Fertilizer Application Methods Research Articles

Effects of Nitrogen Fertilizer Management on Dry Matter Accumulation and Yield of Drip-Irrigated Sugar Beet in Arid Areas

Clarifying the optimal combination of N fertilizer application rate and application method can maximize the yield of drip-irrigated sugar beet in arid areas, which is of great significance for reducing farmland N pollution and achieving sustainable agricultural development. In this three-year field experiment in Xinjiang, China, the effects of three N application rates [75 kg ha−1 (N1), 150 kg ha−1 (N2), and 225 kg ha−1 (N3)] and three N application methods [the proportion of N applied at canopy rapid growth stage, taproot expansion stage, and sugar accumulation stage were (M1) 100%: 0%: 0%, (M2) 70%: 30%: 0%, and (M3) 50%: 30%: 20%] on the dry matter accumulation (DMA) and distribution, leaf senescence, yield, and agronomic N use efficiency (aNUE) of drip-irrigated sugar beet were explored. The results showed that N application (N1, N2, and N3 treatments) increased the shoot DMA by 27.7% (three-year average), 52.6%, and 83.1%, and the taproot DMA by 28.3%, 43.2%, and 61.6%, respectively (p < 0.05), compared with CK (no N supply) treatment. The N application methods M2 and M3 increased the shoot DMA by 5.6% (three-year average) and 1.0% (p > 0.05), respectively, and the taproot DMA by 7.2% and 3.6% (p < 0.05), respectively, compared with M1. In addition, M2 could delay the end of shoot and taproot growth (te) and the occurrence of maximum growth rate (tm). In particular, the N3M2 treatment increased the leaf area index (LAI) by 20.4–75.9% (p < 0.05) compared with other treatments by increasing the leaf area duration (LAD) and decreasing the leaf senescence rate (LSR). The taproot yield and sugar yield of N3M2 treatment reached the maximum at harvest time, but there was no significant difference in taproot yield and sugar yield between N3M2 treatment and N2M2 treatment. The aNUE in N2M2 treatment was the highest (p < 0.05), which was 1.29–7.85 times higher than that of other treatments. Therefore, reducing the N application rate from 225 kg·ha−1 to 150 kg·ha−1 and applying 70% and 30% of 150 kg N ha−1 at the canopy rapid growth stage and the taproot expansion stage, respectively, could achieve the goal of increasing sugar beet yield and N use efficiency. This study will provide an important reference for the sustainable production of sugar beet under drip irrigation in Xinjiang, China.

Regulation of photoassimilate transportation and nitrogen uptake to decrease greenhouse gas emissions in ratooning rice with higher economic return by optimized nitrogen supplies

Mechanized harvesting of the main crop rice, with low stubble height in rice ratooning is scaling up, especially in Southeast China with a higher population density and less cultivated land. Currently, the common nitrogen fertilization for ratoon rice is concentrated within 20 days before and after the harvest of the main crop. However, this fertilization pattern may not be suitable for low stubble regenerative rice due to its extended growth period, leading to diminished nitrogen utilization efficiency and heightened greenhouse gas emissions, particularly nitrous oxide (N2O) emissions. It is imperative to explore a nitrogen fertilizer management model for clean production of low stubble ratoon rice (RR). In this study, we examined the effects of nitrogen fertilizer application rates and methods (single or split application) on yield and greenhouse gas emissions during the regrowth season. We employed a multi-criteria assessment approach combined with field measurements, energy analysis, environmental assessment, and economic evaluation on ratoon rice under various nitrogen fertilizer treatments. The results showed that the ratoon rice produced the highest total energy output under 67.5N+22.5N (Fertilize with 67.5kg nitrogen ha-1 and 22.5kg nitrogen ha-1 3 days after main season rice harvesting and during the heading stage of ratoon rice) treatment compared to the 90N+0N (conventional fertilization, apply 90kg nitrogen ha-1 fertilizer 3 days after harvesting at once) treatment. It was also found that reducing nitrogen application during the tillering stage reduced CH4 emissions, fertilization during the heading stage of the ratoon rice did not increase CH4 emissions, Since fertilization during the heading stage of ratoon rice did not lead to an increase in the partitioning of photoassimilates (photosynthetic product assimilates) to the rhizosphere soil, significant differences in sugar and acetic acid levels were not observed in the rhizosphere soil. As a result, no change was found in the expression of the methanogenic mcrA gene in the microbial community. The study also demonstrated that the 67.5N+22.5N treatment was able to promote the absorption of nitrogen nutrients, reduction in N2O emissions by 16.61%, subsequently increasing resource use efficiency, final yield and net ecosystem economic benefit by 5.96%, 7.19% and 5.57%, respectively, thereby decreasing carbon and nitrogen footprints by 6.64% and 3.50% compared with the 90N+0N treatment in the ratoon rice. These results suggest that a reasonable ratoon rice cultivation scheme is a promising farming system that can simultaneously improve resource use efficiency and economic profits, reduce greenhouse gas emissions and environmental footprint, while still maintaining the high productivity in ratoon rice.

