, Ni, and Co in lactate and chloride salt form were amended to soils and incubated for 28 days. Operationally defined speciation was determined using sequential extraction on samples incubated for 1, 5, or 28 days. The results show a comparable distribution of metals in chloride and lactate form; however, differences were detected in water‐soluble and exchangeable Ni and Zn at each timepoint. For example, in the water exchangeable fraction, there was 2.6%–2.9% less Ni and 0.2%–0.3% less Zn in the metal lactate‐treated soil compared to soil treated with metal chlorides. Furthermore, carbonate‐bound Ni averaged 4.1% and 4% less in metal lactate‐treated soils as compared to metal chloride‐treated soils on days 1 and 5, and Cu decreased 2.9%–3.3% during the treatment period for the lactate‐bound form. Additionally, microbial phospholipid fatty acid (PLFA) was performed and found a stimulatory effect of metal lactates on bacterial biomass with an increase of 12%–18% relative to the metal chloride treatment. Results from this study support the use of metal lactates as a sustainable alternative to conventional fertilizers by providing bioavailable micronutrients for plant nutrition in addition to a labile carbon source to support the growth of microbial populations.

An Updated Isotopic Database of Fertilizers Used in Intensive Organic Farming: A Case Study on Protein Hydrolyzed Derivatives and Chelated Nutrients

The global demand for organic food products has rapidly increased over the last years, becoming an emerging niche market targeting the high-income segment. The higher retailing price for organic food products may increase the risk of fraudulent practices at the different stages of the food supply chain, and consequently, substantial control is needed. Currently, the authentication of organic food products, such as those of plant origin, remains a key challenge in analytical chemistry. While stable isotopes have emerged as a powerful tool for this purpose, most studies have focused on crops, missing the agricultural inputs used for fertilization that influence the isotopic values of the crops. In this study, we aimed to isotopically characterize commonly used fertilizers, soil conditioners, and micronutrient fertilizers in intensive organic agriculture in the largest organic production region in the world (Almería, Spain). Our goal was to clarify the limitations that nitrogen isotopic fingerprinting presents for the fertilizer input industry and to characterize the organic inputs. The conventional fertilizers analyzed in this study showed low δ15N values compared to their organic counterparts, except for some plant-based fertilizers, protein hydrolyzed fertilizers, and chelated nutrients. Both protein hydrolyzed fertilizers and micronutrient fertilizers presented a wide range of variability in their δ15N values, including some very low or even negative values, more similar to those of conventional fertilizers. The results of this study highlight the challenges of authenticating organic foods in agriculture when using nitrogen isotope analysis.

Nanotechnology in Agriculture: Manganese Ferrite Nanoparticles as a Micronutrient Fertilizer for Wheat.

Limited research has focused on nanoparticle (NP) applications' impact on edible wheat parts in a field environment. Here, we studied the nutritional quality of edible parts of wheat (Triticum aestivum L.) with a field experiment by spraying MnFe2O4 nanoparticles. Wheat was foliar sprayed with 0, 25, 50, and 100 mg/L composite manganese ferrite (MnFe2O4) NPs during 220 d of a growth period. Ionic controls were prepared using the conventional counterparts (MnSO4·H2O and FeSO4·7H2O) to compare with the 100 mg/L MnFe2O4 NPs. After three consecutive foliar applications, nanoparticles demonstrated a substantial elevation in grain yield and harvest index, exhibiting a noteworthy increase to 5.0 ± 0.12 t/ha and 0.46 ± 0.001 in the 100 mg/L NP dose, respectively, concomitant with a 14% enhancement in the grain number per spike. Fe, Mn, and Ca content in grain increased to 77 ± 2.7 mg/kg, 119 ± 2.8 mg/kg, and 0.32 ± 7.9 g/kg in the 100 mg/L NPs, respectively. Compared to the ion treatment, the 100 mg/L NP treatments notably boosts wheat grain crude protein content (from 13 ± 0.79% to 15 ± 0.58%) and effectively lowers PA/Fe levels (from 11 ± 0.7 to 9.3 ± 0.5), thereby improving Fe bioavailability. The VSM results exhibited a slight superparamagnetic behavior, whereas the grains and stems exhibited diamagnetic behavior. The results indicate that the nanomaterial did not accumulate in the grains, suggesting its suitability as an Fe and Mn-rich fertilizer in agriculture. Above all, the foliar application of nanocomposites increased the concentrations of Fe, Mn, and Ca in wheat grains, accompanied by a significant enhancement in grain yield. Therefore, the research results indicate that the foliar application of MnFe2O4 NPs can positively regulate wheat grains' nutritional quality and yield.

