Số hóa bởi Trung tâm Học liệu – ĐHTN http //www lrc tnu edu vn Department of Tropical Agriculture and International Cooperation National Pingtung University of Science and Technology Ph D Dissertation[.]
Honeydew melon (Cucumis melo L inodorus) is a highly valued member of the Cucurbitaceae family, which includes various melons like casaba and crenshaw Cultivated since ancient times in regions such as Asia, West Africa, and the Mediterranean, honeydew has gained popularity for its sweet taste and pleasant aroma This vine tender annual crop features smooth-skinned fruits that ripen late and contain minimal musky odor Rich in sugars, vitamins, and minerals, a 100 g serving of honeydew provides 96.5 g of water, 2.2 g of carbohydrates, and essential nutrients like vitamin C and β-carotene Due to its nutritional benefits, honeydew melon is in high demand globally.
Historically, agricultural production focused on maximizing crop yields to meet market demand, heavily relying on capital inputs like fossil fuels, chemical fertilizers, pesticides, and advanced machinery (Beckie, 2000) However, the extensive use of inorganic fertilizers has adversely affected the quality of agricultural products, as well as human health and the environment Today, soil pollution and contamination have emerged as significant global concerns, with over 300 million pounds of harmful substances impacting agricultural practices.
The excessive use of inorganic fertilizers and pesticides, which contain harmful substances like nitrates, phosphates, and heavy metals, has detrimental effects on the environment and human health (Anitha et al., 2014; Serpil, 2012) Industrial agriculture treats farms as factories, leading to significant waste and reliance on fossil fuels (Horrigan et al., 2002) The global increase in inorganic fertilizer use has contributed to serious environmental issues, including greenhouse gas emissions from agriculture, which accounted for about 15% of total emissions in the 1990s (Herencia et al., 2008) In contrast, organic agriculture can reduce carbon dioxide emissions by enhancing soil health and microbial activity, highlighting the importance of decreasing agro-chemical usage to protect the environment.
The application of inorganic fertilizers significantly impacts agriculture by affecting soil quality and the survival of soil organisms These fertilizers are absorbed by plants and can enter the food chain, contributing to pollution in soil, water, and air Additionally, the use of inorganic fertilizers can result in poorly synthesized proteins in plant leaves, leading to subpar crops and potential health issues in animals and humans consuming such deficient food Consequently, health-conscious consumers are increasingly seeking foods with optimized nutritional content and minimal chemical residues, favoring environmentally friendly agricultural practices.
(Fabiyi and Ogunfowora, 1992) so that implementing organic farming and using organic fertilizers to substitute for inorganic fertilizers are common principles in the agricultural production system
Organic farming is a highly advanced and environmentally sustainable agricultural system with a rich history Over recent years, organic agriculture has experienced significant global growth and is now widely practiced across various regions.
120 countries with 51 million hectares currently managed organically by at least
In 2004, organic farming represented a burgeoning sector, accounting for approximately four percent of the total agricultural land in the European Union Meanwhile, Canada experienced substantial growth in organic agriculture, increasing from 1,174 certified producers in 1992 to 3,618 by 2005.
Organic farming reduces the reliance on synthetic pesticides and fertilizers compared to conventional farming methods By focusing on sustainable practices, organic farmers strive to align their agricultural processes with natural systems.
Organic agriculture offers several benefits, including the reduction of negative environmental impacts associated with traditional farming and addressing rural development challenges Additionally, it has the potential to deliver high-quality food while ensuring a stable food supply.
Organic agriculture is viewed as a promising solution for agricultural reform, embodying a century of aspirations for an alternative farming system While it has not met all expectations, it remains the most effective approach to developing an agricultural model that incorporates social and environmental costs Definitions of organic agriculture aim to address the key issues associated with conventional farming, including food contamination from pesticides and pathogens, soil degradation, pollution from agricultural runoff, excessive fossil fuel use, and the decline of biodiversity in crops and rural ecosystems.
Organic agriculture is nowhere near perfect as it stands; its overall
The environmental advantages of organic agriculture may be questioned due to its potential to expand agricultural land, which can lead to negative impacts on climate change and biodiversity However, adhering to the ecological definition of organic farming presents significant opportunities to mitigate the externalities linked to conventional agricultural practices This approach not only enhances ecosystem services but also meets consumer demands for sustainable products.