Applying Boron by Fertigation or as a Foliar Fertilizer Is More Effective than Soil Applications in Northern Highbush Blueberry

Boron (B) is often deficient in many fruit crops, including blueberry (Vaccinium sp.). The objective of the present study was to evaluate different methods for applying B fertilizers to two commercial cultivars of northern highbush blueberry (V. corymbosum Earliblue and Aurora) in western Oregon, USA. Treatments included soil application of sodium tetraborate in early April (before bloom), foliar application of boric acid in late April (during bloom or petal fall), weekly fertigation with boric acid from April through July, and a control with no B. The plants were irrigated by drip, and the fertilizers were applied for two consecutive seasons at a total rate of 1.5 kg·ha−1 B per year. Each method of fertilizer application increased the concentration of B in the soil solution relative to the control, but fertigation was the only treatment that increased extractable soil B to the recommended level of 0.5 to 1.0 mg·kg−1 B. In terms of plant nutrition, foliar application of B was the most effective method for increasing the concentration of B in the leaves, roots, and fruit, followed by fertigation. Soil application of B, on the other hand, was relatively ineffective and, after 2 years, only increased the concentration of B in the leaves of ‘Earliblue’. Although leaf B levels were initially deficient at the site (<30 ppm B), none of the B application methods had any effect on yield, berry weight, fruit firmness, or titratable acidity of the fruit in either cultivar. However, foliar applied B resulted in higher concentrations of soluble solids in the fruit than no B or soil applied B in ‘Earliblue’, whereas B fertigation resulted in higher concentrations of soluble solids than soil applied B in ‘Aurora’. On the basis of these results, applying B by fertigation or as a foliar spray is recommended over the use of soil applications of B fertilizer in northern highbush blueberry.

Effects of Nitrogen Fertilizer Doses and Application Methods on the Yield of Syr Suluy Rice in the Kyzylorda Region

Effects of Nitrogen Fertilizer Doses and Application Methods on the Yield of Syr Suluy Rice in the Kyzylorda Region

Investigating the Impact of the Central Agricultural Research Institute's (CARI) Agricultural Extension Services on the Productivity and Livelihoods of Farmers in Bong County, Liberia, from 2013 to 2017

