Fertilizer Application Research Articles

Performance Assessment of the Small and Medium-Scale Coconut Weeder Cum Fertilizer Applicator Developed by Rajarata University of Sri Lanka

The enhancement of coconut yield significantly hinges on proper weeding and chemical fertilizer application. In Sri Lanka, several mechanical methods have been introduced for weeding and fertilizer application of coconut, but the traditional manual approach persists most popular, despite being time, labor cost intensive. Moreover, the introduced technologies were suited for large-scale coconut cultivation and could not cope with medium or small-scale. Furthermore, most of them are designed for a single application; weeding or fertilizing. Thus, the Faculty of Agriculture, Rajarata University of Sri Lanka (RUSL), developed a coconut weeder cum fertilizer applicator for medium and small-scale coconut cultivations. However, it has not been properly evaluated and recommended for farmers. Consequently, this study sought to evaluate the performance of the above machine by conducting a comparative performance evaluation with the conventional method. A healthy, well-maintained, proper-spacing coconut plantation was selected from the faculty research unit, and each weeding and fertilizer application method was replicated ten times. In terms of performance parameters: effective field capacity, field efficiency, and weeding efficiency in mechanical and manual methods were 0.172 ha h-1, 61.86%, 66.62%, and 0.048 ha h-1, 55.34%, 60.35%, respectively. Statistical analysis indicates the mechanical method had higher field capacity and efficiency than the manual method, while weeding efficiency was not significantly different (p≤0.05). In addition, the machine had a fertilizer spreading uniformity of around 99.98% when operating at an optimum speed of 1.45 km h-1. Fertilizer application rate and performance index as a weeder were 1.7 kg/min and 1145.86, respectively. Furthermore, the fuel consumption rate of the machine was 0.733 L h-1 and its break-even point was recorded as 2.85 ha yr-1. Consequently, the coconut weeder cum fertilizer applicator proves suitable for medium and small-scale coconut cultivations in Sri Lanka.

Effect of nutrient omission on grain and biomass yield of irrigated wheat (triticum aestivum) in Sekota district, Amhara region, Ethiopia

Abstract The Ethiopian government has recently imported and distributed multi-nutrient fertilizers for farmers' use without sufficient research finding. Selecting the appropriate fertilizers based on the actual limiting plant nutrients is crucial for providing timely policy direction to import only fertilizers that could limit crop yield. A field study was carried out to identify the yield-limiting plant nutrients for wheat under irrigation at two farmer’s fields in the Woleh irrigation scheme of the Amhara region of Ethiopia in the 2022 irrigation season. A total of nine treatments, including control, NPSKZnB (all), NPSKZn (all-B), NPSKB (all-Zn), NPKZnB (all-S), NPSZnB (all-K), NKSZnB (all-P), PKSZnB (all-N), and RNP (all-KSZnB), were arranged in a randomized complete block design (RCRD) with three replications. The Kekeba wheat variety was used as a test crop. The collected grain and biomass yield data were analized by using SAS software following the procedure. The analysis of result showed that the application of fertilizer had a significant effect on wheat grain yield. The highest grain yield (4443.5 kg ha-1) was obtained from NPKZnB (All-S). While the lowest grain yield was obtained from the control and nitrogen omitted treatment. There was no significant difference between and among the treatments except Control, All-N, and All-P. The grain yield was reduced by 3181.6 kg ha-1 when N was omitted and 1817.8 kg ha-1 when P was omitted over All-S (NPKZnB). This showed that nitrogen and phosphorous are yield-limiting plant nutrients for wheat under irrigation in the study area. Therefore, the government should give emphasis to nitrogen- and phosphorous-containing fertilizers to increase wheat yield.