Organic farming relies heavily on biological activity and soil organic matter (OM) derived from organic materials, which serve as an affordable fertilizer source These materials enhance soil's physical properties and provide essential nutrients, including phosphorus, potassium, nitrates, and magnesium, while also aiding in disease control from various plant pathogens Numerous studies indicate that organic materials significantly benefit plant growth, particularly when used as soil additives or in seedling production, leading to improved productivity and enhanced soil structure, including better water retention and aeration However, the high pH levels in some organic materials may restrict their agricultural application Elemental sulfur is recognized as an allowed soil conditioner under EU regulation 2092/91, with research showing its effectiveness in lowering the pH of organic materials Despite the advantages of organic materials, excessive use and mixing can negatively affect soil health and crop yields.
This study aims to assess the physical and chemical characteristics of growing media composed of varying ratios of VC, SMS, and S 0, and to analyze their impact on the growth and nutrient absorption of honeydew melon seedlings.
This study aims to assess the effectiveness of using Calcium Magnesium Carbonate (CaMC) and Calcium Hydroxide (CH) as substitutes for certain components of Vermiculite (VC) Additionally, it investigates how the combination of Sugarcane Molasses (SMS), VC, Sulfur (S 0), CaMC, and CH influences the physical and chemical properties of growing media, as well as the growth response of honeydew melon seedlings in a greenhouse setting.
This study aims to assess the impact of seedlings and the combination of spent mushroom substrate (SMS) and Chitosan-Microcrystalline Cellulose (ChMC) on the growth, yield, and fruit quality of honeydew melon Additionally, it seeks to identify the optimal SMS application rate for nursery seedlings and honeydew melon production in a net house environment.
This study aims to assess the impact of SMS, VC, and CaMC, along with their continuous application over two seasons, on the soil properties, growth, and yield of honeydew melon cultivated in pots under net house conditions.
The final objective is to determine the best mixture of organic materials for honeydew melon production in organic cultivation
Melon (Cucumismelo L.)
Melon occur as cultivar varieties of Cucumis melo L, classified within the
Cucurbitaceae family, subfamily Cucurbiloideae, tribe Melothrieae, subtribe
Cucumerinae, as identified by Robinson and Decker-Walker in 1999, encompasses various types of melons, including sweet melon, round melon, muskmelon, casaba, cantaloupe, and winter melon, according to Nayar and Singh in 1998 The melon family consists of approximately 118 genera and 825 species, as noted by Jeffrey.
The family of melons encompasses various plants such as pumpkins, squashes, gourds, and watermelons, with melon species categorized into two subspecies: C melo ssp agrestis and C melo ssp melo, distinguished by the hair types on the female hypanthium While C melo features a diverse array of cultivars, interspecies crosses are typically sterile, leading to a complex variation within the species itself Initial taxonomic research on melons was conducted by Naudin in 1859, contributing to the ongoing discussions in melon classification.
7 confusion, hence, 522 synonyms of C melohave been recognized by Kirkbride
(1993) The taxonomy of the cultivars is complex and has only recently been reviewed and clarified by Pitrat et al (2000) The common groups are:
1 Catalupensis (true Cantaloupe common in Europe, rough or scaly surface but not netted)
2 Reticulatus(Rockmelon, Muskmelon or Cataloupe, fruits are netted and slip from the vine)
3 Inodorus (Winter Melon or Honeydew Melon in Australia)
4 Flexuosus (Snake Melon or Serpent Melon)
6 Chito (Mango Melon or Garden Lemon)
7 Dudaim (Pomegranate melon or Queen Anne’s melon)
* Sweet melon types used as fruit:
Muskmelon (var reticulatus Naudin) is a globular fruit weighing between 1.0 to 1.8 kg, characterized by a strongly reticulate and occasionally furrowed rind that is yellowish-green Its flesh can vary from orange to light green, and it boasts a high sugar content of 10-15%, making it aromatic and sweet Additionally, muskmelons are well-suited for shipping due to their sturdy structure.