In Liberia, a country where agriculture plays a pivotal role in socio-economic development and food security, the effectiveness of agricultural extension services remains crucial yet underexplored, especially in the context of transitioning from subsistence to commercial agriculture. This study focuses on assessing the Central Agricultural Research Institute's (CARI) agricultural extension services' impact on the agricultural productivity and livelihoods of farmers in Suakoko, Jorquelleh, and Yealliquelleh districts of Bong County, from 2013 to 2017. The objectives were to evaluate the accessibility and adoption of agricultural innovations disseminated by CARI and analyze the effectiveness of its extension delivery methods. Employing a mixed-methods approach, the research yielded significant findings: 54.1% of respondents were male, indicating a gender disparity in agricultural engagement. The adoption of new technologies and practices was varied, with 43.3% of farmers reporting access to new fertilizer application methods as the most prominent innovation provided by CARI. Despite the extension efforts, 68.8% of farmers did not receive visits from CARI agents, and a considerable 50% reported no access to new innovations or technologies. The study also highlighted a distinct preference for learning through demonstrations (73.7%) and meetings (25%), underscoring the demand for practical and interactive extension services.

Integrating plant morphological traits with remote-sensed multispectral imageries for accurate corn grain yield prediction.

Sustainable crop production requires adequate and efficient management practices to reduce the negative environmental impacts of excessive nitrogen (N) fertilization. Remote sensing has gained traction as a low-cost and time-efficient tool for monitoring and managing cropping systems. In this study, vegetation indices (VIs) obtained from an unmanned aerial vehicle (UAV) were used to detect corn (Zea mays L.) response to varying N rates (ranging from 0 to 208 kg N ha-1) and fertilizer application methods (liquid urea ammonium nitrate (UAN), urea side-dressing and slow-release fertilizer). Four VIs were evaluated at three different growth stages of corn (V6, R3, and physiological maturity) along with morphological traits including plant height and leaf chlorophyll content (SPAD) to determine their predictive capability for corn yield. Our results show no differences in grain yield (average 13.2 Mg ha-1) between furrow-applied slow-release fertilizer at ≥156 kg N ha-1 and 208 kg N ha-1 side-dressed urea. Early season remote-sensed VIs and morphological data collected at V6 were least effective for grain yield prediction. Moreover, multivariate grain yield prediction was more accurate than univariate. Late-season measurements at the R3 and mature growth stages using a combination of normalized difference vegetation index (NDVI) and green normalized difference vegetation index (GNDVI) in a multilinear regression model showed effective prediction for corn yield. Additionally, a combination of NDVI and normalized difference red edge index (NDRE) in a multi-exponential regression model also demonstrated good prediction capabilities.

Influenced Quality of Wheat (Triticum aestivum L.) and Abate the Environmental Pollution by Soil Applied with Foliar Fertilization of NPK Fertilizer in Saline Soil

A field experiment to assess different levels and methods of NPK fertilizer application on wheat crop was conducted on loamy sand soil at Instructional farm, College of Agriculture, Bikaner during rabi season of 2019-2020. The trial was laid out in split plot design and replicated three times. A total of 20 treatment combinations comprises A. Main plot : four RDF levels prior to sowing viz., F0 = Absolute control, F1= 50% RDF, F2= 75 % RDF and F2= 100 % RDF and B. Sub plot : five foliar fertilization levels of soluble NPK (1%) namely S0= no fertilization (control), S1= two spray (At 45and 60 DAS), S2= three foliar spray (At 45, 60 and 75 DAS), S3= four foliar spray (At 45, 60, 75 and 90 DAS). Basal application of 100% RDF with three foliar spray of soluble NPK (19:19:19) at 45, 60 and 75 DAS gave significantly higher average grain and straw yield and N, P, K content and uptake in grain and straw than other treatments, including control.

Agro-biofortification of maize with selenium for higher grain selenium contents and productivity

Selenium (Se) is a vital mineral nutrient for animal and human health, which can be supplemented through seed biofortification techniques. Present study determined the potential of improving Se content in maize grain via several Se fertilizer application methods to enhance the nutritional status of native populations. Field trials were conducted for two growing years with different Se application methods and application rates to evaluate grain Se content in maize, Se recovery, grain macro- and micro-nutrients and grain yield under rain-fed conditions. Results demonstrated that foliar and soil Se applications showed no significant impacts on maize biomass and grain yield as well as maize grain N, P, K, Ca, Mg, Fe, Mn, Cu and Zn contents. However, both foliar and soil Se application significantly enhanced the maize grain Se content. Foliar application of Se exhibited greater Se recoveries of 54 % and 108 % in the grain over soil Se fertilizer for the first and second growing seasons while the later was recorded with only 1.71 % and 0.97 % increase as compared to control. In conclusion, foliar Se application at silking stage at the rate of 8.85 µM enhanced the grain Se content in maize at minimum costs as compared to soil Se application.

