Compost Fertilizer Research Articles

PENERAPAN TEKNOLOGI MESIN MIXER UNTUK MENINGKATKAN KUANTITAS DAN KUALITAS PRODUK PUPUK KOMPOS DI GAPOKTAN NGUDI MAKMUR, BANJARARUM, KULON PROGO

The Ngudi Makmur Farmer Group (Gapoktan) is one of the productive economic groups located in Banjararum Village, Kulon Progo, Yogyakarta. Gapoktan Ngudi Makmur faces several issues, some of are deemed important and need to be resolved. The mentioned issues include environmental pollution risks and unpleasant odors arising from piles of livestock manure. Livestock manure is generally processed into compost fertilizer to nourish crops managed by the group. The process of turning livestock manure into compost fertilizer is done with the hand tool, resulted in relatively low production quantity and quality due to non-standard/uniform compost grain sizes. This Community Service Activity (PkM) is part of Kosabangsa Program implementation in 2023. The activity is carried out by a combined team from 2 (two) Higher Education Institutions (PT), namely Universitas Jenderal Achmad Yani Yogyakarta (UNJAYA), and Universitas AKPRIND Indonesia. This activity is conducted through 5 (five) stages which is: socialization, training, technology application, mentoring, as well as program evaluation and sustainability. The total duration of the activity is 4 (four) months. The appropriate technology (TTG) applied is a compost mixer machine. Based on the evaluation results after the activity, there was an increase in the quantity of compost production by 16.67% and an improvement in quality of compost with standard/uniform grain sizes. Keywords: mixer machine, quality, quantity, compost, appropriate technology

Role of phytolith occluded carbon of cereales plants for climate change mitigation

Phytolith-occluded carbon (PhytOC) is highly stable, and constitutes an important source of long-term C storage in agrosystems. This stored carbon is resistant to the processes of oxidation of carbon compounds. In our research phytolith content in barley (Estonia) and oat (Poland) grain and straw was assessed at field trials, with Si as a liquid immune stimulant OPTYSIL and compost fertilisation. We showed that cereals can produce relatively high amounts of phytoliths. PhytOC plays a key role in carbon sequestration, particularly for poor, sandy Polish and Estonian soils. The phytolith content was always higher in straw than in grain regardless of the type of cereals. The phytolith content in oat grains varied from 18.46 to 21.28 mg∙g−1 DM, and in straw 27.89–38.97 mg∙g−1 DM. The phytolith content in barley grain ranged from 17.24 to 19.86 mg∙g−1 DM, and in straw from 22.06 to 49.08 mg∙g−1 DM. Our results suggest that oat ecosystems can absorb from 14.94 to 41.73 kg e-CO2∙ha−1 and barley absorb from 0.32 to 1.60 kg e-CO2∙ha−1. The accumulation rate of PhytOC can be increased 3-fold in Polish conditions through foliar application of silicon, and 5-fold in Estonian conditions. In parallel, the compost fertilisation increased the phytolith content in cereals.

Effect of long-term compost fertilization on the distribution of organic carbon and nitrogen in soil aggregates

