Fertilizers are widely used in agriculture to maintain soil fertility and to increase crop yields. Fertilizer is any organic or inorganic material of natural or synthetic origin that is applied through soil or leaves to the plants to supply nutrients essential to the growth and productivity. Soil is vital natural resource on which life supporting system of a country and the socioeconomic development of its people depends. Soils provide food, fodder and fuel to meet the basic needs of human and animal. Rapid increase in population of India has necessitated parallel increase in food grain production. Food grain production in India more than doubled itself during the postGreen Revolution. However, overuse of chemical fertilizers, pesticides, especially in vegetables and fruit plants, resulted in residues above safety levels and showed illeffects; even drinking water is not spared. The land in India suffers from varying degrees of degradation. Soil fertility depletion is a cause of concern for Indian agriculture. The soil analysis results gave valuable information about the distribution pattern of plant nutrients in Indian soils. The available information reflects the fact that the Indian soils are poor in major as well as minor nutrients.
Chapter-VI SUMMARY AND CONCLUSION 6.1 Introduction Fertilizers are widely used in agriculture to maintain soil fertility and to increase crop yields Fertilizer is any organic or inorganic material of natural or synthetic origin that is applied through soil or leaves to the plants to supply nutrients essential to the growth and productivity Soil is vital natural resource on which life supporting system of a country and the socio-economic development of its people depends Soils provide food, fodder and fuel to meet the basic needs of human and animal Rapid increase in population of India has necessitated parallel increase in food grain production Foodgrain production in India more than doubled itself during the post-Green Revolution However, overuse of chemical fertilizers, pesticides, especially in vegetables and fruit plants, resulted in residues above safety levels and showed ill-effects; even drinking water is not spared The land in India suffers from varying degrees of degradation Soil fertility depletion is a cause of concern for Indian agriculture The soil analysis results gave valuable information about the distribution pattern of plant nutrients in Indian soils The available information reflects the fact that the Indian soils are poor in major as well as minor nutrients It was observed that after 1960, micronutrients deficiencies; especially of Zn and Fe was noticed in light textured soils of India Later on, multiple nutrient deficiencies were reported in crops within a period of 1960 to 2005 Despite application of adequate quantity of NPK, the yield remains low due to hidden hunger of micronutrients like Zn, Fe, Cu, Mn and B The major reason for the widespread occurrence of deficiency of micronutrients is the low availability of micronutrients to plant roots rather than their low concentration in soils The low solubility of most micronutrient cations like copper (Cu), iron (Fe), manganese (Mn), and zinc (Zn) in soils means that after the addition to alkaline soil as the soluble form, the metal is rapidly precipitated Even in rainfed areas, micronutrient deficiencies are more prevalent To reduce reactions and precipitation of micronutrients and maintain them in soluble form in soil, chelation of these nutrients with chelating agents is the only solution Chapter-VI: Summary and Conclusion 140 Common chelators are ethylene diamine tetra aceticacid (EDTA) and dimethyl tetra amine penta aceticacid (DTPA) and these molecules increase micronutrient solubility through reversal of charge on the metal Thus, the efficiency of chelates such as EDTA-metal and DTPA-metal in terms of improving crop nutrition is compromised by the poor ability of the complexed forms of micronutrient to be absorbed by plant roots On the other hand, foliar fertilizers as chelate should be easily absorbed by the plants; rapidly transported and should easily release their ions to affect the plant growth Amino acids are moderately strong chelating agents, micronutrients chelated using amino acids remain in soluble forms and readily absorbed by plants Amino acids are recognized by the plant as building blocks and are used in nearly every tissue in the plant, hence, they enter inside the plant and release mineral, and the plant uses left over amino acids as a source of water-soluble nitrogen Considering above revealed views in mind, an experiment was conducted to formulate amino acid chelated micronutrient fertilizer with the following objectives To produce free L-amino acids from seed proteins with fungal proteases To form amino acid –metal nutrient complex/ chelate, and To study effect of amino acid-micronutrient chelate in red-pepper and okra and compare yield and quality of organically grown plant with control 6.2 Formulation of amino acid chelated micronutrient fertilizer This chapter deals with formulation of amino acid chelated micronutrient liquid organic fertilizer by conversion of mung bean, soybean and chickpea seed proteins to L-amino acids with Aspergillus niger PR-4 proteases and synthesis of organic micronutrient chelates with seed amino acids In these process micronutrients like, zinc, copper, ferrous, manganese, molybdenum was dissolved in boric acid solution and were chelated separately with seed amino acids After confirmation of chelation of these metals they were combined in final formulation of chelated micronutrient fertilizer Significant findings In present investigation, results showed that the protease producer Aspergillus niger PR-4 can be used in production of amino acids from seed sources Enzymatically produced amino acid can be used to chelate metal micronutrients Chapter-VI: Summary and Conclusion 141 The chelated micronutrient fertilizer can be useful for providing essential micronutrients to plant at proper growth stages 6.3 Effects of chelated micronutrient fertilizer on growth and productivity in fruit vegetables The pot experiments were carried out at Yeola District Nashik during 2009 and 2010, whereas field experiments were carried out in farmer’s field at Pimpri, Tal Sangamner, Dist Ahmednagar (MS) India during 2010-11 Doses of chelated micronutrient fertilizer at the rate of 1.0%, 1.5% and 2.0% were prepared in demineralized water just before treatment The plants were treated on 15, and 30 days after chilli seedling transplantation and sowing of seed in okra through