Effect of fertilizer application methods and drip irrigation on the productivity of columnar apple plants on sod-podzolic soil

The field agrochemical experiment conducted in 2021–2023 was designed to study the influence of drip irrigation and two methods of mineral fertilizer application on the components of productivity of columnar apple plants when grown on cultivated loamy textured sod-podzolic soil in the conditions of Moscow Oblast. Drip irrigation, solid fertilizer application, and fertigation were found to have different eff ects on plant productivity indicators. Th e eff ects largely depend on the cultivar and weather conditions. Drip irrigation in conjunction with solid fertilizers increased plant productivity to the greatest extent. Thus, the ‘Ostankino’ cultivar yielded by up to 2.16 kg/tree more, i. e. the productivity rose by 27.1 % compared to the controls. In the ‘President’ cultivar, yield per tree increased by up to 2.18 kg/tree (by 35.4 % compared to the controls). The irrigated and fertilized variants of the experiment were distinguished by higher vegetation productivity values for the ‘President’ cultivar plants. For this cultivar, the highest total growth rate was in the fertigation-drip irrigation variant with an increase of up to 459.2 cm/tree in 2022. Th e average growth over two years was 16.5% higher than in the control group. In the ‘Ostankino’ cultivar, the total length value of shoot growth during irrigation and solid fertilizer application decreased compared to the control group by up to 245.2 cm/tree. On average, over two years it decreased by 15.7 % compared to the controls. In the fertigation-drip irrigation variant, there was a decrease in the ammonia nitrogen content in the soil compared to the other variants. As a result, the total mineral nitrogen content in the soil layer to a depth of 60 cm was minimal. Th e highest value of ammonium content and total nitrogen in the rhizosphere were observed in the variant with drip irrigation and solid fertilizer application.

Agronomic efficiency and productivity of transplanted kharif rice (Oryza sativa) as influenced by fertilizer briquettes

An experiment was conducted during rainy (kharif) season of 2022 at the research farm of Assam Agricultural University, Jorhat, Assam to evaluate the effect of fertilizer briquettes on growth and productivity of transplanted rice. The field experiment was laid out in RBD comprising of 13 treatments, replicated thrice. Growth of rice, panicles/m2 and yield were subjected to significant variation under different fertilizer management practices. Higher plant height, tillers/ m2, panicles/m2, yield and agronomic efficiency were recorded under FDP, 120% RDN + 100% P and K + ZnSO4 @10 kg/ha + biofertilizer (T12). This might be owing to reduced losses of nutrients and efficient uptake by plants compared to broadcasted method of fertilizer application where most of the applied fertilizers were susceptible to various losses availing lesser amount of nutrients for crop uptake.

Potassium Rates and Application Methods: Effects on Soil K Availability and Crop Response in Planosols and Ferralsols