Soil fertility is mainly related to soil total organic carbon (C) that should be preserved in order to optimize soil quality and functionality. Consequently, the use of organic amendments could be a possible strategy to increase soil C and nitrogen (N) storage particularly in orchard systems where the disturbance of soil is reduced thus making favorable conditions for C and N stabilization.The aim of this study was to evaluate the distribution and stabilization of organic C and total N in aggregate fractions after a 14-years-period of compost application to a peach orchard. The trial was conducted in the south-eastern Po valley, on a commercial nectarine orchard and the following treatments were compared in a complete randomized block design with four replicates: 1. unfertilized control; 2. mineral fertilization; 3. compost at a rate of 10 Mg dry weight ha−1 yr−1. At the end of orchard lifetime, soil was sampled from the row at four depths (0–0.15, 0.16–0.25, 0.26–0.45, and 0.46–0.65 m) and physically fractionated to separate macroaggregates (> 250 μm), microaggregates (250–50 μm) and silt and clay (< 50 μm) that were analyzed for organic C, total N, δ13C, and δ15N.Compost addition induced a significant increase of macroaggregates (66%), no changes in microaggregates and a decrease of silt and clay (22%) compared to control and mineral fertilization. With compost the accumulation of organic C and total N content in the macroaggregates was four-five times higher than the other two treatments in all the depths, therefore almost 50% of the soil organic C was in this fraction, compared to 20–24% in the control and mineral. In the micro-aggregates more C and N accumulated only in the two top layers, while no effect was observed in the silt and clay fraction. From macro-to microaggregates to the silt and clay fraction, the C/N ratio shifted from 9 to 7.5 to 6 on average indicating that the C and N stabilized in the finer fractions is mainly of microbial origin. The enrichment in C and N isotopic composition from macro-to micro to silt and clay is also indicative of the isotopic fractionation due to microbial metabolism and the consequent stabilization of microbial residues in the finer fractions. In the control and mineral, only receiving orchard litter, this change was observed in all the layers, on the contrary, with compost similar δ13C and δ15N values characterized the fractions in the top soil layer suggesting the occlusion of compost in all the fraction. With depth the macroaggregates maintained the same δ13C and δ15N values indicating consistent redistribution of compost in deep soil layers, while the finest fractions showed a progressive enrichment of δ13C due to the presence of C fractionated during microbial metabolism and progressively stabilized. In conclusion, compost supply leads to positive effects on C and N accumulation and stabilization also in the deeper layers favoring the increase of long-term soil fertility and C storage.

Use of Azolla in organic farming on availability and uptake of N, P, K of rice paddy (Oryza Sativa, L.)

Organic fertilization is very important to maintain sustainable land and environmental productivity. Organic fertilizer from Azolla has the advantage of increasing soil fertility by increasing nutrient availability. This study aimed to determine the effect of Azolla application on the availability and uptake of N, P, and K of Inpari 32 variety rice plants. This research used 9 treatments: (T0= control, T1= 90 kg/h NPK, T2= 45 kg/h NPK, T3= 10 t/h Manure, T4= 2 t/h Manure + 90 kg/h NPK, T5= 10 t/h Rice straw compost, T6= 2 t/h Rice straw compost + 90 kg/h NPK, T7= 10 t/h Azolla, T8= 2 t/h Azolla + 90 kg/h NPK) with as control and 3 replications, so there were 27 experimental plots. This research was located in the paddy field of Madiun Regency, East Java. The results showed that Azolla, manure, and straw compost at a dose of 10 t/ha increased soil C-organic, soil Cation Exchange Capacity (CEC), and soil pH, which was still in the neutral range. Azolla fertilizer increased the highest soil total N compared to cow manure and straw compost and increased the efficiency of NPK fertilizer use. Azolla (T7) increased soil available P (27.02 ppm) and exchangeable K (17.63 me/100g soil). Azolla had the highest available P effect. Azolla (T7) and manure (T4) were affected by increasing K-exchange. Azolla fertilizer, manure, and rice straw compost increased vegetative plant growth (plant height, number of tillers, shoot and root biomass). Among the three, Azolla fertilizer had the highest effect. Organic fertilization affected N, P, and K uptake, which was highest in Azola fertilizer (T7). For manure, varied NPK fertilizer (T4) just showed an increase in P uptake, and compost fertilizer varied NPK fertilizer (T6) showed a rise in K uptake. A positive relationship existed between the availability and uptake of nutrients N, P, and K.