Cantaloupe melon (var cantalupensis Naudin) is a globular to slightly ovoid fruit weighing between 1.2 to 1.8 kg It features a smooth or reticulate rind that is ribbed and grayish-green, with sweet orange flesh known for its high sugar content and rich flavor However, it has limited storability and is primarily cultivated in Western Europe and the United States.
Winter melon (var inodorus Naudin) is an ovoid fruit weighing between 1.5 to 2.5 kg, known for its late maturation The rind is smooth and can be striped or splashed, displaying colors such as gray, green, or yellow Its flesh is firm and typically white or light green, characterized by a high sugar content but lacking strong flavor This fruit boasts excellent storage quality and is primarily cultivated in Iran, Central Asia, and Afghanistan, with additional production in Spain and Japan.
* Non-sweet melon types used as vegetable:
Snake melon (var flexuosusNaudin): fruit long, slender, with smooth rind; used immature as cucumber, mainly in Afghanistan, Iran and the Commonwealth of Independent States
The Oriental pickling melon (var conomon Makino) is a small, elongated fruit resembling a cucumber, primarily found in India, China, Japan, and Southeast Asia Young green fruits are consumed similarly to cucumbers, though they have a flat taste and minimal flavor Mature fruits are oval-cylindrical with a smooth yellow rind featuring white longitudinal stripes and can weigh over 5 kg These larger fruits are often used to make candy or enjoyed as a delicacy when served with ice and sugar In Thailand, this variety is known as Taeng-thai or Taeng-lai (Herklots, 1972).
Garden melon (var chitoNaudin): fruit small, smooth, mottled; used for pickles and as ornamental, mainly in southern Europe and the United States
Pomegranate melon (var dudaimNaudin): fruit small, globular, pubescent; mainly in south-western Asia, Transkaukasia and northern Africa; also used as ornamental and odoriferous fruit
There are also 2 cultivars included in the sweet melon types used as fruit (Paje and Vossen, 1993):
The Chinese Hami melon is an ovoid to oblong fruit weighing between 1.5 to 2.0 kg, featuring a yellowish to light green rind with a slightly reticulate texture Its crisp flesh ranges in color from light orange to pink and offers an exceptionally sweet flavor, containing about 14% sugar This melon boasts a good shelf life and is well-suited for cultivation in cool climates.
The Oriental sweet melon is a small, globular to ovoid fruit weighing between 0.4 to 0.6 kg It features a smooth rind that ranges in color from pale green to yellow, and its crisp flesh is known for being very sweet, though it has a mild flavor This melon thrives in hot and humid climates, and its seeds are relatively small, with a weight of 8 to 10 grams for 1,000 seeds.
Melon plants are trailing vines characterized by simple, five-lobed leaves arranged in a 2/5 phyllotaxy pattern, with one leaf per stem node Their round, centrally hollow stems contain unique bicollateral vascular bundles, where phloem is located both outside and inside the xylem The primary stem produces lateral branches that may further develop additional stems, while coiled tendrils at the leaf axils assist in climbing supports like trellises These plants feature a strong tap root that can reach up to 1 meter deep, depending on soil conditions, but the majority of the root mass is composed of secondary roots found within the top 60 centimeters of soil.
Melon plants can be classified as either monoecious, with separate male and female flowers on the same plant, or andromonoecious, featuring male and hermaphroditic flowers Male flowers are found in clusters on the main stem and lateral branches, while female flowers, which bear the ovary, appear at the first node of each lateral branch Successful pollination of these ovary-bearing flowers is essential and is aided by natural pollinators.
Fruits exhibit a wide range of shapes and sizes, influenced by their cultivar, with monoecious plants typically producing elongated fruits and andromonoecious plants yielding round or ovate varieties Some cultivars feature longitudinal sutures, while others have suppressed sutures, and the fruit surface can be smooth or textured with netted lenticels The number of seeds per fruit varies among cultivars, generally reaching into the hundreds Each seed comprises several layers of testa, a thin collapsed perisperm, endosperm, and an embryo with two large flat cotyledons and a small radicle Notably, seeds are rich in proteins (19.3%) and lipids (32.3%) (De Mello et al.).