ABSTRACT Potassium (K) fertilization guidelines often oversimplify, overlooking factors like soil mineralogy and K application methods. This study aimed to evaluate the influence of K fertilizer rates and application methods on crop yields and the forms of K in soils with different textural and mineralogical features. In 2020, two field trials were conducted to evaluate the impact of varying K rates, added through band or broadcast methods, in Planosol and in Ferralsol. Soybean yield was evaluated in both trials, while flooded rice yield was evaluated only in the Planosol. Soil samples collected from the 0–10 and 10–20 cm layers and soil K content was determined using Mehlich-1, nitric acid (HNO3), and sodium tetraphenylborate. In the Ferralsol, K desorption by HNO3 in the 10–20 cm soil layer was 1.4 times higher the in band application (171 mg kg−1) compared to broadcast method (92 mg kg−1). The Mehlich-1 extractor proved insensitive to detecting K rates in the Planosol (91 and 43 mg kg−1 in the 0–10 and 10–20 cm layers, respectively), while it exhibited responsiveness in the Ferralsol, demonstrating positive increases with K rates. Using a proper chemical extractor is crucial for accurate detection and recovery of applied K in the soil. Grain yields were 4.50 Mg ha−1 for soybeans in the Ferralsol and 9.72 and 5.55 Mg ha−1 for rice and soybeans, respectively, in the Planosol. The findings reveal that applied K distributes into preexisting pools, persisting in the applied location, thereby reducing the anthropogenic K gradient with band reapplication.

Does the Deep Placement of Fertilizers Increase Potato Yields, Fertilization Efficiency and Reduce N2O Emissions from the Soil?

Despite the notable decline in potato cultivation areas across Poland and Europe, potatoes remain a crucial crop with diverse applications. Achieving the ambitious emission targets set by the EU for agricultural production may be easier with the practice of deep placement of slow-release fertilizers, which may increase yields and reduce greenhouse gas emissions. To examine the effect of deep placement of slow-release fertilizers on potato tuber yields, plant nutrient uptake, nutrient use efficiency, and soil N2O-N emissions, a two-year field experiment was conducted on loamy sand soil classified as Alblic Podzol (Ochric) soil, under temperate climate conditions prevailing in central Poland. The experiment involved a three-field rotation (potatoes, wheat, and peas), with potatoes being cultivated after peas in both years of the study. The experiment compared the effects of applying slow-release fertilizer at soil depths of 10 and 20 cm (DP10 and DP20) to fertilization with single-nutrient fertilizers applied to the soil surface (TD). The experiment utilized increasing doses of nitrogen and phosphorus, denoted as D0 (control), D1, D2, and D3, along with a standard dose of potassium across all tested fertilizer application methods. The results of this study confirmed that deep placement of slow-release fertilizers had limited effects on potato tuber yields. Deep placement of slow-release fertilizer increased plant nitrogen uptake by 2.8–13.5% compared to topdressing. Consequently, there was an improvement in nitrogen use efficiency from 29.8–75.0% on sites with fertilizer topdressing to 38.7–89.8% on sites with slow-release fertilizer deep placement. Phosphorus uptake by plants on sites with slow-release fertilizer deep placement was approximately 9.3–13.0% higher than on sites with fertilizer topdressing. This led to an enhancement in phosphorus use efficiency from about 15.1–19.5% on fertilizer topdressing sites to 19.4–25.4% on slow-release fertilizer deep placement sites. The impact of fertilizer deep placement was found to be less pronounced compared to the effects observed with increased nitrogen and phosphorus doses. The most important factors affecting tuber yield and nutrient use in potatoes were rainfall levels during the growing season. Deep fertilization did contribute to reduce soil N2O emissions by about 14%. However, further research involving different fertilization methods is needed to comprehensively assess the effectiveness of this practice in reducing greenhouse gas emissions.

Effect of nitrogen reduction by chemical fertilization with green manure (Vicia sativa L.) on soil microbial community, nitrogen metabolism and and yield of Uncaria rhynchophylla by metagenomics.