PENGOLAHAN LIMBAH ORGANIK UNTUK PEMBUATAN PUPUK KOMPOS DI DESA KERSIK KECAMATAN MARANGKAYU

This training activity is part of a series of efforts to manage organic waste with the aim of producing compost fertilizer in the Kersik Village area, Marangkayu District. Using participatory research methods, this training documents the main processes in managing organic waste from local sources. The focus includes the natural fermentation techniques used as well as assessing the quality and yield of the compost produced. In addition, this activity considers the active involvement of local communities in implementing environmentally friendly waste management practices. The analysis carried out includes technical aspects of the waste composting process as well as exploration of the social, economic and environmental impacts this initiative has on the welfare of local communities as well as efforts to reduce negative impacts on the environment. By holding this training activity, it is hoped that it can provide useful insights in strengthening sustainable organic waste management strategies in Kersik Village, while also contributing to efforts to maintain the sustainability and welfare of the local community.

Pemanfaatan Sampah Organik untuk Produksi Pupuk Kompos Berkualitas: Inovasi Kolaboratif Fakultas Teknik USK untuk Meningkatkan Pendapatan dan Daya Saing Mitra Usaha

The community service activity conducted at the Faculty of Engineering, Syiah Kuala University, is aimed at increasing income and competitiveness through the production of compost fertilizer from organic waste. This activity involves three independent business partners, namely the Student Executive Board of the Faculty of Engineering, the Atsiri Research Center, and Violet Garden. The background of this community service activity is the existence of problems faced by each partner in their respective fields of business, such as limited funds, utilization of waste, and product marketing. The purpose of this activity is to provide a collaborative innovation solution that can improve the quality of products, knowledge, and skills of the partners. The method of this activity is by designing and making a raw material shredder, a compost fertilizer production place, supporting tools, workshops and training, packaging techniques, and marketing strategies. The results of this activity are the creation of quality compost fertilizer products, increased knowledge and skills of the partners, and increased income and competitiveness of the partners. It is expected that this community service activity can contribute to the development of technology and community science, especially in the field of organic waste management into compost fertilizer.

Mechanistic insights into chemical conditioning on transformation of dissolved organic matter and plant biostimulants production during sludge aerobic composting

Inorganic coagulants (aluminum and iron salt) are widely used to improve sludge dewaterability, resulting in numerous residues in dewatered sludge. Composting refers to the controlled microbial process that converts organic wastes into fertilizer, and coagulant residues in dewatered sludge can affect subsequent compost efficiency and resource recycling, which remains unclear. This work investigated the effects of two typical metal salt coagulants (poly aluminum chloride [PAC] and poly ferric sulfate [PFS]) conditioning on sludge compost. Our results revealed that PAC conditioning inhibited composting with decreased peak temperature, microbial richness, enzymatic reaction intensities, and compost quality, associated with decreased pH and microbial toxicity of aluminum. Nevertheless, PFS conditioning selectively enriched Pseudoxanthomonas sp. and resulted in more fertile compost with increased peak temperature, enzymatic reaction intensities, and humification degree. Spectroscopy and mass difference analyses indicated that PFS conditioning enhanced reaction intensities of labile biopolymers at the thermophilic stage, mainly comprising hydrolyzation (H2O), dehydrogenation (-H2, -H4), oxidation (+O1H2), and other reactions (i.e., +CH2, C2H4O1, C2H6O1). Unlike the common composting process primarily conducts humification at the cooling stage, PFS conditioning changed the main occurrence stage to the thermophilic stage. Non-targeted metabolomics revealed that indole (a humification intermediate) is responsible for the increased humification degree and indoleacetic acid content in the PFS-conditioned compost, which then promoted compost quality. Plant growth experiments further confirmed that the dissolved organic matter (DOM) in PFS-conditioned compost produced the maximum plant biomass. This study provided molecular-level evidence that PFS conditioning can promote humification and compost fertility during sludge composting, enabling chemical conditioning optimization for sustainable management of sludge.