Use of small-sized units when spreading fertilizers on mountain slopes

BACKGROUND: The results of RD on a laboratory sample of the unit for spreading mineral fertilizers on mountain slopes, which can increase labor productivity and yield rate of mountain forage lands by 15–20%, are presented. AIM: Development of a small–sized laboratory sample of the unit for surface spreading of mineral fertilizers, ensuring accelerated restoration of productive and qualitative functions of natural grass stands of fallow forage lands. METHODS: The technical expertise and testing of the unit and the technology were carried out in the mountainous zone of the Republic of North Ossetia — Alania (Dargava basin, the station of North Caucasian Research Institute of Highland and Piedmont Agriculture) at an altitude of 1540 meters above sea level. The indicators of the test conditions and functional performance of the unit have been determined according to the OST 10.5.1-2000 industry standard. Surface fertilization was carried out according to the OST 10.7.1.-2000. “Testing of agricultural machinery. Machines for applying mineral fertilizers, lime materials and gypsum” industry standard. The study subject was the technology of spreading granular fertilizers, the design of the unit and working bodies: pendulum spreading devices, spreading rates and method of spreading fertilizers. RESULTS: A laboratory sample of the small-sized unit based on the KChG-2.4 cultivator of North Caucasian Research Institute of Highland and Piedmont Agriculture design for surface application of mineral fertilizers has been developed and manufactured. The block module is a hinged frame structure with a tow-lifting device, pendulum spreading tubes and rolling rollers installed on it. The considered motion of the mining unit is across the slope from top to bottom in a shuttle manner with rolling of the sown granules by rolling rollers. The tests were carried out on a rarefied section of the northern slope with a steepness of 13–16° in the area “Sugsadtanrag”. CONCLUSION: The practical application of the small-sized unit for surface spreading of mineral fertilizers with their subsequent rolling in areas in mountainous and foothill zones will ensure a reduction in the degradation processes of slope areas by accelerating the restoration of the quality and quantity of perennial grasses of fallow forage lands.

Automated control complex of agrotechnology in precision farming

The paper presents a project of an automated complex for managing agricultural technology. The complex consists of two inseparable components, a control unit and an executive robotic technological machine. The control unit implements the modern theory of controlling a complex dynamic system, which is an agricultural field with sowing crops. The main distinctive feature of the proposed management theory is that the object of management is an agrocenoses, which includes sowing crops and weeds. This feature is transferred to the executive technological machine, through which the simultaneous application of mineral fertilizers and herbicide treatment is carried out. At the same time, the formation of optimal technological operations is carried out on the basis of Earth remote sensing data. Based on these data, the parameters of the state of the agrocenoses are assessed, and the resulting estimates are system-wide feedback through which agricultural technology is managed. The presented complex is of interest to specialists developing individual components of modern precision farming systems.

Are Biobased Microfibers Less Harmful than Conventional Plastic Microfibers: Evidence from Earthworms.

Biobased plastics are sometimes promoted as "environmentally friendly" compared to their conventional petrochemical-based counterparts, but their ecotoxicity is only partially understood. Biobased fibers are widely used in clothing and wet wipes and can accumulate in soils through the application of biosolid fertilizers. This study examined the lethal thresholds and sublethal toxicity of chemically characterized, additive-free, biobased (viscose and lyocell) compared to petrochemical-based (polyester) fibers on the key ecosystem engineer, Esenia fetida. Viscose and lyocell had LC20 values of 14.00 and 22.66 mg·L-1, respectively, and no observed effect concentrations (NOEC) of 0-2.8 mg·L-1 (72 h, OECD TG207 filter paper method), while for polyester these were LC20 15.6-31.3 mg·L-1 and NOEC 0-15.6 mg·L-1. Following 28 days of exposure to soils (OECD TG222) contaminated with environmentally relevant concentrations (100 mg kg-1), viscose significantly reduced the mass of progeny compared to polyester. Earthworms exposed to lyocell had a marginal growth reduction (-18%; compared to -11% to -13% in other treatments) linked to increased bioturbation activity. The biobased fibers examined here have greater acute toxicity at high concentrations and broadly similar sublethal effects on E. fetida compared to polyester. Our study highlights the importance of detailed testing before advocating specific materials as plastic alternatives/substitutes to conventional plastics.

Assessment of genotoxicity biomarkers in neotropical fish species from streams of the Ivinhema River basin located in sugarcane cultivation areas