Uncaria rhynchophylla is an important herbal medicine, and the predominant issues affecting its cultivation include a single method of fertilizer application and inappropriate chemical fertilizer application. To reduce the use of inorganic nitrogen fertilization and increase the yield of Uncaria rhynchophylla, field experiments in 2020-2021 were conducted. The experimental treatments included the following categories: S1, no fertilization; S2, application of chemical NPK fertilizer; and S3-S6, application of chemical fertilizers and green manures, featuring nitrogen fertilizers reductions of 0%, 15%, 30%, and 45%, respectively. The results showed that a moderate application of nitrogen fertilizer when combined with green manure, can help alleviate soil acidification and increase urease activity. Specifically, the treatment with green manure provided in a 14.71-66.67% increase in urease activity compared to S2. Metagenomics sequencing results showed a decrease in diversity in S3, S4, S5, and S6 compared to S2, but the application of chemical fertilizer with green manure promoted an increase in the relative abundance of Acidobacteria and Chloroflexi. In addition, the nitrification pathway displayed a progressive augmentation in tandem with the reduction in nitrogen fertilizer and application of green manure, reaching its zenith at S5. Conversely, other nitrogen metabolism pathways showed a decline in correlation with diminishing nitrogen fertilizer dosages. The rest of the treatments showed an increase in yield in comparison to S1, S5 showing significant differences (p < 0.05). In summary, although S2 demonstrate the ability to enhance soil microbial diversity, it is important to consider the long-term ecological impacts, and S5 may be a better choice.

Understanding yield-limiting factors for sorghum in semi-arid sub-Saharan Africa: beyond soil nutrient deficiency

ABSTRACT Even in semi-arid regions of sub-Saharan Africa, low crop yields are often attributed to a lack of soil nutrients and limited use of chemical fertilizers. However, in areas where soils with low effective soil depth are common, water availability may be a more significant factor that limits crop production than a lack of soil nutrients. In Sudan Savanna, the effective soil depths of three dominant soils, namely Pisoplinthic Petric Plinthosols (PT-pt.px), Petric Plinthosols (PT-pt), and Ferric Lixisols (LX-fr), are < 30, 30–50, and ~ 100 cm, respectively. Consequently, a lack of soil water is anticipated for both Plinthosols types. This study investigated the limiting factor in sorghum cultivation for each dominant soil in Sudan Savanna by creating plots with and without irrigation and fertilization. The results indicated that neither rainfall nor irrigation significantly affected sorghum yield under unfertilized conditions in all soil types, suggesting that even in very shallow PT-pt.px, a lack of soil water was not the limiting factor under unfertilized conditions. However, under fertilized conditions, reduced rainfall significantly decreased sorghum yield in PT-pt and PT-pt.px. In conclusion, in addition to the lack of soil nutrients being the limiting factor in sorghum cultivation under unfertilized conditions, regardless of soil type, lack of soil water becomes a limiting factor in soils with an effective soil depth of < 50 cm (e.g., Plinthosols) under fertilized conditions. These findings underscore the importance of knowing the effective soil depth when developing efficient fertilizer application methods to achieve food security in semi-arid regions of sub-Saharan Africa.

Growth and Yield Response of Pea (Pisum sativum L.) Crop to Classical and Regulated Deficit Irrigation along with Nitrogen Fertilization under Drip Irrigation

Background: The conventional methods of applying water and nutrient results lot of wastage and negatively affect the soil, environment and crop response of pea. Methods: The experiments were conducted at Lovely Professional University, Punjab during two years. The five drip irrigated treatments having full irrigation, classical deficit irrigation and regulated deficit irrigation in combination same level of nitrogen fetigation @90% recommended dose of nitrogen (RDN) were taken in 4 replications. One control plot (having flood irrigation with soil application of nitrogen @100% RDN through broadcasting) was taken for comparison. Result: Plant growth, yield contributing parameters, pod yield and water use efficiency (WUE) were significantly affected by drip irrigation in combination with 90% RDN through fetigation over conventional method of irrigation and fertilizer application. Among all the drip irrigated treatments, the increment in crop yield, WUE and irrigation water saving varied from 27.6 to 65.7%, 63.6 to 99.7% and 26.1 to 44.6%, respectively over control plot. In case of same nitrogen fertigation level, the yield and water use efficiency of drip irrigated pea crop can be improved by adoption of moderate water deficit level (which is 15% less than full IWR) under regulated deficit irrigation approach over full irrigation approach. The findings of the work can be utilized by farm managers for irrigation planning and nitrogen management for pea crop and by policy makers to conserve available fresh water resources in water scares regions.