Purseglove (1968) also described Cucumismeloas follows: “A variable,
The plant is a trailing, softly hairy annual vine that can be monoecious or andro-monoecious, featuring a large, superficial root system Its stems are characterized by ridges or striations, while the leaves are orbicular or ovate to reniform, measuring 8-5 cm in diameter, with 5-7 shallow lobes and a dentate margin The base of the leaves is cordate, and the petiole ranges from 4-10 cm in length, accompanied by simple tendrils The flowers vary in type, being either staminate and clustered, pistillate and solitary, or hermaphrodite, with a diameter of 1.2-3.0 cm They are yellow and grow on short, stout pedicels, featuring a 5-lobed calyx that is 6-8 mm long and a deeply 5-partite corolla with round petals.
The plant features flowers measuring 2 cm in length, with three free stamens and elongated connectives of the anthers Its pistil contains 3 to 5 placentas and stigmas The fruit exhibits significant variation in size, shape, and rind texture, appearing either globular or oblong, and can be smooth or colored yellow-brown or green The flesh of the fruit ranges from yellow to pink or green and is filled with numerous seeds The seeds, which are flat and smooth, measure between 5 to 15 mm in length and are typically whitish or buff in color, with approximately 30 seeds per gram.
The origin of melons remains debated, with evidence suggesting they may have originated in either South Asia or Africa While South Asia boasts a rich diversity of melon varieties, the majority of Cucumis species, except for C hystrix, are linked to Africa, often referred to as “the African group.” Recent studies strongly support the idea that melons originated in southern and eastern Africa Historical records indicate that melons have been cultivated in China since around 2000 BC, leading to the development of numerous cultivars and a wide variety of fruits, which have spread globally, particularly in tropical and subtropical regions Melons are primarily consumed as fruit, though immature fruits are used as vegetables, seeds are edible, and roots have medicinal applications Wild inedible forms predominantly exist in Africa, and melons can easily revert to wild forms when cultivated.
Wild melon is predominantly found in arid regions across various continents, with a significant geographical distribution in Africa, including countries such as Angola, Egypt, and South Africa In Asia, it spans nations like India, China, and Japan, while it also thrives in the Pacific, notably in Fiji and Papua New Guinea This diverse presence highlights the adaptability of wild melon to different climates and terrains.
Table 1 Melon production in leading countries and the world (2005-2012)
China 728.47 764.08 761.61 788.14 769.39 853.63 860.75 875.01 Turkey 57.95 55.71 54.58 57.52 54.89 52.95 55.13 57.53 Iran 48.43 42.34 49.90 38.99 43.53 48.55 51.86 52.50 Brazil 22.02 26.93 29.22 29.19 29.84 31.30 32.37 30.87 Egypt 25.15 27.60 27.02 23.09 24.66 25.38 24.58 28.75 United States 29.21 30.34 28.09 28.57 28.02 29.29 27.04 26.96 World 1179.9 1223.6 1228.9 1249.4 1251.7 1328.4 1347.8 1373.0
Honeydew melon
Honeydew, a fruit believed to have originated in Africa, is known in America by this name, while its French and Algerian cultivators referred to it as White Antibes Some sources suggest its roots trace back to Persia Valued by ancient Egyptians, honeydew melons are depicted in hieroglyphics dating back to 2400 BC, where they were considered a revered food The Romans also cultivated honeydew, introducing it to Europe during the Roman Empire, but it gained popularity in the 15th century due to the French royal court's admiration Prior to this, honeydew was not widely grown in Europe, except possibly in Moorish Spain during the later Middle Ages.
Columbus transported honeydew melon seeds to America as well as Spanish explorer settling with what is currently California grown honeydew melon It’s
14 been an essential item in America after that The title ‘honeydew melon’ is definitely the American term for what exactly is also referred to as ‘Balian’ or even
The 'Wallace' melon, historically cultivated in the warm climates of southern France and Algeria during the 15th century, thrives in warm, dry conditions essential for its growth It wasn't until the 1800s, with the settlement and farming of areas like California and Arizona, that honeydew melons made their way to America.
Honeydew melons are typically ready for harvest within 80 to 100 days and are characterized by their green rinds and pale green flesh While most varieties have green rinds, some cultivars showcase yellow rinds or orange flesh, and numerous hybrids have been developed to enhance their characteristics.