Growth of Peanut Plants (Arachis Hypogaea) using Paitan Weed Compost Fertilizer (Tithonia Diversifolia) Combined with Buffalo Kohe

The aim of this research was to determine the effect of fertilizer application on the growth of peanut plants (Arachis hypogaea) using compost from paitan weed (Tithonia diversifolia) combined with buffalo kohe and to analyze the concentration of compost from paitan weed (Tithonia diversifolia) combined with buffalo kohe. offers peanut plants (Arachis hypogaea) the best interaction for growth. This research used a single factor Complete Randomized Block Design (RAKL). The concentration of compost fertilizer is the determining factor for paitan (Tithonia diversifolia) combined with buffalo kohe with three replications per experimental unit, with P_0 = 0 kg/m^2 (control), P_1 = 1 kg/m^2, P_2 = 1, 5 kg/m^2, P_3 = 2 kg/m^2, P_4 = 2, 5kg/m^2, and P_5 = 3kg/m^2.

The Response of giving Gamal, Calliandra, and Lamtoro leaves compost fertilizer to Stevia plant (Stevia rebaudiana Bertoni) growth

Stevia (Stevia rebaudiana Bertoni) is a herbaceous plant, a sweet plant that can replace cane sugar. This plant is a shortday crop that can be harvested within 40-60 DAP. Compost is an organic fertilizer that is made by utilizing the weathering process from the interaction of microorganisms and decomposing bacteria. One of the litters can be utilized include gamal, calliandra and lamtoro. The purpose was to determine the effect of the three composts on the growth and productivity of the stevia. The analysis method used a completely randomized design (CRD) with one factor and four treatments. The results showed that compost had a significant effect on all observed variables including height, diameter, number of leaves, fresh weight and plant biomass. The highest growth and productivity of stevia plants were produced by stevia plants in treatment P3 (lamtoro compost), which influenced all observed aspects, including height and diameter (21.7 and 2 cm), number of leaves (152 leaves), total wet and dry weight (16.54 and 3.58). The lowest yields were produced in treatment P0 (control), which only increases the height and diameter by 5.81 and 1 cm, with only 60 leaves and 6.25 and 1.28 grams for dry and wet weights, respectively.

Impact of Organic Vegetable System on Soil Organic Matter Pools and CO2 Emission in the Tropical Region

ABSTRACT It is widely recognized that the input of organic matter in tropical agriculture is essential to maintain productivity and soil quality. This study aimed to investigate the dynamics of organic C pools and CO2 emission influenced by organic compost fertilization and leucaena biomass in an area of 6 years under organic farming. The system consisted of 5 treatments based on 5 levels of fertilization with organic compost (0, 10, 20, 30, and 40 t ha−1). Each block was surrounded by leucaena and their pruning’s were distributed in equal proportions for all treatments. Two rotating crops were performed per year, cabbage/corn. Soil samples were collected in the 0–10 and 10–20 cm layers in 2-year seasons. TOC and N stocks were between 23.1 and 51.6 t ha−1, and 2.1 and 5.4 t ha−1, respectively. The highest compost doses increased the microbial biomass C and N. The increase in microbial biomass was followed by higher emissions of C-CO2. Increased microbial quotient values indicated C accumulation in the system by a higher amount of active metabolic C. The microbial biomass was less efficient in the use of the high organic compost doses. The dose of compost should be reduced and applied constantly by the farmers to attend the plant demand by nutrients and increase the efficiency of C sequestration in the soil. This C sequestration will also improve biological activity and soil quality in tropical regions, increasing food production.

Effect of pineapple waste biochar and compost application on the growth and yield of pineapple varieties in Ghana