An overview of foliar application of macro and micronutrients on the yield of maize in Ghana

Maize is a major staple crop in Ghana which plays a significant role in consumer diets. For some time now, the farming methods used by the farmers have been negatively affected by components such as climate, soil nutrient depletion, and constant monocropping resulting in the adoption of inorganic fertilizers. Conventional fertilizers supplied through soils are subjected to slow release of nutrients, leaching, fixation, surface runoff, erosion, and volatilization, which hinders optimal plant growth and yield. Foliar application of fertilizer offers an alternative method of fertilizer application that supplies nutrients directly to the stomata and cuticle of the leaves of maize thereby enabling rapid absorption and enhancing crop vigor. The The main objective of this paper is to review research papers which explores the potential of foliar application of vital nutrients – phosphorus (P), sulphur (S), zinc (Zn), and iron (Fe) – to improve the yield of maize crop. According to the literature gathered, foliar fertilization in combination with soil applied fertilizers emerges as a promising strategy, particularly in addressing nutrient deficiencies and stress scenarios. The efficient uptake of nutrients through leaves, as opposed to traditional soil-based approaches, holds promise for augmenting yield and enhancing protein content in maize crops. Notably, prior research highlights the efficacy of foliar-applied P, S, Zn, and Fe in significantly boosting grain yield. By understanding the complex mechanisms of nutrient absorption and the advantages of foliar application, the agricultural sector can explore innovative avenues to surmount soil-related challenges and achieve sustainable crop development.

Studies on Variable Level of N Fertigation on Growth, Yield and Quality of Pomegranate (Punica granatum L.) cv. Kandhari Kabuli

A field trial was conducted to study the effect of variable level of N along with recommended dose of P and K through fertigation on growth, yield and quality parameters of pomegranate on eleven year old pomegranate trees cv. Kandhari Kabuli under mid hill conditions of HP. Treatment consisted of five levels of Nitrogen fertilizer 0%, 25%, 50%, 75% and 100% along with 100% recommended dose of P and K through fertigation and conventional method of fertilizer application (with recommended dose of NPK) kept as control. Fertigation treatments had a promising effect over conventional method and treatment of 75% RD of N and RD of P and K through fertigation proved significant over other fertigation treatments and conventional method. Highest tree growth parameters, fruit set, fruit retention, average fruit weight and yield was recorded highest for 75% RD of N and RD of P and K through fertigation. Physico-chemical fruit characteristics viz. highest TSS, lower acidity, highest TSS acid ratio, highest sugars and ascorbic acid content (Vit. C) was also recorded for 75% RD of N and RD of P and K.

Nutritional qualities and heavy metals accumulation in grains: A study on lowland irrigated rice with different fertilizer inputs and growing seasons

Integrated and organic nutrient management has become a focal point of current production systems seeking better perspectives on environmental friendliness. The food quality in such a scenario requires special consideration for ensuring safety during consumption. This study was conducted to understand the grain quality of the Bg300 rice variety grown under three fertilizer input systems: conventional (100% N supply with the recommended by the Department of Agriculture (DOA), integrated (50% of N provided with DOA recommended fertilizer + 25% of N supply with organic fertilizer), and 50% of N provided with organic fertilizer in dry tropical irrigated lowland systems in Sri Lanka. The grains were analyzed for proximate composition (moisture content, ash, protein, fat, fiber, and carbohydrate), micronutrients (Fe, Cu, Zn, and Mn), and heavy metals (As, Cd, and Pb). The experiment was arranged as a randomized complete block design and conducted during five seasons, from the 2018-19 wet seasons to the 2020-21 wet seasons. The highest moisture content and carbohydrate content were reported with the organic system. The ash content and protein content significantly (p&lt;0.05) changed with the respective levels of fertilizer in the three input systems. Cadmium and arsenic micronutrients were detected below the permissible level (0.4 and 0.2 ppm), while lead was detected above the permissible level (0.2 ppm). Integrated and organic systems can be used instead of the conventional fertilizer application method without compromising the quality of the rice grain.