Green Flesh: Lovers of standard green-fleshed honeydews will appreciate the
The "Honey King," "Earlibrew," and "Moonshine" varieties mature in approximately 90 days, while the early variety "Vanessa" features an attractive white rind that contrasts beautifully with its green flesh For main season options, consider the green-fleshed F1 hybrids such as "Brilliance," "Honey Chow," "Royal Dew," "Haley," "Samantha," "San Isidro," "Saturno," and "Super Dew."
The yellow rind mutation in honeydews creates visually appealing fruits that enhance plate presentation and add a fun element to meals The "Marygold" variety matures in approximately 88 days, showcasing a bright yellow, wrinkled skin Other slower-ripening options include the F1 hybrid "Destacado," which transitions from cream to light yellow at maturity, and "Dewlicious," known for its variety of green to white flesh.
“Unforgettable” with its crisp white flesh
Orange-fleshed honeydews are known for their vibrant color and exceptional sweetness Notable varieties include "Orange Blossom," "Orange County," "Orange Delight," and "Orange Sherbet," the latter of which is distinguished by its white rind Another variety, "Coup d' Orange," adds to the appeal of these delicious fruits.
15 bred with resistance to fusarium wilt “Honey Gold,” “Orange Bowl” and
“Temptation” are main season honeydews with resistance to both fusarium wilt and powdery mildew Although lacking specific breeding for disease resistance,
“Orange Dew” produces a unique salmon-orange flesh in about 112 days
Honeydew melons thrive in warm weather, ideally growing at air temperatures of 65 to 75 °F For optimal growth, it’s important to plant them when the soil temperature reaches 60 to 65 °F, and they should be sown only after the threat of frost has passed.
Honeydew melon seeds can be sown directly in the garden, or you can start transplants for an earlier harvest Typically, melons cultivated from transplants may be ready for harvest up to two weeks sooner than those grown directly from seeds.
Using black plastic mulch is an effective method to kickstart your melon crop, as it absorbs sunlight and warms the soil quickly By simply punching a hole in the plastic, you can easily plant seeds or transplants This technique not only accelerates soil warming in spring but also helps conserve moisture throughout the growing season Additionally, black plastic mulch offers benefits such as weed control and a decrease in fruit rot.
To successfully plant a second or fall crop on black plastic mulch, it's essential to spray-paint the mulch white to mitigate excessive heat absorption during summer and early fall This adjustment helps maintain optimal soil temperatures, preventing heat stress on plants Additionally, row covers should be vented by cutting slits in the sides to avoid overheating, as temperatures beneath these covers can become detrimental to plant growth It's crucial to remove the covers when temperatures rise and also when flowering begins to allow for effective pollination.
Cantaloupes and honeydews require ample space for optimal growth, with rows spaced 6 to 8 feet apart When planting transplants or seeds, ensure they are placed 18 to 24 inches apart within the rows If starting from seed, plant them at a depth of ½ to ¾ inch.
To optimize fertilizer application for melons, it's crucial to conduct a soil test If a soil test is unavailable, apply a 5-10-10 fertilizer at a rate of 30 pounds per 1,000 square feet prior to planting Additionally, side-dress the melons with 1 pound of 33-0-0 or 2 pounds of calcium nitrate per 100 feet of row before the vines begin to spread A second side-dressing should occur after blooming, as the fruits start to develop on the vine.
Be careful: Too much nitrogen fertilizer can encourage excessive vine growth and reduce fruit growth
Melons require ample water, and when using overhead irrigation, it is best to water in the morning to allow foliage to dry before nightfall, as wet leaves can promote foliar diseases Drip irrigation is an effective method since it delivers water directly to the plant's root zone without wetting the leaves Ensure the soil is adequately moistened to a depth of at least 6 inches, particularly during fruit set and development, while avoiding excessive watering in the final week of fruit growth to maintain sweetness.
Combining drip irrigation with plastic mulch is highly effective, as it keeps foliage dry and minimizes disease issues compared to overhead irrigation Additionally, with the right equipment, nutrients can be efficiently injected through the drip line, allowing for precise feeding of plants.
To promote earlier melon growth, utilize a row cover in conjunction with black plastic mulch The row cover can be made from clear polyethylene sheeting supported by wire hoops placed every five feet along the row or can be a lightweight "floating" material.