IntroductionBiochar is one of the commonly used soil amendments for sustainable agriculture. The effect of biochar on crop yields depends on the quality of the biochar, which is influenced by feedstock type and pyrolysis conditions. Sole application of pineapple waste biochar and compost, and their combination has not been rigorously investigated. In this study, we investigated the effects of pineapple waste biochar and compost applied solely or in combination on growth and yield of pineapple on a coastal savanna Acrisol in Ghana.MethodsThe split-plot design with three replications was used, with pineapple varieties as the main plot and fertilizer application rates as the sub-plots.Results and discussionThe results showed that sole application of biochar and compost or their combination as a soil amendment increased pineapple growth and yield as compared to the unamended soil. Biochar applied in combination with compost/or inorganic NPK (nitrogen, phosphorus, and potassium) fertilizer significantly increased plant height and the number of leaves of pineapple plant, which resulted in improved fruits yield of the three (sugar loaf, MD2 and smooth cayenne) pineapple varieties at maturity over control, sole application of biochar, compost and inorganic NPK fertilizer. The Smooth cayenne variety outperformed MD2 and Sugar loaf variety.ConclusionIn conclusion, the results revealed that biochar applied solely or in addition to compost or inorganic NPK fertilizer has the capability to enhance soil quality and improve pineapple yield. Application of biochar in combination with compost/or inorganic NPK improves pineapple growth and yield.

Chemical Analysis of Kitchen Waste for Developing Formulae for Compost Fertilizer

The rapid growth of the global population and changes in food consumption patterns have resulted in issues relating to food insecurity. Improved strategic solutions are needed to allow easy access to food and also to manage large volumes of waste efficiently. From this research, a microeconomic- level solution to manage the aforementioned issues is addressed. Common kitchen waste such as peels and discarded parts of fruits and vegetables can be combined to produce compost fertilizer. Producing compost fertilizer in this manner can be considered a microeconomic-level waste management strategy. Compost fertilizer produced using kitchen waste can subsequently be used in home gardening. Many vegetables and fruits can easily be cultivated in small, confined spaces such as in home gardens. This study analyzed chemical parameters such as total carbon and other total nutrient levels (N, P, Ca, Mg and K) in ten kitchen waste and two supplementary samples using standard methods. The kitchen waste samples consisted of peels and discarded parts of fruits and vegetables. The two supplementary samples- Tithonia diversifolia (Wild sunflower), and Gliricidia sepium were chosen because they are nutrient-rich organic fertilizers. The analysis results were then fed to a computer program developed for this study. It was based on the simulated annealing algorithm. The program generated different formulae for producing 100 g mixtures of raw materials for composting, by mixing the 10 kitchen waste and 2 supplementary samples in 24 different combinations. The nutrient levels of these mixtures were expected to match or exceed a calculated ―target nutrient level‖. It was calculated based on local compost fertilizer standards and the chemical analysis results. The target nutrient level calculated as the minimum required level by dry mass of each material was 25.00% Carbon, 1.25% Nitrogen, 0.63% Phosphorus, 1.25% Potassium, 0.88% Calcium, and 0.63% Magnesium. The program was able to generate mixtures of raw materials in which most of the levels matched or exceeded the target level. However, the phosphorus levels of all formulae fell below the target phosphorus level and in some mixtures, the magnesium level also was less than the targeted level. The actual nutrient level of one of the 100 g mixtures (combination C3) containing 0.19 g banana stem, 0.21 g discarded tea grounds, 0.41 g discarded scraped coconut, 0.57 g banana peel, and 97.34 g Gliricidia leaves was (% by dry mass), 85.68% Carbon, 2.20% Nitrogen, 0.25% Phosphorus, 1.32% Potassium, 2.24% Calcium and 0.71% Magnesium. This promising method can further be developed by adding more nutrient-rich raw materials to the program. The program could be a useful tool for compost fertilizer manufacturing, especially for small-scale horticultural purposes. &#x0D; Keywords: Compost, Waste management, Nutrient analysis, Kitchen waste

Evaluation of dredge fines material in manufactured soil blends on soil health parameters