Harmonizing Agriculture: Nurturing Soil through Micronutrients Management and Texture Dynamics

The present review delves into the essential aspect of micronutrient management and soil texture dynamics in agriculture thus emphasizing their pivotal roles in sustaining soil health and optimizing crop productivity. Micronutrients, though required in trace amounts are critical for various physiological and biochemical processes in plants. Micronutrient deficiencies can profoundly impact plant growth and yield, necessitating effective management strategies such as soil amendments, foliar applications, and balanced fertilization practices. Additionally, the paper explores the potential of soil microbes to enhance micronutrient availability. Soil testing emerges as a crucial tool for monitoring nutrient levels and guiding nutrient application decisions. Furthermore, soil texture dynamics significantly influence nutrient availability, highlighting the importance of soil composition and structure. Conservation tillage practices, crop rotation, and the use of micronutrient fertilizers are discussed as means to promote soil health and optimize nutrient profiles. Overall, the paper underscores the importance of integrating micronutrient management and texture dynamics for harmonizing agriculture, ensuring sustainable soil health, and fostering increased crop yields.

Effect of fertilization and microbial preparations on productivity of chickpea (&lt;i&gt;Cicer arietinum&lt;/i&gt; L.)

The aim of the study was to optimize the nutritional status and increase the productivity of chickpeas through the application of mineral and organic-mineral fertilizers as well as microbial preparations based on nitrogen–fixing, phosphorus–mobilizing, and potassium-mobilizing microorganisms. The research was conducted in 2019-2021 in the Poltava Research Agricultural Station (Ukraine). NPK fertilizers were applied at a dose, of 20, 80, and 80 kg ha&lt;sup&gt;-1&lt;/sup&gt;, respectively. Before sowing, the seeds were inoculated with the microbial preparation BiNitro Chickpea (BN) and Biofosforyn (BF). Foliar feeding was carried out with the microfertilizer Freya–Aqua™ C(12) Legumes (F). The development of chickpea leaf area and the intensity of organic matter production were largely determined by the supply of the main macronutrients to the plants. The introduction of NPK significantly increased leaf area and net photosynthetic productivity, while the effect of BN, BF, and F on the values of these indices was not significant. Their effect was manifested during the accumulation of aboveground biomass and the formation of yield structure elements. An increase in the seed yield was shown in relation to the application of NPK, microbial preparations, and micronutrient fertilizers. Regardless of the NPK, the highest yield was shown in the variant of the combination of BN+BF+F.

Effect of Micronutrient Fertilization on Production and Soil Fertility in Maize

Balanced fertilization in both macro and micronutrients is one strategy in soil fertility management to prevent microelement deficiencies. This fertilization type could increase plant growth and production as well as maintain soil fertility. This research aimed to examine the role of micro fertilization on supporting plant productivity and soil fertility. Research that was conducted in Dau, Malang, East Java was designed using a Randomized Block Design (RBD) with 9 treatments, ie B0 (Control), B1 (100% standard fertilization), B2 (100% standard fertilization and 50% ZnCuB), B3 (100% standard fertilizer and 100% ZnCuB), B4 (100% standard fertilizer and 150% ZnCuB), B5 (75% standard fertilizer and 50% ZnCuB), B6 (75% standard fertilizer and 100% ZnCuB), B7 (75% basic fertilizer and 150% ZnCuB), and three replications of each. 100% of basic fertilization referred to 440 kg Urea/ha, 250 kg SP-36/ha, and 350 kg KCl/ha, while 100% micro fertilizer ZnCuB (4:6:6) was 19 kg/ha. Reducing 25% of basic fertilizer combined with 150% of micro fertilizer (28.5 kg/ha ZnCuB) resulted in a significant increase in plant growth and production by 54% to control. Furthermore, micronutrient fertilizers could maintain soil fertility as well as prevent soil acidification.