About 30 to 35 days are required from fruit pollination to harvest for most honeydew varieties When the stem separates completely, called "full slip," the
Effects of nutrients on melon production
2.3.1 Effects of organic fertilizer on melon production
Curuk et al (2004) found that applying composted cattle manure at rates of 12 and 18 kg/m² did not significantly affect melon yield However, the study revealed notable differences in fruit width and average weight when comparing the control group to the treatments with 12 and 18 kg/m² of manure.
A study by Ijoyah (2007) found that all treatments with decomposed poultry manure (DPM) significantly improved muskmelon fruit quantity and quality, including fruit number, length, weight, and overall yield Specifically, applying DPM at a rate of 30 tons per hectare led to a remarkable 39.4% increase in muskmelon yield compared to the control group.
According to Li et al (2008), the use of cattle manure compost combined with straw (CS) significantly enhances the yield and quality of melon fruit compared to sheep manure with straw (SS) The ideal ratio for incorporating CS into sandy soil is 1:1.
Song et al (2010) indicated that in comparison with conventional farming condition, muskmelon grown under organic farming condition had the same yield
At harvest maturity, the nitrogen (N) concentration in conventional treatments exceeded that of organic treatments, while at the vine growth stage, N levels were comparable across all methods Additionally, conventional conditions exhibited higher ratios of nitrate N to total N in the aboveground biomass compared to organic conditions.
According to Moreno-Resendez et al (2010), a 40:60 volume mixture of vermicompost (VC) and soil positively influenced various growth metrics, including yield, fruit weight, equatorial and polar diameters, pulp thickness, placenta cavity size, fruit count per plant, and days to harvest.
It is possible that the ratio of VC and soil (40:60) supplied enough nutrients for muskmelon
2.3.2 Effects of inorganic fertilizer on melon production
According to Soares et al (1999), applying nitrogen at a rate of 80 kg/ha through urea irrigation for 42 days significantly increased melon yield to 31.14 tons/ha, comparable to other treatments In contrast, the control and ammonium sulfate treatments recorded the lowest yields Additionally, there were no significant differences in total soluble solid content across the various treatments.
Brito et al (1999) found that applying 120 kg P2O5/ha using mono-ammonium phosphate and superphosphate resulted in the highest commercial fruit yields, highlighting the importance of application methods.
19 sources of phosphorus dis not significant influence on the mean fruit weight and on the soluble solid content
Navarro et al (1999) found that increasing calcium (Ca) levels in nutrient solutions under saline conditions significantly boosted melon fruit yield and vegetative growth The research indicated that salinity, phosphorus (P), and Ca nutrients also influenced fruit quality Notably, higher Ca treatments enhanced the levels of sucrose, fructose, and glucose, with the most pronounced effects observed under low salinity conditions The peak sucrose content was achieved with a phosphate concentration of 0.2 mM in the nutrient solution.
Research by Alarcon et al (1999) revealed that muskmelon experiences a significant increase in calcium demand during peak vegetative growth Among various calcium sources, Ca-EDTA was found to induce more severe calcium deficiency symptoms compared to CaCl2 and CaSO4, and it was ineffective in resolving calcium-related issues Additionally, biomass production showed no significant differences between the sulfate and chloride treatments when calcium levels were consistent.
Dasgan et al (1999) reported that under field condition, different N contents supplied to melons influenced on quality and yield of fruit However, the similar
N content and method of supply under soilless cultivation systems showed different results New studies also indicated that 165 kg N/ha resulted in better yield (Hochmuth and Cordasco, 2000)
According to Lin et al (2004), a potassium level of 240 mg/L significantly increases the content of total sugar, total soluble solids, glutamic acid, alanine, aspartic acid, and volatile acetate in the flesh of muskmelon.
According to Lester et al (2005), muskmelon fruits treated with supplemental foliar potassium (K) matured approximately two days earlier than those from the control group Additionally, the application of foliar K led to firmer fruits with increased levels of potassium, soluble solids, vitamin C, and total sugar content compared to the control treatment.