foliar sprays (approximately average 25 ml plant-1) At the same time 2.0 % solution of seed amino acids and unchelated micronutrients along with water treated plants as control were also planned Before actual planting/ sowing of test crops, soil was analysed for pH, EC and organic carbon as well as major and minor nutrients The farm yard manure was added to the soil before plantation and recommended doses of NPK were applied Hand weeding and plant protection measures were conducted as per need Growth parameters like plant height, number of branches per plant, number of leaves per plant and leaf area per plant were observed at flowering stage of chilli and okra crops The data regarding productivity parameters like number of fruits per plant, fruit length, fruits weight and total yield per plant were calculated after harvesting The data obtained were statistically analyzed by single way ANOVA and the critical differences were calculated at 5% probability level Significant findings The results pertaining to growth and productivity characters showed similar trend in pot as well as field experiments, which suggest that amino acid chelated micronutrient fertilizer is efficient in improving growth and productivity in test crops The data further suggest that the 1.5% and 2.0% concentrations of chelated micronutrient fertilizer showed maximum values for respected characters; whereas, insignificant differences were registered in between these two treatments Chapter-VI: Summary and Conclusion 142 6.4 Effect of chelated micronutrient fertilizer on leaf biochemicals Leaf biochemical parameters were evaluated from pot experiments carried out at Yeola District Nashik (MS) India Different leaf biochemicals like photosynthetic pigments, carbohydrates (reducing sugars and soluble carbohydrates) and total phenols were evaluated from treated and control plants All the biochemicals were estimated from physiologically active fresh leaves Chlorophyll were extracted and estimated by Porra’s (2002) method Reducing sugars were estimated by Miller (1972) The soluble carbohydrates were estimated by anthrone reagent as per Hedge and Hofreiter (1962) given in the book ‘Biochemical Methods’ by Sadasivam and Manickam (1996) Proteins were estimated by using Lowry et al (1951) method Total phenols were estimated as per the method given by Farkas and Kiraly (1962) Significant findings Results showed that amino acid chelated micronutrient fertilizer not only enhanced growth and productivity but also various leaf biochemicals in test vegetable crops The metal nutrients supplied by chelated micronutrient fertilizer might have contributed in synthesis and accumulation of various biochemicals in leaf tissues Besides, results exhibited that 1.5% and 2.0% concentrations of amino acid chelated micronutrient fertilizer found to register maximum values for all the leaf biochemicals 6.5 Effect of chelated micronutrient fertilizer on fruit qualities Amino acid chelated micronutrient fertilizer was examined for its efficacy regarding fruit quality parameters of chilli and okra Fresh green fruits selected from treated and control plants were used to determine the effect of amino acid chelated micronutrient fertilizer on fruit quality parameters Different fruit quality parameters like, reducing sugars, soluble carbohydrates, proteins, total phenols, ascorbic acid, capsaicin and free radical scavenging activity were estimated from green fruits Ascorbic acid content was estimated by titrimetric method suggested by Ghosh et al (1966) from green coloured chilli and okra fruits Capsaicin was estimated using calorimetric method in accordance to method given in book “Biochemical Methods” (Sadasivam and Manickam, 1996), from green coloured chilli fruits Chapter-VI: Summary and Conclusion 143 Determination of the scavenging effect on DPPH was carried out with methanolic extracts of fresh fruits of treated and control plants Percent free radical scavenging activity was calculated according to Montalleb et al., (2005) and compared with L-Ascorbic acid which was used as standard antioxidant (Aquino et al., 2001) Nitrogen was estimated by Micro Kjeldahl method (Tandon, 1998), Phosphorus according to method of Murphy and Riley (1962) and potassium by Flame photometer method (Jackson, 1973) Micronutrients were analysed on Atomic Absorption spectrophotometer according to Bhargava and Raghupathy (1993) Similarly, fresh and healthy fruits randomly selected from treated and control plants were utilized to find out the effect of amino acid chelated micronutrient fertilizer on quality parameters like shelf life and physiological loss in fruit weight Significant findings The results pertaining to fruit quality parameters and fruit biochemicals showed almost similar trend as seen in leaf biochemicals Amino acid chelated micronutrient fertilizer significantly enhanced shelf life and quality parameters in both vegetable crops due to availability of required metal nutrients at proper growth stages through foliar fertilization The fruit quality parameters in chilli and okra showed maximum values for 1.5% and 2.0% concentrations of amino acid chelated micronutrient fertilizer which suggests that the biochemicals accumulated during the growth stage might be translocated easily in to the fruits and might have enhanced the fruit qualities 6.6 Conclusions: This eco-friendly technology, utilizes the seed amino acids as chelating agents to chelate micronutrients for sustainable organic farming The protease producer Aspergillus niger PR-4 can be used in production of amino acids from seed sources Technology is inexpensive and affordable even to marginal farmers Organically chelated micronutrients overcome short-term deficiencies of nutrients during early growth and fruit setting in test crops The methodology and protocols developed during this investigation will be helpful for further research studies in micronutrient chelation for sustainable organic farming ≈≈ ≈≈ Chapter-VI: Summary and Conclusion 144 ... form amino acid –metal nutrient complex/ chelate, and To study effect of amino acid-micronutrient chelate in red-pepper and okra and compare yield and quality of organically grown plant with control... the rate of 1.0%, 1.5% and 2.0% were prepared in demineralized water just before treatment The plants were treated on 15, and 30 days after chilli seedling transplantation and sowing of seed in... organic carbon as well as major and minor nutrients The farm yard manure was added to the soil before plantation and recommended doses of NPK were applied Hand weeding and plant protection measures