The Ivinhema River basin has experienced the greatest expansion of sugarcane cultivation in the state of Mato Grosso do Sul, Brazil. Theassessment of water quality through physical and chemical parameters and ecotoxicological studies, employing both bioindicators collected in situ and laboratory tests, provides more robust results for this region. In this context, the objective of this study was to analyze the composition and structure of the landscape around the sampling sites located in three streams (Vitória, Rosário, and Piravevê) belonging to the Ivinhema River basin to evaluate the impacts of sugarcane cultivation expansion on water quality and genotoxicity biomarkers in situ and ex situ using native fish species. Inthe sampling sites in the Rosário and Vitória streams, sugarcane is the main land use, while in the Piravevê stream, pasture areas represent the main land use. The acidic pH observed in the Vitória and Rosário streams seems to be related to the application of fertilizers and the fertigation in the sugarcane crop. Two species of detritivorous and five of omnivorous fishes were collected. A higher frequency of genotoxic damage was identified in detritivorous fish species. In the genotoxicity tests with Astyanax lacustris, the most frequent nuclear alteration induced by the water samples from all sampling sites was nuclear invagination. Our results indicated that the expansion of the sugarcane ridge in the Ivinhema River basin may cause negative impacts on the aquatic environment and native biota. These results contribute to the generation of data and information that can be used for public hearing requests that aim to discuss and review many aspects of legislation regarding agricultural activities around streams, as well as the need for restoration and management programs in these areas in order to conserve biodiversity.

Biomass yield potential, feedstock quality, and nutrient removal of perennial buffer strips under continuous zero fertilizer application

Abstract. Perennial-based buffer strips have been promoted as having the potential for improving ecosystem services from riparian areas while producing biomass as livestock feed or as a bioenergy feedstock. Both biomass production and nutrient removal of buffer strips are substantially influenced by the vegetation types for the multipurpose perennial buffers. In this 2016–2019 study in western Illinois, two perennial cropping systems, including forage crops composed of cool-season grass mixtures (forage system) and bioenergy crops made up of warm-season grass mixtures (bioenergy system), were used to establish buffer strips for assessing biomass production, feedstock quality, nutrient removal, and buffer longevity. Treatments for this study reflecting agronomic practices included (1) two harvests occurring in summer (at anthesis) and fall (after complete senescence) and (2) one harvest in fall for the forage system (two-cut vs. one-cut forage) and (3) one fall harvest for the bioenergy system (one-cut bioenergy). Successively harvesting without any fertilizer input resulted in a yield decline in forage biomass over 3 years by approximately 30 % (6.3 to 4.4 Mg DM ha−1 (dry matter) with a rate of 1.0 Mg ha−1 yr−1) in the two-cut forage and by 35 % (4.9 to 3.2 Mg DM ha−1 with a rate of 0.9 Mg ha−1 yr−1) in the one-cut forage systems. The feed quality also decreased over the years by showing declined rates of 12.9 (crucial protein), 0.9 (calcium), 0.7 (copper), and 1.3 g kg−1 DM yr−1 (zinc). Empirical models predicted enteric CH4 emissions from cattle ranged from 225.7 to 242.6 g per cow per day based on the feed nutritive values. In contrast, bioenergy biomass yield increased by 27 % from 4.9 to 6.7 Mg DM ha−1 with a consistent quality (cellulose of ∼ 397.9 g kg−1; hemicellulose of ∼ 299.4 g kg−1), corresponding to the increased total theoretical ethanol yield from 1.8 × 103 to 2.4 × 103 L ha−1 (∼ 33 % increase). Annual nutrient removals of N, P, K, Ca, and Mg were significantly higher in the forage systems (e.g., two-cut: 52.6–106.9 kg N ha−1; one-cut: 44.5–84.1 kg N ha−1) than those in the bioenergy system (e.g., 25.9–34.4 kg N ha−1); however, the removal rate declined rapidly over 3 years (e.g., ∼ 49 % reduction) as the annual biomass yield declined in the forage systems. This on-farm field study demonstrated the potential of the perennial crop used as buffer strip options for biomass production and buffer sustainability at the edge of the field.

Influence of Crop Residue Management on Maize Production Potential

Residue management at the farm level is essential for ensuring sustainable agricultural productivity. This field experiment, initiated in 2005, provides maize data from 2016 to 2018. This study evaluates the impact of crop residue management and fertilization on maize yield and yield components. Maize was grown in a crop rotation sequence consisting of field pea (Pisum sativum L.), durum wheat (Triticum durum Desf.), milk thistle (Silybum marianum (L.) Gaertn.), and maize (Zea mays L.). The measures studied include aboveground biomass removal (K), aboveground biomass incorporation (R), mineral fertilizer application (F), and their combination (RF). The results indicate that R and RF significantly improve yield parameters, such as kernel number per ear (KNE), thousand seed weight (TSW), stalk yield, and harvest index (HI), compared to control (K) or aboveground biomass incorporation alone (R). Grain yield varied across the years, with significant increases being observed for the fertilizer treatments, particularly when combined with straw or stalk incorporation. A nominal increase in grain yield of 1.43 t ha−1 for the F treatment and 1.86 t ha−1 for the RF treatment represents an increase of 39% to 51% compared to K and R. Strong positive correlations were observed between grain yield and several factors, including ears per hectare (0.61), KNE (0.94), TSW (0.61), and HI (0.85). These findings underscore the role of crop residue management and promoting sustainable crop production.