A study by Lester et al (2006) found that muskmelon fruits from plants receiving additional foliar potassium (K) exhibited higher potassium levels in the edible mesocarp compared to control plants Additionally, the firmness of the fruit tissue was enhanced due to increased tissue pressure potentials in the K-treated plants Overall, the findings suggest that potassium supplementation positively affects muskmelon fruit quality.
K had higher soluble solid content, total sugar, P-carotene, total ascorbic acid than those in the control treatment
Ferrante et al (2008) reported that the total fruit yield and fruit nitrogen content linearly increased with N levels Antioxidant compounds decreased after storage but were not influenced by N fertilization levels
De Oliveira et al (2009) demonstrated that the largest accumulation of N and
The application of 126 kg N/ha and 322 kg K/ha significantly boosted the dry biomass of the vegetative part of the plants Additionally, higher nutrient doses led to an increase in the percentage of nitrogen (N) and potassium (K) within the vegetative tissue.
According to Jifon and Lester (2009), applying potassium (K) foliar spray during muskmelon cultivation significantly enhanced K levels in plant tissues, resulting in increases of 19% in potassium content, 1% in fruit sugar, and 15% in bioactive compounds The findings also revealed that relying solely on soil potassium was insufficient to enhance these quality attributes.
According to Kano et al (2010), the most significant increase in nutrient uptake for net melon occurs from the onset of flowering to the start of fruit production Additionally, the highest accumulation of dry matter takes place between the beginning and the midpoint of the fruit production period.
Organic agriculture production
2.4.1 The definition of organic agriculture
Organic agriculture standards differ by country, but the core definition remains largely consistent As defined by the FAO/WHO Codex Alimentarius Commission, organic agriculture is a holistic management system that enhances agro-ecosystem health, promoting biodiversity, biological cycles, and soil activity It prioritizes management practices over off-farm inputs, recognizing the need for locally adapted systems based on regional conditions This approach favors cultural, biological, and mechanical methods over synthetic materials to achieve specific functions within the agricultural system.
2.4.2 Effects of organic materials on the soil
2.4.2.1 Effects of organic materials on physical properties of the soil
* Bulk density and penetration resistance
Research by Zebarth et al (1999) demonstrated that various organic amendments, such as biosolids and food waste compost, effectively reduced soil bulk density Similarly, Giusquiani et al (1995) found that both municipal sludge compost and urban waste compost contributed to a decrease in bulk density.
Mixing soil with less dense organic materials can lead to expected changes in soil structure However, research by Bazoffi et al (1998) indicated that the addition of urban refuse compost actually increased soil bulk density.
Compost use induced decrease penetration resistance (Aggelides and Londra,
Low soil penetrometer readings signify better conditions for root growth Research by Bazoffi et al (1998) demonstrated that compost can mitigate increased penetration resistance due to heavy trafficking Additionally, Edwards et al (2000) noted that compost applications reduced penetration resistance in subsoil beneath potato crops, likely indicating enhanced soil structure.
* Water holding capacity and porosity
Enhancing soil water holding capacity is essential for providing plants with more available water and improving drought resistance Research by Edwards et al (2000) revealed that compost made from sawdust, potatoes, and manure significantly increased soil moisture compared to untreated soil Additionally, studies by Baziramakenga et al (2001) and Hernando et al (1989) confirmed that applying urban waste improves soil water retention Furthermore, Aggelides and Londra (2000) and Giusquiani et al (1995) found that urban waste compost boosts total porosity, which is crucial for aeration and water movement Compost application not only enhances total porosity but also alters pore size distribution, as noted by Pagliai et al (1981), who observed an increase in small and medium-sized pores in compost-amended soils, leading to improved soil structure and potential for plant growth.
Numerous studies have explored the impact of organic materials on aggregate stability, revealing that paper sludge generally enhances aggregation (Gagnon et al., 2001; Nemati et al., 2000) Similarly, research on sewage sludge and composted municipal wastes has demonstrated both positive (Aggelides and Londra, 2000; Albiach et al., 2001) and neutral effects (Guidi et al., 1988) Paré et al (1999) found that fresh cattle manure reduced stability against dissolution and disruptive forces, while stockpiled manure showed no significant effect; however, fresh manure significantly improved resistance to slaking forces Evidence suggests that the impact on aggregate stability may be temporary due to organic matter decay (Bazoffi et al., 1998), although consistent use of organic materials can yield long-term benefits (Haynes and Naidu, 1998) Debosz et al (2001) noted an immediate effect on aggregation from sewage sludge, while the influence of municipal compost was more gradual, attributed to extracellular polymeric substances formed during the anaerobic storage of sewage sludge.
