نوع مقاله : مقاله پژوهشی
نویسندگان
1 گروه علوم باغبانی، دانشکدگان کشاورزی و منابع طبیعی دانشگاه تهران، کرج، ایران.
2 مؤسسه تحقیقات خاک و آب کشور، سازمان تحقیقات، آموزش و ترویج کشاورزی، کرج، ایران.
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Objectives
This study aimed to evaluate the effects of amino acid–rich hydrolysates produced from fish waste, corn residues, and chicken feathers on growth, mineral nutrition, biomass partitioning, and yield of cucumber (Cucumis sativus L.) under greenhouse conditions. A further objective was to characterize the chemical composition of these organic hydrolysates (total amino acids, organic carbon, and macro- and microelements) and to determine how different sources and concentrations influence source–sink relationships and allocation of assimilates to vegetative versus reproductive organs. The work was also designed to assess the potential of recycling plant and animal residues as sustainable organic fertilizers enriched with amino acids.
Methodology
Organic amino acid fertilizers were produced by fermenting finely chopped fish, corn, and chicken feather residues with sugar beet molasses using Lactobacillus (Electrobacillus/Lactobacillus) at room temperature for 30 days, followed by filtration and chemical analysis. Total free amino acids in the liquid fertilizers were quantified by HPLC (C18 reverse-phase column, UV detection at 254 nm), and organic carbon and nutrient elements (N, P, K, Ca, Mg, S and selected micronutrients) were determined using wet digestion and analysis by ICP-AES. A pot experiment was conducted as a factorial arrangement in a completely randomized design with three amino acid sources (fish, corn, chicken feather) at two application concentrations (2% and 4%), plus an unfertilized control, using cucumber cv. Vihan grown in cocopeat–perlite substrate under controlled greenhouse conditions. Plants were fertigated with a basal nutrient solution and received the organic amino acid fertilizers twice weekly; root, stem, leaf and fruit fresh weight, dry matter, nutrient contents, total plant biomass, and biomass allocation to organs, as well as fruit yield and average fruit weight, were measured and analyzed by ANOVA and Duncan’s test.
Results
Chicken feather hydrolysate contained the highest total amino acid percentage (32.46%), while the fish-based amino acid showed the highest total N, P, Ca and S contents and a distinctive amino acid profile rich in glutamic and aspartic acids. All three amino acids significantly increased root fresh weight and root dry matter compared with the control, with fish hydrolysate producing the greatest root mass (145 g fresh weight and 13.76% dry matter). Although root N, K and Mg concentrations were sometimes higher in the control, amino acids markedly improved shoot and leaf growth, as reflected in higher leaf fresh weight, particularly under the fish fertilizer. In the stem, fish hydrolysate significantly enhanced P and K concentrations relative to the control, while chicken feather at 2% gave the highest Ca and Mg contents, indicating source-specific effects on mineral partitioning. For reproductive traits, fish and chicken feather fertilizers produced the highest individual fruit fresh weight (about 75.7 g, 20% higher than control), whereas fish at 2% concentration maximized total fruit yield, increasing it by roughly 40% compared with the unfertilized control. Biomass allocation analysis showed that fish hydrolysate at 2% led to the highest proportion of total biomass directed to fruits (74%), while corn fertilizer favored allocation to leaves.
Conclusion
Amino acid–enriched hydrolysates derived from recycled plant and animal residues can effectively improve cucumber growth, nutrient uptake, and yield, with fish-based hydrolysate showing the strongest overall biostimulant effect. The results indicate that amino acids in these fertilizers enhance nutrient acquisition and translocation, stimulate photosynthesis, and modulate source–sink relations so that a greater share of assimilated carbon and nitrogen is directed to reproductive sinks, thereby increasing fruit weight and total yield. The observed reduction of some root nutrient concentrations under amino acid treatments, together with higher allocation of biomass and nutrients to fruits, supports the role of amino acids in regulating phloem loading and partitioning rather than simply enriching the root nutrient pool. Overall, amino acid hydrolysates from fish, corn, and chicken feather residues represent promising sustainable organic fertilizers that can recycle agro-industrial wastes while enhancing cucumber productivity and resource-use efficiency in protected cultivation systems.
کلیدواژهها [English]
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