Selenium Utilization, Distribution and Its Theoretical Biofortification Enhancement in Rice Granary of China

Selenium, as an essential trace element, is intricately linked to the onset and progression of numerous diseases due to deficiencies in selenium intake. Selenium compounds exhibit tumor specificity and can efficiently inhibit the growth of tumor cells, making them potential candidates for cancer treatment. Nevertheless, given its status as one of the most widely consumed crops globally, increasing the selenium content in rice could prove advantageous in alleviating the prevailing issue of selenium intake deficiency, particularly in China. This review explored the regulatory role of selenium in rice growth, the regional distribution characteristics of soil selenium content in various rice-growing regions in China, and the impact of cultivation practices on selenium fortification in rice, aiming to suggest improved rice cultivation management strategies to enhance the capacity for rice selenium biofortification. The findings revealed that: (1) In Northeast and North China, characterized by alkaline soils and severe selenium deficiency, it is advisable to moderately decrease the duration of flooding, elevate the soil redox potential, and apply organic and nitrogen fertilizers in a judicious manner. (2) In Southwest China, which is characterized by acidic soils, alternating wet and dry irrigation should be employed, and the biofortification of selenium can be facilitated by applying lime and foliar spraying of selenium fertilizer. (3) In the south-central region of China, distinguished by acidic soils and double-cropped rice, it is recommended that intermittent or alternating wet and dry irrigation be employed, and the reasonable application of organic, silica, and selenium fertilizers is advocated. (4) In the northwest region, characterized by slightly alkaline soil and mild selenium deficiency, it is recommended to implement various water management practices, including shallow water during the seedling stage, deep water during the booting stage, and wet grain filling. Additionally, a rational application of nitrogen, phosphorus, and potassium fertilizers, along with foliar application of selenium fertilizer, should be employed. (5) Cultivating selenium-enriched, high-yielding, and high-quality rice varieties proves to be an effective strategy in addressing selenium deficiency. In conclusion, the unique characteristics of diverse rice-growing regions in China indicate that suitable water management, fertilization techniques, and varietal selection practices can effectively enhance the selenium content in rice, thereby maximizing the nutritional requirements for selenium.

Groundnut (Arachis hypogaea L.) Response to Nitrogen Fertilizer and Earthing Up Practices in the Tigray Region of Ethiopia

To increase groundnut yields, integrated agronomic techniques must be implemented. The current study focuses on using starter nitrogen fertilizer in conjunction with earthing up for groundnut cultivation. Three replications and a factorial combination were used in the complete randomized block design of the experiment. Two types of earthing up (no earthing up and earthing up) and four levels of nitrogen fertilizer (0, 15, 30, and 45 kg ha-1) were used in the treatment combinations. For each of the Hamedo 1 and Hamedo 2 experimental sites, two undisturbed and two disturbed composite soil samples were collected at a depth of 20 cm before sowing. The data analysis showed that neither the combination application of N fertilizer and earthing up nor the individual independent applications of N fertilizer and earthing up had a significant effect on groundnut flowering and maturity. Groundnut plant height, number of branches per plant, number of pods per plant, number of seeds per plant, seed weight per plant, and haulm yields were not significantly affected by earthing up alone or by the co-application of nitrogen fertilizer and earthing up. On the other hand, the exclusive use of nitrogen fertilizer significantly affected groundnut plant height, the number of branches per plant, the number of pods per plant, the number of seeds per plant, seed weight per plant, and haulm yield. Applying 45 kg ha-1 of nitrogen fertilizer to the Hamedo 1 and Hamedo 2 trial sites enhanced the haulm yield by 70.53% and 78.76%, respectively, compared to the unfertilized plots. Individual applications of nitrogen fertilizer, earthing up, or a combination of both had a significant effect on groundnut pod and kernel yields. In comparison to plots that received a combined application of 45 kg ha-1 of nitrogen fertilizer and earthing up, the Hamedo 1 and Hamedo 2 trial sites exhibited increases in pod yields of 57.73% and 55.97%, respectively, when earthing up was combined with 15 kg ha-1 of nitrogen fertilizer. In the same way, applying 15 kg ha-1 of nitrogen fertilizer to the earthing-up soil in the Hamedo 1 and Hamedo 2 experimental sites boosted the kernel yields by 70.05% and 75.43%, respectively, in comparison to soil earthing-up plots that received 45 kg ha-1 nitrogen. The findings of the economic and agronomic analyses showed that applying nitrogen fertilizer and earthing up together greatly increases groundnut yields and revenues. Therefore, to increase groundnut yields and receive more financial advantages, farmers can consider the combined application of 15 kg ha-1 of nitrogen fertilizer and earthing-up.