The use of composted wastes as commercial soil conditioners has gained attention, particularly due to studies like Canarutto et al (1996), which found that green waste compost enhances micro-aggregation These composts not only promote plant growth but also support beneficial microbial populations, making them potentially valuable for high-value horticultural crops, provided that cost-effective extraction methods are developed Additionally, for organic farming applications, it is essential to assess the acceptability of these materials within organic standards, which will depend on the source material and extraction methods used.
2.4.2.2 Effects of organic materials on chemical properties of the soil
The impact of organic materials on soil pH varies based on the initial pH of the materials and the existing soil pH Research indicates that organic materials can both raise and lower soil pH, with some studies reporting no significant effect at all (Bevacqua and Mellano, 1994; Crecchio et al., 2001; Mokolabate and Haynes).
In acid soils, the addition of organic residues significantly enhances soil pH, with poultry manure being the most effective, followed by filter cake, household compost, and grass residues (Mokolabate & Haynes, 2002).
Organic materials can effectively lower the pH of alkaline soils, while livestock manures have been shown to increase the pH of acidic soils This increase in pH is beneficial as it enhances the availability of microelements and reduces the solubility of certain toxic elements Consequently, it is worth exploring the potential of livestock manure as a substitute for lime application, utilizing locally available resources.
Electrical conductivity serves as an indicator of salt content in soil solutions Research by Chang et al (1991) and Eghball (2002) shows that higher application rates of manure and compost lead to increased electrical conductivity Shiralipour et al (1992) found that while municipal solid waste compost can cause salinity damage to soil properties, its effects are generally less severe compared to sewage sludge at equivalent application rates Additionally, Bevacqua and Mellano (1994) highlighted that the use of municipal compost can elevate salinity levels, posing risks to the growth of sensitive horticultural crops.
Organic materials are an important source of nutrients The quantity and
The quality of organic materials significantly affects the formation of soil organic matter and the timing and availability of nutrient release for subsequent crops For instance, cereal straw provides approximately 35 kg of nitrogen per hectare, while certain vegetable residues can contribute over 150 kg of nitrogen per hectare (Jarvis et al., 1996; Rahn et al., 1992).
Organic materials with a low carbon to nitrogen (C:N) ratio, specifically 15 or less, promote rapid mineralization and a significant increase in soil mineral nitrogen, as noted by Kirchmann (1985) Fresh organic materials yield higher mineralization rates compared to composted materials, which typically have higher C:N ratios and result in lower total nitrogen mineralization over time (Hadas and Portnoy, 1997; Tyson and Cabrera, 1993; Ekbladh, 1995; Kirchmann, 1989) Additionally, residues with very high C:N ratios, such as paper waste, can cause net nitrogen immobilization in the short to medium term (Simard et al., 1998).
Continuous application of organic materials enhances phosphorus (P) content in the soil (Sharpley and Rekolainen, 1997) However, in soils with elevated P levels, the use of composts and manures poses a risk of P runoff To mitigate unnecessary P enrichment and leaching, Smith et al (1998) recommend limiting topsoil extractable P levels to 70 mg/l.
Composting low nutrient organic materials with high nutrient sources like poultry manure enhances their value for crops Research by Baziramakenga et al (2001) indicates that a composted blend of poultry manure and paper sludge boosts extractable phosphorus (P) and potassium (K) levels in soils Additionally, the use of lime as a manure amendment has been found to reduce the solubility of P in poultry litter (Moore and Miller, 1994) Incorporating rock phosphate with manures and composts can improve phosphate availability in soil, as the acids produced during the decomposition of organic matter facilitate the dissolution of rock phosphate.
27 chelation of soluble aluminium and iron with organic matter will restrict phosphorus fixation in soil (Bohn et al., 1979 )
Cooperband et al (2002) studied to determine the influence of poultry litter compost of different maturities on soil P Immature composts (composted for 1 and