Increasing iron use efficiency by controlling emitter clogging in drip irrigation systems

Iron is one of the essential elements for crop growth. Traditional iron fertilizer application method by injecting iron into soil results in low utilization efficiency of iron fertilizer and a considerable amount of iron residue in the soil. Applying iron fertilizer by drip irrigation system could effectively improve the utilization efficiency of iron fertilizer. However, emitter clogging seriously restrict this technology. Here, the effects of different types of iron fertilizers [Ferrous sulfate (FeSO4); Ferric citrate (FC-Fe); Sodium ferric ethylenediamine tetraacetate (EDTA-Fe); And no iron fertilizer (CK)] on emitters clogging were assessed. The components of emitter clogging substances were detected through X-ray Diffraction and Fourier Transform Infrared Spectrometer. The results showed that different types of iron fertilizers significantly affected emitter clogging. EDTA-Fe application significantly mitigated emitter clogging, reduced the total amount of clogging substances by 49.6% on average, and increased the emitter flow rate by 21.0%. This is due to EDTA-Fe chelated scaling cations (e.g., Ca2+) in water through its functional groups, thereby reducing the contents of calcite, monohydrate calcite and dolomite. However, FeSO4 and FC-Fe application aggravated emitter clogging, and increased the total clogging substances by 52.3% and 105.8%, respectively. Surprisingly, iron precipitation was not detected in the clogging substances. FeSO4 and FC-Fe aggravated clogging mainly by increasing the formation of particulate fouling (e.g., muscovite) and chemical precipitation (e.g., calcite). This study suggested choosing EDTA-Fe in drip irrigation systems to reduce emitter clogging. The research results are of significance for improving the utilization efficiency of iron fertilizer and promoting the application of iron fertilizer drip irrigation technology.

Comparative Study of Three Varieties and Application Methods of Muriate of Potash Fertilizer on Growth and Yield of Onion

A comparative study on the growth and yield of onions was conducted at Sher-e-Bangla Agricultural University's Horticulture farm from October 2021 to March 2022 during the Rabi season. The experiment employed a Randomized Complete Block Design (RCBD) with two factors: onion varieties (V1=BARI Piaz-1, V2=BARI Piaz-4, V3=BARI Piaz-6) and muriate of potash fertilizer application methods (M1=Basal application (Full dose), M2 = ½ basal application + ½ 25 DAT (Days after transplanting), M3 = ⅓ basal application + ⅓ 25 DAT + ⅓ 50 DAT). The results showed significant impacts of both onion varieties and potash fertilizer application methods on growth and yield. Among the onion varieties, BARI Piaz-4 (V2) exhibited the highest bulb weight per plant (66.52g), yield per plot (1.60 kg), and yield per hectare (17.74 t). Regarding potash fertilizer application, the ⅓ basal + ⅓ 25 DAT + ⅓ 50 DAT method (M3) resulted in the highest bulb weight per plant (59.97 g), bulb yield per plot (1.44 kg), and onion yield per hectare (15.99 t). The combination treatment of BARI Piaz-4 and the ⅓ basal + ⅓ 25 DAT + ⅓ 50 DAT potash fertilizer application (V2M3) produced the best results, with the highest bulb weight per plant (73.50 g), yield per plot (1.76 kg), and bulb yield per hectare (19.59 t). In conclusion, cultivating BARI Piaz-4 with a three-times split application of muriate of potash fertilizer (V2M3) can significantly enhance onion growth and yield, facilitating improved quality production.