Newly Established Blueberry Plants: The Role of Inorganic Nitrogen Forms in Nitrogen and Calcium Absorption

Efficient nitrogen (N) management is crucial for maximizing the growth of young blueberry plants (Vaccinium corymbosum). This study evaluates the effects of the N fertilization form (ammonium, NH4+; nitrate, or NO3−) and application timing on the blueberries’ establishment, N and Ca absorption, and N distribution. The experiment was conducted in the southern hemisphere, in Chile, from October 2023 to January 2024. Six-month-old blueberry cv. Blue Ribbon plants were cultivated in pots. NH4+ and NO3− were used as full or split-dose applications using the 15N isotopic dilution technique. Plant leaves, stems, root growth, and biomass, as well as their N and Ca contents, were measured. Our results showed that 90 days after nitrogen application, blueberry plants obtained the lowest biomass in their leaves, stems, and roots when NO3− was applied in T1 or T1T2. The same pattern was observed for N and Ca contents, hence for N recovery. During the first period (T1) of application, heavy rain (100 mm) was registered over the course of a few days and caused leaching. Therefore, applying nitrate to young blueberry plants cultivated in areas with spring rainfall and low temperatures would not be recommended because the leaching losses and lower growth conditions, such as low temperatures and high precipitation, led to reduced transpiration, resulting in lower calcium and nitrogen contents. These confirm that N fertilization management (form and timing) can ensure a better establishment for young blueberry plants, optimizing their growth and sustainable production by minimizing nitrogen losses.

Effects of Combined Farm Yard Manure and Chemical Fertilizer Application on Plant Growth, Tuber Yield, and Quality of Potato (Solanum tuberosum L.)

Effects of Combined Farm Yard Manure and Chemical Fertilizer Application on Plant Growth, Tuber Yield, and Quality of Potato (Solanum tuberosum L.)

Biological Strategies to Minimize Fertilizer Use in Maize: Efficacy of Trichoderma harzianum and Bacillus subtilis

The present study investigated the efficacy of Trichoderma harzianum and Bacillus subtilis in minimizing phosphorus fertilizer use in maize cultivation. Maize plants, cultivar Bm207, were subjected to 10 treatments with varying levels of phosphorus fertilization (0, 50, and 100%) and inoculation with B. subtilis, T. harzianum, or both. The plant growth parameters, including the height, stem diameter, shoot, and root dry weight, root volume, phosphorus content in the soil and plant tissues, and chlorophyll and carotenoid content, were evaluated. Treatments without mineral fertilization showed the lowest values for most parameters, despite the microbial inoculation. The combination of 100% mineral fertilizers with microbes did not improve the plant growth compared with the controls. However, the treatments with 50% mineral fertilization along with microbial inoculation generally maintained parameter values similar to those of the 100% fertilized control, suggesting the potential for reducing fertilizer doses by 50% without compromising plant development. Inoculation with B. subtilis and T. harzianum coupled with the use of mineral fertilizers improved the soil phosphorus availability compared to fertilizer application alone. This study highlights the potential of these microorganisms to enhance soil fertility and plant growth while reducing chemical fertilizer use in maize cultivation, although further field research is necessary to verify the long-term sustainability of this approach.