Influence of Foliar Application of Microelements on Yield and Yield Components of Spring Malting Barley

Barley is an economically important plant cultivated primarily for animal feed and in the brewing industry for the production of barley malt. Climate changes and an increase in grain demand result in a constant need to improve the volume and stability of cereal species yields and better use the potential of cultivars. In cereal production, an important aspect is the use of microelements, especially by foliar spraying. Microelements, as components or enzyme activators, play a significant role in plant growth and metabolic processes occurring in the cell. As a consequence, their availability is a factor determining plant development. The aim of this study was to determine the effect of foliar fertilization with selected microelements on the yield of two-row malting barley cultivars. In 2019–2021, a two-factor field experiment with barley was conducted in south-eastern Poland. The experimental factors were three spring barley cultivars (Baryłka, KWS Irina, and RGT Planet) of the brewing type and four single-component micronutrient fertilizers containing copper (Cu), manganese (Mn), molybdenum (Mo), and zinc (Zn). The foliar application of microelements resulted in improvements in selected elements of the yield structure and an increase in grain yield, and the effect depended on the fertilization applied. The highest grain yield was obtained from plots where fertilizer with Mo or Zn was used. Barley plants sprayed with Mo fertilizer developed the longest spikes and were characterized by the highest number of productive tillers per plant. The foliar application of Zn resulted in the formation of the highest number of spikes per unit area and grain uniformity. The RGT Planet cultivar was characterized by higher values of the measured parameters compared to Baryłka and KWS Irina.

Synthesis and Characterization of Activated Carbon/Alginate-Fe Composites as Slow Release Fertilizer

Research on the slow release kinetics of Fe(III) ions from Activated Carbon/Alginate-Fe(III) composites or abbreviated as K/A-Fe(III) has been carried out. The aim of this research was to synthesize K/A-Fe(III) composite as a material that has the potential to become a slow release micronutrient fertilizer and to study the kinetics of slow release of Fe(III) ions from the composite. The K/A-Fe(III) composite was synthesized by mixing alginate suspension and activated carbon (alginate: activated carbon weight ratio = 1:3 and 3:1) until homogeneous. Composite grains were characterized using Fourier Transformed Infrared (FTIR) spectroscopy, the kinetics of Fe(III) release from the three composite variations found that KAlg31 composite showed more absorption and release of Fe ions than KAlg13.

Technology of obtaining micronutrient fertilizers based on micronutrient secondary raw materials of the industry

The article presents the research results of obtaining nitrogenphosphorus- calcium-microelement fertilizers by adding suspensions obtained by activating phosphorite with microelement industrial waste in different proportions to the superphosphate mass formed by decomposition of Central Kyzylkum phosphorite flour at different rates of sulfuric acid in laboratory conditions. Experiments were carried out with low-quality phosphorite flour, non-enriched phosphorite flour and washed-burned (thermoconcentrate) phosphorite concentrates (UzDSt 2825:2014) obtained on the basis of phosphorites of the Central Kyzylkum. Also, in order to obtain superphosphate fertilizers with microelements, secondary raw materials with acidic microelements of the РН environment formed during molybdenum processing of Almalyk mining and metallurgical combine joint-stock company were used. Studies have shown that under the influence of micronutrients (copper, zinc, molybdenum, etc.), important physiological and biochemical processes can be controlled, thereby increasing the yield and quality of agricultural products. The use of microelements together with basic fertilizers is an effective and economically important (convenient) agrochemical method. The purpose of the research is to implement new types of phosphoric fertilizers based on incomplete standards of mineral fertilizers and acids, which are widely used in agriculture, or their salt mixtures, using trace element salts and secondary raw materials containing trace elements of hydrometallurgy.

Optimizing the Zn, Mn, and Fe mineral dose as tank mix foliar application for improvement of fruit yield, quality, and uptake of nutrients in the kinnow mandarin

Kinnow production is hampered due to the lack of micronutrient applications such as zinc (Zn), iron (Fe), and manganese (Mn), which play a significant role in the metabolic activities of the plant, affecting yield and quality. The farmers of the region use mineral micronutrient fertilizers, but it leads to phytotoxicity due to unoptimized fertilizer application dose. In the present investigation, an attempt has been made to optimize the Zn, Mn, and Fe minerals dose as tank mix foliar application for improvement of fruit yield, quality, and uptake of nutrients. The twelve combinations of different doses of zinc sulphate, manganese sulphate, and ferrous sulphate fertilizers replicated three times were tested at kinnow orchards established at Krishi Vigyan Kendra, Bathinda, Punjab, India. The data revealed that the fruit drop was significantly low in the treatment F12 (43.4%) (tank mix spray of 0.3% ZnSO4 + 0.2% MnSO4 + 0.1% FeSO4 ) compared to control treatment. The fruit yield per tree was significantly higher in the treatment F12 compared to untreated control. The juice percentage was also recorded higher in treatment F12 as compared to control, and the juice percentage improved by 2.6%. The leaf nutrient analysis also revealed translocation of higher amount of nutrient from leaf to fruit under optimized supply of micronutrient. Thus, the application of tank mix spray of 0.3% ZnSO4 + 0.2% MnSO4 + 0.1% FeSO4 may be used for better fruit yield and quality.