AbstractSolutions are needed to address increasing concerns over degraded land and global food insecurity. One solution is to design soil blends that can restore soil quality and fertility. Dredge material has many soil‐like properties, which makes it a good candidate for the main component of manufactured soil blends. Questions have arisen over contaminants of concern (heavy metals and polyaromatic hydrocarbons [PAH]) in dredge fines precluding them from reuse. One approach is to remove the fine fraction of dredge to lower the contaminant concentration; however, it may result in a lower quality soil substitute for land reclamation. In this study, soil blends were designed to compare the use of whole dredge to dredge fines (e.g., dredge with silt and clay fraction) and to assess the benefits of compost material, clay, and fertilizer additions. Dredge fines blends led to increases in soil quality, dry matter growth, plant available water, total and active C, potentially mineralizable N, and micronutrients. The addition of compost material led to better soil quality for a vast majority of the tested parameters. Dredge fines were below regulatory standards for contaminants of concern (e.g., carinogenic polyaromatic hydrocarbon and heavy metals), allowing their reuse in soil blends. Removal of fines from dredge decreases the quality of soil blends and should not be removed from dredge material for use as topsoil or in topsoil blends. The 80% (v/v) dredge fines blend with 20% (v/v) additions of compost material resulted in the greatest improvements in the assessed soil health parameters.

Environmental Assessment of Dryland and Irrigated Winter Wheat Cultivation under Compost Fertilization Strategies.

Wheat (Triticum aestivum L.) is a strategic agricultural crop that plays a significant role in maintaining national food security and sustainable economic development. Increasing technical performance considering lowering costs, energy, and environmental consequences are significant aims for wheat cultivation. For drylands, which cover approximately 41% of the world's land surface, water stress has a considerable negative impact on crop output. The current study aimed to assess the environmental aspects of chemical fertilizer in combination with compost in dryland and irrigated winter wheat production systems through life cycle assessment (LCA). The cradle-to-farm gate was considered as the system boundary based on one tone of wheat yield and four strategies: D-C (dryland with compost), D (dryland without compost), I-C (irrigated with compost), and I (irrigated without compost). Based on the results, the highest and lowest amounts of wheat yield were related to the I-C and D strategies with 12.2 and 6.7 ton ha-1, respectively. The LCA result showed that the I strategy in comparison with other strategies had the highest negative impact on human health (49%), resources (59%), ecosystem quality (44%), and climate change (43%). However, the D-C strategy resulted in the lowest adverse effect of 6% on human health, 1% on resources, 10% on ecosystem quality, and 11% on climate change. Utilizing a combination of fertilizer and compost in dryland areas could ensure a higher yield of crops in addition to alleviating negative environmental indicators.

Pelatihan Pengelolaan Sampah Di Kampung Gedong Guna Peningkatan Pendapatan Masyarakat

This community service activity was carried out with the aim of making the kampung gedong community an independent and creative community group. Through waste management into valuable products. In addition, this activity is expected to provide knowledge for the community in managing waste, so that they have alternative income. More effective waste management can also open up new business opportunities for waste pickers, such as processing organic waste into compost fertiliser or managing plastic waste into paving blocks. This activity was carried out using the lecture method when providing the material. While during the simulation, the team conducted a direct sim.

Pemanfaatan Limbah Sayuran Busuk terhadap Pertumbuhan Tanaman Sawi (Brassica juncea L)

This research was conducted in the courtyard of Lau Dendang Village, Medan, North Sumatra. Which is carried out from October to November. This research was conducted to study the manufacture of compost using the vermicomposting method which utilizes organic waste such as rotting vegetables and to determine differences in growth rates from applying compost and water to mustard greens. The results of this study indicate that the application of compost from rotting vegetable waste has an impact on mustard plants which produce stem height, number of leaves and leaf width, in the application of water the resulting impact also develops well, but not as well as in the application of compost fertilizer. So it can be concluded that the application of compost has more influence on the rate of growth and development of mustard greens because it can increase the fertility in the soil.