Correction: Sharma et al. Rhizophagus irregularis and Nitrogen-Fixing Azotobacter with a Reduced Rate of Chemical Fertilizer Application Enhances Pepper Growth along with Fruit Biochemical and Mineral Composition. Sustainability 2022, 14, 5653

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Effect of Nano-fertilizers in Wheat Crop Nutrition: A Review

The use of nano - fertilizers in wheat cultivation represents a promising approach to overcoming some of the inefficiencies and environmental challenges associated with conventional fertilizer practices. Traditional fertilizers often suffer from low nutrient use efficiency, leading to excessive application, nutrient runoff, and environmental harm. Nano fertilizers, due to their nano-scale size and enhanced reactivity, improve nutrient uptake by plants, leading to better growth, higher yields, and reduced nutrient wastage. Studies show that Nano formulations of both macronutrients (such as nitrogen, phosphorus, and potassium) and micronutrients (like zinc and iron) can significantly enhance wheat productivity. Nano fertilizers not only increase crop yield but also reduce the overall cost of fertilizer application by minimizing nutrient loss and improving absorption by the plants.

Use Efficiency, Reduction Potential, and Effects of Fertilizers on Carbon Emissions in China’s Major Citrus Regions

Enhancing the efficiency of fertilizer utilization and advancing fertilizer reduction efforts constitutes a pivotal initiative for augmenting the quality and productivity of the citrus industry; this constitutes an indispensable prerequisite for attaining green and sustainable development. Utilizing panel data from seven prominent mandarin-producing regions and seven prominent tangerine-producing regions in China spanning from 2002 to 2022, this study employed the stochastic frontier analysis (SFA) method to develop a translog production function model for precisely measuring the fertilizer use efficiency for mandarins and tangerines. Employing the calculated optimal fertilizer use rates, we further ascertained the fertilizer reduction potential for mandarin and tangerine; then, we estimated the associated carbon emission reduction potential within these key citrus regions. The research revealed the following findings: the overall level of citrus fertilizer use efficiency in China is comparatively low, with the mean values for mandarin and tangerine fertilizer use efficiency being merely 0.4403 and 0.3887, respectively, indicating substantial room for improvement by approximately 60%; substantial potential exists for decreasing fertilizer use in China’s citrus industry, with average reduction potentials of 66.27% for mandarins and 64.83% for tangerines, signifying a notable redundancy in fertilizer application within major citrus-producing areas. The magnitude of carbon emission reduction potential through the diminution of citrus fertilizer use is tremendous. When optimal fertilizer rates are applied, the average carbon emission reductions resulting from fertilizer reduction in mandarins and tangerines amount to 815.8681 kg/hm2 and 602.3551 kg/hm2, respectively. The average carbon reduction potential for mandarins and tangerines reach levels of 55.9673% and 61.1299%, respectively, both surpassing the threshold of 55%. Significant differences exist in the technical efficiency of fertilizer input, reduction potential, and carbon emission mitigation potential among major citrus-producing regions. Citrus orchards in Guangdong exhibit higher potential for fertilizer reduction but demonstrate a relatively low level of technical efficiency. In contrast, Hunan Province shows an opposite trend, necessitating the development of region-specific strategies. Therefore, to minimize citrus fertilizer use and augment the technical efficiency of citrus fertilizer, it is imperative to comprehensively integrate and promote the “three new” technologies aimed at reducing fertilizer use and enhancing its efficiency within the citrus industry; implement a regional coordinated development strategy for citrus fertilizer reduction; and intensify policy guidance, publicity, and training efforts related to citrus fertilizer reduction, efficiency enhancement, and carbon emissions reduction.

Effect of Black Soldier Fly Larvae Frass as Organic Fertilizer on Postharvest Quality and Shelf Life of Open-field-grown Tomato (Solanum lycopersicon L.)

Open-field-grown tomatoes in Saudi Arabia are stressed by poor soil fertility because of the low organic matter content, low nutrient availability, and high pH. Thus, high chemical fertilizer inputs are crucial for commercial production; however, they cause economic loss as well as negatively affect environmental sustainability. The use of efficient organic fertilizers would be useful for developing more cost-effective, environmentally friendly, and sustainable agriculture. The current study evaluated the impact of Black soldier fly (Hermetia illucens L.) frass (BSFF) fertilizer applications as organic fertilizer on postharvest fruit quality and shelf life of open-field-grown F1 hybrid ‘Sinag Tala’ tomatoes compared with those grown under control treatment (received recommended doses of chemical fertilizers for tomato production under open field conditions). The experiment was conducted using a randomized complete block design with four replicates. The results showed that the application of BSFF fertilizer, especially at the higher rate (5 ton/ha; BSFF3), improved the overall quality of tomato fruit. The BSFF fertilizer treatments reduced weight loss, maintained higher firmness, antioxidants [vitamin C, total phenol content (TPC) and total flavinoid (TFC)], total soluble solids (TSS), and titratable acidity (TA) contents, and lowered the TSS/TA ratio of fruits during shelf life compared with those of the control. The decay incidence was only detected after 9 days of shelf life and was significantly lower in all the BSFF fertilizer treatments (range, 8.40%-12.05%) than in the control (15.9%). In addition, BSFF fertilizer treatments reduced both disease incidence and severity of gray mold following pathogen inoculation during shelf life compared with those of the control. These results might be attributable to the higher antioxidants content (vitamin C, TPC, and TFC) and higher polyphenol oxidase activity in BSFF-fertilized tomatoes. In conclusion, BSFF fertilizer could be used as a potential eco-friendly alternative to chemical fertilizers to improve tomato fruit quality during shelf life.