Effect of micron (micronutrients) fertilizer on the growth and yield of Wheat variety Sarsabz

The Department of Chemistry Soil Section Agriculture Research Institute, Tando Jam, conducted an examination in order to find out how micron (micronutrient) fertilizer affected the growth and yield of the wheat variety Sarsabz. Three replicates of a Randomized Complete Block Design were used to investigate the effects of micron (micronutrients) fertilizer utilized at rates of 0, 50, 100, and 150 kg ha-1 having a plot size of 46 m x 44 m. The results of the study revealed that applying micronutrient fertilizer to crops significantly altered the crop’s parameters. The application of Micron (micronutrients) fertilizer applied at a rate of 150 kg ha-1, with proposed N (168) and P (84) doses, resulting in the maximum wheat plant height (101.73), more tillers plant-1 (9.73), spike length (13.7), more grain spike-1 (51.66), heavier seeds (39.3), and higher grain yield (3453.3 kg ha-1). Therefore the micro nutrient is essential for achieving maximum yield production and should be applied with recommended doses on the wheat crop, performed better results in soil conditions of Tando Jam.

Potassium and Micronutrient Fertilization for Enhancement of Tef Yield in Vertisols of Hawzen and Enderta Districts, Tigray Region, Ethiopia

Field study was conducted in Enderta and Hawzen districts of Tigray region on six farmers’ fields aimed at evaluating potassium and micro-nutrient effect on yield and yield components of the tested crop. The experiment comprised of eight treatments including control and recommended NP arranged in Randomized Complete Block Design with two replications. Phosphorus fertilizers were applied at planting, while the nitrogen fertilizer was applied in two splits. The micronutrients and Typrosine were applied in foliar forms. SAS version 9 statistical software was used for data analysis. The analyzed results depicted that Tef yield was increased with potassium and micro-nutrient application in both districts mathematically even though it was not consistent. In line to this, the highest grain and straw yields of Tef was recorded at recommended NP with application of 50 kg/ha K2SO4 and recommended NP with a foliar application of Typrosine, respectively. But this result was statistically similar with the recommended NP. Thus, application of additional fertilizer without yield increment is uneconomical rather than maximizing costs. Hence, potassium, copper, and zinc in the current sources were not Tef yield limiting nutrients in the study sites even though the soil statuses are low. On the other hand nitrogen and phosphorus were observed the Tef yield limiting nutrients in this study. For this reason maximizing the use of nitrogen and phosphorus fertilizers with detailed research on its level and their interactions, sources and application times is important to maximize the Tef productivity in the Vertisols of Enderta and Hawzen district.

Varied Macro- and Micronutrient Fertilization Rates Impact Root Growth and Distribution and Fruit Yield of Huanglongbing-affected Valencia Orange Trees

Candidatus Liberibacter asiaticus (CLas), which causes huanglongbing (HLB) in citrus trees, has a great impact on tree root health, fruit development, and juice quality. HLB-affected trees have a fibrous root density loss of ∼30% to 80%, resulting in the limited capacity of citrus trees to uptake nutrients. Therefore, this study was conducted for 3 years to 1) assess the temporal changes in root density as a result of varied fertilization, 2) determine dynamics of HLB with regard to root growth and distribution as a result of varied fertilization for Valencia orange trees, and 3) evaluate the impact of varied fertilization rate and method of fertilization on fruit yield for HLB-affected trees. Macronutrients and micronutrients were applied at varying fertilization rates (0×, 1×, 2×, and 4×, of University of Florida guidelines). Root scans were done using minirhizotrons at 0 to 19.1 cm, 19.1 to 40.7 cm, 38.2 to 59.8 cm, and 57.3 to 78.9 cm soil depths. Results obtained from the study showed that root growth and distribution were greater in 0 to 19.1 cm than 19.1 to 40.7 cm to 57.3 to 78.9 cm soil depths. Thus, root growth decreased (P &lt; 0.0004) with increasing soil depth due to variation in nutrient availability for tree uptake. Increased nutrient availability at occurrence of physiological processes in citrus trees also influenced root growth and distribution, resulting in root growth flushes in the months of Nov to early Feb and Jul to early Aug. Fruit yield was significantly different between treatments in 2 of the 4 years of the study (P = 0.001 and P = 0.003), and largely ascribed to soil fertilization of micronutrients compared with foliar. Therefore, at higher fertilization rates, particularly via soil application, nutrient availability was increased, thus promoting root growth and distribution and fruit yield in HLB-affected orange trees.