Quality analysis of coffee waste compost with the addition of cassava tapai local microorganism (LMO) bioactivator

Coffee waste contains a large amount of nutrients, making it a potential raw material for compost fertilizer. The nutrients contained in coffee waste include N, P, K, Mg, and Ca. Utilization of coffee waste as compost requires bioactivators to accelerate the decomposition process. This study aims to determine the difference in compost quality from coffee waste by using bioactivators in the form of local microorganisms (LMO) of cassava tapai. This study was conducted from April to May 2023 at the greenhouse of LPP Polytechnic Yogyakarta, consisting of two stages: making the LMO and making the compost. Cassava tapai LMO was prepared as a treatment for composting coffee waste. Each treatment was repeated three times. After that, the fermentation results in the form of compost were tested, then the results were compared with the standards of the Decree of the Minister of Agriculture No. 261/KPTS/SR.310/M/4/2019 on the minimum technical requirements for organic fertilizers, biological fertilizers, and soil conditioners. The results reveal that the provision of cassava tapai LMO bioactivator affected the quality of coffee waste compost produced. The quality of composts produced from control, cassava tapai LMO of 90 ml, and EM-4 treatment does not meet the standards of the Decree of the Minister of Agriculture in the parameter of chemical properties, namely the C/N ratio. The quality of compost produced from cassava tapai LMO of 120 ml meets the standards of the Decree of the Minister of Agriculture and SNI 2004 in all parameters of physical properties, chemical properties, and nutrient content.

Effects of compost fertility on the growth, yield, and nutrient content of lettuce (Lactuca sativa)

Effects of compost fertility on the growth, yield, and nutrient content of lettuce (<i>Lactuca sativa</i>)

Responses of avocado (Persea americana) to various doses of compost fertilizer and watering interval

Avocado is a multifunctional plant that can be utilized in all parts. The growth of avocado and its yield can be achieved by fulfilling requirements for the growth and maintenance of the plant well. Planting on dry land requires the addition of organic fertilizer and optimal water requirements to increase organic matter content and plant fertility. This research aims to obtain the optimal dosage of compost and watering intervals for the growth of avocado (Persea americana). The research was carried out in the Greenhouse Faculty of Agriculture, Universitas Sumatera Utara. This research used a factorial completely randomized design (F-CRD) with the addition of compost fertilizer doses (K0:0 kg, K1:0.5kg. K2: 1 kg. K3: 1.5 kg and K4: 2 kg) and watering intervals (A1: once a day. A2: once every three days. A3: once every five days and A4: once every seven days) with parameters of observation of height, diameter, top fresh weight, root fresh weight, top dry weight and root dry weight. The results showed that the interaction of compost and watering intervals significantly affected the height and diameter increase, root fresh weight, and root dry weight of avocado plants. The interaction of giving 1.5 kg of compost and watering intervals every day had the best effect on the growth and quality of avocado seedlings

Effects of kitchen waste compost and chemical fertilizer application on spinach (Spinacia oleracea L.) c.v. Matador plant growth and nitrate accumulation

In this study, the effects of organic and chemical fertilizer sources on some essential nutrient elements content, nitrate (NO3 −-N) accumulation, and the growth of spinach plant (Spinacia oleracea L.) were investigated. The experiment was carried out in a randomized plot design under greenhouse conditions, with two levels. 1st level; applications with chemical fertilizer. 2nd level; applications without chemical fertilizer. One compost material (kitchen waste compost = KWC), five different doses (0, 0.4, 0.8, 1.2, and 1.6%), and three replications. For chemical fertilization, nitrogen (N) dose of 150 kg ha−1 was applied by using 15-15-15 NPK (N:P2O5:K2O) fertilizer. Overall, KWC applications increased plant growth and nutrient content. However, the most significant increases occurred in the trial subjects where chemical fertilizer and KWC were applied together. The use of KWC together with chemical fertilization increased the leaf width, leaf and stem length, fresh weight, and dry weight, as well as nitrate accumulation, N, potassium (K), and iron (Fe) content of the plant. The highest values of these parameters were obtained at 0.8% dose of KWC + NPK medium. As a result, compost applications were effectively uptake of nutrients and nitrate accumulation remained at acceptable values.