Biodiversity-safeguarding threshold for urea-fertilizer application on paddy fields: Protozoa-based toxicity tests

Urea is a widely applied fertilizer to enhance crop yields. Ecological risks associated with the excessive application of urea fertilizer threaten the paddy fields' sustainable agriculture and biodiversity preservation. There are no practical thresholds based on proven data on microbial communities. Protozoa are nitrogen-sensitive organisms. For the first time, this study conducted acute and chronic urea toxicity tests on eight species of organisms. The results indicate that Blepharisma sp. is the most sensitive species to urea exposure and is a suitable indicator for determining the safe threshold of urea. This study estimated the predicted no-effect concentration using species sensitivity distribution curves. Subsequently, it established the threshold for urea application in rice fields based on the fields' area and the surface water's height. The short-term safety threshold for urea in the studied paddy field with black soil is 87.7mg/L, equivalent to 43.85kg of urea per hectare for a single nitrogen fertilizer application. The long-term safety threshold is 5.02mg/L, representing the concentration for re-applicating urea. The biodiversity-safeguarding application threshold provides the basis for developing a urea fertilizer reduction protocol to safeguard the paddy fields' biodiversity.

Effect of foliar application of water-soluble fertilizer (NPK) with microbial consortia seed treatment on growth, yield and nutrient uptake by blackgram in Alfisols

Effect of foliar application of water-soluble fertilizer (NPK) with microbial consortia seed treatment on growth, yield and nutrient uptake by blackgram in Alfisols

Variations in the level of available phosphorus with changes in the status of water-soluble organic matter derived from different organic materials in soil

The combined application of organic material and phosphorus fertilizer is an effective method to enhance phosphorus use efficiency for plant growth. This is partly because the presence of water-soluble organic matter (WSOM) derived from different organic materials can enhance the level of available phosphorus in the soil; however, it is poorly understood how this level varies with changes in the WSOM status (i.e., decomposed, dissolved, and retained) in the soil depending on WSOM types. This study aimed to (i) understand how changes in the WSOM status enhances the available phosphorus level in the soil, and (ii) determine the WSOM type that contributes to such enhancement. The incubation test showed that fractions of 73%–92% and 8%–27% of WSOM-derived organic carbon were retained and dissolved, respectively, at the beginning of incubation, while 31%–45% was decomposed during the incubation period. The WSOM derived from cattle manure compost (CM) and sewage sludge compost (SSC) that was initially retained was maintained until the late stage of the incubation test, whereas that derived from hydrothermal decomposed liquid fertilizer (HDLF) was rapidly desorbed during the first 14 days of the incubation period. The available phosphorus level was higher under the combined application of CM- and SSC-derived WSOM than under the single phosphorus application throughout the incubation period, while it was high only during the first 3 days of incubation under the application of HDLF-derived WSOM. The amounts of retained organic carbon at each sampling point during the incubation period compared to those at the beginning were positively and linearly correlated to the available phosphorus levels that were enhanced by the WSOM present in the soil. This study for the first time provides quantitative experimental evidence that 1) the longer the WSOM continues to be retained, the higher the amount of available phosphorus remaining in the soil, and 2) the available phosphorus level decreases with WSOM sorption or decomposition. Furthermore, it was shown that highly humified WSOM has a great potential for the maintenance of higher available phosphorus levels. This study provides the insight that a combined application of highly humified organic materials with a chemical fertilizer is necessary for not only cost effective but also sustainable fertilization design.